Supremacy of Polymer Banknotes:

A Comparative Study Between Paper and Polymer Banknotes

By: Dr. Ahmed Saad Goher

Riyadh - 2012 © Naif Arab University for Security Sciences, 2012 King Fahd National Library Cataloging-in-Publication Data

Goher, Ahmed Saad Supremacy of Polymer Banknotes (A Comparative Study Between Paper and Polymer Banknotes) / Ahmed Saad Goher - Riyadh, 2012 P. 192 ; 17 x 24 cm ISBN: 978-603-8116-10-4

1 - Polymers 2 - Polymerization 3- Banknotes I-Title

547.7 dc 1433/7027

Legal Deposit No. 1433/7027 ISBN: 978-603-8116-10-4

All Rights Reserved Naif Arab University for Security Sciences Contents Preface 5

Chapter I: Introduction to Paper 7 1.1. Fibrous Raw Materials for Pulp and Paper ‎Industry 7 1.2. Chemistry of Cellulose 8 1. 3. Types of Cellulose 11 1. 4. Hemicellulose 12 1. 5. Lignin 14

Chapter II: Pulping Processes 17 ‎2.1. Conventional Pulping Processes 17 2.2. Non-Conventional Pulping Processes (Organosolv pulping) 19 2.3. Bleaching of Wood Pulp 20

CHAPTER 3: Paper Manufacturing Process 27 3.1. Making Pulp 27 3.2. Beating 28 3.3. Pulp to Paper 28 3.4. Finishing 30 3.5. Additives in Papermaking 30 3.6. Filler in Papermaking 30

CHAPTER 4: Introduction to Polymer 33 4.1. Chemical and Physical Properties of Polypropylene 34 4.2. Degradation of Polypropylene 36 4.3. Synthesis of Polypropylene 36 4.4. Practical Applications of Polypropylene 39 4. 5. Adoption of Polymer Banknotes 40 CHAPTER 5: Security Features in Banknotes 49 5.1. Substrate Features 49 5.2. Ink Features 68 5.3. Design Features 73 5.4. Security in Machine Readable Features 78

CHAPTER 6: Hygiene 79

CHAPTER 7: Environmental Impacts 83

CHAPTER 8: Chemical and Physical Analysis of Paper and Polymer Banknotes 89 8.1. Raw Materials 89 8.2. Analysis of Banknotes 89 8.3. Physical Properties of Banknotes 90

CHAPTER 9: Mechanical Properties of Banknotes 91 9.1. Tensile Strength and Breaking Length 91 ‎9.2. Burst Strength 92 9.3. Tear Resistance and Tear Initiation Test 92 9.4. Folding Endurance 94

CHAPTER 10: Aging of Banknotes 95 10.1. The Effect of Aging on Breaking Length 99 10.2. The Effect of Aging on Tear factor 101 10.3. The Effect of Aging on Burst factor 102 10.4. The Effect of Aging on Folding Endurance 103 10.5. Effect of Aging on Lightness and Colour Changes of Paper Banknotes 103 CHAPTER 11: Thermal Analysis 115 11.1. Thermogravimetric (TG) Analyses 115 11.2. Calculation of Activation Energy 116

CHAPTER 12: Crumple Resistance 119

CHAPTER 13: Chemical Resistance Tests 123

CHAPTER 14: Soil & Wear Resistance Tests 131

CHAPTER 15: Colour Fastness Test 135

CHAPTER 16: Exposure to Humidity & Weathering Test 137

CHAPTER 17: Taber Abrasion Test 141

CHAPTER 18: Machine Washability Tests 143

CHAPTER 19: Tape Adhesion Test 147

CHAPTER 20: Rub Resistance 149

CHAPTER 21: Effect of Solvents on Polymer and Paper Banknotes 151 21.1. With Acetone 151 21.2. With Ethyl Acetate 152 21.3. With Benzene 154 21.4. Effect of Solvents on Folding Endurance 155

CHAPTER 22: FT-IR Spectra of Paper and Polymer Substrate 157 22.1. FT-IR Spectra of Paper 157 22.2. FT-IR Spectra of BOPP Substrate 158

CHAPTER 23: Comparison between security elements in Paper and Polymer banknotes 159

CHAPTER 24: Comparison between Counterfeit Rates in Paper and Polymer banknotes 163

CHAPTER 25: Durability of Banknotes 169

CHAPTER 26: Cost-effectiveness 173

Conclusion 179

Abbreviations 180

References 183 Preface Counterfeiting is a present threat for universal economy. Nowadays this threat looms even larger as improvements in the quality of colour photocopiers, computer scanners and imaging software, accompanied by falls in the cost of such technology, brought high quality counterfeits within the reach of unskilled “casual” counterfeiters. As such, this threat results in finding an alternative way to face this catastrophe. A new creative experiment appeared in Australia, based on changing the traditional rag security paper (natural polymer) used in banknotes to synthetic polymer substrate (Polymer). Polymer banknotes were developed by the Reserve Bank of Australia (RBA), Commonwealth Scientific and Industrial Research Organization (CSIRO) and the University of Melbourne. Togather the latter were first issued as currency in Australia in 1988. These banknotes are made from the polymer biaxially-oriented polypropylene (BOPP) which greatly enhances durability of the banknotes. Polymer banknotes also incorporate many security features not available to paper banknotes, making counterfeiting much more difficult. Innovia market the unique BOPP film used for banknotes as “Clarity-C”. Guardian is unique form of opacified BOPP Clarity-C film. By applying the Australian experiment on all its denominations, the world divided into two viewpoints. One of them supports the Australian experiment, Thirty five countries applied it, based on the fact that Polymer banknotes are more durable than the Paper (natural polymer) banknotes (lasting around four times as long). Finally, these have a clear window, which is an effective optical security device. Finally, these are cleaner and more hygienic because of their non-porosity. The other viewpoint is conservative to the Australian experiment based on the fact that paper banknotes are more effective than polymer banknotes in combating counterfeiting by most counterfeiting ways. The well-established technology to create watermarks and security threads within the fibers during manufacturing of the paper, in addition to the porosity of the paper substrate enables printing inks to interact with the paper substrate absorptionaly and not adsorptionaly. In this book, a comparison between the use of paper and polymer substrate in banknotes is investigated in twenty six chapters. This investigation covers the following areas:

5 - Mechanical properties and the effect of thermal treatments on these properties, Chemical analysis, infrared spectroscopy and thermogravimetric analysis. - Security, and the security features that exist in both substrates. - The standard banknote durability and hazard tests, such as, Crumple Resistance Test, Soil & Wear Resistance Test, Colour Fastness Test, Exposure to Humidity & Weathering, Tape Adhesion Test, Rub Resistance Test, Chemical Resistance Tests, Taber Abrasion Test and Machine Washability Tests measuring colour changes of the treated banknotes. - Printability, the thermal treatments on colour changes are investigated. i.e. the effect of temperature on the colour of the note. - Durability, counterfeit detection rates, cost-effectiveness, environmental aspects and hygiene were investigated. First and foremost, the author would like to thank Allah for helping him to accomplish this work. ‎ Profound thanks to all the staff of the Rakta paper mills Co., Alexandria, Egypt and to all the staff of the Securency International Pty Ltd in Craigieburn, Australia, for their help to complete this work. The author heartily appreciates Dr. ‎Mohamed Y. EI-Kady, Professor of Organic Chemistry, Department of Chemistry, Faculty of Science, Ain Shams University, Egypt, for his interest, encouragement and valuable discussion. The author feels also indebted to Prof. Dr. Abd-Alla Mohamed Abd-Alla Nada, Professor of Organic Chemistry, Cellulose and Paper Department, National Research Center, Egypt, for his constant, effective help, supervision, and precious criticism. The author wishes to express his sincere appreciation and respect to Prof. Dr. Gorge Nubar Simonian, Professor of Printing, Faculty of Applied Art, Helwan University, Egypt, for his efficient keen suggestions and valuable help and advices during the process this work. The author wishes to express his thanks and respect to chemist, Riad F. Basalah, General Director, Forgery and Counterfeit Department, Ministry of Justice, Egypt, for his help, continuous guidance and encouragement. Finally, the author is grateful to my family, father, mother, daughters (Sarah, Salma and Sohyla) and special thanks to my greatest wife for her patience, help and continuous encouragement.

6 Chapter I Introduction to Paper Formed from wood pulp or plant fiber, paper is chiefly used for written communication. The earliest paper was papyrus, made from reeds by the ancient Egyptians (Biermann, Christopher J, 1993). Paper was made by the Chinese in the second century, probably by a Chinese court official named Cai Lun. His paper was made from such things as tree bark and old fish netting. Recognized almost immediately as a valuable secret, it was 500 years before the Japanese acquired knowledge of the method. Papermaking was known in the Islamic world from the end of the eighth century A.D. Knowledge of papermaking eventually moved westward, and the first European paper mill was built at Jativa, in the province of Valencia, Spain, in about 1150. By the end of the 15th century, paper mills existed in Italy, France, Germany, and England, and by the end of the 16th century, paper was being made throughout Europe (Bell, Lilian A, 1992; Ferguson, Kelly, ed, 1994). Paper, whether produced in the modern factory or by the most careful, delicate hand methods, is made up of connected fibers. The fibers can come from a number of sources including cloth rags, cellulose fibers from plants, and, most notably, trees. The use of cloth in the process has always produced high-quality paper. Today, a large proportion of cotton and linen fibers in the mix create many excellent papers for special uses, from wedding invitation paper stock to special paper for pen and ink drawings. 1.1. Fibrous Raw Materials for Pulp and Paper ‎Industry: Pulp and paper can be made from many different plants, but whether or not a plant is well-suited for this purpose depends largely on the suitability of fibers, dependability of supply, cost of collection, transportation, preparation and tendency to deteriorate in storage (Hale, 1969). The parts of plants that are used for papermaking must contain adequate amounts of fibers. Fibrous raw materials for pulp production are generally divided into two main categories: i) Wood fibers: Wood is the most widely used raw material for the production

7 of paper and chemical pulps (Rydholm, 1965; UNIFAD, Rome, 1973). There are two main classes of wood, the hardwoods (short-fiber) such as oak and birch and softwoods (long-fibers) such as spruce and hemlock (Atchison, 1973). ii) Non-Wood Fibers: Non-wood fibers have gained an ‎importance as a raw material for pulp production, especially in countries with little or no wood resources such as Egypt, India and China. Non-wood plant fibers are classified into three main categories: 1. Agricultural Residues, This include rice straw, cotton stalks, sugar cane bagasse, cereal straw and corn stalks. Pulping of bagasse was carried with soda (Saad, M.S et al, 1988) or with Kraft cooking liquor (Nada, A.M.A, et al 1990) and by batch or continuous system. Comparing with softwood, bagasse has lower α-cellulose and higher pentosans. 2. Natural Growing Plants, This include bamboo, reeds, esparto, elephant grass and other grasses (Hurter, Robert W., 1997). 3. Cultivated Fiber Crops, This include jute and hemp (Misra, 1980). Cotton stalks offer a relatively low cost fibrous structure that within the limits of its characteristics and competitive position with other agricultural wastes could be converted economically into a variety of useful products such as animal feed, pulp and paper (Mobarak and Fahmy, 1977; Ali, U. and Oya, B.N. 1998), panel board and fuel (Kozlowski et al., 1994; Reddy, B.S. and Bhatt, S. 1998). The production of this type of pulp has increased more rapidly than pulp from wood in last two decades. By a factor of about two in Latin America and three in Africa and the middle East (Casey, J., 1990). Fibrous raw material such as wood or agricultural residues consist of three dominating polymers; cellulose, hemicelluloses and lignin. Accordingly, it is called as lignocellulosic material. 1.2. Chemistry of Cellulose: Cellulose, Figure (1), is the principal component of the cell walls of plant. Cellulose ‎fibershave found important industrials uses as the source for paper making ‎and dissolving pulps (Browning, 1967).

8 Lignocellulosic material is one of the oldest and most renewable sources of raw materials of the chemical industry in the world. During the recent decades the chemistry of cellulose has been decisively promoted by the discovery of non aqueous solvent system for cellulose. This broadens the scope of derivatization reaction at homogeneous conditions as well as by the general progress in synthesis and characterization of saccharide derivatives. Cellulose fibers still occupy an important position among raw materials for textile industry. They presently account for about 8% of all manmade fiber consumed worldwide by the textile industry (Urbanowski, 1996). Cellulose never occurs in pure form, in softwood and hardwood. It constitutes about 40-50% of the weight, whereas cottonseed hairs, which are the‎ purest source, contains more than 90%. Cellulose is a natural polymer consisting of identical repeated units (D-­ glucose) linked together through a glucosidic bond in the beta configuration between C - I and C -4 of the adjacent units to form long chain (I →4 )-β-glucans by 1, 4-β-glucosidic linkage. This polymer is of similar size in both breadth and depth, while hundreds or even thousands of times as long in the third direction (length) i.e. it is similar in shape to the fiber it forms; very long when compared with its diameter. This fibrous property of cellulosic material imparts some physical properties, such as moisture uptake, tensile strength, elasticity and luster on its structure. The arrangement of such ‎macromolecules in the fiber and due to the H-bonding property produces ordered regions (called crystalline regions), while the other disordered ‎regions called amorphous regions (Hebeish and Guthrie, 1981).

‎Because of cellulose fibril1ar morphology, it forms a natural polymer

9 composite of excellent material properties together with other plant polysaccharide (hemicellulose) and lignin. The size of cel1ulose molecule occurring in nature, indicated by its degree of polymerization (DP) of chain length is dependent heavily on its source (Hon, 1988). → As strictly linear (l 4)- β -glucan biosynthesized by region and sterio­selective multi-steps polycondensation reaction. Cellulose is a highly uniform polyacetal containing three reactive hydroxyl groups per so-called “anhydroglucose” unit occupy the 2, 3 and 6 positions. The groups have decreasing acidic properties in the order 2, 3 and 6. The primary hydroxyl group at position 6 is sterical1y the most unhindered. Based on this molecular structure, ordered hydrogen bond systems form various types of super molecular semicrystal line structure, the latter are essential for natural functions and commercial applications (e.g. fibers) of cellulose (Klemm et al.,1997; Nada et aI., 2000a). Formation of hydrogen bonds in cellulose is considered one of the most factors, which effect on physical properties of cellulose and its derivatives. It has been studied extensively by infrared ‎spectroscopy (Nada et aI., 1990; Kondo, 1994) and known in two following ways. Cellulose has intermolecular and two different intramolecular hydrogen bonds which are between OH-3 and adjacent ring O-5 and between OH-6 and OH-3. The intramolecular hydrogen bridges, Figure (2), anchor the anhydroglucose units to a very limited region of free play around the acetal linkage. Thus, they impart certain stiffness to the cellulose molecule: ‎

→ This and the fact that the (l 4) - β -bond, Figure (3), demands a rotation of

10 180 0 of ‎each subsequent glucose unit to fit the β-configuration of the connecting hemiacetal linkage, gives the cellulose molecule a rod-like chain structure:

‎ The β-glucosidic linkage in cellulose and the resulting Intramolecular hydrogen bonds render the cellulose molecule straight and stiff (Hebeish and Guthrie, 1981). ‎‎Native cellulose provides a degree of polymerization (DP) up to several thousand and three active sites within each of the anhydroglucose unit at three positions 2, 3 and 6. ‎The main characters of cellulose ‎functionalization results from the polysaccharide structure of the macromolecules. Due to the susceptibility of the (1-4)-glucosidic bond to acid hydrolysis, all reactions in acid medium are accompanied by more or less significant chain degradation (Yalpani, 1985). A functionalization in alkaline medium is also usually accompanied by some decrease in DP via various routes of chain degradation (Gotze, 1967). 1. 3. Types of Cellulose: ‎The treatment of cellulose preparations with sodium hydroxide solutions is the oldest and best known of the alkaline solubility tests. In the early part of the 20th century, Cross and Bevan (Cross. C. F. and Bevan. E. J, 1907) as pan of their pioneering researches on cellulose, used strong sodium hydroxide solutions to isolate what was termed normal cellulose from wood after the lignin had been removed by chlorination. They definedα-cellulose as the portion of the material ‎insoluble in the sodium hydroxide solution, β-cellulose as that portion which is dissolved but reprecipitated when the solution is neutralized,

11 and γ-cellulose as that part of the dissolved material which remains soluble in neutral or slightly acid solutions. ‎According to methods now in use, α -cellulose is defined as the residue which is insoluble in 17.5% sodium hydroxide when the treatment is carried out under specified conditions and the insoluble material is separated by filtration. It is then washed, dried and weighed. β- and γ- celluloses are determined less frequently than α-cellulose. The filtrate from the α cellulose­- determination is used. The precipitate of β -cellulose that is obtained when the filtrate is neutralized can be filtered off and weighed, but the material is gelatinous and filtration is likely to be difficult. ‎Determination of the dissolved materials by the wet-combustion oxidation method with potassium dichromate in strong sulfuric acid is simple and more rapid (Browning, 1967). 1. 4. Hemicellulose: ‎Hemicelluloses are any of several polysaccharides that are more complex than a sugar and less complex than cellulose. i.e. intermediate in complexity between sugar and cellulose that hydrolyze to mono-saccharides more readily than cellulose. It was found in plant cell walls and produced ‎commercially from grain hul1s. DP ranges from 50-300. Hemicellulose is ‎class of plant cell wall polysaccharide that cannot be extracted from the wall by hot water or chelating agents, but can be extracted by aqueous alkali. Includes xylan, glucuronoxylan, arabinoxylan. arabinogalactan II, glucomannan, xyloglucan and galactomannan part of the cell wall matrix a polysaccharide found in plant cell walls. Previous studies (Winandy and Morrell, 1993) have demonstrated a relationship between the degradation of hemicellulose components, such as arabinose and mannose, and wood strength losses. The significant reduction in strength observed during ‎incipient decay is therefore likely to be due to hemicellulose decomposition. ‎In softwoods, there are two principal hemicelluloses: galactogluco­mannan (70% mannan), which makes up approximately 60% of the total hemicellulose content, and arabino-4-0-methylglucuronoxylan (65% xylan), which constitutes the remaining 40(%. Thus the amount of galactose / mannan and arabinan/xylan

12 can be used to estimate the quantities of the major and minor, respective]y, hemicellulose component of the wall (Timell,‎ 1967; Highley, 1987). ‎Some monomers of hemicellulose, Figure (4), are shown in the sketch, which show that hemicellulose consists mainly of sugars and sugar acids. ‎‎Usually, all of the pentoses are present. There may even be small amounts of L-sugars. Note that there are hexoses as well as acids formed by oxidation of sugars. Mannose and mannuronic acid tend to be present, and there can be galactose and galacturonic acid. The pentoses are also present in rings (not shown) that can be 5-membered or 6-membered. Xylose is always the sugar present in the largest amount.

In contrast to cellulose that is crystalline, strong, and resistant to hydrolysis, hemicellulose has a random, amorphous structure with little strength. It is easily hydrolyzed by dilute acid or base, but nature provides an arsenal of hemicellulase enzymes for its hydrolysis. These enzymes are commercially important because they open the structure of wood for easier bleaching, and older methods of bleaching consume larger amounts of chemicals such as chlorine that are bad for the environment. ‎(www.rpi.edu/dent/chem.eng/Biotech.environ/FUNDAMNT/hemicel.htm)

13 1. 5. Lignin: ‎ Lignin, Figures (5,6), is the second most abundant chemical component of ‎lignocellulosic plants after carbohydrates (α-cellulose and hemicellulose). It holds the cellulosic fibers together in plant construction. Therefore, it adds rigidity to the cell wall and it resists decay because of its random linkages among aromatic rings. It was found in two different forms, guaiacyl (G) and syringyl (S) lignin according to the methoxyl groups attached to the phenyl ring as illustrated structurally below. Commercially, it is obtained as a byproduct of pulping and paper industries. Because lignin is constituted basically from phenylpropane units, they are interesting alternative source for aromatic compounds. They can also be used in dispersant, emulsifiers, metals sequestrate, adhesives, ion exchangers (Nada and Hassan, 2003) and phenolic resins (Benar et aI., 1999; Nada et aI., 2003; Nada et aI., ‎2000b).

Lignin is separated from cellulose rich fibers by either conventional pulping methods e.g. alkali and sulfite pulping or non-conventional pulping methods e.g. organosolv pulping methods (Nada et al., 1999; Nada et al., 1994a; Nada et al., 1994b). Organosolv lignin shows significantly better solubility and thermal flow properties than conventional pulping lignin(Glasser and Jain, 1993).

14 ‎ Unmodifiedlignin are often poorly soluble and resist fluid flow when heated, while modified lignin differ in its solubility and thermoplasticity character with regard to method of its isolation (Goncolves et al., 1998). Oxidation in alkaline medium is stabilized method for depolymerization of lignin. Vanillin and other aromatic aldehydes and acids are industry obtained by alkaline oxidation of lignin. Oxidation of lignin is researched to incorporate polar groups into the lignin structure like carbonyl, carboxyl and even hydroxyl for chelating materials for treatment of effluent containing heavy metals. Esterfication especially acetylation is widely used practically in the lignin field (Cotrim et al., 1995). ‎

15 Chapter II Pulping Processes ‎ Pulping is the process by which wood is reduced to a fibrous mass, i.e. it is the mean of rupturing the bonds within the wood structure (http:// naturalresources.ncsu.edu/wps/k12activities/ ppts/forest/sld052.htm). ‎2.1. Conventional Pulping Processes: ‎ The conventional pulping methods had been designed on the basis of the utilized technique, mechanically, semichemically or chemically. The chemical pulping processes had been classified principally as alkaline or acidic pulping processes. There are a number of different processes which can be used to separate the wood fibers: 2.1.1. Mechanical Pulping: Manufactured grindstones with embedded silicon carbide or aluminum oxide can be used to grind small wood logs called “bolts” to make “stone groundwood” pulp (SGW), Figure (7). If the wood is steamed prior to grinding it is known as “pressure groundwood” pulp (PGW). Most modern mills use chips rather than logs and ridged metal discs called refiner plates instead of grindstones. If the chips are just ground up with the plates, the pulp is called “refiner mechanical” pulp (RMP) and if the chips are steamed while being refined the pulp is called “thermomechanical” pulp (TMP). Steam treatment significantly reduces the total energy needed to make the pulp and decreases the damage (cutting) to fibers. The defibering action in mechanical pulping resulted from a loosening of fiber by repeated compression-decompression cycles to which the water plasticized fibers are subjected by the travel of the alternating high and 1ow profile of the abrader removing at right angles to the fiber axis (Vroom, 1957; Wilder and Daleski, 1965). Mechanical pulps are used for products that require less strength, such as news print and paperboards (http://en.wikipedia.org/wiki/Bleaching_of_ wood_pulp).

17 2.1.2. Chemithermomechanical (or Semichemical) Pulping: Wood chips can be pretreated with sodium carbonate, sodium hydroxide, sodium sulfite and other chemical prior to refining with equipment similar to a mechanical mill. The conditions of the chemical treatment are much less vigorous (lower temperature, shorter time, less extreme pH) than in a chemical pulping process since the goal is to make the fibers easier to refine, not to remove lignin as in a fully chemical process. Pulps made using these hybrid processes are known as chemithermomechanical pulps (CTMP). 2.1.3. Chemical Pulping: Chemical pulp is produced by combining wood chips and chemicals in large vessels known as digesters where heat and the chemicals break down the lignin, which binds the cellulose fibers together, without seriously degrading the cellulose fibers. Chemical pulp is used for materials that need to be stronger or combined with mechanical pulps to give product different characteristics. The Kraft process is the dominant chemical pulping method, with sulfite process being second. Historically soda pulping was the first successful chemical pulping method.

2.1.3.1. Alkaline Pulping: ‎ It is based on the use of reagent that will react with lignin in the wood in a manner that will result in its dissolution. Caustic soda has been used for this purpose for more than 100 years. However, the pulp showed strength properties superior to those of any pulp known at that time was named ‘’‎Kraft Pulp”. The term ‘’Kraft pulping’’ has evolved to summarize all the processes involving heating of wood chips in an aqueous solution of sodium hydroxide and sodium sulfide from approximately 70°C to a cooking temperature of about 170°C, then sustained for 1-2 hours cooking period (Carnö and Hartler, 1976; Hartler, 1978; Teder and Olm, 1981).

‎2.1.3.2. Sulfite Pulping: ‎ The sulfite processes are based on the fact that lignin will react with sulfurous acid, bisulfite, and neutral sulfite, either alone or in combination, and that the produced lignin sulfonates can be extracted from wood. The

18 main advantage of alkaline sulfite pulping is that it enhances the rate of delignification, lowers the bleach requirement, raises the yield and improves the brightness (Sayner and laundrie, 1964).

2.2. Non-Conventional Pulping Processes (Organosolv Pulping): ‎ Organosolv pulping was considered as a non-conventional method for pulping of fibrous raw materials. A substantial increase in research and development activity is now being devoted to organosolv pulping i.e . processes, which delignify woody materials with organic solvent-based systems, compared to the strictly aqueous inorganic-based systems universally used at present in commercial processes. Number of organic solvents may be used in pulping, but only aqueous MeOH and EtOH have shown potential for practical applications. The reaction probably follows a course similar to that of soda pulping but with MeOH, promoting lignin dissolution and decrease condensation (Milichovsky, 1991).

19 ‎ Mixture of ethanol-water and dioxane-water were present together with sodium hydroxide during pulping. Compared to soda pulping, the presence of low concentrations of ethanol resulted in a marked increase in the yield. It lowered α-cellulose and increased the pentosan content. On the other hand, at higher ethanol concentrations, the long-chain cellulose macromolecules were mainly stabilized and indicated by the increase in α-cellulose and decrease in pentosan (EI-Masry et al., 1997). Recycled pulp is also called deinked pulp (DIP). DIP is recycled paper which has been processed by chemicals, thus removing printing inks and other unwanted elements and freed the paper fibers. The process is called deinking. DIP is used as raw material in papermaking. Many newsprint, toilet paper and facial tissue grades commonly contain 100% deinked pulp and in many other grades, such as lightweight coated for offset and printing and writing papers for office and home use, DIP makes up a substantial proportion of the furnish. 2.3. Bleaching of Wood Pulp Bleaching of wood pulp is the chemical processing carried out on various types of wood pulp to decrease the colour of the pulp, so that it becomes whiter. The main use of wood pulp is to make paper with whiteness (similar to but not exactly the same as “brightness”) as an important characteristic (http://www. paperonweb.com/paperpro.htm#Brightness). The processes and chemistry described in this article are also applicable to the bleaching of non-wood pulps, such as those made from bamboo or kenaf. Brightness is a measure of how much light is reflected by paper under specified conditions (Biermann C. J. 1993) and is usually reported as a percentage of how much light is reflected, so a higher number represents a brighter or whiter paper. In the US, the TAPPI T 452 (Ducey M. 2004) or T 525 standards are used. The international community uses ISO standards. Table (1), shows how the two systems rate high brightness papers, but there is no simple way to convert between the two systems because the test methods are so different (http://www.tappi.org/s_tappi/doc- .asp?CID =13 &DID=512204). Note that the ISO rating is higher and can go above 100. This is because today’s white paper manufacturing uses fluorescent whitening agents (FWA). Because the ISO standard only measures a narrow range of blue light,

20 it is not an adequate measure for the actual whiteness or brightness (“Pulp bleaching chemicals information from PQ Corp.”. http://www.pqcorp. com/applications/PulpandPaper_application.asp#topic01).

Table (1): TAPPI and ISO Brightness

TAPPI Brightness ISO Brightness

84 88

92 104

96 108

97 109+

Newsprint ranges from 55-75 ISO brightness (Ducey M. 2004). Writing and printer paper would typically be as bright as 104 ISO. While the results are the same, the processes and fundamental chemistry involved in bleaching chemical pulps (like kraft or sulfite) are very different from those involved in bleaching mechanical pulps (like stoneground, thermomechanical or chemithermomechanical). Chemical pulps contain very little lignin while mechanical pulps contain most of the lignin which was present in the wood used to make the pulp. Lignin is the main source of colour in pulp due to the presence of a variety of chromophores naturally present in the wood or created in the pulp mill. 2.3.1. Bleaching Mechanical Pulps: Mechanical pulps retain most of the lignin present in the wood used to make the pulp and thus contain almost as much lignin as they do cellulose and hemicellulose. It would be impractical to remove this much lignin by bleaching, and undesirable since one of the big advantages of mechanical pulp is the high yield of pulp based on wood used. Therefore the objective of bleaching mechanical pulp (also referred to as brightening) is to remove only the chromophores (colour-causing groups). This is possible because the structures responsible for colour are also more susceptible to oxidation or reduction.

21 Alkaline hydrogen peroxide is the most commonly used bleaching agent for mechanical pulp. The amount of base such as sodium hydroxide is less than that used in bleaching chemical pulps and the temperatures are lower. These conditions allow alkaline peroxide to selectively oxidize non-aromatic conjugated groups responsible for absorbing visible light. The decomposition of hydrogen peroxide is catalyzed by transition metals, and iron, manganese and copper are of particular importance in pulp bleaching. The use of chelating agents like EDTA to remove some of these metal ions from the pulp prior to adding peroxide allows the peroxide to be used more efficiently. Magnesium salts and sodium silicate are also added to improve bleaching with alkaline peroxide (“Pulp bleaching chemicals information from PQ Corp.”, http:// www.Pqcorp- .com/applications/Pulp and Paper _application .asp#topic01 ).

Sodium dithionite (Na2S2O4), also known as sodium hydrosulfite, is the other main reagent used to brighten mechanical pulps. In contrast to hydrogen peroxide, which oxidizes the chromophores, dithionite reduces these colour-causing groups. Dithionite reacts with oxygen, so efficient use of dithionite requires that oxygen exposure be minimized during its use (Biermann C. J. 1993). Chelating agents can contribute to brightness gain by sequestering iron ions, for example as EDTA complexes, which are less coloured than the complexes formed between iron and lignin (Biermann C. J.1993). The brightness gains achieved in bleaching mechanical pulps are temporary since almost all of the lignin present in the wood is still present in the pulp. Exposure to air and light can produce new chromophores from this residual lignin (Sjöström E. 1993). This is why newspaper yellows as it ages. 2.3.2. Bleaching of Recycled Pulp: Hydrogen peroxide and sodium dithionite are used to increase the brightess of deinked pulp. The bleaching methods are similar for mechanical pulp in which the goal is to make the fibers brighter. 2.3.3. Bleaching Chemical Pulps: Chemical pulps, such as those from the Kraft process or sulfite pulping, contain much less lignin than mechanical pulps, (<5% compared to approximately 40%). The goal in bleaching chemical pulps is to remove

22 essentially all of the residual lignin; hence the process is often referred to as delignification. Sodium hypochlorite (household bleach) was initially used to bleach chemical pulps, but was largely replaced in the 1930s by chlorine. Concerns about the release of organochlorine compounds into the environment prompted the development of Elemental Chlorine Free (ECF) and Totally Chlorine Free (TCF) bleaching processes. Delignification of chemical pulps is rarely a single step process and is frequently comprised of four or more discrete steps. These steps are given a letter designation, Table(2), (“Paper On Web description of bleaching sequences”. http://www.paperonweb.com/bleach- .htm).

Table (2): Letter Designation in Chemical or Process Used in Bleaching Chemical Pulps

Chemical or Process Used Letter Designation

Chlorine C

Sodium Hypochlorite H

Chlorine Dioxide D

Extraction with Sodium Hydroxide E

Oxygen O

Alkaline Hydrogen Peroxide P

Ozone Z

Chelation to Remove Metals Q

Enzymes (Especially Xylanase) X

Peracids (Peroxy Acids) Paa

Sodium Dithionite (Sodium Hydrosulfite) Y

23 A bleaching sequence from the 1950s could look like: CEHEH . The pulp would have been exposed to chlorine, extracted (washed) with a sodium hydroxide solution to remove lignin fragmented by the chlorination, treated with sodium hypochlorite, washed with sodium hydroxide again and given a final treatment with hypochlorite. An example of a modern totally chlorine-free (TCF) sequence is OZEPY . In this process, the pulp would be treated with oxygen, then ozone, washed with sodium hydroxide then treated in sequence with alkaline peroxide and sodium dithionite. 2.3.4. Chlorine and Hypochlorite for Pulp Bleaching: Chlorine replaces hydrogen on the aromatic rings of lignin via aromatic substitution, oxidizes pendant groups to carboxylic acids and adds across carbon carbon double bonds in the lignin sidechains. Chlorine also attacks cellulose, but this reaction occurs predominantely at pH 7, where un-ionized hypochlorous acid, HClO, is the main chlorine species in solution (Fair, G. et al 1948). To avoid excessive cellulose degradation, chlorination is carried out at pH <1.5. ⇋ + - Cl2 + H2O H + Cl + HClO At pH >8 the dominant species is hypochlorite, ClO-, which is also useful for lignin removal. Sodium hypochlorite can be purchased or generated in situ by reacting chlorine with sodium hydroxide. ⇋ 2 NaOH + Cl2 NaOCl + NaCl + H2O The main objection to the use of chlorine for bleaching pulp is the large amounts of soluble organochlorine compounds produced and released into the environment. 2.3.5. Chlorine Dioxide for Pulp Bleaching:

Chlorine dioxide, ClO2 is an unstable gas with moderate solubility in water. It is usually generated in an aqueous solution and used immediately because it decomposes and is explosive in higher concentrations. It is produced by reacting sodium chlorate with a reducing agent like sulfur dioxide. → 2 NaClO3 + H2SO4 + SO2 2 ClO2 + 2 NaHSO4 Chlorine dioxide is sometimes used in combination with chlorine, but it is used alone in ECF (elemental chlorine-free) bleaching sequences. It is used at moderately acidic pH (3.5 to 6). The use of chlorine dioxide minimizes the amount of organochlorine compounds produced (Sjöström E.1993).

24 2.3.6. Extraction or Washing All bleaching agents used to delignify chemical pulp, with the exception of sodium dithionite, break lignin down into smaller, oxygen-containing molecules. These breakdown products are generally soluble in water, especially if the pH is greater than 7 (many of the products are carboxylic acids). These materials must be removed between bleaching stages to avoid excessive use of bleaching chemicals since many of these smaller molecules are still susceptible to oxidation. The need to minimize water use in modern pulp mills has driven the development of equipment and techniques for the efficient use of available water (Sillanpää M. 2005). 2.3.7. Oxygen-Based Chemicals for Pulp Bleaching: Oxygen exists as a ground state triplet state which is relatively unreactive and needs free radicals or very electron-rich substrates such as deprotonated lignin phenolic groups. The production of these phenoxide groups requires that delignification with oxygen be carried out under very basic conditions (pH >12). The reactions involved are primarily single electron (radical) reactions (Starnes W.H.1991; Singh, R.P.1979). Oxygen opens rings and cleaves sidechains giving a complex mixture of small oxygenated molecules. Transition metal compounds, particularly those of iron, manganese and copper, which have multiple oxidation states, facilitate many radical reactions and impact oxygen delignification(McDonough T. J. 1983; Johansson E.; Ljunggren S. 1991). While the radical reactions are largely responsible for delignification, they are detrimental to cellulose. Oxygen-based radicals, especially hydroxyl radicals, HO•, can oxidize hydroxyl groups in the cellulose chains to ketones, and under the strongly basic conditions used in oxygen delignification, these compounds undergo reverse Aldol reactions leading to cleavage of cellulose chains. Magnesium salts are added to oxygen delignification to help preserve the cellulose chains (McDonough T. J. 1983), but mechanism of this protection has not been confirmed. 2.3.8 Hydrogen Peroxide in Pulp Bleaching: Using hydrogen peroxide to delignify chemical pulp requires more vigorous conditions than for brightening mechanical pulp. Both pH and temperature

25 are higher when treating chemical pulp. The chemistry is very similar to that involved in oxygen delignification, in terms of the radical species involved and the products produced (Suss, H.U.; N.F. Nimmerfroh 1993). Hydrogen peroxide is sometimes used with oxygen in the same bleaching stage and this gives the letter designation Op in bleaching sequences. Metal ions, particularly manganese catalyze the decomposition of hydrogen peroxide, so some improvement in the efficiency of peroxide bleaching can be achieved if the metal levels are controlled. 2.3.9. Ozone for Pulp Bleaching: Ozone is a very powerful oxidizing agent and the biggest challenge in using it to bleach wood pulp is to get sufficient selectivity so that the desirable cellulose is not degraded. Ozone reacts with the carbon carbon double bonds in lignin, including those within aromatic rings. In the 1990s ozone was touted as good reagent to allow pulp to be bleached without any chlorine-containing chemicals (totally chlorine-free, TCF). The emphasis has changed and ozone is seen as an adjunct to chlorine dioxide in bleaching sequences not using any elemental chlorine (elemental chlorine-free, ECF). Over twenty-five pulp mills worldwide have installed equipment to generate and use ozone (“Use of Ozone from web page by Air Liquide”.http://www.ca.airliquide .com/ en/ business/industry/pulp_paper/applications ozone bleaching -.asp). 2.3.10. Other Bleaching Agents: A variety of more exotic bleaching agents have been used on chemical pulps. They include peroxyacetic acid (Ragauskas, A.J.; K.M. Poll and A.J. Cesternino 1993), peroxyformic acid, potassium peroxymonosulfate (Oxone), dimethyldioxirane (Bouchard et al 1996), which is generated in situ from acetone and potassium peroxymonosulfate, and peroxymonophosphoric acid (Springer, E.L. 1997). Enzymes like xylanase have been used in pulp bleaching (Ragauskas, et al 1993) to increase the efficiency of other bleaching chemicals. It is believed that xylanase does this by cleaving lignin-xylan bonds to make lignin more accessible to other reagents (Biermann C. J. 1993). It is possible that other enzymes such as those found in fungi that degrade lignin may be useful in pulp bleaching (Harazono et al 1996).

26 CHAPTER 3 Paper Manufacturing Process Paper Manufacturing Process is a complicated process. It takes several steps to occur as follow: 3.1. Making Pulp: Several processes are commonly used to convert logs to wood pulp. In the mechanical process, Figure (8), logs are first tumbled in drums to remove the bark. The logs are then sent to grinders, which break the wood down into pulp by pressing it between huge revolving slabs. The pulp is filtered to remove foreign objects. In the chemical process, wood chips from de-barked logs are cooked in a chemical solution. This is done in huge vats called digesters. The chips are fed into the digester, and then boiled at high pressure in a solution of sodium hydroxide and sodium sulfide. The chips dissolve into pulp in the solution. Next the pulp is sent through filters. Bleach may be added at this stage, or colourings. The pulp is sent to the paper plant (Ferguson K. 1994).

27 3.2. Beating: The pulp is next put through a pounding and squeezing process called, appropriately enough, beating. Inside a large tub, the pulp is subjected to the effect of machine beaters. At this point, various filler materials can be added such as chalks, clays, or chemicals such as titanium oxide. These additives will influence the opacity and other qualities of the final product. Sizings are also added at this point. Sizing affects the way of the paper will react with various inks. Without any sizing at all, a paper will be too absorbent for most uses except as a desk blotter. A sizing such as starch makes the paper resistant to water-based ink (inks actually sit on top of a sheet of paper, rather than sinking in). A variety of sizings, generally rosins and gums, is available depending on the eventual use of the paper. Paper that will receive a printed design, such as gift wrapping, requires a particular formula of sizing that will make the paper accept the printing properly. 3.3. Pulp to Paper: In order to finally turn the pulp into paper, the pulp is fed or pumped into giant, automated machines. One common type is called the Fourdrinier machine, Figure (9), which was invented in England in 1807 (http://www.industrialcenter.org/ GasIRPaper/Learn-%20About/Paper_Manufacture.htm).

Pulp is fed into the Fourdrinier machine on a moving belt of fine mesh screening. The pulp is squeezed through a series of rollers, while suction devices below the belt drain off water. If the paper is to receive a water-mark, a device called a dandy moves across the sheet of pulp and presses a design into it.

28 The paper then moves onto the press section of the machine. Here, it is pressed between rollers of wool felt. The paper then passes over a series of steam-heated cylinders to remove the remaining water. A large machine may have from 40 to 70 drying cylinders. There are also machines with entire Fourdrinier sections mounted above a traditional Fourdrinier. This allows making multi-layer paper with special characteristics. These are called Top Fourdriniers and they make multiply paper or paperboard. Commonly this is used for making a top layer of bleached fiber to go over an unbleached layer. 3.3.1. Mould Made Paper Making Process: Another type forming section is the cylinder mould machine, Figure (10), using a rotating cylinder partially immersed in a tank of fiber slurry in the wet end to form a paper web, giving a more random distribution of the cellulose fibers. Cylinder machines can form a sheet at higher consistency, which gives a more three-dimensional fiber orientation than lower consistencies, resulting in higher caliper (thickness) and more stiffness in the machine direction (MD). The VAT mould made paper making process is used to produce a majority of banknote paper.

29 3.4. Finishing: Finally, the dried paper is wound onto large reels. Here it will be further processed depending on its ultimate use. Paper is smoothed and compacted further by passing through metal rollers called calendars. A particular finish, whether soft and dull or hard and shiny, can be imparted by the calendars. The paper may be further finished by passing through a vat of sizing material. It may also receive a coating, which is either brushed on or rolled on. Coating adds chemicals or pigments to the paper’s surface, supplementing the sizings and fillers from earlier in the process. Fine clay is often used as a coating. The paper may next be supercalendered, that is, run through extremely smooth calendar rollers, for a final time. Then the paper is cut to the desired size. 3.5. Additives in Papermaking: Additives play an important role in papermaking. All types of paper contain one or more added non-fibrous substance. These additives modify sheet properties to meet the specific requirements for its intended use (Mobarak et al, 1997). ‎ Additives are classified according to their ‎effect on strength on paper to: the initial wet strength, dry strength, and finally the wet strength (Ullmanns.,voI.18,1991). 3.6. Filler in Papermaking: The paper industry uses large quantities of filler, particularly in fine paper and magazine paper grade. The most widely used filler pigments are Calcium carbonate, Titanium dioxide and clay (Anja Kemppi., 1997). ‎Fillers can plug the cavities and reduce the unevenness of the surface. The individual filler particles are very small in comparison with the length of fibers. These small finer particles fit well between the long fibers and can ledge within the network of the fibers. The fined paper has a more attractive appearance because of this finer, more closed texture. Fillers play an important role in printing processes where, cellulosic fibres do not accept printing ink easily, while fillers have a much better wet-ability. The addition of fillers creates a system of finer capillaries, which are essential for a controlled uniform ink acceptance.

30 Fillers help to obtain printed dotes which are evenly inked and not distorted in shape. If fillers were not present in the voids between the fibers, the printing ink would penetrate through these voids to backside of the paper, causing strike through. The printed paper would become unattractive and difficult to read. In addition to their importance in printing processes, fillers are considered as opacifying agents as they are added not only in printing papers but in many other grades of papers to increase their opacity and also to improve their brightness or whiteness or to raise or smooth out their reflectance curves.

31 CHAPTER 4 INTRODUCTION TO POLYMER Polymer banknotes are made from the polymer biaxially-oriented polypropylene (BOPP). First of all we have to speak about polypropylene. IUPAC name of polypropylene, Figure (11), is poly (propene). Other names are Polypropylene; Polypropene, Polipropene 25 [USAN]; Propene polymers; Propylene polymers; 1-Propene homopolymer.

Polypropylene was first polymerized by Dr. Karl Rehn at Hoechst AG in Germany in 1951, who didn’t recognize the importance of his discovery. It was then rediscovered on March, 11th 1954 by Giulio Natta. At first it was thought that it would be cheaper than polyethylene (http://www.newscientist.com/ -article/mg19426014.900-this-week-50 years-ago.html).

The Molecular formula of Polypropylene is (C3H6) x, its Density is 0.855 g/cm3 (amorphous) and 0.946 g/cm3 (crystalline).The Melting point of Polypropylene is ~ 160 °C. Polypropene (PP) is a thermoplastic polymer, made by the chemical industry and used in a wide variety of applications, including packaging, textiles (e.g., ropes, thermal underwear and carpets), stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes (http://en.wikipedia.org/ wiki/Polypropyl-ene). An addition polymer made from the monomer propylene, it is rugged and unusually resistant to many chemical solvents, bases and acids. Polypropene

33 is commonly recycled, and has the number “5” as its recycling symbol: ( http://en.wikipedia.org/wiki/ Resin_ identification code). Melt processing of polypropylene can be achieved via extrusion and molding. Common extrusion methods include production of melt blown and spun bond fibers to form long rolls for future conversion into a wide range of useful products such as face masks, filters, nappies and wipes. The most common shaping technique is injection molding, which is used for parts such as cups, cutlery, vials, caps, containers, house wares and automotive parts such as batteries. The related techniques of blow molding and injection- stretch blow molding are also used, which involve both extrusion and molding. The large number of end use applications for PP is often possible because of the ability to tailor grades with specific molecular properties and additives during its manufacture. For example, antistatic additives can be added to help PP surfaces resist dust and dirt. Many physical finishing techniques can also be used on PP, such as machining. Surface treatments can be applied to PP parts in order to promote adhesion of printing ink and paints (http://www. en.wikipedia.org/wiki/polypropylene). 4.1. Chemical and Physical Properties of Polypropylene: Most commercial polypropylene is isotactic and has an intermediate level of crystallinity between that of low density polyethylene (LDPE) and high density polyethylene (HDPE); its Young’s modulus is also intermediate. Through the incorporation of rubber particles, PP can be made both tough and flexible, even at low temperatures. This allows polypropylene to be used as a replacement for engineering plastics, such as Acrylonitrile butadiene styrene (ABS). Polypropylene is rugged, often somewhat stiffer than some other plastics, reasonably economical, and can be made translucent when uncolored but is not as readily made transparent as polystyrene, acrylic or certain other plastics. It can also be made opaque and/or have many kinds of colours through the use of pigments. Polypropylene has very good resistance to fatigue, so that most plastic living hinges, such as those on flip-top bottles, are made from this material. Very thin sheets of polypropylene are used as a dielectric within certain high performance pulse and low loss RF capacitors.

34 Polypropylene has a melting point of ~160°C (320°F), as determined by Differential Scanning Calorimetry (DSC). Many plastic items for medical or laboratory use can be made from polypropylene because it can withstand the heat in an autoclave. Food containers made from it will not melt in the dishwasher, and do not melt during industrial hot filling processes. For this reason, most plastic tubs for dairy products are polypropylene sealed with aluminum foil (both heat-resistant materials). After the product has cooled, the tubs are often given lids made of a less heat-resistant material, such as LDPE or polystyrene. Such containers provide a good hands-on example of the difference in modulus, since the rubbery (softer, more flexible) feeling of LDPE with respect to PP of the same thickness is readily apparent. Rugged, translucent, reusable plastic containers made in a wide variety of shapes and sizes for consumers from various companies such as Rubbermaid and Sterilite are commonly made of polypropylene, although the lids are often made of somewhat more flexible LDPE so they can snap on to the container to close it. Polypropylene can also be made into disposable bottles to contain liquid, powdered or similar consumer products, although HDPE and polyethylene Terephthalate are commonly also used to make bottles. Plastic pails, car batteries, wastebaskets, cooler containers, dishes and pitchers are often made of polypropylene or HDPE, both of which commonly have rather similar appearance, feel, and properties at ambient temperature. The MFR (Melt Flow Rate) or MFI (Melt Flow Index) is an indication of PP’s molecular weight. This helps to determine how easily the melted raw material will flow during processing. Higher MFR PPs fill the plastic mold more easily during the injection or blow molding production process. As the melt flow increases, however, some physical properties, like impact strength, will decrease. There are three general types of PP: homopolymer, random copolymer and impact or block copolymer. The comonomer used is typically ethylene. Ethylene-propylene rubber added to PP homopolymer increases its low temperature impact strength. Randomly polymerized ethylene monomer added to PP homopolymer decreases the polymer crystallinity and makes the polymer more transparent (http://www.en.wikipedia.org/wiki- /poly-propylene).

35 4.2. Degradation of Polypropylene: Polypropylene is liable to chain degradation from exposure to UV radiation such as that present in sunlight. This is one main reason for not using it transparent instead of glass. For external applications, UV-absorbing additives must be used. Carbon black also provides some protection from UV attack. The polymer can also be oxidized at high temperatures, a common problem during moulding operations. Anti-oxidants are normally added to prevent polymer degradation (Kleinschmidt R. et al, 2000). 4.3. Synthesis of Polypropylene: An important concept in understanding the link between the structure of polypropylene and its properties is tacticity, Figure (12). The relative orientation of each methyl group (CH3 in the figure at left) relative to the methyl groups on neighboring monomers has a strong effect on the finished polymer’s ability to form crystals, because each methyl group takes up space and constrains backbone bending.

Like most other vinyl polymers, useful polypropylene cannot be made by radical polymerization due to the higher reactivity of the allylic hydrogen (leading to dimerization) during polymerization. Moreover, the material that would result from such a process would have methyl groups arranged randomly. It is called atactic PP. The lack of long-range order prevents any crystallinity in such a material, giving an amorphous material with very little strength and only specialized qualities suitable for niche end uses. A Ziegler-Natta catalyst is able to limit incoming monomers to a specific orientation (Hill, A.F, 2002; Kissin, Y.V. 2008), only adding them to the polymer chain if they face the right direction. Most commercially available

36 polypropylene is made with such Ziegler-Natta catalysts, which produce mostly isotactic polypropylene (the upper chain in the figure above). With the methyl group consistently on one side, such molecules tend to coil into a helical shape. These helices then line up next to one another to form the crystals that give commercial polypropylene many of its desirable properties. More precisely engineered Kaminsky catalysts have been made, which offer a much greater level of control. Based on metallocene molecules, these catalysts use organic groups to control the monomers being added, so that a proper choice of catalyst can produce isotactic, syndiotactic, or atactic polypropylene, or even a combination of these. Aside from this qualitative control, they allow better quantitative control, with a much greater ratio of the desired tacticity than previous Ziegler-Natta techniques. They also produce narrower molecular weight distributions than traditional Ziegler-Natta catalysts, which can further improve properties. To produce a rubbery polypropylene, a catalyst can be made which yields isotactic polypropylene, but with the organic groups that influence tacticity held in place by a relatively weak bond. After the catalyst has produced a short length of polymer which is capable of crystallization, light of the proper frequency is used to break this weak bond, and remove the selectivity of the catalyst so that the remaining length of the chain is atactic. The result is a mostly amorphous material with small crystals embedded in it. Since each chain has one end in a crystal but most of its length in the soft, amorphous bulk, the crystalline regions serve the same purpose as vulcanization. 4.3.1. Mechanism of Metallocene Catalysts: The reaction of many metallocene catalysts requires a co-catalyst for activation. One of the most common co catalysts for this purpose is Methylalmuinoxane [commonly called MAO, a white solid with the general formula (Al(CH3)O)n.] (Kleinschmidt R. et al, 2000). Other co catalysts include, Al (C2H5)3 (Kyung-Jun Chu. Eur. Polym, 1998).There are numerous metallocene catalysts that can be used for propylene polymerization. (Some metallocene catalysts are used for industrial process, while others are not, due to their high cost.) One of the simplest is Cp2MCl2 (M = Zr, Hf). Different catalyst can lead to polymers with different molecular weights and properties.

37 Active research is still being conducted on metallocene catalyst. Organometallic zirconium complexes of the type used to produce polyethylene, Figure (13), are also effective catalysts for the synthesis of polypropylene as in the following Scheme:

In the mechanism the metallocene catalyst first reacts with the co-catalyst. If MAO is the co-catalyst, the first step is to replace one of the Cl atoms on the catalyst with a methyl group from the MAO. The methyl group on the MAO is replaced by the Cl from the catalyst. The MAO then removes another Cl from the catalyst. This makes the catalyst positively charged and susceptible to attack from propylene (http://www.chemistry.wustl.edu/~edudev /Designer /session6.html). Once the catalyst is activated, the double bond on the propene coordinates with the metal of the catalyst. The methyl group on the catalyst then migrates to the propene, and the double bond is broken. This starts the polymerization. Once the methyl migrates the positively charged catalyst is reformed and another propene can coordinate to the metal. The second propene coordinates and the carbon chain that was formed migrates to the propene. The process of coordination and migration continues and a polymer chain is grown off of the metallocene catalyst (Song et al, 2004; P. Mercandelli et al, 2007). If we look closely at the structure of the polypropylene that is produced + in the [Cp2Zr(R)] -catalyzed polymerization of propylene, Figure (14), we

38 see that it results from head-to-tail polymerization. This, in turn, implies that each alkyl migration step in the mechanism must involve transfer of the alkyl group to the b-carbon (the methyl-bearing carbon) of the propylene, as shown in the scheme. However, although the propylene units are stitched together in a rigorous head-to-tail fashion, there is no regular pattern to the orientation of the methyl groups along the polymer chain. The methyl groups project toward us or away from us in a totally random fashion, i.e., the polymer is atactic. The randomness results from the fact that when propylene coordinates to the zirconium center, there is no preference for the methyl group to point up or down, because both orientations result in the same interactions between the methyl group and a cp ligand . This is true whether the propylene coordinates to Zr in the front site or in the rear site.

+ When propylene coordinates to [cp2Zr(R)] , there is no preference for the methyl group to be oriented up or down (http://www.chemistry. wustl. edu/~edudev/Designer/session6-.html). 4.4. Practical Applications of Polypropylene: A common application for polypropylene is as Biaxially Oriented polypropylene (BOPP). These BOPP sheets are used to make a wide variety

39 of materials including clear bags. When polypropylene is biaxially oriented, it becomes crystal clear and serves as an excellent packaging material for artistic and retail products and the most important application to be used as a banknote substrate. Polypropylene, highly colourfast, is widely used in manufacturing rugs and mats to be used at home (http://www.fibersource.com/f-tutor/olefin. htm Rug fibers). Recently, in Australia in 1988, Biaxially-oriented polypropylene (BOPP) is used as a substrate for Polymer banknotes (synthetic polymer), were developed by the Reserve Bank of Australia (RBA), Commonwealth Scientific and Industrial Research Organization (CSIRO) and the University of Melbourne and were first issued as currency. BOPP greatly enhances durability of the banknotes (John Colditz, 1997). Trading as Securency International (a joint venture between the RBA and Innovia Films, Formed in 1996, the supplier of a range of unique substrates which are used for the printing of banknotes and other security documents) markets BOPP as ‘Guardian®’ for countries with their own banknote printing facilities (John Colditz, 1997). 4. 5. Adoption of Polymer Banknotes: Polymer banknotes were developed by the Reserve Bank of Australia (RBA), Commonwealth Scientific and Industrial Research Organization (CSIRO) and the University of Melbourne were first issued ascurrency in Australia in 1988. These banknotes are made from the polymer biaxially-oriented polypropylene (BOPP) which greatly enhances durability of the banknotes. Polymer banknotes also incorporate many security features not available to paper banknotes, making counterfeiting much more difficult. Innovia market the unique BOPP film used for banknotes as “Clarity-C”. Guardian is unique form of opacified BOPP Clarity-C film. Note Printing Australia (NPA) and around 10 other accredited polymer printers have produced banknotes for about 35 countries, Figure (15), (Australia, Bangladesh, Brazil, Brunei, Canada, Chile, China, Dominican Republic, Guatemala, Honduras, Hong Kong, Indonesia, Kuwait, Malaysia, Mexico, Mozambique, New Zealand, Nepal, Nicaragua, Nigeria, Northern

40 Ireland, Papua New Guinea, Paraguay, Romania, Singapore, Solomon Islands, Sri Lanka, Taiwan, Thailand, Vanuatu, Vietnam, Western Samoa and Zambia).

An alternative polymer of polyethylene fibres marketed asTyvek by DuPont was developed for use as currency by the American Bank Note Company in the early 1980s. Tyvek did not perform well in trials, smudging of ink and fragility was reported problems. Only Costa Rica and Haiti issued Tyvek banknotes (test notes were produced for Ecuador, El Salvador, Honduras and Venezuela but never placed in circulation); additionally, English printers Bradbury Wilkinson produced a version on Tyvek but marketed as Bradvek for the Isle of Man in 1983; however, they are no longer produced and have become collectors’ items. As of 2012, seven countries have converted fully to polymer banknotes: Australia, Canada, New Zealand, Romania, Vietnam, Brunei and Papua New Guinea. Other countries with notes printed on Guardian polymer in circulation include: Bangladesh, Brazil, Chile, Hong Kong (for a 2-year trial), Indonesia, Israel, Malaysia, Mexico, Nepal, Nicaragua, Singapore, Solomon Islands (no longer issued), Sri Lanka, Thailand, Samoa and Zambia. Countries that have issued commemorative banknotes (which are not in circulation) on Guardian polymer include: China, Taiwan, Kuwait, Northern Ireland and Singapore (http://en.wikipedia.org/wiki/-Polymer banknote).

41 4.5.1. Timeline of Adoptions and Withdrawals: • In 1982 and 1983, the American Bank Note Company printed banknotes for Costa Rica (20 colones dated 1983 and trial notes of 100 colones) and Haiti (1, 2, 50, 100, 250 and 500 Gourdes, on DuPont’s Tyvek polymers. These had fairly limited release, but did circulate in each country. Additional trial and specimen banknotes were developed for Honduras, Ecuador and El Salvador. Unfortunately, in tropical climates, ink did not bind well to the polymer and the notes began smearing quite badly. • In 1983, the British printers Bradbury Wilkinson produced a promotional version of polymer banknotes, which were marketed as Bradvek. The Isle of Man issued a 1-pound Bradvek banknote, which circulated from 1983 to 1988. Another British printer, Harrison and Sons Limited also produced a promotional banknote, but did not have any buyers. • In 1988, Australia issued a commemorative 10-dollar banknote, the first of many issues. • In 1990, Western Samoa, later renamed Samoa issued a 2 Tala commemorative banknote honouring 50 years of service by His Highness Malietoa Tanumafili II. This banknote was placed in circulation and has the distinction of having the longest period of circulation, as of 2006 it had been circulating for 16 years, and has been reprinted with minor variations at least 7 times. • In August 1990, Singapore issued a $50 commemorative banknote, and in 2004 issued its first circulating $10 banknote, followed by a $2 issue in 2006. The $5 banknote and the commemorative $20 banknote were issued in 2007. • In June 1991, Papua New Guinea issued a commemorative 2 Kina banknote, its first polymer issue. • In 1992, Australia began issuing polymer notes for general circulation. • In February 1993, Kuwait issued the first of its commemorative banknotes, a 1 Dinar issue honouring the liberation of Kuwait during the First Gulf War. • In 1993, Indonesia issued its first polymer banknote, the 50,000 rupiah note commemorating 25 years of development. A paper equivalent was also available at the same time. • In 1996, Australia became the first country with a full set of circulating polymer banknotes in each denomination, from 5 to 100 dollars.

42 • In 1996, Thailand issued both a 50 and a 500 baht note commemorating the 50th anniversary of the reign of Bhumibol Adulyadej. • In February 1996, Brunei issued 1, 5 and 10 ringgit banknotes. These were the first non-commemorative banknotes issued outside of Australia (and the 1982 issues). • In 1997, Thailand issued a 50 baht note as its first polymer note for general circulation. • In February 1998, Sri Lanka issued a 200 Rupee commemorative polymer banknote. • In 1998, Malaysia issued a commemorative banknote in conjunction with the XVI Commonwealth Games; it issued a 5 ringgit circulating banknote in 2004. • On 3 May 1999, New Zealand released the polymer $20 note, by the end of the year replacing all denominations from $5 to $100 with polymer banknotes. • In 1999, Romania was the first European country to introduce a full set of circulating polymer banknotes (the banknotes were issued between 1999 and 2001). • In 1999, Indonesia issued its first polymer banknote for general circulation, the 100,000 rupiah note. • In June 1999, the Republic of China (Taiwan) issued a 50-dollar note to commemorate the 50th anniversary of the issuance of the New Taiwan dollar. • In 1999, the Northern Bank, one of five banknote-issuing authorities in Northern Ireland issued a 5-pound commemorative note celebrating the year 2000; this note was placed in circulation, and was also sold at a premium to collectors with a Y2K serial number prefix. • In April 2000, Brazil released a 10 real polymer bill to celebrate the 500th anniversary of the Portuguese arrival in America. Casa da Moeda do Brasil printed 250 million banknotes, around half the 10 real bills in circulation. • In November 2000, the People’s Republic of China issued a 100 yuan note to commemorate the millennium.

43 • In December 2000, Bangladesh issued 10-Taka polymer notes. • In 2000, the Chatham Islands issued the first of three sets of commemorative banknotes for the collecting market. • On 1 January 2001, Australia issued a commemorative $5 polymer banknote. It commemorated the centenary of federation. • In June 2001, the Solomon Islands issued $2 polymer banknotes. However they reverted back to paper notes in 2006. • In the summer of 2001, Vietnam issued a 50-dong commemorative banknote. • In February 2002, Nepal issued a 10 rupee polymer banknote, commemorating the new King Gyanendra. In 2005 it issued a version for circulation without the commemorative text. • In September 2002, Mexico switched 20 peso banknotes from paper to polymer banknotes. Two more new polymer notes issued in 2006, for the 20 pesos (new design) and 50 pesos. • In 2003, Zambia was the first African country to adopt polymer banknotes, with 500 and 1000 kwacha denominations. • In November 2003, Papua New Guinea issued a 20 kina banknote, and began the process of issuing all denominations in polymer format. The only remaining denomination not in polymer is the 5 kina note. • From December 2003 to August 2006, Vietnam adopted polymer banknote in 10,000, 20,000, 50,000, 100,000, 200,000 and 500,000 đồng for general circulation,[2] becoming the fourth country to fully convert to polymer notes. • In September 2004, the 2000 Chilean peso bills began to be issued in polymer banknotes • In 2004, it was estimated that there were over 3 billion polymer notes in service. • In 2004, the only polymer note for general circulation in Thailand, the 50 baht note issued in 1997, was reissued in paper format. Commemorative notes continue to be issued in polymer format. • In 2004, the only polymer note for general circulation in Indonesia, the 100,000 rupiah note issued in 1999, was re-issued on paper. • In 2005, Papua New Guinea issued the new 100 kina note, its first denomination that was never printed in paper format.

44 • In July 2005, Romania became the first country to issue a full second generation of plastic notes of each of its denominations. The notes bore the same design format as the old notes, but their size brings them in line with euro banknotes, and are denominated in a reformed currency with 1 new leu = 10,000 lei • In 2005, Bulgaria issued the first hybrid paper/polymer banknotes, denominated 20 (new) leva, featuring two plastic “windows” and a hologram. • In November 2006, Mexico issued a new 50 pesos polymer banknotes. • In 2006 CSIRO, the Australian Government agency issued a non legal tender polymer note to celebrate 80th year of the formation of CSIRO. These notes were issued and distributed to staff members and at selected public events.[1] • On February 28, 2007, Nigeria issued the 20 naira note as polymer banknotes. Printed by the Nigerian Minting and Printing Co. and Giesecke & Devrient (G&D). • In mid 2007, Hong Kong issued the polymer 10 dollar note for a 2-year trial period. • In June 2007, Brunei became the fifth country to fully convert to polymer notes. • In August 2007, Guatemala issued a 1 quetzal polymer banknote. • On 13 April 2008, Israel started to issue 20 NIS Banknotes, due to the high deterioration of 20 NIS paper banknotes. The Israeli polymer notes are printed by Orell Füssli Security Printing of Zürich, Switzerland. • On 15 April 2008, Papua New Guinea issued 5 and new 10 kina banknotes for general circulation. 5 Kina being the last denomination for Papua New Guinea on polymer (http://www.en.wikipedia.Org /wiki/polymer banknote). • On 15 May 2009, first circulating polymer banknotes issued in Nicaragua. • On 15 May 2009, Nicaragua released new polymer ten and twenty Nicaragua Córdoba banknotes to replace their paper counterparts, Printed by Giesecke & Devrient (G&D) (IPCA- The New Paradigm In Currency). After an announcement from the Central Bank of Nicaragua in 2008 stated that a new 200 Córdoba banknote would be in circulation, it took the country

45 an additional year to prepare its new set of banknotes. A new polymer two hundred and a hundred Córdoba banknote was first issued on the first of June, 2009. In December 2009, a new 50 banknote was released, later followed by a new 500 C$ banknote that was issued on January 12, 2010 (http://www.banknotenews.com/files/tag-nicaragua.html). • In September 2009, Reserve Bank of India announced that it will introduce 100 Crore (1 billion) Rs. 10 notes (http://www.banknotenews.com/files/ tag-nicaragua.html). • In September 2009, Central Bank of Chile introduced the new series of the Chilean Peso, starting with the redesigned 5000 Pesos banknote (Reserve Bank of Australia, Polymer Banknotes Launch. Retrieved 9 December 2010). • In March 2010, Finance Minister Jim Flaherty announced that The Bank of Canada will introduce new polymer notes by 2011 as part of a plan to modernize the currency and crack down on counterfeiting (http://www. theglobeandmail.com/-news/politics/ottawa-notebook/open-your- wallets-for-plastic-cash/article1489845/). • In June 2010, The Central Bank of the Dominican Republic announced the introduction of a new polymer based 20 pesos bill (http://www.bancentral. gov.do/billetes_monedas/billetes_ 20.html). • In October 2010, The Central Bank of Chile announced the redesigned 2000 Pesos that would be on circulation on November 20, as a program to change the old designs and make them more secure (http://www.nuevosbilletes. cl/nuevos-billetes/2000/). • On October 1, 2011, the Banco de Mozambique began printing of the 20-, 50-, and 100-metecai banknotes on a polymer substrate. • In November 2011, The Bank of Canada began circulation of $100 polymer banknotes. In March 2012 $50 banknotes will be released, followed by $20, $10, $5 Denominations by late 2013.

46 4.5.2. Synthesis of Guardian® Substrate: The Guardian® Substrate is a complex material that incorporates a durable core opacified with special materials. The core of the Substrate is made from Biaxially- Oriented Polypropylene (BOPP), Figure (16), specially produced for the banknotes to provide security, durability and processability characteristics. The Guardian® Substrate is coated with specially formulated opacifying inks to the customer’s specified colours. It is synthesized by a process called” BUBBLE PROCES”.

The Guardian® based banknote contains the following basic structure: Guardian® substrate including clear window and specified substrate features, Offset print, Intaglio print, Numbering and Protective overcoating, Figure (17).

47 CHAPTER 5 Security Features in Banknotes Dealing with security in banknotes, we should take into consideration four elements: Substrate Features, Ink Features, Design Features and Security in machine readable features. 5.1. Substrate Features: Substrate features are an integral part of the material on which the banknotes are printed. The choice of substrate is very important as it has to be a very durable material resistant to tearing, withstanding crumpling and stable to environmental effects such as humidity. (http://www.indigoimage.com/ count/feat2- .html). 5.1.1. Paper Substrate Features: For each currency produced a corresponding paper is manufactured. Paper Banknote is made from cotton pulp which gives it better durability than commercial papers and a very distinctive feel. Much of the time, it is the initial feel of a counterfeit that urges someone to have a closer look at what they are holding. If banknote paper is held under ultra violet light it is dull compared to commercial papers. The specialized and secure manufacturing process of banknote paper allows for a number of features to be created that is unique to banknote paper.

5.1.1.1. Watermark: The watermark, Figure (18), is one of the most obvious security features of a paper banknote. When held up to the light an image can be seen in the paper, usually a portrait similar to that printed on the note. The image of the watermark is caused by different thicknesses of paper, with light areas of the watermark being a result of thinner paper. The highlighted effect of “ ultra thin” paper is sometimes used as an added security effect in small specific areas within a watermark, e.g. A denomination may appear as a “highlighted” portion compared to the main bulk of the watermark.

49 A watermark is an excellent security feature. A counterfeiter is very unlikely to manufacture his own paper. Having said that there are some ways watermarks can be simulated although the effects are crude.

5.1.1.2. Threads: Threads, Figure (19), are embedded within the paper fiber and can be completely invisible or have a star burst effect. Here, the thread appears to weave in and out of the paper when viewed from one side. However, if it is held up to the light, the thread will always appear as a solid line.

Features can be built into the thread material, Figure (20), e.g. microprinting on a transparent plastic thread or adding materials so they fluoresce under ultraviolet light. The thread is a difficult feature to counterfeit but some counterfeiters have been known to print a thin grey line or a thin line of varnish in the area of the thread.

50 5.1.1.3. Other Embedded Features: While the paper is in the pulp stage various elements can be added that then become embedded in the paper in a random fashion. e.g Tiny fibres which fluoresce under ultra violet light or tiny iridescent foils known as planchettes. It is also possible to tint the paper.

5.1.1.3.1. Fibers: The fibers, Figure (21), are very small viscose or nylon threads, and can be either visible or invisible to the naked eye, randomly distributed in the paper or in a band. There are a wide choice of colours and lengths. Visible fibers may be discerned under normal light conditions. Some invisible fibers have a different colour when exposed to UV light.

51 5.1.1.3.2. Planchettes: Planchettes, Figure (22), are small coloured discs randomly distributed all over the paper or in a band. They have the advantage of being readily visible to the naked eye, or by fluorescence under UV light (http://www. securityarjowiggins.com/english/elements_prod-.htm).

5.1.2. Polymer Substrate Features: A polymer substrate has been adopted by some countries as the chosen medium for their currency. Security features are built into the plastic is coating with an opaque white leaving a window of transparency and pseudo watermarks are produced by printing additional designs in opaque white. These features offer good protection from colour copier counterfeiting. Polymer substrates provide a platform for new and additional security features with durability, quality and cost-efficiency. It is a valuable addition to the arsenal of technologies available to note issuers for ensuring the integrity and quality of their currency (http://www.noteprinting. com/report_ 001. html). With the growth of digital printing and technology, counterfeiters can reproduce paper banknotes with little knowledge or experience, and more

52 easily and quickly than ever before. Polymer banknotes are a deterrent to the counterfeiter, as they are more difficult and time consuming to reproduce. The Guardian® polymer substrate starts as specialized clear plastic film produced by Innovia Films. This biaxially oriented polypropylene film is produced using a unique patented technology that results in a film with printing and handling properties similar to paper substrate. Films of the same type and physical characteristics as the BOPP used in printing processes are not available commercially. The clear film is then opacified with multiple layers of specialized coatings to produce a range of security features, embedded within the substrate. This includes light diffracting features. These embedded features are retained for the life of the note. Different colours and designs can be used in the substrate on each side of the banknote to add complexity against counterfeiters (www.securency.com). Guardian® is created by the application of opacifying layers on the Clarity C film, and the multicolour version (MultiCLR™ ), Figure (23), is created by adding colour pigments which will enhance the aesthetic and security value of the banknote, and which integrates with the other stages of security printing.

53 MultiCLR™ is available in many colour and design options and includes a choice ranging from a dual-coloured substrate. Here one side of the substrate is a different colour to the other side, or multi-coloured, which uses different colour layering combinations producing 3, 4 or even 5 colour substrate. The design opportunities also include the production of multi-colour half windows. MultiCLR™ offers improved security as it requires additional production steps that present greater technical and economic barriers to counterfeiters. It also creates attractive design options for banknotes since the colours, which can be contrasting or complementary, can be integrated with all security printing processes and the colour palettes of offset and intaglio inks to optimize the colour effects and aesthetics of the note (www.IPCA.com/ May 2009). Interestingly, colour copies of polymer notes on the substrate are not possible with copiers using heat sensitive toners. The result is that the substrate would shrink and distort in the machine (www.securency.com).

5.1.2.1. Shadow Image: The shadow image in polymer substrate, Figure (24), is similar in effect to the watermark on a paper banknote. It is an optically variable device that is not obvious in reflected light but visible when the note is held up to the light.

54 It is produced by altering the opacity and sometimes the colour of the opacifying layers and can be a portrait, text or numerical. A ‘shadow image’ incorporated in the substrate depicts a familiar design when viewed in transmission. A multi-tonal portrait would be very effective because, with polymer substrate, sharper definitions are possible and can be located in the clear window or on another part of the substrate. The advantage is that the full tonal range from clear to opaque can be used to achieve the different effects. The use of multi-tonal portraits is especially important for banknote designs. At this point, the multi-tonal portrait is similar to the intaglio-printed portrait. An added benefit is that the shadow image does not deteriorate as a result of soiling, crumpling or high humidity (www.securency.com).

5.1.2.2. Optical Machine Readable Security Thread: Threads, Figure (25), have been one of the most recognizable overt security features for currency authentication. Threads can be introduced in the polymer substrate. These threads contain metallic, magnetic, phosphorescent and fluorescent pigments. As these threads are printed they can vary in their shape and size and include micro-text. In addition, they can be windowed. Printed security threads can be incorporated during the manufacture of polymer substrate. The method of producing polymer substrate allows for an added dimension in security threads. As well as being straight along the machine direction of the sheet, the thread can be a complex curved pattern, non-continuous or multi-directional. The reflective metallic, windowed or optically variable threads are particularly effective in preventing reproduction by colour photocopying or scanning.

55 An added benefit with synthetic polymer substrate is that the various security threads, besides being straight along the machine direction, can be in a wavy pattern and in any direction, and do not add any significant dimension that could affect the good profile of the substrate(www.securency.com) . The complex structure of the polymer substrate provides the background for the incorporation for security features that can utilize substrate optical properties to the best advantage. Security features that utilize substrate optical properties can be classified in the following major groups: • Clear Window type security features • Self-Authenticating Window based security features

5.1.2.3. Clear Window Type Security Features: The clear window used in polymer substrate is one of the pillars of polymer banknote technology, along with durability and cleanliness. The clear window is a simple and effective deterrent to photocopying and/or scanning. It is the most publicly recognizable feature on Australian banknotes, and the fact that it is difficult to reproduce renders it as a very important security feature (Hardwick B., Ghioghiu A. 2004). However, the clear window provides an excellent platform for a large number of security devices that require the use of its optical properties. So far the following features have been produced that utilize this important property: Complex Window, Transitory Image, DOVD and DOE.

5.1.2.3.1. Complex Window (WinTHRU®): The ability to create transparent areas (or clear and complete windows), Figure (26), is a prime security feature within polymer substrate. Including a clear area in a banknote has proven to virtually eliminate the problem of the ‘casual counterfeiter’, who tries to copy or scan banknotes on readily available reprographic equipment (like colour copiers and scanners) found in most modern offices and many homes. The inclusion of at least one transparent window is a simple, yet highly effective security feature, and is a standard feature in all polymer substrate

56 designs. However, more than one window can be incorporated and they can be of any shape and size.

A clear window is a feature which is readily identifiable, and enables the public to quickly ascertain the authenticity of a banknote. This feature can range from total transparency to a high level of opacity. The image is divided into various levels of opacity by varying the number of opacifying layers – from no layers (clear window) to maximum opacity. This method of design makes insertion of a piece of clear film into a paper copy more difficult. Once again, this device uses the transparency of the substrate to make a simple, secure and aesthetic feature. The complex window is also a medium for housing additional security features.

5.1.2.3.2. Diffractive Optical Element (WinDOE®): The diffractive optical element (WinDOE®) , Figure (27), is a transmission Fourier transform hologram (FTH) that projects an image, either virtual or real, depending on illumination conditions. The device that is applied on the security document appears as a translucent patch in the clear window. The Fourier transform is a 3D phase structure of a given image that can visibly reconstruct the image to an observer when illuminated by a collimated beam of light. The collimated light can be provided by a directed light beam source or distant point source of light and in either case can be either monochromatic or polychromatic (Hardwick B., Ghioghiu A. 2004).

57 When illuminated by a directed light beam source, such as a pen torch or laser, the collimated light in passing through the phase structure in the clear window is transformed into a real projection of the original image that can be observed on any nearby surface. On the other hand, the observer can view a virtual image reconstruction directly by holding the WinDOE® to the eye and looking directly at a suitable light source through the WinDOE®. The visual effect that is observed will depend on the chromaticity of the light source. If essentially monochromatic light is used, a monochromatic image will result. If a polychromatic light source, chromatic aberration will cause a rainbowing effect because of the wavelength dependence of the image reconstruction from the phase structure. The method of observation suggests two different uses for this device. When the device is used to observe a virtual image directly, it is providing overt security suitable for use by the public. In this mode, it is akin to a holographic watermark; not seen until held up to the eye. When the device is used to project a real image, it can be used by members of the public who have available a suitable light source, however it is operating in a mode that is more suitable for machine readable applications. WinDOE® allows the user to verify their banknote interactively using any commonly available point light source such as downlights, household light bulbs, car taillights, distant street lamps or the moon. The DOE works in poor lighting conditions or complete darkness, for example at night, where most other security features cannot be used. This is because the dark background of such lighting conditions provides excellent contrast to the diffracted image seen against the point light source.

58 5.1.2.3.3. Transitory Emboss and Transitory Images (WinBOSS®) : The ability of polymer substrate to accept a permanent emboss is an important feature which utilizes a further element of the intaglio process, Figure (28), to enhance the security of the banknote. This is achieved by leaving the engraved areas of the intaglio plate uninked to create an embossed design during the intaglio printing process. This is effective when the uninked design is a ‘transitory image’ (bottom) embossed into the transparent window area, generating an image that is visible in both transmission and reflection. The transitory image is a 3D-line structure embossed into the clear window. The image is created by the combination of two line structures that are set at predetermined viewing angles. This creates an optically variable effect. When viewing the feature from different angles each part becomes more or less visible because of the difference in reflection of the light from the two different line structures. No distinct image is observable when viewed at a third viewing angle.

59 5.1.2.3.4. Vignette (WinVU®): Vignette, Figure (29), is an immediately recognizable design feature placed in the window, which adds both an aesthetic and security dimension to the complex window. It creates another degree of difficulty for the casual counterfeiter who is already challenged with the task of emulating a window. Complex line structures can be introduced into the design to make it difficult to create a window. Additionally, the Vignette feature can be integrated with other complex window features, such as half windows and shadow images to make it more difficult, time-consuming and costly to try to counterfeit.

5.1.2.4. Dynamic Optical Colour Shift (G-Switch®): G-switch®, Figure (30), is a dynamic optical feature that changes colour when tilted under a light source. The bright and transient colour-switching effect is produced in the substrate layers. When viewed at different angles, it alternates between two complementary colours, creating an optically reflective effect. The colour change is easily observed without special equipment or skill, making it easy to recognise by the public (www.securency.com). A number of colour switches are available to suit different banknote colour tones and designs, with a contrasting colour switch. The G-switch® effect is obvious under many different lighting conditions. The G-switch® is most

60 effective when two different colour applications are used together giving contrasting switch effects. The G-switch® may be fully integrated as a key element of the overall design of the banknote, and complementary to other Guardian® security features. It can be in a full window or half window, and when put up to the light can provide a shadow image effect.

The benefits of this feature can be summarized in three points as follow: • Security against counterfeiting. Casual counterfeiting is rapidly increasing in communities with easy access to scanners and digital printers. The G-switch® cannot be reproduced by digital printing. • Durability. Because of its construction, this feature is highly durable. It functions well in full windows, and has the benefit of additional strength and protection as a half window. Here, the reflecting colour gains additional reflective brilliance through clear polymer film.

61 • Cost effective. The feature is produced during the construction of the substrate, and is a cost effective security feature which can tolerate the tough handling conditions usually associated with low denomination banknotes(www. securency.com).

5.1.2.5. AURORA™ AURORA™, Figure (31), is an innovative design technology that has taken the use of colour shifting effects observed while tilting banknotes to a sophisticated new level. Named after the vibrant colour shifts seen in the natural polar phenomenon, AURORA™ uses specific colour combinations to create complex and distinct colour shifts that cannot be replicated by even the most advance digital technology.

Key Benefits of AURORA™ is seemed in two factors: • Easy-To-Use – AURORA™’s high colour contrast switching allows for easy authentication. • Multi-Colour Shifts – AURORA™ can be configured with two or three colour switches giving added security and aesthetics value as follow:

62 a) Colour Split Effects, Figure (31 a), AURORA™ can switch from a single colour to two distinctly different colours. A hidden image is revealed once tilted.

b) Colour Movement Effect, Figure (31 b), Two colours switch into two alternative colours, where colours can move from one area to another.

c) Combination Effects, Figure (31 c), When using three colours pairs, both splitting and movement effects can be achieved simultaneously.

63 Like G-Switch, AURORA™ offers security through the complexity of colour shifts. Through the advanced formulations and subsequent effects available, AURORA™ greatly increases the challenge for the counterfeiter. AURORA™ can be integrated within transparent or half windows in Guardian® and reflects a contrasting picture on the front and back. Further enhancements to the AURORA™ feature can be achieved with the addition of other Guardian® features such as WinVU® vignettes and/or METALIX™ inks to provide designs using integrated security elements (www. securency.com).

5.1.2.6. Self-Authenticating Window Based Security Features: Advancement in the development of security features for banknotes has been the concept of a self-authenticating banknote (Hardwick B., Ghioghiu A. 2004). The potential available with synthetic polymer substrate is used to its advantage. The transparent window is the focus of these developments by converting the optical properties of the transparent area to a tool for verification. The innovation here is that the tool for verification is carried within the note. The self-authenticating features currently available are µSAM® and Metamerics.

5.1.2.6.1. Metameric Filter: Metamerism is a well known phenomenon that relies on materials changing their colour when viewed under different lighting conditions. In the polymer substrate case this property has been exploited to maximize the combined benefits of its own security as well as the substrate specific features. The self-authenticating metameric feature is composed of two parts. A see- through colour filter in the window is used to view an image on other elements on the note. The metameric image is generally printed using special metameric inks that match in colour in normal light and mismatch when viewed through the filter. This security feature is an example of using the combination of the transparent and opaque areas of the polymer substrate.

64 5.1.2.6.2. µSAM® Screener (Micro Screen Angle Modulation): The µSAM® feature, Figure (32), is a Joh. Enschede development and has been used on polymer substrate based banknotes by incorporating both the see-through screener and modulated image in the one document. The window component of the polymer substrate is used as a carrier for the screener that is composed of a series of very fine line structures. The pattern of the line structure is specially designed to complement that of an image that is part of the self-verifying feature (µSAM®). The line structure of the µSAM® conceals a hidden image or text. This only becomes recognizable when the two are overlapped.

5.1. 2.7. Half Window: The half window, Figure (33), is a variation to the clear/complex window. The difference lies with the fact the window is opacified on one side of the note only, therefore one side acts as a glossy surface while the other side acts

65 as a normal printing surface. The glossy surface is difficult to copy using photocopiers and scanners. The result acts as a carrier for other security features such as DOVD’s, OVI and reflective inks.

5.1.2.8. Laser Perforation: Laser perforation is a technique whereby tiny holes are burnt into the substrate (paper or polymer) using a laser beam. Laser perforation can also be used to create images and numbers in the substrate (http://en.wikipedia. org/-wiki/Perforation). Each of these applications has its own name:

5.1.2.8.1. ImagePerf: This technique enables images of photographs to be created on the substrate, Figure (34). By making thousands of tiny perforations - each of a different size - it is possible to reproduce a half-tone image (image in grey scale) of photograph. As the perforations are very small, the image is only visible if the substrate is held to the light (http://www.echtheidskenmerken.nl/securityfeatures/ image-perftli.html). ‎

66 5.1.2.8.2. NumberPerf: NumberPerf, Figure (35), uniquely identifies each passport, card, cheque, banknotes or driving license, as a unique number is perforated. The laser creates holes, which have a conical shape and no reverse embossing (http://www.iai. nl/numberperf.php).

‎

5.1.2.8.3. MicroPerf: MicroPerf, Figure (36), is an optically variable security device (OVD), which have been developed especially for banknotes. MicroPerf is made by means of a special laser perforation technology not previously used in banknote manufacturing. The patterns created by these microscopic perforations (MicroPerf), are easily and quickly verifiable by holding the banknote up to the light (http://www.ofs.ch/fileadmin/user_upload/brochures/of bulletin _microperf.pdf). MicroPerf is highly counterfeit-proof. The different-sized oval laser holes are extremely hard to imitate. No copying or printing process can reproduce the perforations, and even high-performance copiers and scanners cannot detect them.

67 5.1.2.8.3.1. MicroPerf Latent Image: The MicroPerf Latent Image combines two MicroPerf patterns, one hidden within the other. Production requires a special laser perforation technology (http://www.ofs.ch/en/products/-security technologies/microperf latent- image/). In a Latent MicroPerf Image the first, unhidden MicroPerf pattern is visible when the banknote is held up against a light source. The second or hidden MicroPerf pattern, concealed in the same place, only appears when the note is tipped backwards from the vertical. 5.2. Ink Features: All of the inks used in banknote printing offer a certain amount of security because they are not commercially available and hence not available to would be counterfeiters (http://www.indigoimage. com/count/feat2.html). The inks used have to have a high performance and be resistant to environmental conditions such as sunlight, heat, moisture, etc. It would be no good if we accidentally dropped a note in a puddle and all the ink fell off, or we casually left our money lying around in the sunshine and all the ink faded away! Surprisingly the choice of colours in which a note is printed can provide quite a security element. Many commercial reproduction methods have problems telling some colours apart for instance colour copiers tend to reproduce lime

68 green as yellow. Knowing the limitations of technology used in counterfeiting can enable the banknote printers to add protection in a cheap but effective way. There are some secure inks used in banknotes. These are as follow: 5.2.1. Fluorescent Inks: Materials which fluoresce under ultra violet light can be added to most inks. They can be incorporated into a visible design element or an invisible design element (i.e. printed as a transparent feature), Figure (37). When viewed under ultra violet light all is revealed. The following graphic shows what this note revealed under UV light. The 10 will have been printed as an invisible feature. Note also the fluorescent fibers in the paper.

5.2.2. Metallic Inks: Metallic inks produce a seen effect when printed as compared to the matter effect seen with other inks. They are generally used in large areas of solid colour so that their effect is maximized. They offer good protection from colour copy counterfeiting. In polymer banknotes Metalix™, is a breakthrough metallic- effect feature that is available exclusively from Securency. Until now, metallic inks have been restricted to embedded banknote features such as threads and foils. Exposure to alkaline substances such as washing detergent quickly breaks down the integrity of traditional metallic inks, making them unfit for printing on banknotes. METALIX™, however, is resistant to alkalis retaining

69 a brilliant lustre throughout the life of the note. This exciting new colour range opens up an entirely new landscape of options for banknote design: Metallic green, blue, violet, red, copper, silver and gold can now be printed directly over transparent windows, creating yet another integrated security option for client nations (www.securency.com.au). 5.2.3. Metameric Inks: Metameric inks work on the principle of Metamerism, two colours matching under one set of lighting conditions can appear and quite different under another set. The effect of such a feature can be seen below, Figure (38). Under normal viewing conditions nothing is apparent but when viewed under a red filter a numeral appears.

5.2.4. Magnetic Inks: Magnetic inks enable areas of a note to be read by a magnetic detector. They are sometimes used for the letterpress component of the bank note, the serial numbers. 5.2.5. Optically Variable Inks: Optically variable inks or OVI, Figure (39), contain tiny flakes of special film which changes colour as the viewing angle is varied. The result is

70 an ink which has this same optical property, changing colour as the viewing angle is varied. They are very expensive inks and generally only used in small areas. An OVI feature is sometimes printed using the silk screen process. They do, however, offer excellent protection against all counterfeiting methods.

5.2.6. Metallic Patch: This is a metallic pigment that is made up as ink and printed on top of the synthetic polymer substrate as a patch. This patch may then be used as the platform for other security features such as ICE® (Intaglio Contrast Effect) and TIED® (Transparent Intaglio Disappearing Effect), Figure (40). The ICE® involves printing an intaglio image on top of the metallic patch using specially developed intaglio inks. It produces an optically variable colour effect where the colour of the intaglio print intensifies when viewed at a highly oblique angle to the surface of the note. TIED® is also printed onto the reflective metallic gold or silver substrate. This combination creates a disappearing effect because the intaglio print is only visible at viewing angles where the background is in high reflection. The metallic patch is enhanced by the smoothness of polymer and provides protection against reproduction methods, which utilizes four-colour process methods, including colour laser copiers and ink jet printers. The feature is also

71 significantly enhanced when it is used as a secure base for other more advanced features such as ICE® and TIED® (www.securency.com).

5.2.7. Iridescent Coatings: The iridescent coating, Figure (41), is a design on the surface of the paper with glossy appearance. It changes colour according to the angle of the light. It can be laid in stripes or all over the sheet with personalized designs. Visible to the naked eye, the iridescent coating cannot be reproduced by copiers or scanners (http://www.security.arjowiggins.com/english/elements-prod. htm#).

72 5.2.8. Iridescent Feature: A colour changing ink with a pearlescent sheen is used to print broad colour bands or images onto the polymer substrate, Figure (42). When the note is viewed at different angles the colour and the texture of the iridescent feature will change. Iridescent features on notes are strong visual features, which are easy to recognize and to see the colour change.

5.3. Design Features: Designing a banknote is never a case of sitting down with a pen and paper and drawing something that looks attractive. It is desirable that as many components of the note as possible give some sort of counterfeit protection.

73 Many of the design features are built around precision printing that can be achieved by the highly specialized printing presses used in the production of bank notes. These can be extremely intricate. Others rely on the type of print that can be produced e.g. the tactile nature of intaglio print. There are many types of design elements that can be worked into a banknote to give protection, and the following list reflects a general sampling of these. Rainbow Printing, Anti Copy Features, See Through Features, Microprinting, Intaglio Detail, Latent Images, Blind Embossing and Blind Recognition features. (http: //www.noteprinting.com/report_001.html) 5.3.1. Rainbow Printing: For each colour printed during the lithographic process, a different printing plate is required. However, this is not strictly true! It is possible to divide the ink duct feeding the printing plate into sections and place different colours side by side. During the printing process the inking rollers oscillate and this leads to a natural blending of the colours. This is called rainbowing, Figure (43).

In this example we have a design that rainbow from blue to green to yellow to green and back to blue again. This can be achieved by having just blue and yellow ink in the ink duct. The green is caused by the yellow/blue blending. Commercial printing presses are not designed for this type of procedure and hence rainbow printing not only adds aesthetic value to notes but also adds complexity to some counterfeiting techniques.

74 5.3.2. Anti Copy Features: Colour copiers and electronic scanners have become a major counterfeit threat in recent years and bank note producers have designed features that are not easily reproduced by these types of machines. Anti copy features are generally composed of fine lines or dots and often have the word “VOID” or “FAKE” embedded within them. If copied these features are reproduced in a “distorted” form compared to the original, throwing up secret messages or interference effects. 5.3.3. See Through Features: The precision equipment used to print banknotes enables the back and front of the litho portions of the notes to be printed simultaneously. They can also be accurately registered to one another, Figure (44). A feature utilizing this accurate registration capability is the see through feature. It comprises of two different images, one on the front and the other on the back. When the note is held up to the light a third image is produced by the combination of each image.

75 5.3.4. Microprinting: Tiny messages can be worked into designs and printed by both the intaglio and litho printing processes. With most, if not all counterfeiting techniques these tiny messages are lost, so in that respect they offer good protection, Figure (45).

5.3.5. Intaglio Detail: This is not strictly a design feature but the hand engraving mechanism by which intaglio images are initially generated produces such tonal variety and detail that it is in itself is a security feature, Figure (46). Printing plates are covered with ink and then the surface of each plate is wiped clean which allows the ink to remain in the design and letter grooves of the plates. Each sheet is then forced, under extremely heavy pressure (estimated at 20 tons), into the finely recessed lines of the printing plate to pick up the ink. The printing impression is three dimensional in effect and requires the combined handwork of highly skilled artists, steel engravers, and plate printers. The surface feels slightly raised (http://www.banknotes. com/faq.htm). Details such as are seen on the right are difficult to capture by

76 5.3.4. Microprinting: any counterfeiting technique and as a result areas in which Intaglio is primarily used generally appear flatter and lacking in the tonal variety seen Tiny messages can be worked into designs and printed by both the intaglio in an original. and litho printing processes. With most, if not all counterfeiting techniques these tiny messages are lost, so in that respect they offer good protection, Figure (45).

5.3.6. Latent Images: Latent images, Figure (47), are produced by intaglio print and the protection they offer is directly a result of the tactile nature of intaglio print. When viewed 5.3.5. Intaglio Detail: straight on, a latent image reveals nothing but lines...and that is if you look closely! But viewed at a glancing angle, an image appears. This is a result of This is not strictly a design feature but the hand engraving mechanism the intaglio print occluding the paper and creating a contrast. by which intaglio images are initially generated produces such tonal variety and detail that it is in itself is a security feature, Figure (46). Printing plates are covered with ink and then the surface of each plate is wiped clean which allows the ink to remain in the design and letter grooves of the plates. Each sheet is then forced, under extremely heavy pressure (estimated at 20 tons), into the finely recessed lines of the printing plate to pick up the ink. The printing impression is three dimensional in effect and requires the combined handwork of highly skilled artists, steel engravers, and plate printers. The surface feels slightly raised (http://www.banknotes. com/faq.htm). Details such as are seen on the right are difficult to capture by

77 5.3.7. Blind Embossing: The paper deformation that occurs during Intaglio printing is sometimes used as a feature in its own right or can be used to produce an embossing effect of a feature produced by the lithographic process. It is also possible to produce inkless latent image effects using blind embossing. 5.3.8. Blind Recognition Features: It is often difficult for people with impaired vision to discriminate between one denomination and another and features have been developed to assist them. The features are often shapes printed in different colours. For example, a red circle might be used on a lower denomination, and a blue triangle on a higher denomination. Very often blind recognition features also have a tactile effect built into them (http://www.indigoimage.-com/count/feat2.html). 5.4. Security in Machine Readable Features: The rapidly increasing requirement to authenticate banknotes by note processing machines and vending machines make machine-readable features a necessity in banknotes. Machine-readable features can be made available in many areas of the banknote, in the substrate, in the printing or as an applied feature. Machine-readable features, including High Level Authenticating System (HLAS) features for Central Banks, can be readily incorporated in the polymer and paper substrate and are already in use today. In some instances, the substrate requires only very small quantities of the HLAS additive to be effective (http:// www.noteprinting.com/report_001.html).

78 CHAPTER 6 Hygiene ‎ Banknotes are exchanged for goods and services worldwide. Paper currency are made of a rugged mix of 75% cotton and 25% linen or 100% cotton (Gadsby P. 1998). They offer more surface area for bacteria and microorganisms to reside on both sides. On the other hand, the older the paper notes become, the more space they offer for germs and microorganisms (pathogenic and nonpathogenic) to accumulate (Brown A. 2003). Accordingly, this increases the amount of bacteria circulated and distributed among its handlers. ‎ In a recent study, 94% of 68 US one-dollar bills were found to be contaminated with potentially pathogenic or pathogenic micro-organisms (Pope’ IW, et al 2002). Studies on Chinese currency (China) after the outbreak of SARS in Asia found some banknotes carried over one hundred thousand types of bacteria and 9500 E. coli-like organisms (Brown A. 2003). Newer banknotes from the Hong Kong area carried a lower count than in those in China; however, banknotes from Northern Korea were almost bacteria free. Older notes studied in China, Hong Kong, India, Pakistan, Cambodia and the Philippines carried overwhelming amount of bacteria on both surfaces. Some of these organisms found were considered potentially dangerous to healthy humans and may infect the body through scratches on the hands or when the hand touches the mouth or nose (Siddique S. 2003). The more the paper bill stays in circulation, the more opportunity there is for it to become contaminated (Gadsby P. 1998; Brown A. 2003). In effect, the wear and tear on these older notes offers more hiding space for germs to reside. Studies in some Asian countries revealed that these older notes carry an overwhelming number of bacteria (Brown A. 2003). The rugged texture of these paper notes was found to accommodate chemicals as well as germs within (Gadsby P. 1998). A study concerning the one US dollar found that drug particles accumulate ‎by being easily squeezed into the fiber matrix(Gadsby P. 1998). ‎Most of the 25 Egyptian Piaster paper notes (Farida et al 2005) provided positive indications of bacterial contamination. On the 2001 notes (58% of

79 the total sample), the maximum bacterial count obtained was 11.1 cm2 and the minimal was 0.64 cm2. Only one note from this year group showed no signs of infection. Results for the 2002 notes revealed a bacterial count range between 1.6 cm2 and 10 cm2. However, the crisper notes from 2003 had a comparatively higher range from 5.0 to 10 cm2.The higher bacterial count for the 2001 notes may be attributed to the fact that they have been in circulation for almost two and a half years and by appearance, they were already worn out. The 1, 5 and 50 LE notes had similar maximum bacterial counts of 10 cm2 followed by the 10 LE (5.5 cm2) and the 100 LE (4.3 cm2). This may be an indication that the first group of currency denominations may be more frequently used as they represent the other common paper denominations exchanged when using a 100 LE bill. It could mean that smaller change may be required to render or receive more services. The Egyptian currency denominations showed similar bacterial counts comparable to those reported for some US currency denominations. In 2000, it was reported that the one-dollar bill had an 8.2 cm2 bacterial count, the five dollar 7.9 cm2, the ten dollar 5.8 cm2 and, finally, the twenty-dollar bill 5.4 cm2 (Chase R. 2000). ‎ Concerning the general identification of microorganisms contaminating these 25 paper bills, the three types of microorganisms identified (namely: Staphylococcus aureus, Staphylococcus albus and klebsiella pneumonia), were similar with those identified on US one-dollar bills (Pope’IW, et al 2002; Gadsby P. 1998; Leutwyler K. 2001; Bonifazi WL. 2002). The more virulent aureus is a potential pathogen present on hands, normal skin, nasal cavities and suppurative lesions of man (Wilson GS, Miles AA. 1957) as well as on the skin of people suffering from eczema (Gadsby P. 1998). This organism can survive outside a living host for prolonged periods (Pope’IW, et al 2002). The relatively harmless albus (Staphylococcus epidermidis albus) is feebly pathogenic or non-pathogenic organism present on skin, in the hair and in abscesses after suturing of operation wounds as well as in the air, water and dust (Wilson GS, Miles AA. 1957) . Pneumonia is another virulent organism that is isolated from the respiratory tract of man and animal (Wilson GS, Miles AA. 1957). It causes both community and hospital acquired infections (Pope’IW, et al 2002). ‎ Polymer banknote substrate is non-fibrous and non-porous. This means

80 that polymer banknotes are impermeable to water, sweat, liquid etc. They also result in relatively dust free banknotes, which remain impressively clean throughout their life. The final overcoating adds to the cleanliness by resisting the accumulation of dirt, and protects the banknote from excessive ink wear (Peter Eu. Et al 2007). Further, scientific evaluation has shown that there is significantly less bacteriological growth on polymer banknotes, and that any bacteria, which gets onto the banknotes quickly dies because of the lack of nutrients on the non-porous and non-fibrous material. Die-off of the microbial populations is more rapid on polymer notes than on paper notes and is probably due to lack of moisture and nutrient on the notes. Polymer notes appear to absorb less moisture than paper notes and fewer micro-organisms adhere to the surface. The change from paper to polymer for banknotes will result in even lower populations of micro-organisms being carried on money, and in more rapid decline of those micro-organisms, which do adhere to the notes (Duncan A. et al 1995).

81 CHAPTER 7 Environmental Impacts Polymer banknotes eliminate many of the environmental problems associated with the disposal of paper (natural) banknotes, such as landfill and incineration. Polymer banknotes can be easily recycled by polymer recyclers into other useful plastic products resulting in a second life cycle (Peter Eu. Et al 2007). Because of the much longer service life compared with paper banknotes, polymer banknotes have reduced environmental impact in respect to cumulative energy demand, global warming, consumption of water, discharge of heavy metals, emission of carcinogens, and formation of photo-oxidants as seen in the following tables (AS/NZS ISO 14040:1998; Life Cycle Assessment (LCA), TUV Rheinland, Sicherheit und Umweltschutz, 2005).

83 Table (3): Life Cycle Analysis of Polymer and Paper Banknotes. Life Cycle Polymer Paper Stage Growing cotton Extraction and Production of and cleaning raw material raw cotton refining of petroleum 1 Collection of rags Initial conversion cotton combers / of raw material poly-propylene Production of Synthesis of 2 Manufacture of rag fiber paper polypropylene & rolling of to substrate conversion Secondary Extrusion material film 3 Offset, intaglio, offset, intaglio, – printing and of banknotes Manufacture overcoating, guillotining, guillotining, numbering, numbering, Gravure, finishing sorting sorting 4 Mean service Mean service Banknotes in life set as the that of paper standard for life 5 times comparison banknotes service 5 Granulated and Withdrawn and and mixed for incineration bundled for landfill OR Granulated cancelled mixed 6 Secure landfill Final disposal for consumer incinerat-ion disposal OR Recycled as feed stock products 7

84 Table (4): Materials, Energy and Waste Profile of the Paper Banknote Life Cycle. 3. Manufacture of rag used linen and cotton 1. Growing cotton & cleaning raw cotton 2a. Production of 2b. Collection of cotton combers 4. Manufacture fabrics - rags fibre paper banknotes Stage Banknote paper; offset ink; intaglio platemaking materials; constituents Soil as natural resource; fertilizers cotton fabrics; process chemicals; Rags which would otherwise be for PVC roller making; banding plate-making materials; intaglio Raw cotton; process chemicals; Raw cotton; recycled linen and ink constituents; graphic repro tape and shrinkwrap plastic. and insecticides; cleaning chemicals. water. Input waste water Materials for web-fed presses) of paper Press-ready reams (or reels contaminated and depleted Sorted for use in paper- Cleaned cotton bolls; Cotton combers. New banknotes Output making soil. produce steam and hot water natural gas to produce steam machinery; Electricity for Electricity for equipment; Electricity; natural gas to for printing process heat. Fuels for agricultural cleaning equipment for process heat. Electricity Energy Input N/A Chemicals into soil & water; net waste recycling process Negligible because this is a chemicals; granular wastes chemicals; granular wastes offcuts; defective products sludge, waste water, paper as sludge. Edge offcuts cotton cleaning wastes Solvent emissions, ink recycled to pulping. Waste water; waste Waste water; waste Produced as sludge. Waste

85 Table (5): Materials, Energy and Waste Profile of the Polymer Banknote Life Cycle. refining petroleum 6. Withdrawn and 1. Extraction & 7. Final disposal 5. Banknotes in cancelled service Stage Petroleum as a natural resource Granulated, mixed paper OR New & recirculated banknotes Worn and damaged banknotes bundles Input Materials and exhaust gas, mainly CO2 Land-fill paper waste, with incinerator ash for landfill Granulated, mixed paper ink contamination OR Refined fractions of Banknotes in service petroleum Output heat input from (gas-fired) machinery; Electricity & fuel gas to reach operating temperature of incinerator Energy for transport and Electricity for banknote (for incineration) initial steam generators for refinery equipment Fuels for drilling sorting machines. Electricity Energy Input flared gases & tar wastes; Drilling muds; oil wastes Shrinkwrap plastic; banding increasingly scarce resource from drilling operations; containing heavy metals Use of landfill volume, an tape; fugitive dusts; waste petrochemical wastes. Fugitive dusts and waste energy as heat and noise landfill and exhaust gas, OR incinerator ash for waste heat; general mainly CO2 Produced Waste energy

86 polypropylene film (polyolefines if not 6. Withdrawal and 7. Final disposal 5. Banknotes in 2. Synthesis of 4. Manufacture polypropylene 3. Extrusion cancellation & rolling of polyprop.) banknotes service MIBK); catalyst; gravure ink minor constituents; chemicals for wiping Polypropylene resin, propylene Polypropylene reels; gravure ink; New & recirculated banknotes Worn and damaged banknotes additives; offset ink; intaglio ink Petroleum fractions, catalysts solvents (if ok, substitute MEK, roller making; banding tape and materials; constituents for PVC materials; intaglio platemaking solution and water treatment; graphic repro plate making Granulated, mixed shrink wrap plastic. polypropylene monomer recycling stock to produce Banknotes in service Polypropylene resin, Polymer granules as propylene monomer Press-ready reels of consumer products Granulated, mixed New banknotes polypropylene polypropylene water for printing process Electricity and heat input to produce steam and hot Electricity for banknote Electricity; natural gas from (gas-fired) steam sorting machines. Electricity Electricity Electricity generator heat. emissions; waste intaglio ink waste heat; catalyst scrap Chemical wastes; VOCs; and ink sludge; waste water waste metal from old plates from water treatment plant; (recycled); Waste polymer particulates i.e. fugitive cycloned out of recycle dusts and fine material (recycled); waste heat. emissions; waste heat; banding tape; fugitive waste PVC from rollers, Polypropylene scrap scrap (recycled); VOC dusts; waste energy. Shrinkwrap plastic; Defective products Fugitive vapour Polypropylene edge off cuts (zeolites). (recycled). stream.

87 CHAPTER 8 Chemical and Physical Analysis of Paper and Polymer Banknotes 8.1. Raw Materials: The banknotes used in this work are 25 Egyptian Piasters printed in year 2002 and 2004 as paper banknotes, 10.000 Romanian Lei and 20 Nigerian Naira printed in year 2000 and 2008, respectively, as polymer banknotes. 8.2. Analysis of Banknotes: 8.2.1. Ash Content Estimation: The ash content of raw material has been determined by burning the extracted raw material in a muffle furnace in a porcelain crucible first at 400 0c for 30 minutes, then at 850°c for 45 minutes and then gravimetrically estimated by TAPPI Standard methods (T15 Wd-80). The average ash content of paper banknotes is 2.6 % and that of polymer is 9.1 %. 8.2.2. Alpha - Cellulose Estimation: ‎ The method employed in this work was according to a German Standard Method (Zellchemig Merkblatt IV\ 29A). ‎About 3 gram of the sample hollocelluIose, were placed in a porcelain beaker then 25m1 of 17.5 % sodium hydroxide (w/w) were added. After leaving to swell for 4 minutes (time was exactly measured from the last drop of sodium hydroxide) the pulp was pressed with a glass rod for 3 minutes. After pressing, another 25 m1 of sodium hydroxide was added and the contents were mixed thoroughly till one gets a homogeneous past (mixing for about ‎1 minute). The beaker was then covered and left for 35 minutes at 20°C, then 100 m1 distilled water were added and quickly filtered under suction using a sintered glass funnel. The filtrate was poured on the past twice before washing with distilled water. After washing with distilled water till neutrality, 100 m1 of 10% acetic acid was

89 added drop-wise for washing followed by distilled water. The temperature must be kept constant at 20°C during the whole experiment. The alpha-cellulose was estimated gravimetrically after dryness in a drying oven at 105 - 106°C. It was found that, the used paper banknote sheets are mainly cellulose. It contains 94.1% Alpha-cellulose. This means that these paper sheets are made from cotton or rags. 8.3. Physical Properties of Banknotes: 8.3.1. Basis Weight: ‎ Basis weight has been measured in the metric system. Basis weight is the number of grams per square meter of paper. i.e., weight in grams of one square meter of paper. wt.of paper sheet O.D. (g.) ‎ Basis weight = ______area of the paper sheet (m2) The Basis Weight of paper banknote sheet is 87.64 gm/m2 and that of polymer banknote sheet is 92.75 gm/m2.The thickness of paper banknote sheet is 0.144 mm. and that of polymer banknote sheet is 0.102 mm. It is clear that the basis weight of polymer banknote sheets is higher than that of the paper banknote sheets. This can be attributed to the higher ash content (i.e. filler) of polymer banknote than paper banknote. On the other hand, as shown in table (6), the density of polymer banknote (0.93 gm/cm3) is higher than that of paper banknote (0.61 gm/cm3).

Table (6): Chemical and Physical Analysis of Paper and Polymer Banknotes

Composition Paper Banknote Polymer Banknote

Ash % 2.6 9.1 Basis Weight (gm/m2) 87.64 92.75 Thickness (mm.) 0.144 0.102 Density (gm/cm3) 0.61 0.93

90 CHAPTER 9 Mechanical Properties of Banknotes 9.1. Tensile Strength and Breaking Length: The tensile strength was estimated according to German standard methods by means of Alwetran TH-l tester (Lorentzen & Wettre Sweden). The tensile strength represents the load in kg at which a paper strip of 15 mm width breaks. This can be converted to the breaking length which is more accurate since it takes the basis weight of paper sheet into consideration. Breaking length can be estimated as follows: Breaking length, m = Tensile strength (kg) x length of strip (m) / wt. of strip (kg) Tensile index = Breaking length (km) x 9.81 N.m/g Breaking length estimated for paper and polymer banknotes in machine direction are 10516.0 and 14375.0 m, respectively, while breaking length estimated for paper and polymer banknotes in cross direction are 4801.3 and 13297.0 m, respectively as shown in table (7). It is seen that the breaking length of the polymer sheets are higher than that in case of the paper sheets. This can be attributed to the highest elasticity and elongation value of the polymer sheets than the paper sheets. This elasticity increases the elongation value of the polymer. Therefore, under load or tension the polymer sheets elongate are not cut immediately as in case of paper sheets. Table (7): Mechanical Properties of the Paper and Polymer Banknote Sheets

Polymer Banknote Mechanical Properties Paper Banknote Sheets Sheets Breaking length (MD) 10516.0 14375.0 (CD) 4801.3 14297.0 Burst factor 50.54 >109.22 Tear factor (MD) 87.44 28.79 (CD) 98.13 28.79 Folding endurance 6400 >16000

91 ‎9.2. Burst Strength: Burst strength was conducted according to TAPPI standard methods 403. A Mullen tester (Perkins, Chicopee, Mass, U.S.A.) was used for paper sheets and TMI (Testing Machines, Inc.) for board sheets. The bursting strength is given as the pressure at which the paper sheet bursts. The burst factor is defined as bursting strength divided by basis weight. ‎If bursting strength = a lb/in2 Basis weight ‎= b g/m2 Then g/cm2 Burst factor = a x 70.31 b g/m2

Burst index = a x 6.898 kPa.m2/g b

Note that 1 kPa = 1 kN/m2, where kPa stands for kilopascal and kN for kilo Newton. Burst factor estimated for paper and polymer banknotes are 50.54 and >109.22. It is also seen that the burst factor of the polymer banknote sheets are higher than that in case of the paper banknote sheets, this can be attributed to the highest elasticity and elongation value of the polymer sheets than that of the paper sheets. This elasticity increases the elongation value of the synthetic polymer. Therefore, under load or tension, the polymer sheets elongate and are not cut immediately as in case of paper sheets. 9.3. Tear Resistance and Tear Initiation Test: 9.3.1. Tear Resistance of Paper Sheet: The tear resistance was measured according to TAPPI standard methods 414 by means of an SE009 L& W Tearing tester (AB-Lorentzen & Wettre, U.S.A., Inc.). The tearing resistance is the average force in gram required to tear the sheet clamped in the tester. If tearing strength = a g

92 Basis weight = b g/cm2 Then a Tear factor = x 100 dm2 b

Where 1 m = 10 dm Tear index = a x 9.81 mN.m2/g b 9.3.2. Tear Resistance (Graves Tear) of Plastic (Polymer) Film D1004-09: Tear resistance of plastic film or sheeting is a complex function of its ultimate resistance to rupture. The specimen geometry and speed of testing in this test method are controlled to produce tearing in a small area of stress concentration at rates far below those usually encountered in service. Experience has shown the test to have its best reliability for materials which do not have brittle failure or do not elongate greater than two hundred percent during testing. The data from this test method furnish comparative information for ranking the tearing resistance of plastic specimens of similar composition. Actual use performance in tearing of some plastics may not necessarily correlate with data from this test method. The resistance to tear of plastic film and sheeting, while partly dependent upon thickness, has no simple correlation with specimen thickness. Hence, tearing forces measured in Newtons (or pounds-force) cannot be normalized over a wide range of specimen thickness without producing misleading data as to the actual tearing resistance of the material. Data from this test method are comparable only from specimens, which vary by no more than ±10 % from the nominal or average thickness of all specimens tested. Therefore, the tearing resistance is expressed in maximum Newtons (or pounds-force) of force to tear the specimen. The tear resistance of plastic film may be a specification that requires the use of this test method, but with some procedural modifications that take precedence when adhering to the specification. Therefore, it is advisable to refer to that material specification before using this test method. Table 1 of Classification System D 4000 lists the ASTM materials standards that currently exist.

93 This test method covers the determination of the tear resistance of flexible plastic film and sheeting at very low rates of loading, 51 mm (2 in.)/min. and is designed to measure the force to initiate tearing. The specimen geometry of this test method produces a stress concentration in a small area of the specimen. The maximum stress, usually found near the onset of tearing, is recorded as the tear resistance in Newtons (or pounds-force). The method is not applicable for film or sheeting material where brittle failures occur during testing or where maximum extension is greater than 101.6 mm (4 in.). To evaluate the tear propagation of the substrate, the initial tear resistance of Guardian® substrate, referred to as the tear initiation strength, is extremely high - much higher than it is for paper. However, once a tear has been initiated (for example by a small cut), the substrate will tear very easily, which is referred to as the tear propagation. The tear factor measured for paper and polymer banknotes in machine direction are 87.44 and 28.79, respectively, while the tear factor measured for paper and polymer banknotes in cross direction are 98.13 and 28.79, respectively. From the obtained data, it is clear that, the paper banknote sheets have a higher value than that in case of polymer sheets. This can be explained by the nature of cellulose chains, which arranged over each other and the presence of hydrogen bonds between chains, these increase the resistance of paper sheets than the polymer sheets in which the Propylene was polymerized and not found in arranged chains as in case of cellulose. 9.4. Folding Endurance: This method describes the use of the Schopper type of folding apparatus to determine the folding endurance of paper and polymer. Folding endurance tests have been used for the estimation of the suitability of paper and polymer in use to withstand repeated bending, folding, and creasing. Folding endurance was conducted according to TAPPI standard methods T 423m-50. (Schopper Type Tester). Folding endurance is a measure of the strength and flexibility of the paper. The folding endurance measured for paper and polymer banknotes are 6400 and >16000, respectively. It is seen that folding endurance of the polymer sheets is higher than that in case of paper sheets due to its higher elasticity and elongation.

94 CHAPTER 10 Aging of Banknotes The effect of thermal treatment, expressing the aging, on the physical and mechanical properties on the banknote sheet between 50 and 200ºc for different periods were investigated. Thermal treatment of the polymer banknote sheets is carried out at 50ºc and increasing the temperature to 80ºc deteriorated the mechanical properties and gave unregulated value. So the thermal treatment of polymer sheets was not completed after 80ºc while, the paper sheets was completed to 200ºc. The following tables (8-14) represent the effect of temperature on the mechanical properties of paper banknotes:

Table (8): The Effect of Temperature on the Mechanical Properties of Paper Banknotes at 50ºc. Paper Banknote at 50Cº Test 4hr. 8hr. 12hr. 24hr. 36hr.

Burst Factor 50.54 50.54 50.3 50.14 49.9

Breaking Length 10440.33 10440.33 10440.33 10440.33 10287.92 (M.D)

Breaking Length 4801.03 4801.03 4801.03 4724.82 4724.82 (C.D)

Tear Factor 83.64 83.64 82.15 82.15 81.81 (M.D).

Tear Factor 95.85 95.85 95.85 95.85 93.56 (C.D).

Folding 3080 2850 2443 2380 2320 Endurance

95 Table (9): The Effect of Temperature on the Mechanical Properties of Paper Banknotes at 100ºc. Paper Banknote at 100Co Test 4hr. 8hr. 12hr. 19hr. 24hr.

Burst Factor 49.74 49.58 49.34 48.94 48.94 Breaking Length 10211.71 10135.50 9906.88 9906.88 9449.64 (M.D). Breaking Length 4724.82 4648.61 4572.41 4572.41 4877.24 (C.D) Tear Factor 81.81 81.81 81.81 80.67 80.67 (M.D). Tear Factor 93.56 91.28 91.28 91.28 94.36 (C.D). Folding 2549 2389 2346 2483 2670 Endurance

Table (10): The The Effect of Temperature on the Mechanical Properties of Paper Banknotes at 120oc. Paper Banknote at 120Co Test 3hr. 8hr. 16hr. 20hr. 24hr.

Burst Factor 48.78 48.58 48.74 48.62 48.38 Breaking 9906.88 9830.68 9830.68 9830.68 8458.95 Length(M.D) Breaking 4648.61 4648.61 4648.61 4648.61 4419.99 Length(C.D) Tear Factor 80.67 79.87 79.87 79.07 79.07 (M.D). Tear Factor 89.8 88.20 88.20 86.72 86.72 (C.D). Folding 2782 2545 2350 2335 2313 Endurance

96 Table (11): The Effect of Temperature on the Mechanical Properties of Paper Banknotes at 140oc. Paper Banknote at 140Co Test 1hr. 2hr. 4hr. 6hr. 8hr.

Burst Factor 47.98 47.73 47.33 47.09 47.09 Breaking Length 9754.47 9754.47 9525.85 9754.47 9830.68 (M.D). Breaking Length 572.41 4801.03 4596.0 4572.41 4549.55 (C.D) Tear Factor 77.59 77.59 82.15 76.45 75.31 (M.D). Tear Factor 84.44 84.44 74.51 82.15 82.15 (C.D). Folding 2382 1771 662 890 201 Endurance

Table (12): TThe Effect of Temperature on the Mechanical Properties of Paper Banknotes at 160oc. Paper Banknote at 160Co Test (1/2) hr. 1hr. 2hr. 4hr. 6hr.

Burst Factor 46.85 46.77 46.53 46.37 46.13 Breaking Length 9830.68 9830.68 9830.68 9678.26 9678.26 (M.D). Breaking Length 4572.41 4267.58 4496.20 4419.99 4572.41 (C.D). Tear Factor 74.51 73.03 73.03 70.74 69.95 (M.D). Tear Factor 80.67 69.95 79.07 71.54 83.64 (C.D). Folding 1482 1412 1205 948 1263 Endurance

97 Table (13): The Effect of Temperature on the Mechanical Properties of Paper Banknotes at 180oc. Paper Banknote at 180Co Test (1/4) hr. (1/2) hr. (3/4) hr. 1hr. 1.5hr.

Burst Factor 45.97 44.93 43.88 43.08 42.92 Breaking Length 9678.26 9602.06 9525.85 9449.64 9373.44 (M.D). Breaking Length 4496.20 4877.24 4496.20 4496.20 4267.58 (C.D). Tear Factor 69.26 68.46 65.38 63.10 60.82 (M.D). Tear Factor 82.15 82.15 80.67 80.67 79.07 (C.D). Folding 2674 1979 1420 577 1442 Endurance

Table (14): The Effect of Temperature on the Mechanical Properties of Paper Banknotes at 200oc. Paper Banknote at 200Co Test (1/4) hr. (1/2) hr. (3/4) hr. 1hr. 1.5hr.

Burst Factor 41.72 39.95 38.51 40.51 34.90 Breaking Length 9373.44 9373.44 9068.61 8839.99 8230.33 (M.D). Breaking Length 4648.61 4259.85 4191.37 3810.34 3353.10 (C.D). Tear Factor 60.82 56.25 48.72 45.64 38.00 (M.D). Tear Factor 77.59 75.31 68.46 63.90 63.90 (C.D). Folding 1450 1147 995 864 482 Endurance

98 10.1. The Effect of Aging on Breaking Length: Figures (47, 48) show the effect of aging on the breaking length at machine and cross direction. From the figures, it is clear that the breaking length is slightly decreased by aging at 100 and 120ºc and nearly the loss in breaking length is become constant after aging for 4 hours. The decrease in the breaking length is increased by enhancing the aging temperature more than 120ºc. For short time than 120ºc. Increasing the temperature to 180ºc, the breaking is highly decreased within time ranges from 1/4 to 1.5 hours. This can be attributed to the hardening of cellulose fiber and decrease in moisture of the sheets which cause a brittleness to cellulose fiber and consequently the breaking length decreases. The loss in breaking length in machine direction (MD) by aging is higher than that in the case of cross direction (CD) due to Kinetic of breaking length loss in paper sheets.

99 By applying the first order on the relation between losses in breaking length and heating temperature. - dc/dt =KC

..-d (So-S)/dt =K [So-(So-S)] =KS Where So is the breaking length of unheated sheets, S is the breaking length of aged paper sheets at time t. By derivation of the above equation

(Sefain M.Z., and El- Saied H., 1984), a plot of ln So/S vs t should be straight line. Figures (49 and 50) illustrate the linearity of the above equation. The slope of these plots determines K, the rate constant. The activation energy of this aged paper sheets was calculated by applying Arhenius equation (Glastone S., 1962). Plot ln K vs 1/T (T is absolute temperature) gave a straight line. The slope is equal to –E/2.303R (E is activation energy and R is gas constant).It was found that E value is equal to 188.9 kJ. This activation energy resultant of several factors in the original fiber structure, of cellulose in the paper covalent bonds and /or hydrogen bonds and net like structure bonding which formed during paper sheet formation. This value is higher than any kind of paper sheets. So, the activation energy of Kraft sheets is nearly equal to 90 kj. i.e. the paper banknote sheet is more resistant to thermal treatment.

100 10.2. The Effect of Aging on Tear Factor: Tearing resistance is dependent of (a) total number of the fibers participating in the sheet rapture, (b) fiber length and (c) number and strength of the fiber –to- fiber bonds (Barowning W.J., 1974). Aging affects only the latter factor. Figures (51, 52) illustrate the effect of aging on tear factor at machine and cross direction.

101 From the Fig., it is clear that aging has a slight effect on tear factor at low temperature i.e. it slightly decreases at long time of aging at 100 and 120ºc. Increasing temperature more than 120ºc, the tear factor of paper banknote sheet is highly decreased. This can be also seen in the cross direction. The loss in the tear factor in the cross direction is higher than that in the machine direction due to the increase of hardening of the fiber which is perpendicular to the fiber in the cross direction and consequently its resistance to aging is highly affected than that in machine direction. From the fig, it is also seen that, the tear factor of the unaged paper sheet in cross direction is higher than that in the machine direction. This can be attributed to the fact that the tear of paper sheet in cross direction is perpendicular to the fiber and consequently it has a higher resistance to tear than that in case of machine direction in which the fibers in paper sheets are nearly parallel to each other and thus it is easily to tear. 10.3. The Effect of Aging on Burst Factor: Bursting strength is a complex function of tensile strength and stretch. Two factors are responsible for bursting strength, fiber length and inter fiber bonding. The effect of aging on the burst factor is shown in figure (53).

It is clear that aging of natural polymer banknote sheet is nearly not affected by heating at 50 and 100ºc even at long time. Increasing the aging temperature to 120ºc and 160ºc, the decrease in the burst factor is clear especially at long time. Nearly the burst factor is highly decreased by aging at 180ºc and 200ºc at any aging time. This can be due to the high aging temperature that causes a dryness of the fiber with increase the interfiber bonding to a degree, which

102 causes a hardening to the paper sheets causing a cracking of the fiber. Therefore, the high aging temperature has a high effect on the determination of burst factor of paper banknote sheets. 10.4. The Effect of Aging on Folding Endurance: Folding endurance is a measure of the strength and flexibility of the paper. The effect of aging on the folding endurance is shown in figure (54).

From figure (54), it is clear that the folding endurance is highly affected by aging more than the other mechanical properties. This is due to that aging decrease the moisture content in the paper sheet causing a hardness of the cellulose fiber in the sheet, which is easy to be broken and cracked. 10.5. Effect of Aging on Lightness and Colour Changes of Paper Banknotes: Effect of Temperature on Lightness (L) and Colour changes, where (a) and (b) represent the colour value in x and y directions, of paper banknotes were investigated at 50 oc to 200 oc. It was found that at 50 oc, both of paper and polymer banknotes did not show any noticeable change in lightness or colour appearance as shown in figure (55a).

103 10.5.1. Effect of Aging on Lightness and Colour Changes of Paper Banknotes at 100 oc: (L, a, b) Colour Value is the best neutral way ISO certified to measure colours, where (L) is the Lightness (0-100%) (a) and (b) are colours co-ordinates (x,y) to determine the colours’ position in the Lab colour circle.

2 2 2 ΔE= � {(L1­­­­-L2­) + (a1-a2) + (b1-b2) } From the results obtained of this test, as shown in table (15) and figures (55b, 56), it was clear that in the paper banknotes, the amount of Lightness was slightly decreased by only 0.36% (can be considered unchanged), towards the darker shades; the (a) value was changed only by 1.05 towards the Green colour, while the (b) value was decreased by 0.36 towards the Yellow colour, this can be attributed to the initial loss of moisture. Table (15): (L, a, b) Values for Paper Banknotes at 100 oc at Different Intervals. L a b 0 92.58 -0.59 -2.97 4 91.48 -1.91 -4.73 8 92.21 -2.05 -4.15 16 91.89 -1.64 -3.91 19 91.87 -1.36 -3.22 24 92.22 -1.64 -2.61

104 10.5.2. Effect of Aging on Lightness and Colour Changes of Paper Banknotes at 120oc: From the results obtained of this test, as shown in table (16) and figures (58, 59), it was clear that in the Egyptian banknotes, the amount of Lightness was decreased by only 1.48%, towards the darker shades, the (a) value was changed only by 1.29 towards the Green colour, while the (b) value was decreased by 3.26 towards the Yellow colour, this may be attributed to the initial loss of moisture.

105 Table (16): (L, a, b) Values for Paper Banknotes at 120oc at Different Time Intervals Hours L a b 0 92.58 -0.59 -2.97 3 92.1 -1.52 -2.11 8 92.48 -1.75 -0.68 16 91.14 -1.93 -0.7 20 91.4 -1.61 -1.46 24 91.1 -1.88 0.29

106 10.5.3. Effect of Aging on Lightness and Colour Changes of Paper Banknotes at 140oc: From the results obtained from this test, as shown in table (17) and figures (61, 62), it was clear that in the paper banknotes, the amount of Lightness was decreased by 1.51%, towards the darker shades; the (a) value was changed only by 1.12 towards the Green colour, while the (b) value was decreased by 5.21 towards the Yellow colour, this may be attributed to the initial pyrolysis of paper sheet and printed inks. Table (17): (L, a, b) Values for Paper Banknotes at 140oc at Different Time Intervals. Hours L a b 0 92.58 -0.59 -2.97 1 91.60 -1.02 5.09 2 92.10 -1.86 0.61 4 91.49 -2.16 -1.19 6 90.86 -1.12 3.85 8 91.07 -1.71 2.24

107 108 10.5.4. Effect of Aging on Lightness and Colour Changes of Paper Banknotes at 160oc: From the results obtained of this test, as shown in table (18) and figures (64, 65), it was clear that in the paper banknotes, the amount of Lightness was decreased by 4.41%, towards the darker shades; the (a) value was changed only by 0.14 towards the Green colour, while the (b) value was decreased by 5.15 towards the Yellow colour, this may be attributed to the pyrolysis of paper sheet and printed inks.

Table (18): (L, a, b) Values for Paper Banknotes at 160 oc at Different Time Intervals. Hours L a b 0 92.58 -0.59 -2.97 0.5 90.74 -1.87 -0.41 1 90.74 -1.87 -0.41 2 90.11 -2.06 -1.23 4 89.2 -2.31 1.29 6 88.17 -1.73 2.18

109 110 10.5.5. Effect of Aging on Lightness and Colour Changes of Paper Banknotes at 180 oc: From the results obtained of this test, as shown in table (19) and figures (67, 68), it was clear that in the Egyptian banknotes, the amount of Lightness was decreased by 4.41%, towards the darker shades, the (a) value was changed only by 2.19 towards the Green colour, while the (b) value was decreased by 4.83 towards the Yellow colour, this may be attributed to the pyrolysis of paper sheet and printed inks.

Table (19): (L, a, b) Values for Natural Polymer Banknotes at 180 oc at Different Time Intervals Hours L a b 0 92.58 -0.59 -2.97 0.25 90.12 -1.74 -2.32 0.5 89.73 -2.03 2.48 0.75 88.44 -2.02 4.23 1 88.16 -1.71 3.74 1.5 87.8 -1.9 1.86

111 112 10.5.6. Effect of Aging on Lightness and Colour Changes of Paper Banknotes at 200 oc: From the results obtained of this test, as shown in table (20) and figures (70, 71), it was clear that in the Egyptian banknotes, the amount of Lightness was decreased by 4.41%, towards the darker shades, the (a) value was changed only by 4.28 towards the Red colour, while the (b) value was decreased by 21.18 towards the Yellow colour. This may be attributed to the pyrolysis of paper sheet and printed inks.

Table (20): (L, a, b), Values for Paper Banknotes at 200 oc at Different Time Intervals. Hours L a b 0 92.58 -0.59 -2.97 0.25 90.74 -1.69 1.46 0.5 90.74 -1.75 1.71 0.75 90.11 -0.45 8.69 1 89.91 2.64 16.8 1.5 88.17 3.69 18.21

113 114 CHAPTER 11 Thermal Analysis Another tool to compare between paper and polymer banknote sheets. Thermal properties of the two kinds of sheets were studied to show the difference in the thermal behaviour of them. 11.1. Thermogravimetric (TG) Analyses: Thermogravimetric (TG) analyses were carried out using a Perkine- Elmer Thermogravimetric analyzer TGA-7. All experiments were carried out under the nitrogen atmosphere, where the heating rate was 10 oc. Thermogravimetric curves for paper and polymer sheets were shown in figures (73, 74).

115 After initial loss of moisture at 100-120ºc from paper sheets loss in weight decreased. This loss was attributed to the actual pyrolysis by minor decomposition reaction table (21). These temperatures were 310 ºc &285 ºc for paper and polymer banknote sheet respectively. The loss in weight percentage at this minor temperature in case of polymer sheet is higher than that in case of paper sheets. A major decomposition temperature was preceded at 420 & 390ºc for paper and polymer sheet respectively. The loss in weight at major decomposition temperature of paper sheet was lower than that in case of polymer sheets. Although the major decomposition temperature of paper sheet is higher than in case of polymer sheet, the loss in weight percentage at this temperature of paper sheet is lower than polymer one. This means that the paper sheet has more resistance to thermal treatment than the polymer. Table (21): The Minor & Major Decomposition Temperature and Loss in Weight Percentage of Paper and Polymer Banknote Sheets

Minor Decomposition Loss in Major Decomposition Loss in Weight Temp(initial) Weight % Temp (Changing Temp) Paper 310 7% 420 85% Polymer 285 9% 390 93% 11.2. Calculation of Activation Energy: This is another way to compare the properties of paper and polymer banknote. The data from TG curves were analyzed by differential method used by Tang (Tang, 1967 W.K.) in which ln (wo-winf)/ (wt-winf) is plotted against the time t, where (wo) is the initial weight, (wt) is the weight at time t and (winf) is the weight of ash remaining after the final heating. The slope of the obtained line is the rate constant for the thermal decomposition (Glastone S., 1962),

Plotting ln (wo-winf) / (wt-winf) against time under isothermal condition gave two parts of line (fig 75a). The first part, which occurs over initial 30 minutes are due to the loss in water. The second step, straight-line portion, which cover the following few minutes are due to thermal decomposition of the sample. This indicates that the loss in weight due to thermal decomposition is a first order reaction.

116 Activation energy in the main decomposition temperature region (300- 800ºc). The activation energy of the paper sheet is 94 kj /mol and in case of polymer sheet is 80 kj /mol (Table22).

Table (22): Shows the Activation Energy of Natural and Synthetic Polymer Sheets Activation energy Paper Banknote Sheet 137.835 kj Polymer Banknote Sheet 88.214 kj

117 CHAPTER 12 Crumple Resistance For this study, experiments have been carried out according to (NPA QC 002 / ISO 105 A02 /A03 1993). The notes were crumpled up to 24 times in an IGT Crumpler for both 25 Piastres (as paper) and 20 Naira (as polymer) banknotes as follows: 1. Using the template cut samples from an overcoated sheet or finished banknotes. Select an area with the greatest print coverage. 2. Insert the sample into the slit of the tube containing the rolling device on the IGT Crumpler, and roll the sample within the tube. 3. Transfer the rolled sample to the crumpling tube and compress the sample against the rod of the IGT Crumpler until the weighted arm rises. 4. Remove the crumpled sample, unroll it and smooth out creases slightly. 5. Repeat the crumpling operation three more times with the same side facing up, but using a different edge of the sample for rolling. The sample will thus have been crumpled a total of four times. 6. Turn the sample over and repeat the crumpling operation four more times on the other side. The sample has now been crumpled eight times. 7. Look at the sample very carefully including observation under a low powered microscope. Check for indications of coating or ink removal resulting from crumpling (disregard damage caused by crumpler plunger i.e. Scrapes, etc). 8. Test the crumpled sample using the Tape Adhesion test (QC) on both front and back sides. 9. Place the test tape onto a white A4 sheet. 10. Assess the sample for loss of colour using "Gray Scale for Assessing Change in Colour" ISO 105 A02. 11. Place the tested sample onto a white A4 sheet or stick back onto the sheet (see note). 12. To assist the assessment, take into consideration observations from step 7

119 and from the removed tape, for evidence of removal of coatings from the note. 13. Record the results on the quality record from and also the relevant Finished Notes Test Summary Form. Place unused pieces of notes on the back of A4 sheets. 14. Repeat steps 2 to 13 on the second sample but crumple 24 times (12 each side). If 24 crumple test is required. Table (23) represents the (L, a, b) values and the Colour Difference (ΔE) for both paper and polymer banknotes. From the results obtained of this test, as shown in Table (23), it was clear that in the polymer banknotes, the amount of Lightness was decreased by 1.13%, towards the darker shades, the (a) value was changed only by 0.51 towards the Green colour, while the (b) value was decreased by 1.0 towards the Blue colour. The total (ΔE) value was only 1.77, which is within the acceptable range according to the ISO 12647-2 Standards. Also, the polymer banknotes subjected to this test are assessed as 5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A02 /A03 1993. Also from the results, it was clear that in case of paper banknotes, the amount of Lightness was decreased by 3.14%, towards the darker shades, the (a) value was changed by 1.4 towards the Green colour, while the (b) value was changed by 0.21 towards the Blue colour. The total (ΔE) value was only 2.94, which is within the acceptable range according to the ISO 105 A02 /A03 1993 and ISO 12647-2 standards. The possible cause for these changes is that the crumple had affected the surface smoothness of the paper substrate more than that of the polymer substrate, which in turn created multi grooves, as shown in the photos, which caused light diffraction in different directions. The paper banknotes subjected to this test are assessed as 5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A02 /A03 1993.

120 Table (23): (L, a, b) Values and (ΔE) for Paper and Polymer Banknotes After Crumple Resistance Tests (L, a, b) values ΔE Description Polymer Banknote Paper Banknote L a b L a b Polymer Paper Reference 86.26 -1.64 10.86 88.62 2.35 -10.52 Crumple 84.9 -2.15 9.86 85.48 0.95 -10.73 1.77 2.94 Resistance

121 CHAPTER 13 Chemical Resistance Tests For this study, experiments have been carried out according to (NPA QC 005/ ISO 105 A03 / BS 1006 A3 1993). The 25 Piastres banknotes (as paper banknotes) and the 20 Naira banknotes (as polymer banknotes) were tested using common solvents, acids, alkalis, detergents and soaps. The chemical test methods are based on BS 4321 except that the prints were immersed in the test solutions for the times and temperatures specified as in table (24). Table (24): Times and Temperatures Specified for Chemical Resistance Tests.

Solvent Perchloroethylene 24 hrs at 23°c Acid 5% of Hydrochloric Acid 30 min at 23°c Acid 20% of Conc. Acetic Acid 30 min at 23°c Alkali 2% Sodium Hydroxide 30 min at 23°c Detergents 2% FAB Laundry Detergent 30 min at 80°c Industrial Laundry 1% FAB, 2% Sodium Carbonate 30 min at 80°c The method is done as follows: 1. Use a glass beaker weigh 8.0 grams of Sodium Hydroxide. Dissolve in distilled water and make up to 400mls with distilled water. Mark the beaker NaOH and cool to room temperature. 2. In yet another beaker using a pipette measure 20mls of concentrated Hydrochloric Acid into approximately 200 mls of distilled water and make up to 400ml with distilled water. Mark the beaker HCL and cool to room temperature. 3. In another beaker place 400 mls of Perchloroethylene. Mark the beaker Perchloroethylene and place in the fume hood at room temperature. 4. In another beaker weigh 4.0 grams of Fab, (or equivalent strength) laundry detergent, add 400 mls of distilled water and dissolve the Fab. Mark the beaker Fab.

123 5. Place the beaker marked Fab onto a hot plate, add magnetic stirrer and thermometer and heat the solution to 80°C. 6. Place two full notes into each beaker making sure they are fully immersed and leave for 30 minutes. Stagger note input so that steps 7 and 8 can be carried out continually. 7. For each beaker remove one note from the solution. Place the note on a paper towel and dab dry by placing a piece of paper towel on top and pressing onto note. Remove the note from the paper towel. 8. Remove the second note from the solution. Place immediately onto a paper towel (do not dry the note), and with a tissue in the form of a pad, wipe the note firmly from one side to the other - once only. Turn the note over and repeat the wipe on that side with a fresh tissue. 9. Transfer the solutions to the glass jars for storage and label jars accordingly. 10. Renew Perchloroethylene solution when badly discoloured and the other solutions after approximately one month of use. 11. Evaluate the dabbed notes for colour change using the standard grey scale for change in colour. 12. Evaluate the wiped notes for staining using the standard grey scale for staining. 13. A change in colour of the opacified coating may be noticed on polymer notes that have been in the NaOH and the Fab. This is due to a reaction with the opacifying coat and should not be disregarded when evaluating. 14. Place the notes on A4 quality record sheets or stick back onto sheets (see note). 15. Record the results on the quality record forms and the Finished Notes Test Summary. The minimum acceptance rating is 4 on the Grey Scale for Assessing Change of Colour ISO 105 A03 - BS 1006 A3: 1993 Standard.

124 On treating with Hydrochloric Acid, as shown in table (25), in the case of Naira (polymer) banknotes, the amount of Lightness was decreased by 1.88%, towards the darker shades, the (a) value was changed only by 1.62 towards the Green colour, while the (b) value was decreased by 1.71 towards the Yellow colour. The total ΔE value was only 3.01, which is within the acceptable range according to the ISO 12647-2 Standard. The banknotes subjected to this test are assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard. Also from the results, as shown in table (25), it was clear that in case of the 25 Piastres, the amount of Lightness was decreased by 0.58%, towards the darker shades, the (a) value was changed by 0.58, towards the Green colour, while the (b) value was changed by 0.13 towards the Blue colour. The total ∆E value was only 0.83, which is within the acceptable range according to the ISO 12647-2 Standard. The banknotes subjected to this test are assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard. On treating with Acetic Acid, as shown in table (25), it was clear that in the case of the Naira banknotes, the amount of Lightness was decreased by 1.53%, towards the darker shades, the (a) value was changed only by 1.49 towards the Green colour, while the (b) value was changed by 1.38 towards the Yellow colour. The total ∆E value was only 2.55, which is within the acceptable range according to the ISO 12647-2 Standard. The banknotes subjected to this test are assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard.

125 Table (25): (L, a, b) Values and the ΔE Values for Both Paper and Polymer Banknotes After Chemical Resistance Tests (L, a, b) values Delta E 20 25 20 Naira 25 Piastres Description Naira Piastres L a b L a b

Reference 86.26 -1.64 10.86 88.62 2.35 -10.52 Chemical Resistance Acids: 5% of Hydrochloric Acid 84.38 -3.26 12.57 88.04 1.77 -10.39 3.01 0.83 20% of Conc. Acetic 84.73 -3.13 12.24 89.67 0.73 -9.79 2.55 2.08

Acid Alkalis: 85.67 -2.25 13.55 89.56 0.66 -7.33 2.83 3.62 2% Sodium Hydroxide Solvents: 84.62 -3.42 12.33 89.82 1.1 -11.33 2.83 1.91 Perchloroethylene Detergents: 2% FAB Laundry 86.08 -2.44 12.86 90.93 3.59 -16.65 2.16 6.47 Detergent

1% FAB, 2% Na2CO3 85.35 -3.40 12.85 101.14 1.56 -5.72 2.81 13.43

126 Also from the results, as shown in table (25), it was clear that in case of the 25 Piastres, the amount of Lightness was increased by 1.05%, towards the lighter shades, the (a) value was changed by 1.62, towards the Green colour, while the (b) value was changed by 0.73 towards the Blue colour. The total ∆E value was only 2.08, which is within the acceptable range according to the ISO 12647-2 Standard. Also the banknotes subjected to this test are assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard. On treating with Sodium Hydroxide, as shown in table (25), it was clear that in the case of the Naira banknotes, the amount of Lightness was decreased by 0.59%, towards the darker shades, the (a) value was changed only by 0.61 towards the Green colour, while the (b) value was changed by 2.69 towards the Yellow colour. The total ∆E value was only 2.83, which is within the acceptable range according to the ISO 12647-2 Standard. The banknotes subjected to this test are assessed as 5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard. Also from the results, table (25), it was clear that in the 25 Piastres, the amount of Lightness was increased by 0.94%, towards the lighter shades, the (a) value was changed by 1.69, towards the Green colour, while the (b) value was changed by 3.19 towards the Yellow colour. The total ∆E value was only 3.62,

127 which is within the acceptable range according to the ISO 12647-2 Standard. The banknotes subjected to this test were assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard.

On treating with Perchloroethylene, as shown in table (25), it was clear that in the case of the Naira banknotes, the amount of Lightness was decreased by 1.64%, towards the darker shades, the (a) value was changed only by 1.78 towards the Green colour, while the (b) value was changed by 1.47 towards the Yellow colour. The total ∆E value was only 2.83, which is within the acceptable range according to the ISO 12647-2 Standard. The banknotes subjected to this test are assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard.

Also from the results, as shown in table (25), it was clear that in the 25 Piastres, the amount of Lightness was increased by 1.2%, towards the lighter shades, the (a) value was changed by 1.25, towards the Green colour, while the (b) value was changed by 0.81 towards the Blue colour. The total ∆E value was only 1.91, which is within the acceptable range according to the ISO 12647-2 Standard. The banknotes subjected to this test are assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range

128 according to the ISO 105 A03 - BS 1006 A3: 1993 Standard.

On treating with FAB laundry, as shown in table (25), it was clear that in the case of the Naira banknotes, the amount of Lightness was decreased by 0.16%, towards the darker shades, the (a) value was changed only by 0.8 towards the Green colour, while the (b) value was changed by 2 towards the Yellow colour. The total ∆E value was only 2.16, which is within the acceptable range according to the ISO 12647-2 Standards. The banknotes subjected to this test are assessed as 5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard.

Also from the results, as shown in table (25), it was clear that in the 25 Piastres, the amount of Lightness was increased by 2.3%, towards the lighter shades, the (a) value was changed by 1.24, towards the Red colour, while the (b) value was changed by 6.13 towards the Blue colour. The total ∆E value was 6.47, which is not within the acceptable range according to the ISO 12647-2 Standard. The banknotes subjected to this test are assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard.

In the case of Industrial Laundry, as shown in table (25), in the case of Naira banknotes, the amount of Lightness was decreased by 0.91%, towards the darker shades, the (a) value was changed only by 1.76 towards the Green colour, while the (b) value was changed by 1.99 towards the Yellow colour. The total ∆E value was only 2.81, which is within the acceptable range according to the ISO 12647-2 Standard. The banknotes subjected to this test are assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard.

Whereas, in the 25 Piastres, the amount of Lightness was increased by 11.38%, towards the lighter shades, the (a) value was changed by 0.79, towards the Green colour, while the (b) value was changed by 4.8 towards the Yellow colour. The total ∆E value was 13.43, which is not within the acceptable

129 range according to the ISO 12647-2. The banknotes subjected to this test were assessed as zero on the Grey Scale for Assessing Change in Colour, which is not within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard.

130 CHAPTER 14 Soil & Wear Resistance Tests For this study, experiments have been carried out according to (NPA QC 001/ ISO 105 A03 - BS 1006 A3: 1993) on the 25 Piastres and the 20 Naira banknotes as follows: 1. Preparation of Perspiration Solution: Weigh out the following compounds, dissolve or mix each with the water and store in a 250ml bottle: 1.40 g of Sodium Chloride, 0.20 g of Lactic Acid, 0.04 g of Citric Acid, 0.20 g of Caprylic Acid, 0.10 g of Ascorbic Acid and 200.00 g Water. 2. Preparation of Synthetic Soiling Mixture: Weigh out the following compounds, mix together until a homogeneous mixture is obtained. Use a laboratory shaker if required. 66.0 g of Silicon Dioxide 300 mesh, 30.0 g of Clay (Kaolin), 1.0 g of Carbon Black and 3.0 g of Perspiration Solution. 3. Preparation of Soiling Apparatus: Weigh out the 20 g of Polypropylene Beads and 0.5 g of Synthetic Soiling Mixture, mix together and place in the drum. 4. For a new mix of beads only: Place the drum in the tumbling apparatus, turn on, and tumble for 72 hours. This is to ensure that there are no sharp corners on any of the polypropylene beads. 5. On the notes to be tested for soil and wear, punch a hole (using the hole punch) at the top of the note - approximately in the middle. 6. Place a rubber weight in the middle of the note, making sure that one washer goes on each side of the note. 7. Screw the rubber weights on tightly using a screw driver. 8. Place the samples into the drum containing the polypropylene beads and

131 soil mixture and place the lid on the drum. 9. Place the drum into the Tumbling apparatus and secure the drum (refer to Tumbler Manual). 10. Rotate the drum at 60 rpm for 30 minutes. 11. Remove the samples from the drum and remove the weights from the notes. 12. Place each note flat on a piece of cloth then wipe three times with another cloth so as to remove excess soiling mixture. 13. Repeat on the other side of the note. 14. Using the Gray scale for Staining and a standard note determine the level of staining. 15. Place the notes on the A4 sample quality record sheet, or stick back onto the sheet. 16. Record the results on the quality record sheet and also on the Finished Notes Test Summary. The note when tested uncrumpled in an NPA type Soil and Wear Tester (QC001) for a specified time shall be evaluated as follows. For Soiling, the apparent change in colour from soiling shall not be less than three on the grey scale for assessing staining according to ISO 105 A03 - BS 1006 A3: 1993. And for Wear, the note shall have no tears, holes, missing corners or corner folds. There shall be no loss of ink in any area. From the results of this test, as shown in table (26), it was clear that in the case of the Naira banknotes, the amount of Lightness was decreased by 7.38%, towards the darker shades, the (a) value was changed only by 1.47 towards the Green colour, while the (b) value was changed by 1.26 towards the Blue colour. The total ∆E value was 7.63. The banknotes subjected to this test are assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993 Standard. Also from the results, it was clear that in case of the 25 Piastres, the amount of Lightness was increased by 6.35%, towards the darker shades, the (a) value was changed by 1.92, towards the Green colour, while the (b) value was changed by 2.49 towards the Yellow colour. The total ∆E value was 8.19.

132 Paper banknotes pass this test with assessed value of 4/5 on the Gray Scale for Assessing Change in Colour», which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993.Standard.

Table (26): (L, a, b) Values and the ΔE Values for Paper and Polymer Banknotes after Soil and Wear Resistance Tests. (L, a, b) values ∆E 20 25 Description 20 Naira 25 Piastres Naira Piastres L a b L a b Reference 86.26 -1.64 10.86 88.62 2.35 -10.52 Soil and Wear 78.88 -3.11 9.60 82.27 0.43 -8.03 7.63 8.19

133 CHAPTER 15 Colour Fastness Test The colour fastness of a note is determined after exposure for 72 hours under UV light of a QUV Weather-o-meter. The colour fastness is evaluated according to ISO 105 A02 - BS 1006 A02: 1993. For this study, experiments have been carried out on the 25 Piastres and the 20 Naira banknotes. From the results after this test, as shown in table (27), it was clear that in case of the Naira banknotes, the amount of Lightness was decreased by 1.06%, towards the darker shades, the (a) value was changed only by 0.92 towards the Green colour, while the (b) value was changed by 1.47 towards the Yellow colour. The total ∆E value was only 2.03, which is within the acceptable range according to ISO 12647-2 standards. The banknotes subjected to this test are assessed as 4/5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A02 - BS 1006 A02: 1993 standard. Also from the results, it was clear that in the 25 Piastres, the amount of Lightness was increased by 2.39%, towards the lighter shades, the (a) value was changed by 1.34, towards the Green colour, while the (b) value was changed by 1.59 towards the Yellow colour. The total ∆E value was 3.17, which is within the acceptable range according to the ISO 12647-2 standards. The banknotes subjected to this test are assessed as 5 on the Grey Scale for Assessing Change in Colour, which is within the acceptable range according to the ISO 105 A02 - BS 1006 A02: 1993 standard.

Table (27): (L, a, b) Values for Synthetic and Natural Polymer Banknotes after Colour Fastness 72 Hours’ Tests. (L, a, b) values ∆E 20 25 Description 20 Naira 25 Piastres Naira Piastres L a b L a b Reference 86.26 -1.64 10.86 88.62 2.35 -10.52 Colour Fastness 72 hr 85.20 -2.56 12.33 91.01 1.01 -8.93 2.03 3.17

135 136 CHAPTER 16 Exposure to Humidity & Weathering Test When banknotes are subjected to environments of high humidity and temperatures, the performance of the banknotes in regard to ink and coatings fitness should be similar to the banknotes that were not subjected to this type of exposure. For this study, experiments have been carried out according to (NPA QC 008) on the 25 Piastres and the 20 Naira banknotes as follows: Test specimen: Cut one crumple size sample for each test required (24hr, 72hr, 1 week, 1 month etc….) or use full notes/materials depending on end use. Machine Preparation: Fill base of Humidity cabinet with distilled water. Do not overfill. Any excess water will run out of overflow tube. Test Conditions: The conditions used for this test are: - 50degC/95 +/-5% Relative Humidity for 12 hours - 26degC/95 +/-5% Relative Humidity for 12 hours Note: Machine to cycle between the two conditions over 24 hours. To set timer: Note: The time spent at the set temperature 1 is displayed by the timer as “T-OFF”. The time spent at the set temperature 2 is displayed by the timer as “T-ON”. 1. To adjust T-OFF press the timer button labeled PR once. The first digit of the lower digital display (set time) will be flashing. Press the UP arrow to alter the desired value and / or press the side arrow to move to the next digit. (Note: increments are 0.1 of an hour: 6 mins). 2. Press PR again and the T-ON time will be displayed for adjustment, if required. Use exactly the same procedures as described above to adjust this. Press PR one final time and the digital display will show the initials ENT. Press the RST/ENT button. This will enter and save any changes to the timing cycle that have been made. Note: The upper digital display of the temperature controller shows the actual cabinet temp in deg oc, while the lower display shows the set point. In deg oc. Single set point operation (Refer operating manual)

137 Two set point operation To have the cabinet cycle between two set points, follow these steps: 3. To set the first point: SP1 (the temperature required during the timing period T-OFF), press the scroll button (F) once until SP1 is shown in the lower digital display. 4. Adjust the current setting for SP1 by pressing the raise/lower buttons. 5. To set the second set point: SP2 ( the temperature required during the timing period T-ON), press the scroll button (F) once more until SP2 is shown in the lower digital display. 6. Adjust the current setting for SP2 by pressing the raise/lower buttons. 7. Press the scroll button once more to return the controller to its usual display mode. Note: The cycle will now operate automatically when the timer switch is pressed. 8. Place two test samples between the slats in the cabinet and leave one for 24 hours and one for 72 hours. 9. After completion of each test, remove samples and assess them for the following: - Change in appearance, Coating damage, Colour change, Softness of coating, General feel of sample compared to before exposure, Brittleness and any other differences observed. 10. After observations are reported, perform 24 crumples on the test samples using the IGT crumple apparatus. 11. Assess the standard and the sample under the microscope and report any differences. From the results of this test, as shown in table (28), it was clear that in the case of the Naira banknotes, the amount of Lightness was increased by 0.09%, towards the lighter shades, the (a) value was changed only by 0.06 towards the Green colour, while the (b) value was changed by 0.32 towards the Yellow colour. The total ∆E value was only 0.34, which is within the acceptable range according to the ISO 12647-2 standards. Also from the results, it was clear that in the 25 Pilasters, the amount of

138 Lightness was increased by 1.75%, towards the lighter shades, the (a) value was changed by 0.88, towards the Green colour, while the (b) value was changed by 0.05 towards the Yellow colour. The total ∆E value was only 1.96, which is within the acceptable range according to the ISO 12647-2 standards.

Table (28): (L, a, b) Values for Paper and Polymer Banknotes after Exposure to Humidity & Weathering Tests (L, a, b) values ∆E 20 25 Description 20 Naira 25 Piastres Naira Piastres L a b L a b Reference 86.26 -1.64 10.86 88.62 2.35 -10.52 Exposure to Humidity/ Weathering 72hr 86.35 -1.70 11.18 90.37 1.47 -10.47 0.34 1.96

139 CHAPTER 17 Taber Abrasion Test A banknote subjected to the abrasion test (QC003) should be rated as no less than 4 on the Grey Scale for Assessing Change of Colour ISO 105 A03 - BS 1006 A3: 1993. For this study, experiments have been carried out according to (NPA QC 003) on the 25 Piastres and the 20 Naira banknotes. A banknote subjected to the abrasion test (NPA QC003) should be rated as no less than 4 on the Grey Scale for Assessing Change of Colour ISO 105 A03 - BS 1006 A3: 1993. From the results of this test, as shown in table (29), it was clear that in the case of the Naira banknotes, the amount of Lightness was increased by 0.36%, towards the lighter shades, the (a) value was changed only by 0.18 towards the Green colour, while the (b) value was changed by 0.29 towards the Blue colour. The total ∆E value was only 0.49, which is within the acceptable range according to the ISO 12647-2 standards and the banknote subjected to the abrasion test are assessed as 4 on the Grey Scale, which is within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993. Also from the results, it was clear that in the 25 Piastres, the amount of Lightness was increased by 6.88%, towards the lighter shades, the (a) value was changed by 2.3, towards the Green colour, while the (b) value was changed by 5.34 towards the Yellow colour. The total ∆E value was only 9.01, which is outside the acceptable range according to the ISO 12647-2 standards and the banknote subjected to the abrasion test are assessed as 3 on the Grey Scale, which is not within the acceptable range according to the ISO 105 A03 - BS 1006 A3: 1993.

Table (29): (L, a, b) Values for Paper and Polymer Banknotes after Taber Abrasion Tests. (L, a, b) values ∆E Description 20 Naira 25 Piastres 20 Naira 25 Piastres L a b L a b Reference 86.26 -1.64 10.86 88.62 2.35 -10.52 Taber Abrasion 86.62 -1.82 10.57 95.5 0.05 -5.18 0.49 9.01

141 142 CHAPTER 18 Machine Washability Tests The Machine Washability test is designed to determine the wear characteristics of banknotes when subjected to machine washing. For this study, experiments have been carried out according to (NPA QC 009) on the 25 Piastres and the 20 Naira banknotes for five washing cycles. A banknote subjected to the Machine Washability test (QC009) should be rated as no less than 3 on the Grey Scale for Assessing Change of Colour ISO 105 A03 - BS 1006 A3: 1993 as follows: 1. Cut samples into banknote size or appropriate size for end use. 2. Prepare 150 grams of FAB detergent in glass beaker. 3. Crumple each sample four times by hand to ensure each edge is crumpled. 4. Place each sample into a fabric pocket (one sample per pocket). 5. Weigh a 2kg load of makeweights (dummy load) and add to the washing machine along with the samples (in pockets) and 150 grams of FAB detergent. 6. Set the machine using the following parameters: Water level: Low Wash temp: Warm (40°C). Check temp with thermometer Wash cycle: Super wash 7. To start machine pull out the wash cycle timer. 8. Leave the machine to operate. The super wash cycle is completed after 45 minutes. 9. The samples are to be examined and crumpled after each wash for five (5) complete wash cycles. 10. The test result is recorded as the evaluation of change in appearance of the abraded area of the sample compared to the Grey Scale for Assessing Staining ISO 105 A03. From the results after this test, Table (30), it was clear that in the case of the Naira banknotes, the amount of Lightness was decreased by 1.46%, towards the darker Shades, the (a) value was changed only by 1.02 towards the Green

143 colour, while the (b) value was changed by 1.77 towards the Yellow colour. ∆E of polymer banknotes for the 1st cycle was 2.32 which is within the acceptable range according to the ISO 12647-2 standards and the banknotes subjected to the Machine Washability test were assessed as 4/5 on the Grey Scale for Assessing Change of Colour ISO 105 A03 - BS 1006 A3: 1993, which are accepted. The maximum colour difference (∆Emax) value in the 5th cycle was only 2.52, which is within the acceptable range according to the ISO 12647-2 standards. Also from the results, it was clear that in the 25 Piastres, the amount of Lightness was increased by 2.85%, towards the lighter shades, the (a) value was changed by 0.76, towards the Red colour, while the (b) value was changed by 4.73 towards the Blue colour. ∆E for paper banknotes for the 1st cycle was 3.93 which is within the acceptable range according to the ISO 12647-2 standards and the banknotes subjected to the Machine Washability test were assessed as 4/5 on the Grey Scale for Assessing Change of Colour ISO 105 A03 - BS 1006 A3: 1993, which are accepted. ∆Emax value in the 5th cycle was 5.57, which is not within the acceptable range according to the ISO 12647-2 standards

Table (30): (L, a, b) Values for Paper and Polymer Banknotes after Machine Washability Tests.

(L, a, b) values ∆E 25 Description 20 Naira 25 Piastres 20 Naira Piastres L a b L a b Reference 86.26 -1.64 10.86 88.62 2.35 -10.52 Machine Wash- 85.07 -1.70 12.81 90.28 2.39 -14.08 2.32 3.93 ability 1st cycle

2nd cycle 85.55 -2.11 12.46 90.90 2.42 -14.01 2.03 4.17 3rd cycle 85.35 -1.77 12.89 91.65 2.52 14.92 2.19 5.35 4th cycle 85.42 -2.39 13.22 91.43 3.02 -15.09 2.30 5.46 5th cycle 84.80 -2.66 12.63 91.47 3.11 -15.25 2.52 5.57

144 Folding endurance values were measured after the first cycle of Washing and the average folding endurance values were calculated as shown in the following table:

Table (31): The Average Folding Endurance Values after Washing for Paper and Polymer Banknotes.

Banknote Reference After Washing Paper Banknote 10061 6500 Polymer Banknote >74000 >74000

From the table (31), it is clear that the average folding endurance value of paper banknotes are strongly affected by washing, whereas the average folding endurance values of polymer banknotes are not affected.

145 CHAPTER 19 Tape Adhesion Test For this study, experiments have been carried out according to (NPA QC 004) on the 25 Piastres and the 20 Naira banknotes as follows: 1. Cut a 5cm length of sticky tape. 2. Place the tape down onto the front of the overcoated note or sheet so that the tape covers some offset and some intaglio print. (It is important to use the same area of design on the note for subsequent tests, so comparisons can be made). 3. Hold one edge of the tape up. Using your thumb rub the tape firmly down onto the sheet in a sweeping motion three times. 4. Holding the sheet firmly rip the tape off upwards and towards the operator. 5. Place the tape piece onto a black card and onto the quality record form. 6. Put the serial number and batch number of the test piece above the tape. 7. Repeat the tape test for the back of the note or sheet. 8. Observe the tape for overcoating removal. Compare the tape with the Standard Samples and determine a grading for the test. (Note: 1 is poor, 5 is excellent). 9. For weekly tests, record results on the quality record form and then on the relevant Finished Notes Test Summary Form. From the results after this test, as shown in table (32), it was clear that in the case of the Naira banknotes, the amount of Lightness was increased by 0.76%, towards the lighter shades, the (a) value was changed only by 0.33 towards the Red colour, while the (b) value was changed by 0.36 towards the Yellow colour. The total ∆E value was only 0.9, which is within the acceptable range according to the ISO 12647-2 standards. Also from the results, it was clear that in the 25 Piastress, the amount of Lightness was increased by 11.38%, towards the lighter shades, the (a) value was changed by 0.85, towards the Red colour, while the (b) value was changed

147 by 1.78 towards the Blue colour. The total ∆E value was only 0.8, which is within the acceptable range according to the ISO 12647-2 standards.

Table (32): (L, a, b) Values for Paper and Polymer banknotes after Tape Adhesion Tests. (L, a, b) values ∆E 20 25 Description 20 Naira 25 Piastres Naira Piastres L a b L a b Reference 86.26 -1.64 10.86 88.62 2.35 -10.52 Tape 87.02 -1.31 11.22 102 3.2 -12.3 0.9 0.8 Adhesion

148 CHAPTER 20 Rub Resistance For this study, experiments have been carried out according to (NPA QC 003/ISO 105 A02 /A03 1993) on the 25 Piastres and the 20 Naira banknotes. The prints are tested on the NPA Rumba Rub Resistance type tester, where the print is rubbed on a strip of blank polymer substrate as follows: 1. Use the template cut samples from the overcoated sheets. Ensure that the main portrait area is present on the samples. (If there is no portrait area choose a major print area on each side of the note). 2. Place a clear strip of polymer substrate for polymer notes, or blotting paper for paper notes, on the base of the rub tester. Ensure that this strip is taut between the clamps. 3. Wrap the sample to be tested on the bottom side of the metal block that has the rubber blanket backing. The sample should be centered on the block. 4. Secure the sample with sticky tape so that no tape is on the bottom of the block rubbing on the strip. 5. The metal block with the sample is placed into its holder and onto the clear strip of polymer substrate or so that the portrait contacts the strip. 6. Set the Rub Tester at 100 rubs (back and forth is one rub). The Rub tester is started and by its reciprocating action rubs the sample a distance of 200 mm along the polymer substrate or blotting paper. After the 100 rubs it is examined for wear. 7. The portrait should be intact, with little or no staining on the polymer substrate or blotting paper. 8. Evaluate the strip for staining against the Grey Scale for Assessing Staining ISO 105 A03 9. Place the samples back onto the sheet (see note). 10. Place the strips on A4 sample sheet or attach to results sheet. 11. Record the results on the quality record sheet and also on the Finished Notes Test Summary. Place unused pieces of cut notes on back of A4 sheet. The extent of staining on the note shall not be less than four on the Grey Scale for assessing staining ISO 105 A03 - BS 1006 A3: 1993.

149 From the results of this test, as shown in table (33), it was clear that in the case of Naira banknotes, the amount of Lightness was decreased by 1.36%, towards the darker shades, the (a) value was changed only by 0.61 towards the Green colour, while the (b) value was changed by 1.00 towards the Blue colour. The total ∆E value was only 1.77, which is within the acceptable range according to the ISO 12647-2 standards. The extent of staining on the note is 4/5 on the Grey Scale for assessing staining ISO 105 A03 - BS 1006 A3: 1993, which is accepted. Also from the results, it was clear that in the 25 Piastress, the amount of Lightness was decreased by 0.09%, towards the darker shades, the (a) value was changed by 0.12, towards the Green colour, while the (b) value was changed by 1.02 towards the Blue colour. The total ∆E value was only 1.04, which is within the acceptable range according to the ISO 12647-2 standards. The extent of staining on the note is 4 on the Grey Scale for assessing staining ISO 105 A03 - BS 1006 A3: 1993, which is accepted. Table (33): (Lab Values) for Paper and Polymer Banknotes After Rub Resistance Tests. (L, a, b) Values ∆E Description 20 Naira 25 Piaster 20 Naira 25 Piaster L a b L a b Standard 86.26 -1.64 10.86 80.83 -0.93 -5.78 Rub Resistance 84.90 -2.15 9.86 80.74 -1.05 -6.80 1.77 1.04

150 CHAPTER 21 Effect of Solvents on Polymer and Paper Banknotes For this study, experiments have been carried out according to standard recommendations on the 25 Egyptian Piastres banknotes and the 10000 Lei Romanian banknotes (as polymer banknotes). 21.1. With Acetone: From the results of this test, as shown in table (34), it was clear that in the case of the polymer banknotes, the amount of Lightness was increased by 3.8%, towards the lighter shades; the (a) value was changed only by 0.7 towards the Red colour, while the (b) value was changed by 1.5 towards the Blue colour. The total ∆E value was only 4.15, which is within the acceptable range according to the ISO 12647-2 standards. Table (34): (L, a, b) Values for Both Paper and Polymer Banknotes After Treatment with Acetone. (L, a, b) Values ∆E 10000 Lei 25 Piastres Description 10000 25 L a b L a b Lei Piastres Reference 82.2 -21.5 19.0 70.4 3.5 -21.5 After Treatment 86.0 -20.8 17.5 70.9 3.1 -19.9 4.15 1.72

As for the Density measurements, table (35), the Density change in the case of the Lei banknotes was a decrease by 0.06, which means that the total ink film was decreased by this value due to the Acetone effect. Table (35): The Colour Density for Both Paper and Polymer Banknotes. Density Before Treatment After Treatment Density Change Polymer 0.24 0.18 0.06 Paper 0.35 0.32 0.03

151 Also from the results of this test, table (34), it was clear that in the case of the 25 Piastres banknotes, the amount of Lightness was increased by 0.5%, towards the lighter shades, the (a) value was changed only by 0.4 towards the Green colour, while the (b) value was changed by 1.6 towards the Blue colour. The total Delta E value was only 1.72, which is within the acceptable range according to the ISO 12647-2 standards. As for the Density measurements, table (35), in the case of the 25 Piastres banknotes, the change was a decrease by 0.03, which means that the total ink film was decreased by this value due to the Acetone effect.

21.2. With Ethyl Acetate: From the results after this test, as shown in table (36), it was clear that in the case of the Lei banknotes, the amount of Lightness was increased by 1.7%, towards the lighter shades; the (a) value was changed only by 1.7 towards the Green colour, while the (b) value was changed by 1.4 towards the Blue colour. The total ∆E value was only 2.8, which is within the acceptable range according to the ISO 12647-2 standards. Table (36): (L, a, b) Values for Both Paper and Polymer Banknotes After Treatment With Ethyl Acetate. (L, a, b) Values ∆E Description 10000 Lei 25 Piastres 10000 Lei 25 Piastres L a b L a b Reference 82.2 -21.5 19.0 70.4 3.5 -21.5 After Treatment 83.9 -19.8 17.6 87.4 0.4 2.8 2.8 25.4

152 As for the Density measurements, table (37), the Density change in the case of the Lei banknotes, was a decrease by 0.06, which means that the total ink film was decreased by this value due to the ethyl acetate effect.

Table (37): The Colour Density for Both Paper and Banknotes After Treatment With Ethyl acetate.

Density Before Treatment After Treatment Density Change Polymer 0.24 0.18 0.06 Paper 0.35 0.16 0.19

Also from the results of this test, it was clear that in the case of the Egyptian banknotes, the amount of Lightness was increased by 17%, towards the lighter shades, the (a) value was changed only by 3.1 towards the Green colour, while the (b) value was changed by 18.6 towards the Yellow colour. The total ∆E value was 25.4, which is not acceptable according to the ISO 12647-2 standards. As for the Density measurements, table (37), the Density change in the case of the 25 Egyptian Piastres banknotes was a decrease by 0.19, which means that the total ink film was decreased by this value due to the Ethyl Acetate effect.

153 21.3. With Benzene: From the results after this test, Table (38), it was clear that in the case of the Lei banknotes, the amount of Lightness was increased by 3.5%, towards the lighter shades; the (a) value was changed only by 0.5 towards the Green colour, while the (b) value was changed by 1.7 towards the Blue colour. The total ∆E value was only 3.9, which is within the acceptable range according to the ISO 12647-2 standards.

Table (38): (L, a, b) Values for Both Paper and Polymer Banknotes After Treatment With Benzene. (L, a, b) Values ∆E Description Polymer Paper Polymer Paper L a b L a b Reference 82.2 -21.5 19.0 70.4 3.5 -21.5 After treatment 85.7 -21.0 17.3 69.6 2.4 -20.9 3.9 1.5

As for the Density measurements, the change was a decrease by 0.07, which means that the total ink film was decreased by this value due to the benzene effect.

Table (39): The Colour Density for Both Paper and Polymer Banknotes After Treatment With Benzene.

Density Before Treatment After Treatment Density Change Polymer 0.24 0.17 0.07 Paper 0.35 0.26 0.09

Also from the results after this test, it was clear that in the case of the Egyptian banknotes, the amount of Lightness was decreased by 0.8%, towards the darker shades; the (a) value was changed only by 1.1 towards the Green colour, while the (b) value was changed by 0.6 towards the Yellow colour. The total ∆E value was only 1.5, which is within the acceptable range according to the ISO 12647-2 standards.

154 As for the Density measurements, the change was a decrease by 0.09, which means that the total ink film was decreased by this value due to the benzene effect.

21.4. Effect of Solvents on Folding Endurance: After treating both paper and polymer banknotes with acetone, ethyl acetate and benzene solvents, folding endurance was measured for both kinds.

Table (40): The Average Folding Endurance Values After Treatment With Solvents. Banknote Standard Acetone Ethyl Acetate Benzene Paper 10061 5503 6440 8587 Polymer >74000 >74000 >74000 >74000 From the table (40), it is clear that the average folding endurance value of paper banknotes are strongly affected by the solvents, which weaken the substrate, whereas the average folding endurance values of polymer banknotes are not affected, which means that solvents do not affect the polymer substrate.

155 CHAPTER 22 FT-IR Spectra of Paper and Polymer Substrate 22.1. FT-IR Spectra of Paper: Infrared Spectra of banknotes were obtained by using (Jaco FTIR 8000 E) spectrometer. The sample was determined by using KBr disc technique. The Fourier transform IR (FT-IR) spectra of paper substrate are marked that are characteristic for the crystalline structures in the OH stretching region (3,000–3,700 cm−1) and the OH out-of-plane bending region (650–800 cm−1). The band (2850-300 cm−1) are characteristic for the C-H stretch of alkenes.

157 22.2. FT-IR Spectra of BOPP Substrate: The IR spectra of biaxially oriented polypropylene showed absorption peak at 2868-2962 cm-1 corresponding to ν CH aliphatic, 1377 cm-1 corresponding -1 to δ-CH of -CH3 and 1458 cm corresponding to δ-CH of aliphatic CH.

158 CHAPTER 23 Comparison between security elements in Paper and Polymer banknotes After a thorough study of all the available security features in both Paper and Polymer banknotes, & comparing what is available in both substrates, as shown in table (41), we get the following conclusions: i- security features based on the design, inks and printing processes can be applied on both paper and polymer substrates with no significant differences. ii- The main differences exist in the substrates themselves whereby paper and polymer have their own unique security properties but with similar objectives. For example, watermark, threads and fluorescent fibres embedded in the paper substrate and in polymer, the clear window and all the security elements attached to it. iii- Although polymer is manufactured differently to paper, it offers an alternative, unique and secure substrate for banknotes through its complex window structures which act as a platform for integrating shadow images, intaglio blind embosses, colourshifting inks, diffractive optical elements. The potential available with polymer substrate is used to its advantage. The transparent window is the focus of these developments by converting the optical properties of the transparent area to a tool for verification. The innovation here is that the tool for verification is carried within the note. The self-authenticating features currently available are µSAM® and Metamerics, in addition, the polymer substrate contains a number of unique security features which closely integrate with the banknote printing to create a highly complex and secure finished banknote as mentioned before. Table (41): Comparison Between Security Elements in Polymer and Paper Banknotes.

No. Security Element Polymer Banknote Paper Banknote

1 Complex Window Available N/A 2 Diffractive Optical Elements Available Available

159 No. Security Element Polymer Banknote Paper Banknote

3 Printed Optical Colour Shift Element Available Available 4 Transitory Emboss Available Available 5 Metallic Patch Available Available 6 Iridescent Feature Available Available 7 Shadow Image Available Water mark 8 Optical Machine Readable Security Thread Available Available 9 Vignette Available Available 10 MicroSam® Available Available 10 Self Authenticating MicroSam® Available N/A 11 Water Mark Shadow Image Available 12 Threads Printed Available 13 OVI Available Available 14 Colored Fibers Printed Available 15 Colored Disks (Planchettes) N/A Available 16 See Through Register Available Available 17 UV Dull Substrate Available Available 18 UV Inks Available Available 19 IR Inks Available Available 20 Multi UV Inks Available available 21 Iridescent Inks Available Available 22 Magnetic Inks Available Available 23 Thermo-Chromic Inks Available Available 24 Fluorescent Inks Available Available 25 Metameric Inks Available Available 26 Electro-Chromic Inks Available Available 27 Foiling Available Available

160 No. Security Element Polymer Banknote Paper Banknote

28 Metallic Inks Available Available 29 Micro Text Available Available 30 Hidden Image Available Available 31 Fine Lines Available Available 32 Guilloches Available Available 33 Anti Scan Available Available 34 Anti Copy Available Available 35 Security Hologram Available Available 36 Kinegram Available Available 37 Special Screening Available available 38 Tactile Printing Available Available 39 Rainbow Printing Available Available 40 Secure Core Print Available Available 41 Serial Numbering Available Available 42 Demetallization Available Available 43 Nano Text Available Available 44 Nano Graph Available Available

161 CHAPTER 24

Comparison between Counterfeit Rates in Paper and Polymer banknotes Since polymer banknotes contain many advanced security features that cannot be successfully reproduced by photocopying or scanning, they are very difficult to counterfeit. The complexities of counterfeiting polymer banknotes act as a deterrent to counterfeiters. By the year 2000, New Zealand had introduced its full series of circulating polymer notes. New Zealand has experienced a landmark reduction in counterfeiting since the introduction of polymer as shown in figure (93)(http:// www. rbnz.govt.nz/). The counterfeits detected in 2000 and 2001 were all paper notes (mainly $10 and $50 notes which were the last denominations to be converted to polymer). To date New Zealand has detected no counterfeits reproduced on polymer; all have been produced on paper. In the year ending 30 June 2004, New Zealand machine processed 66 million notes and detected just 28 counterfeits (www. IPCA.au.com/ February 2005).

163 Since the introduction of polymer banknotes in Mexico, refer to table (42) and figure (95), there has been a reduction in counterfeit levels. Guardian® polymer 20 Pesos banknotes were first issued in Mexico at the end of September 2002. At that time the counterfeit figure was 18.1 ppm and since then the counterfeits of the 20 Pesos has reduced dramatically and is now less than 1 ppm. The 50 Pesos polymer note was launched in November 2006 with a counterfeit figure of 215.1 ppm and has since reduced to 59.4 parts per million in 2008 (www.banxico.org.mx). All other denominations are made from paper and comparison the levels of counterfeits are very low. Guardian® polymer banknotes have led to a landmark reduction in counterfeiting in Australia, Mexico, and many other countries, and are providing note life many times that of paper (www.banxico.org.mx).

Table (42): Counterfeit Detection Rates (parts per million in circulations) in Mexico. Polymer Paper Year $20 $50 $100 $200 $500 $1000 2000 14.8 179.7 178.5 83.9 26.6 0.0 2001 13.1 150.5 136.8 64.4 20.9 0.0 2002 18.1 109.7 64.2 97.3 35.7 0.0

164 Polymer Paper Year $20 $50 $100 $200 $500 $1000 2003 9.4 140.9 60.1 77.6 42.9 0.0 2004 1.5 149.2 117.8 80.5 34.0 10.2 2005 1.0 249.3 142.9 117.8 43.6 50.3 2006 0.7 215 106.5 88.8 70.9 131.1 2007 0.6 122.5 77.1 78.6 90.5 364.2 2008 1.0 59.4 87.6 97.7 91.7 416.8 2009 3 28 81 136 91 393 2010 3 68 101 140 96 232

Australia’s level of counterfeiting, (Table 43), continues to remain low in comparison with most other countries. In 2009/10, a total of 7836 counterfeits were detected, with a nominal value of $413 995. This corresponds to around seven counterfeits passed per million genuine banknotes in circulation, a small decline from 2008/09 and around the average over recent years. As in previous years, the $50 note was the most commonly counterfeited denomination, accounting for 88 per cent of the counterfeits passed in 2009/10 (www.rba.gov.au).

165 Table (43): Counterfeit Detection Rates (parts per million in circulations, ALL DENOMINATIONS – GUARDIAN POLYMER NOTES ) in Australia.

Number of Counterfeit Notes Per Million Year Notes In Circulation

1995/96 16 1996/97 9 1997/98 5 1998/99 3 1999/00 4 2000/01 5 2001/02 14 2002/03 9 2003/04 5 2004/05 5 2005/06 6 $5 $10 $20 $50 $100 Total 2006/07 0.4 3 5 10 4 6 2007/08 0.5 1.9 2.9 13 6.1 7.4 2008/09 0.4 1.7 1.4 13.0 5.7 7.4 2009/10 0.3 1.1 1.2 14.3 3.2 7.4

A comparison between detected counterfeit paper and polymer notes until September 2011, (Table 44 and figure 96), in three countries adopting polymer; Australia, Mexico and Romania, and paper notes; Euro, Mexico (Paper Notes) and United Kingdom (Paper Notes) showed that the number of counterfeit polymer notes are less those that of paper.

166 Table (44): Counterfeit Detection Rates (parts per million in circulations), GUARDIAN AND PAPER NOTES COMPARISON September 2011 Counterfeit Notes 2002 2003 2004 2005 2006 2007 2008 2009 2010 - PPM Australia 14 9 5 5 6 6 7 7 7 (Guardian Notes) Mexico (Guardian 69 32 17 37 Notes) Romania 2 2 3 5 4 (Guardian Notes) Euro (Paper 22 67 67 60 54 50 51 63 53 Notes) Mexico (Paper 73 73 83 115 99 87 101 114 117 Notes) United Kingdom 256 209 175 253 192 139 299 231 116 (Paper Notes) Average 2002 2003 2004 2005 2006 2007 2008 2009 2010 Guardian Notes 14 9 5 5 4 20 13 9 14 Paper Notes 67 92 87 97 81 67 89 91 68

167 CHAPTER 25 Durability of Banknotes In Australia, Polymer notes have turned out to be more durable than Australian original expectations, lasting around four times as long as their paper counterparts. For example, the paper $5 note had an average life of just 6 months, whereas experience has shown that it is over 2 years for the polymer $5 note. Similarly, Australian paper $10 note had an average life of just 8 months, whereas it has risen to over 4 times that with polymer. (Colditz J., 1994, 1995). Experience in New Zealand to date confirms that polymer banknotes retain their structure and cleanliness over a much longer period than paper notes. In the March year 1997/98, Figure (97), when all banknotes in circulation were paper notes, the Bank destroyed 57 % (40 million notes) as unfit of $20 for circulation. In the year to 31 March 2005 the Bank has destroyed just 15 percent (17 million notes). In addition, before being destroyed as unfit, the polymer notes are currently lasting 82 months on average. This is more than four times the life of a typical paper note (Boaden, A. 2005).

169 The average life for the lower denomination polymer banknotes in New Zealand, Figure (98), is 7.2 years compared with 1.4 years when all notes were paper (http://www.rbnz.govt.nz/).

Besides high anti-counterfeit quality, polymer banknotes have other advantages over cotton banknotes - higher durability and cleaner than cotton banknotes. In the context of high humidity and typical circulation conditions of Vietnam, cotton banknotes are often dirty, curl and lime, absorbing many soils. Therefore, the average lifetime of cotton banknote is just about 1.5-3 years, depending on denominations. On the other hand, the classification and selection of cash is currently done by hand and in a cash-based economy like Vietnam, the pressure to count and process cash of the banking system is very huge. It also implies that in such context, it is very difficult to avoid wastes and cost-inefficiency of slow process of money selecting, classification un-timely delivery of banknotes at standard quality back to circulation, leading to the costs of maintaining cash at vaults. Moreover, because of the slow speed of circulation and selection, part of money in circulation (not yet back to the bank) has low quality, being dirty and torn, creating opportunities for mixing with counterfeited money and lengthening the time for counting of the whole banking system of the country. Tests in Vietnamese laboratories and experience in countries applying the polymer technology show that polymer banknotes are 3-4 times more durable than cotton banknotes. Moreover, polymer banknotes are consistent, sustainable, cleaner and do not create “money dust” like cotton ones; thus, the counting of polymer banknotes by machines is more productive, as well as money processing can be more automated (Nguyen Chi Thanh M.A., 2005).

170 The effective note life of polymer banknotes, Table (45), is much longer than paper banknotes. Recent developments to try and improve the durability of paper have not affected the note life ratio to polymer. The life ratio is the improved effective note life, e.g. In Australia the polymer $5 note is lasting 4.6 times longer in circulation than the paper $5 (http://www.rba.gov.au/ Currency-Notes/Conference Papers/cu_ 6.2.html).

Table (45): Life Ratio of Polymer Banknotes in Seven Countries.

Country (2004) Guinea 2 Mexico 20 Nigeria 20 Chile 2000 Papua New Zambia 500 Australia $ 5 New Zealand $5

Life 4.6 4.6 4.0 3.5 5.0 5.8 5.8 Ratio

171 CHAPTER 26 Cost-effectiveness The cost/benefit evaluation has only considered the banknote acquisition costs. As the polymer notes retain their quality while in circulation, significantly reduced volumes of notes are required to replace poor quality notes. With the significant reduction in new note requirements, this can lead to significant savings for “downstream” currency operations costs – note distribution, inventory management, note destruction and waste disposal. As the polymer notes have a good level of security and retain their quality in circulation, they do not require high volume authenticity validation and quality sorting. Significant reductions in the volumes of note processed can be considered while still maintaining an acceptable level of confidence in the security and quality of the notes. Reduction in processing volumes provides significant cost savings in operational resource requirements and equipment capital expenditure. In 2000 the Banco de México launched a research project on the viability of using alternative substrates, the main aim being to increase durability and, in particular, to enhance the quality of the lowest denomination banknote (the 20 peso note). When the Banco de México decided to study the possibility of opting for polymer, a number of questions arose. Cost-benefit analysis was conducted, considering the direct production costs, the estimated decline in productivity, the distribution cost and the coating cost. The analysis showed that if the lifetime of a polymer banknote was at least 2.2x the mean lifetime of the paper banknote it was to replace, then the project would be economically viable , Figure (99), In the end, the estimated mean lifetime of the polymer banknotes proved to be 3.5x that of their paper counterparts. The calculations showed that the mean lifetime, with a confidence interval of 95%, was between 3.2x and 3.8x higher than that of the paper banknotes, implying an annual saving of 42%, assuming the same number of banknotes in circulation. The mean lifetime of the 20 peso note rose from 8.3 to 28.8 months (Billetaria , 2009).

173 In Australia, around 400 million paper banknotes were produced each year in the decade before polymer banknotes were introduced, about the same as the number in circulation. By comparison, Figure (100), average annual banknote production since 1997 has been less than half this figure even though the number of banknotes in circulation has doubled since the earlier period (www.IPCA. au.com/ February 2008).

In New Zealand, Polymer notes have also proved very cost-effective. In the four years prior to the introduction of polymer notes, Figure (101), note issue expenses averaged $3.4 million per annum or 5.2 cents per note in circulation.

174 In the year to 31 March 2005, note issue expenses were $2 million or 1.8 cents per note (Boaden, A. 2005). Since 2002, Figure (102), total expenditure In New Zealand on note issue and cash operations has been under 20% of total Bank expenditure ((http:// www.rbnz.govt.nz/).

175 Many countries in recent times have successfully made changes to their currency structure (eg. the Euro).Traditionally issuing a coin to replace a paper banknote has been cost effective for a Central Bank. Over time the longer life of a coin has outweighed the initial replacement and higher production costs. However, the significant increase in the price of metals that occurred from late 2002 until very recently and the proven durability of polymer substrate has influenced this equation; even to the extent that reverting from a coin back to a banknote can be a viable cost effective long-term option. While the very recent fall in metal prices will certainly improve the cost effectiveness of coins; it does highlight the fact that metal prices will be subject to significant variability over the 25 to 30 years life-span of most coins issued. The cost of the metal used in coins is priced at the time the metal is purchased for the coin, thus an issuing authority cannot foresee future expenditure with any degree of certainty. PolyTeQ® Services (a division of Securency International) has developed a coin/ note cost benefit model, Figure (103). The modeling process consists of two steps; first is an analysis of the coin cost based on a calculation of the metal content taken from global commodity pricing; and an estimate of its production cost. The second step involves comparing the annual cost of issue over a 10 year period, including switching costs and the costs of issuing a coin, a paper banknote and a polymer banknote. This analysis was done for a number of countries and clearly shows the following: The ongoing annual cost of issuing paper banknotes is significantly higher than that of coins and polymer notes. The introduction of a coin will provide no long term cost benefit compared with issuing a polymer banknote (assuming metal prices show the same variability as in recent years). In August last year, Guatemala issued a 1 Quetzal polymer banknote to replace a paper note of the same face value which will co-circulate with a 1 Quetzal coin (www.IPCA.au.com/ November 2007). A cost benefit analysis for this denomination at that time showed that a polymer banknote was a cost competitive option for the Central Bank. In conclusion, if issuing a coin

176 does not provide a cost benefit for the Central Bank in the long-term, then the advantages of a coin over a banknote are significantly diminished. At this time only polymer banknotes have the proven durability to compete with a coin in cost effectiveness (www.IPCA.au.com/ January 2009).

Polymer banknotes cost twice as ‎much to make, but they can last four times longer. ‎The increased functionality and cleanliness of banknotes printed on polymer substrate results in significant cost savings from the reduced frequency of printing, processing requirements and the ability to recycle polymer banknotes withdrawn from circulation. Furthermore, since counterfeiting is virtually difficult, this means that checks on authenticity and fitness for reissue have greatly reduced time and cost whilst increasing efficiency(Peter Eu. et al 2007). ‎ It is estimated that the Reserve Bank of New Zealand, Figure (104), has saved NZ $81 million since 1998/99 in operational costs (including transitional costs).

177 Operating expenses includes staff remuneration, office & storage rentals, depreciation, security, IT and allocation of Central Bank overheads. Increase in 2006/07 due to ‘one-off’ expenditure related to introduction of new coins (http://www.rbnz.govt.nz/).

178 Conclusion Polymer Paper Test Banknotes Banknotes 1-Mechanical Properties Properties +ve -ve 2-After Crumple Resistance Test, Soil & Wear Resistance Test, Colour Fastness Test, Tape +ve +ve Adhesion Test And Rub Resistance Test 3- On treating with Acids, Alkalis and Solvents +ve +ve (ΔE) 4- On Treating with Laundry Detergent (ΔE) +ve -ve 5- On Treating with Industrial Laundry (ΔE) +ve -ve 6-After Machine Washability Tests (ΔE) +ve -ve 7- The Average Folding Endurance After +ve -ve Washing and Solvents 8-After Taber Abrasion Test, ΔE +ve -ve 9- Exposure to Humidity & Weathering +ve -ve 10- Hygiene +ve -ve 11- Rates of Counterfeit banknotes +ve -ve +ve 12- Durability (last four -ve times longer) 13- Cost Savings +ve -ve Polymer offers an alternative, unique and more secure substrate for banknotes through its complex window structures which act as a platform for integrating high security features, not available to paper banknotes, making counterfeiting much more difficult. Accordingly, polymer banknote is the optimal solution for all the problems that obstruct paper banknote.

179 Abbreviations RBA The Reserve Bank of Australia

CSIRO Commonwealth Scientific and Industrial Research Organization BOPP Biaxially-Oriented Polypropylene

Clarity-C The Unique Bopp Market Film Used for Banknotes

Guardian Unique Form of Opacified BOPP Clarity-C Film

DP Degree of Polymerization

SGW Stone Groundwood

PGW Pressure Groundwood

RMP Refiner Mechanical Pulp

TMP Thermomechanical Pulp

CTMP Chemithermomechanical Pulp

DIP Deinked Pulp

TAPPI The Technical Association of the Pulp and Paper Industry

ISO International Organization for Standardization

FWA Fluorescent Whitening Agents

EDTA Ethylene Diaminetetraacetic Acid

ECF Elemental Chlorine Free

TCF Totally Chlorine Free

IUPAC The International Union of Pure and Applied Chemistry

PP Polypropene

LDPE Low Density Polyethylene

180 HDPE High Density Polyethylene

ABS Acrylonitrile Butadiene Styrene

RF Radio Frequency

DSC Differential Scanning Calorimetry

MFR Melt Flow Rate

MFI Melt Flow Index

UV Ultraviolet

G&D Giesecke & Devrient

WinDOE® Diffractive Optical Element

FTH Transmission Fourier Transform Hologram

WinBOSS® Transitory Emboss and Transitory Images

WinVU® Vignette

G-switch® Dynamic Optical Colour Shift

OVD Optically Variable Security Device

OVI Optically Variable Inks

ICE® Intaglio Contrast Effect

TIED® Transparent Intaglio Disappearing Effect.

181 References Adler J. (1977). Wood Sci. Technol., 11, 169. Anja Kemppi, ( 1997). “Studies on the Adhesion Between Paper and Low Density Polyethylene:3. The Influence of Fillers “Paperi Ja Puu-Paper and Tirnber" V 01. 79/NO. 5. Ali, U. and Oya, B.N. (1988). Proceedings of the 1998 7th International Conference on Biotechnology in the Pulp and Paper Industry, Part 3 (of 3), C 175- C181. AS/NZS ISO 14040: (1998). Australian / New Zealand Standard, Environmental management - Life Cycle Assessment - Principles and Framework, Standards Australia, Homebush, NSW & Standards New Zealand, Wellington. Atchison, J. E. (1973): Paper Trade J., 147 (19), 30. Barowning W.J., (1974). Research Lab, Inc.” Permanence/ Durability of the Book, VII- Physical and Chemical Properties of Book Papers 1507-1949 Barrow Res- Lab.” (Richmond Va. 23221) 48p. Benar P., Gencalves, A.R., Mandelli, D., Schuchardt, U., (1999). Biochem ‎Technol., 68, (11-16).

Biermann C. J. ­­(1993). Essentials of Pulping & Papermaking. Academic Press. Billetaria, (2009). International Review on Cash Management Issue No. 5. Boaden, A., (2005). Reserve Bank of New Zealand Bulletin, Vol. 68. No.2. June, pp 4-12 available in (http://www.rbnz.-govt.nz/research/ search/article.asp?id=3890). Bell L. A. (1992). Plant Fibers for Papermaking. Liliaceae Press. Bonifazi WL. (2002). ‘Money’s Dirty, But Health Risks Overstated’. Natural Foods Merchandiser XXIII (3):36. Available: http://www. naturalfoods merchandiser.com. Bouchard, J.; C. Maine, R.M. Berry, and D.S. Argyropoulos (1996). “Kraft Pulp Bleaching Using Dimethyldioxirane: Stability of the Oxidants”. Can. J. Chem. 74 (2): 232–237. doi:10.1139/v96-026.

183 http://article.pubs.nrc-cnrc.gc.ca/ppv/RPViewDoc?issn=1480- 3291&volume- =74&issue=2&startPage=232. Retrieved on 2007-09-20. Brown A. (2003). ‘How Dirty is Your Money?’ CNN International. http:// edition.cnn.com!2003/WORLD/ asiapcf/ Browning B.L., (1967). “Methods of Wood Chemistry” John Wiley & Sons, Volume 11(387). ‎Browning B.L., (1967). “Methods of Wood Chemistry” John Wiley & Sons, Volume 11(416). Carlin P., (2002). Interpol 10th International Conference on Counterfeiting and the 5th International Conference on Fraudulent Travel Documents. ‎‎Carnö, B. and Hartler, N., (1976). Tappi, 59(8), 48. ‎Casey J ., Pulpa Y Papel, (1990). (Vol.1 ), Noriega-Limusa, Mixico. Chase R. (2000). ‘Dirty Money: Amount of Bacteria on Different Denominations of money’. Available: http:// www.ga.kI2.pa.us(academics/ms. Colditz J., (1994). The CSI Currency Conference Hong Kong. Colditz J., (1995). The Pacific Rim Banknote Printers’ Conference Sydney. Colditz J., (1997). XIII Pacific Rim Banknote Printers’ Conference, India. Colditz J.and Taylor J., (1998). Paper Presented at The International Currency Conference. Cotrim, A.R., Ferraz, A. and Silva, F.T.: (1995). 8th Int. Symp. on Wood and Pupling Chem.: Finland, 3, 313-318. Cross. C. F. and Bevan. E. J. (1907).”Researches on Cellulose” 1895-1900, 2nd edition Longmans, Green, and Co., Ducey M. (June 2004). “Matching newsprint qualities to press technology”. The International Journal of Newspaper Technology. http:// www.newsandtech.com/issues/2004/06-04/nt/06-04_newsprint. htm. Retrieved on 2007-09-15. Duncan A. McLean K. and Kelly J. (1995). “Microbial Populations on Banknotes, CSIRO, Australia).

184 ‎Edel E.: (1990). Das papier, l0A, (44). EI-Kalyobi.S.F. and EL-Shinnawy. N. A, (1985). Thermochemica Acta.:94, (231-238). ‎El-Masry A.M., El-Torky A.M.M. and Hegab N.A.E.: (1997). Cellulose Chem.‎Technol., 31, (247). ‎El-Masry A.M., Mostafa N.Y., Hassan A.H. and Abou-State M.A.: (1998). Cell. ‎Chem. Technol., 32, (433). El-Saied H., Nada ‎A.M.A., (1993). Polymer Degradation and Stability, 40, (417-‎421). Fair, G. M.; J. C. Morris, S. L. Chang, I. Weil, and R. P. Burden. (1948). “The Behavior of Chlorine as A Water Disinfectant”. J. Am. Water Works Assoc. 40: (1051–1061). Farida M. S. El-Din El-Dars & Wael M. H. Hassan, (2005). “ A Preliminary Bacterial Study of Egyptian Paper Money” International Journal of Environmental Health Research; 15(3): (235-,239). Ferguson K., (1994). ed. New Trends and Developments in Papermaking. Miller Freeman, Inc. Friedberg R. (1995). Paper Money of the United States, 14th Edition. The Coin and Currency Institute, Inc. Gadsby P. (1998). “Filthy Lucre - Money is Contaminated with Bacteria - Including Related Article on Money Taken from Magazine Editors”. Available: http://www.findarticels.com. Glasser W.G. and Jain R.K.: (1993). “Lignin Derivatives” Holzfroschung, 40, (225-‎233). Glastone S.. (1962). Text Book of Physical Chemistry, Mac Millan, London, (828). ‎Goncolves A.R., Cotrin A.R., Silva F.T. and Ferraz A.: ( 1998). “Modification of Organosolv Lignin by Oxidation” 2nd Int. Symp. on Natural Polymer and Composite ISNaPol/98, Säo Carlos, Brazil, (255-259). Gotze F.: ‎(1967). Chemcfasern Nach Dern Viskoseverfahren Springer, Berlin, (1282).

185 Hale, J.D.: (1969). Pulp and Paper Manufacture, 2nd Ed., Vol. 1, McGraw-Hill Book Company, New York. Harazono K.; Kondo R.and Saki K. (March 1996). “Bleaching of Hardwood Kraft Pulp with Manganese Peroxidase from Phanerochaete Sordida YK-624 without Addition of MnSO4” (PDF). Applied and Environmental Microbiology 62 (3): (913–917). Hardwick B., and Ghioghiu A., (2004). “GuardianTM Substrate as An Optical Medium for Security Devices” Note Printing Austalia Limited. Hartler N. and Mao B.: (1994). Tappi, 77(11). (149). Hartler N..: (1978). Svensk Papperstidn., 81 (15), (483). Hebeish A. and Guthrie J.T.: (1981). “The. Chemistry and Technology of Cellulosic Copolymers", Springer-Verlag, Berlin Heidelberg, New York, 4, (‎1-10). Hernane S. Barud, Adalberto M. de Araújo Júnior, Daniele B. Santos, Rosana M.N. de Assunção, Carla S. Meireles, Daniel A. Cerqueira, Guimes Rodrigues Filho, Clóvis A.Ribeiro, Younes Messaddeq and Sidney J.L. Ribeiro, (2008). Journal of Thermochimica Acta, Volume (471), Issues 1-2, (61-69). ‎Highley T.L.: (1987). Changes in Chemical Components of Hardwood and Softwood by ‎Brown-Rot Fungi. Material und Organisrnen. 22(1), (39-45). ‎Hill, A.F. (2002). Organotransition Metal Chemistry Wiley-InterScience: New York, (136-139). Hon D.N.S.: (1988). Polymer Neas, 13, (134-140). Hurter, Robert W., (1997). “Agricultural Residues”, TAPPI, Non wood Fibers Short Course. Johansson, E.; S. Ljunggren (1991). “The reactivity of lignin model compounds and the influence of metal ions during bleaching with oxygen and hydrogen peroxide”. Proceedings of the Seventh International Symposium on Wood and Pulping Chemistry vol. I: Kissin, Y.V. (2008). Alkene Polymerization Reactions with Transition Metal Catalysts” Elsevier: Amsterdam, Chapter 4. ‎Kleinert T. and Cotton S.T.: (1970). Tappi. 40. (813).

186 Kleinschmidt R., Griebenow Y. and G. Fink. (2000). Journal of Molecular Catalysis A: Chemical, 157 (83–90). Klemm D., Heinze T., Philipp B., and Wagen-knecht W.: (1997). Acta Polymer, 48, (277-297). Kondo T.: (1994). J. Polyrn. Sci., B. Polymer Phys., 82, (1219-1236). Kozlowski, R. ;Mieleniak, B. and Przepiera, A. (1994). Proceedings of the 28th Washington State Uni. International Particleboard/ Composite Materials Symposium (Washington State Uni.), (181-197). Krause, Chester L. and Robert F. Lemke. (1990). Standard Catalog of U.S. Paper Money. Krause Publications. Kyung-Jun Chu. (1998). Eur. Polym. J. Vol. 34, No. 3/4, (577-580). Life-Cycle analysis (sic) of recycling and recovery of households plastics waste packaging materials. (2005). TUV Rheinland, Sicherheit und Umweltschutz, GmbH, Koln, Germany. Leutwyler K. (2001). ‘Estimating the Dollar’s Bacterial Exchange Rate’. Scientific American Inc. Available: http://www.sciam.com. Les Coventry, (2001). XV Pacific Rim Banknote Printers’ Conference, Thailand. McDONOUGH T. J. (January 1983). “Oxygen Bleaching Processes : An Overview” (PDF). IPC technical paper series132. http://www. smartech.gatech.edu/bitstream/-1853/2685/1/tps-132.pdf. Retrieved on (2007-09-19). Mercandelli P., Sironi A., Resconi L. and Camurati I. (2007). Journal of Organometallic Chemistry 692 (4784–4791). Michael K.: (1993). “Tappi Test Methods”. Milichovsky M.: (1991). Tappi, 73, (221). Misra, D.K. (1980). Pulp and Paper Chemistry and Chemical Trchnology, 3rd Edn., Vol. 1, Pulp and Paper, Ed. Casey, J.P., Wilew-Interscience, New York.

187 Munsell, Joel. (1992). Chronology and Process of Papermaking, 1876-1990. Albert Saifer Publisher Mobarak, F. and Fahmy, Y.: (1977). Indian Pulp and Paper J., (15-22). ‎Mobarak F.,Nabila A El-Shinnawy, Aisha A. A. Soliman and El-Gendy A. A. ( 1997). J.Sci.and Ind. Res.,Vol.57, (316-323). Nada, A.M.A, Ibrahem, A.A., Saied, M.S. and Mohamed, H.T.: (1990). Cellu1.Chem. ‎Technal 24 (4) 22. Nada A.M.A., Abou-Yousef H.E., EI-Gohary S.: (2003). Polym. Plast. Technol. of ‎Eng. 42, (643-658). Nada A.M.A., Dawy M., and Shabaka A.A.: (2000a). Intern. J. Polymeric Mater., 47, (195-204). Nada A. M. A. and Hassan M.L.: (January 2000). J.Polymer Degradation and Stability, Volume 67, Issue 1, (111-115). Nada, A.M.A. and Hassan M.L.: (2003). J. Appl. Polym. Sci., 89, (2950). Nada, A.M.A. , EI-Saied H., Fadl M. and Nassar M.: (1994a). Polym. Degrad. Stab., ‎43, (55- 67). ‎Nada, A.M.A., Fahmy Y. and Abou-Yousef H.E.: (1994b). Polym. Degrad. Stab., 46, ‎(293- 302). Nada, A.M.A., Yousef M.A., Shafie Kh. and Salah A.: (2000b). Pigments & Resin Technol., 29, (337-348). Nada, A.M.A., (1999). Ibrahem, A.A .. Fahmy Y. and Abou-Yousef, H.E., J. Ind.‎Res., 58, (620-628). Nada, A.M.A., Ibrahem,A.A., Saied, M.S.and Mohamed, H.T.: (1990). Cellul.Chem.‎Tcchnal 24(4) 22. Nguyen Chi Thanh M.A., (15-16 December, 2005). Regional Polymer Banknote Symposium Hanoi, Vietnam. Peter Eu. Ben Chiew. Stane Straus. World Polymer Banknotes, 2nd Edition (2007). Peter J. T., Polymer Pioneers: A Popular History of the Science and Technology of Large Molecules. Chemical Heritage Foundation. p. 76. ISBN 0941901033.

188 Pope’ IW, Ender PT, Woelk WK., Koroscil MA, Koroscil TM. (2002). Bacterial Contamination Paper Currency. Southern‎ Medical Journal 95(12): (1408-1410). Ragauskas, A.J.; K.M. Poll and A.J. Cesternino (April 1993). “Effect of Xylanase Pretreatment Procedures for Nonchlorine Bleaching” (PDF). IPST Technical Paper Series,Institute of Paper Science Atlanta, Georgia and Technology NUMBER 482. http:// smartech.gatech.-edu/bitstream/1853/2037/1/tps-482.pdf. Retrieved on 2007-09-20. Reddy, B.S. and Bhatt, S. (1981) :Holzforsch. Holzverwert, 33, no. 6, (110- 114). Rydholm, S.: (1965). ’’Pulping Process’’, First Published, John Wiely & Sons, New York. Saad,M.S.,Nada,A.M.A.,Ibrahcm,A.A and Mohamed H.T. (1988). Holz Forschung, ‎(42-67). Sayner N. and Laundrie J.F.: (1964). Tappi. 10 (47) 640. Sefain M.Z., and El- Saied H., (1984). Thermochemica acta 74 (201-206). ‎Sefain M. Z.and Nada A.M.A., (1984). Thermochemica Acta 78 (211-218). Siddique S. (2003). ‘Dirty Money:’ You’re Carrying More Than Cash in Your Wallet’. Philippine Headline News Online. Available: http:// www.newsflash.org/2003/. Sillanpää M. (2005). (Thesis). Studies on Washing in Kraft Pulp Bleaching. Faculty of Technology University of Oulu, Finland. http:// herkules.oulu.fi/isbn9514278771/isbn9514278771.pdf. Retrieved on 2007-09-19. Singh, R.P. (1979). The Bleaching of Pulp, 3rd ed.. Atlanta: TAPPI Press. Sjöström E., (1993). Wood Chemistry: Fundamentals and Applications. Academic Press. ISBN 012647480X. OCLC 58509724. Song F., Hannant M. D., Cannon R. D., Bochmann M. Macromol. Symp. (2004), 213,(173-185).

189 Springer, E.L. (December 1997). “Delignification of Wood and Kraft Pulp with Peroxymonophosphoric Acid”. Journal of Pulp and Paper Science 23 (12): (582–584). Starnes, W.H. (1991). Chemistry of Delignification with Oxygen, Ozone and Peroxides. Ann Arbor, MI: UMI Out-of-print Books on Demand. Sϋss H. and Heiming O.: (1986). Das Papier, 40(6), (258-263). Sϋss, H.U.; N.F. Nimmerfroh (1993). Peroxide Bleaching _ Technology Review“. Workshop on Emerging Pulping and Chlorine-Free Bleaching Technologies. (80–187). Tang W.K.. (1967). US Forest Serv. Res. Fpl. (71). ‎Teder A. and Olm L.: (1981). Paperi Je Puu, 63(4), .3 15. Teodorovic M. , Majdanac Lj. , Cosic D. and Nesovic V. (1992). Journal of Thermal Analysis and Calorimatry, 38, No 4. ‎Timell T.E.: (1967). Wood Science and Technology, 1, (45-70). Timell T.E., J .Amer. (1960). Chem. Soc.82, (5211). TUV Rheinland, Sicherheit und Umweltschutz (2005). Urbanowski, A. (1996). Chemical Fiber International, 46, (260-262). UNI FA D, (1973). Guide for Planning and Paper Enterprises, Rome. USAF, (Nov. 2002). Flying Magazine Safety. Ullmanns Encyclopidia of industrial Chemistry. (1991). Vol.18. VCH Verlagsgesell-schaft, mblin.D-6940 Weinheim. Vroom K.E.: (1957). Pulp Pap. Mag. C, 58, (228). Wilder H.D. and Daleski E. J.: (1965). Tappi. 48(5). (293). ‎Wilson GS, Miles AA. (1957). "Topley and Wilson’s Principles of Bacteriology and Immunity", vol. 1. London: Edward Arnold Ltd. pp 699 - 777. Winandy.J.E. and Morrell J. J.: (1993). Relationship Between Incipient Decay, ‎Strength. and Chemical Composition of Douglas-Fir Heartwood. Wood and Fiber Science, 25(3), (278-288).

190 ‎Wise L.E., Murphy M. and Addieco A.A.D.: (1 946 ). Paper Trade J., 122(1), 35. ‎Yalpani M.: (1985). Tetrahedron, 41, 2957. “Use of Ozone from Web Page by Air Liquide”. http://www.ca.airliquide.com/en/business/ industry/pulp_paper/applications/ozone_bleaching.asp. Retrieved on 2007-09-19. http:// www.rba.com.au http://www.en.wikipedia.org/wiki/polymerbanknote. http://www.en.wikipedia.org/wiki/polypropylene. http://www.chemistry.wustl.edu/~edudev/Designer/session6.ht ml. http://www.newscientist.com/article/mg19426014.900-this-week-50-years- ago.html. http://www.fibersource.com/f-tutor/olefin.htm Rug fibers http://peosoldier.army.mil/factsheets/SEQ_CIE_ECWCS.pdf ECWCS Gen. III http://www.lehighgroup.com/fiber.htm Rope Materials http://www.paperonweb.com/paperpro.htm#Brightness. www.IPCA.au.com/ February 2005. www.IPCA.au.com/ November 2007. www.IPCA.au.com/ February 2008. www.IPCA.au.com/ January 2009. www.IPCA.au.com/ May 2009. www.banxico.org.mx. http://www.rbnz.govt.nz/. http://www.pqcorp.com/applications / Pulp and Paper application .asp#topic01. http://www.ca.airliquide.com/en/business/industry/pulp_paper/applica- tions /ozone_bleaching.asp).

191 http://www.industrialcenter.org/GasIRPaper/Learn%20About/Paper_ Manufacture.htm) http://en.wikipedia.org/wiki/ Resin_ identification code. http://www.en.wikipedia.org/wiki/polypropylene. http://www.en.wikipedia.org/wiki/poly-propylene. http:// www.securency.com.au http://www.indigoimage. com/count/feat2.html

192