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Historical Perspective and Evolution

CHAPTER MENU

Introduction, 3 Survey of Packaging Use, 9

Abstract

This chapter covers a brief chronology of the development of packaging materials and types of packaging through time. The chapter goes on to survey packaging use in terms of k containment or collation of units. Following on from this is the fundamental classification of k packaging and its role in terms of providing information. The chapter then moves on to a brief description of the various types and subtypes of packaging materials.

Keywords use; application; marketing; benefits; classification; identity; novel materials

1.1 Introduction

1.1.1 The Chronology of Packaging Development

The use of packaging is often thought of as an industrial-age concept but this is entirely untrue. In more ancient times products of economic or nutritional value were always wrapped in a suitable material to convey the need to protect the contents. The Roman emperors and Byzantine kings frequently wrapped precious goods in all manner of materials from wovenCOPYRIGHTED rattan baskets to carved and MATERIAL gilded in-laid ebony . Expen- sive luxury goods such as chalices and ceremonial goods are almost always stored in a suitable presentation that demonstrates the value of the product contained within. Perfumes, chrism oils, and ceremonial jewellery have always been contained in sculpted and carved lidded boxes and glazed pottery. However, the use of bespoke packaging is really a modern-age phenomenon. Packaging use began with leaves and birch bark and other natural materials. In antiquity and prehistoric times humans wrapped their foods in crudely fashioned carriers and containers and also pelts and hides. The mass production of containers later involved woven materials (e.g. rushes and reeds) to create baskets

Packaging Technology and Engineering: Pharmaceutical, Medical and Food Applications, First Edition. Dipak K. Sarker. © 2020 John Wiley & Sons Ltd. Published 2020 by John Wiley & Sons Ltd.

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and carriers and also textiles, pottery, and bronze and carved objects (e.g. ivory, antler horn, and wood). Recent estimates place ‘crude ’ or vitrified materials and wood packaging use to at least 3000 BCE and these artefacts come from the Indus Valley civilisations and Mesopotamia. In the modern era, that is, since the early 1900s, and cardboard have become extremely important packaging materials. Following the invention of , the emerg- ing industries making commercial packaging substituted for paper as a primary packaging material. Many modern environmentalists hanker back to the times of the English Georgian and Victorian periods when forms of waxed paper were commonly used to wrap foods, such as cheese, butter, or meat, and pharmaceutical products, such as dried forms of poultices, pills (comprimés), and lozenges or oral dosage forms. A revolutionary step in packaging occurred in 1810 when Peter Durand, a British merchant, obtained a patent (UK no. 3372) for the first metal can. This can was for preservation packaging made from sheet metal to create a ‘cylindrical canister’. The actual invention of the ‘tin can’ is put down to Philippe de Girard of France, from whence the idea was taken up by Peter Durand. The idea of using hermetically sealed ‘’ containers, based on ab initio food preservation work in glass containers, had been proposed initially by the inventor Nicolas Appert in 1809. Appert’s outstanding work, looking at increasing the nutritional and microbiological safety of foods, pioneered sterilisation technology and glass preservation. Durand went on in 1812 to sell his patent to two entrepreneurs, Bryan Donkin and John Hall, who refined the process and product. Donkin and Hall k established the world’s first commercial canning factory in Southwark Park Road, London, k UK. Unfortunately, the earliest tin cans were sealed by soldering based on a tin–lead alloy. A cumulative poisoning causing persistent ingestion did occur after a period owing to the toxic nature of the lead in the solder, which was particularly enhanced when the contents of the can were mildly acidic. As a result, a double-seamed three-piece can began to be used from 1900. In later times the lead-based solder was replaced with arc welding of the sheet ‘tinplate’. Tinplate became widely popular as it represented a stable, long-lasting, and impenetra- ble means of packaging for foods. The choice of packaging used conveys information as to the value of the product. For example, since approximately 2015 (and unchanged as of 2019), and depending on the source, glass is valued at US$0.1–0.6/kg (recovered glass US$0.02/kg), aluminium is valued at US$2–4/kg, tinplate is valued at US$0.7–1.1/kg, and higher grade is valued at US$0.3–0.6/kg; these contrast with most routine poly- olefins (cheaper plastics, such as [PP] and [PE]), which are valued at US$0.1–0.5/kg. Therefore, choosing glass, which is dense (2.5–3.4 times that of paper and plastic), with a prerequisite for a greater than 0.2 cm wall thickness for strength, in the modern era suggests a high-value content since glass is both expensive and heavy and, therefore, has associated increased shipping costs. For many premium products the additional cost may be deflected by the large cost of the contents. For example, the costof a can of green beans versus the cost of a bottle of champagne. In the former the can cost is approximately £0.02–0.05, whereas in the latter the bottle cost is approximately £0.50–1.00; this is because in the latter the contents cost at least 500 times more. A series of different types of pharmaceutical packaging from across a 100 year period are shown in Figure 1.1. Amber glassware represents about 30% of medicine . Modern

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1.1 Introduction 5

(a) (b)

(c)

(d) (e)

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Figure 1.1 Packaging of the past.

medicine bottles are often fabricated from tinted to mimic the old-style amber glass bottles. A blue-tinted bottle is shown in the insert in Figure 1.1a. Other forms of bot- tles, such as frosted or tinted vessels, were also used across products in the past; in modern times, these are used to aid product promotion. Figure 1.1b shows all-aluminium screw-top medicine cans that were used in the past but are used much less in the modern era. These have been superseded in many respects by the push-out or ‘’ form of medicines. Figure 1.1c shows a very old cork-topped bottle and a Victorian–Edwardian steel for pills, which are practically never seen in the modern era, except for marketing promotions. Figure 1.1 shows a range of mid-twentieth century, Edwardian, Victorian, and earlier pack- aging materials used for medicines. The containers cover green chromium glass, iron oxide amber glass, flint glass, and other common forms seen more routinely today, such aspaper- board and aluminium closures. The ‘earthenware’ pottery vessel used in the past for medicine, milk, beer, and oil is rarely used in contemporary society but does find a place in speciality products as a marketing tool used to infer tradition and antiquity. Looking care- fully at the range of packaging and comparing it with that seen customarily in pharmacies, artisanal, ‘24 hour’, and mini-mart shops and supermarkets used mostly today there is a stark contrast and difference in Figure 1.1 by virtue of the absence of plastic packaging in the period before 1950 [1].

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1.1.2 The Origins of Commercial Packaging

Andreas Bernhardt began wrapping products in paper and waxed paper for water retention stamped with his name and identification in Germany in 1551. Packaging uses and require- ments have changed a lot in the modern era and most spectacularly over the last 150 or so years of purpose-crafted commercial containment. The diversity of past packaging can be seen in Figure 1.1, with examples of flint, amber, green, and blue glass pharmaceutical sam- ple bottles and a range of aluminium cans, paper, card, and pottery primary and secondary packaging. Some of the samples in Figure 1.1 date from the 1960s and 1970s but others date back to the Victorian and Edwardian periods (1870s–1900s). The sometimes perceived as ‘modern-era’ plastics industry actually started with John Wesley Hyatt, who invented mod- ified cellulose in 1869, and, Leo Hendrik Baekeland, who invented resinous early plastic in 1907 in the USA. Other product examples include the ubiquitous tobacco snuff box (Man- der Brothers) of the 1800s, the Beechams pills (UK) of the Victorian era in the 1840s, and the Lyons loose tea can (Ireland) and Laymon’s aspirin tin (USA) of the Edwardian era in the 1900s. The more familiar forms of plastic containment that first appeared in the 1950s–1970s include the detergent and – the now infamous – mass-produced carbonated drinks polyethylene terephthalate (PET) bottle. The tin can means of excluding air, light, and water for tea leaves is still used by many companies such as Jin Jun Mei (China), Whit- tard (UK), Tafelgut (Germany), and Twinings (UK), as part of a value-adding marketing tool and for protection of delicate flavours and volatile oils. The sea-change position of theuseof tin-plated steel (tinplate) and the tin can as a standard form of packaging will be discussed k k in Chapter 3.

1.1.3 Closures, Films, and Plastics

Rubber used in sealings and liddings became a mainstay of commercial packaging when, in 1849, Charles Goodyear and Thomas Hancock developed a method that destroyed the ‘tacky–sticky’ property of the material and added extra elasticity to natural rubber. In 1851 hard rubber, often referred to as ebonite, became commercially available in the Western world. A completely new revolutionary form of packaging was created in the invention of plastic. The innovative original artificial plastic was created by Alexander Parker in 1838 and was displayed at the Grand International Fair in London in 1862. This ‘parkesin’ rigid ‘resin’ was thought to be able to replace natural materials such as hardwoods and ivory. In 1892 William Painter patented the still ubiquitously used ‘crown cap’ (see Figure 3.3c) for bottles shaped from glass [1], which kept air (containing degrading oxygen) out and product flavours locked in. Also, in 1870 Hyatt took out a patent for ‘celluloid’ produced from cellulose in highly controlled conditions, under high pressure and temperatures. This created a polymer with low nitrate content for many different types of product wrappings. This discovery is now thought of as the first commercialised plastic and remained the only ‘plastic’ until 1907, when Baekeland produced ‘Bakelite’ (also spelt as Baekelite). Bakelite was universally used until the 1970s but was replaced by a new wave of plastics. A more exact understanding of plastics arose in 1920, when Hermann Staudinger’s revolutionary idea was extolled and the notion of a plastic as a physical property rather than a chemical class came into fruition. All plastics, rubber, and cellulose are polymers or macromolecules

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1.1 Introduction 7

but notably some do not show significant plasticity or deformability without brittle rupture. Staudinger’s pioneering work concerning ‘polymer science’ was awarded the Nobel Prize in 1953.

1.1.4 Major Types of Packaging

Plastic packaging had begun to be used widely across the globe after the 1950s and this has led to the present ‘mountains’ of undegraded waste that are still added to. Polyvinylidene chloride, or Saran , was first used as a moisture barrier in 1946. In 1960 the two-piece drawn and wall-ironed® (DWI) can was developed and in 1967 the ring-pull opening was invented. Towards the end of the 1970s the plastic packaging sector had begun to grow, with the blow-moulded PET bottle invented by DuPont. It was not until after the Second World War that general use of plastics in packaging applications started at a significant level. PE was mass produced during this period in Europe and became an easily obtained material from the late 1940s. At the beginning of this period it was a substitute for the wax paper used in bread packaging and still observed until the 1980s. The growth in plastic packag- ing use has accelerated at an astonishing pace since the 1970s. The technology available today and the requirements for a non-perishable nature mean that many previously used materials (e.g. waxed paper) have been replaced by more suitable and economically viable materials such as glass, metal, plastic, paper, and cardboard. Before the 1950s packaging was essentially only used to protect the product during transport and storage. However, k with the plethora of newer materials it has also begun to be used to advertise the prod- k uct with the form, colour, , including fonts, and logos being a major part of the marketing process. This is simply because form-differentiated packaging creates a distinc- tion between the same types of products placed side by side on outlet shelves. The modern practice of favouring plastic as the packaging material of choice is, however, not without sig- nificant environmental concerns, with some amount greater than 15 million tonnes being present in the seas in 2017 and possibly as much as 30 million tonnes in 2019 according to recent estimates. The USA and Western European countries in 2000 consumed about 24% each of the world’s plastics. Plastics such as PP are thought (based on chemical mod- elling and accelerated ageing study tests) to be able to persist in landfill for approximately 500 years. Single-use plastics, which are discarded after one use (incinerated or sent for landfill), accounted for approximately 50% of all plastic packaging in2019. Glass-based packaging is a form of packaging that has stood the test of time. This type of packaging first began to be used around 1500 BCE by artisans in Egypt. Glass, an amor- phous silicate matrix, was first used in the form of a pot or vessel. Its fabrication starts when limestone, soda, sand, and silicates are co-melted and shaped during the fluid phase at a temperature of many hundreds of degrees Celsius and allowed to cool into glass pack- aging. From about 1200 BCE, pots and containers started to be made from moulded glass on a semi-commercial basis. Completely transparent glass was invented in the centuries fol- lowing the development of reproducible blowing and with the aid of a ‘drawing pipe’ by the Phoenicians in 300 BCE. During the two millennia that followed, the development of clear (flint) glass, via augmented techniques, has been incrementally improved and expanded to all manner of products. To date, the development of the automated rotary glass-manufacturing machine in 1889 affected industrial-scale glass manufacturing and,

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therefore, packaging the most of any of these innovations. Surprisingly, given its cost, after the 1970s glass packaging began to be used ubiquitously for the protection of high- and low-value products and to aid the visibility of pack contents. It continues to demonstrate a wide variety of uses today and remains a form of packaging that can be recycled; in the modern era this is an important consideration. Metal packaging, used in antiquity in the form of gold, silver, and pewter boxes as well as strong alloys such as bronze and brass for coverings and to protect many products, is find- ing new uses in modern packaging technology. Tin – an essential part of tin-plated steel, the basis of almost all food cans – became a viable surface treatment following the production of tin in sheet form in Bohemia from 1200. Later, at the beginning of the 1300s, metal cans were first used to store food. These cans were different from those of the modern erabut remained an unwritten ‘secret’ until the 1600s. William Underwood aided in the further development of the food can by the development of an improved process for fabricating steel plate. The notions of food cans and of canning were pushed to the forefront of pub- lic awareness in 1809 when Napoleon Bonaparte offered a reward of 12 000 French Francs (∼£1000), a huge prize in that period, to any inventor who could develop a method to protect army food supplies during envisioned military excursions and campaigns. The opportunity was seized by Nicolas Appert, a confectioner from Paris (portrayed in Figure 6.4), who pre- sented a selection of pasteurised lidded glass , following on from initial investigations. He found that a steel can covered with a fine layer of tin was able to preserve food post heat- ing in an aseptic process and without the can rusting in the damp. A year later k Englishman Peter Durand patented the familiar-shaped cylindrical can with his coated tin- k plate as an invention. This development spawned a host of subsequent modifications and adaptations. The first printed box was made in the USA in 1866 but went on to be usedfor containment of many types of product. Fast-forwarding to 1910, the tin box was found in commercial environments ubiquitously until the point when aluminium in a suitable form became available. The box was developed in the early part of 1950, and in 1959 the first aluminium can-based food became available. In the nineteenth century sharp objects combined with hammers were used to open metal packaging and tin cans, which was a highly unsatisfactory state of affairs. Later on and at least until the middle of the twentieth century, the ‘pig-stick’ tin can opener – a brutal spear-looking object, based on a steel spike and sliding blade – was used to open food prod- ucts. The routine use of the pig-stick device and the sharp serrated edge it created resulted in many hand injuries. The pivoting can opener was developed by E.J. Warner in 1858, fol- lowed by the ‘church key’ of 1892. The pivoting can opener was improved on in 1925 by the Star Can Opener Company, and yet further improved in the now familiar pliers-form Bunker-type modern can opener first developed in 1931 by the Bunker Clancy Company. Electric can openers were developed in the late 1950s and the side can opener was devel- oped in the 1980s. Packaging with tear-open was first developed in 1966 and has become increasingly evident in use over the last five decades. Paper, which is still used universally in the present times, is the oldest conveniently reshaped packaging material available. In ancient Egypt in 5000 BCE, papyrus – a material based on marsh reeds – was used to wrap foods and hold objects together. Many millennia later in China, mulberry tree bark, reconstituted as paper, was used in the first and second centuries BCE to pack food. Paper-making methodologies and techniques improved during

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1.2 Survey of Packaging Use 9

the subsequent 15 centuries. These high-quality and products and technological know-how were then transferred to the Middle East. From there paper-making techniques reached Europe, and then from Western Europe they reached England in 1310 and subsequently America in 1609. In 1817 the first commercial cardboard box was produced in England, almost 200 years after being made in a basic and simplistic form in China. The corrugated form of cardboard was invented in the 1850s, gradually replacing wooden boxes in the trade and transportation of goods such as fruit to the point at which, today wooden boxes are barely seen for food products. Selected examples of continuing or use do persist but these are relatively rare. The twentieth century has been the most prominent period for universal paper and cardboard use with the added advantage of recyclability and biodegradability. This is an important consideration since, in the UK in 2013 alone, approximately 750 000 tonnes of household waste, rich in plastic and paperboard materials, went for landfill disposal.

1.2 Survey of Packaging Use

Consumers demand convenience from their packaging, so packages can have features that add convenience in distribution, handling, stacking, display, sale, opening, reclosing, use, and reuse. Packaging materials are used for a host of commercial product-containment purposes. These traverse informatics and IT, such as CD or USB stick packaging, through k to the diverse range of degradable (e.g. cooked meat) and non-degradable (e.g. retorted k canned fish) foods and also the protective and containing roles of packaging usedfor over-the-counter and prescription-only medicines, surgical aids, or emergency medicines, and to safeguard the consumer against accidental consumption or contamination. Every- thing from furniture to garden centre compost and on to mobile phone devices is enveloped in an informative and protective sheath of packaging. In this book, topics centre on foods, medicines, and medical devices but these still account for only approximately 45–50% of global packaging use. Packaging accounts for about one-third of the use of all polymeric materials and is by far the single biggest use of the materials. Medicine bottles and closures alone, for example, account for about one-third of pharmaceutical packaging use. A definition of the meaning of packaging indicates that packaging fulfils at least fiveroles. The first of these is the socioeconomic role of packaging; since the packaging hasavalue of its own this is not simply attributable to the contents being of significant value. Conse- quently, a good definition suggests that packaging is a precious material that protects the product within, allows the product to reach the customer in the most hygienic and safest form, and makes it easier to transport and store the product after delivery. The socioeco- nomic influences on packaging form are technological, political, sociocultural, availability (being at hand), ecological, economic, and demographic. Packaging has often been referred to as originating as a consequence of these socioeconomic influences, as the ‘silent sales- man’, and both has managed to enter the commercial sphere and is used as a vehicle in the marketing arena in the form of the ‘8P’s’ or ‘holy octet’ concept. The holy octet involves the product itself as well as aspects of pricing, placement, promotion, participant involvement, physical form, process of use, and finally a notion of personal targeting, all obtained from the idea of a malleable marketing mix to appeal to the customer [2]. The other four criteria

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that define packaging cover the basic functions of any packaging, which can be effectively summarised as relating to the provision of a description (information, salesmanship, and promotion) of the product, very important containment, equally important protection for storage capability, and the ability to be successfully transported or shipped across the globe. The reasons for adherence to packaging use are manifold but are based on the ability of the materials to reduce wastage and, in doing so, because of scarcity or perishable status, reduce the product cost. A crude estimate suggests that 30–50% of ‘thrown food’ and medic- inal products are disposed of because of inadequate storage; therefore, extending by a means that requires passive storage without energy consumption consequently saves energy (need for freezing/refrigeration/cooling). The pack itself also has a very important mechanical role in that it reduces damage while presenting the product in an aesthetically pleasing form. For a number of products that require a guarantee of microbial security, the pack also serves as a means to avoid pack tampering (see Chapter 8). At the same time the pack must provide information (safety, nutrition, dosage strength, mode of operation) to the customer and, therefore, aid selection or choice-making. When well designed, a pack- age can provide convenience, as in the case of ring-pull or easy-opening closures, and may in the presentation of an easily recognisable form aid the marketing of goods. However, the complexity and sheer number of layers of packaging in composite materials combined with the non-biodegradable nature of some forms of packaging (plastic, laminated paper, glass) have contributed enormously to concerns raised over packaging persistence in the envi- ronment, unsightly littering, and global pollution. These then lead to angst over after-use, k disposal in terms of the cost, and the extent of ‘effective’ disposal or energy recovery. These k more negative aspects have led to a perception of overpackaging among the general public for products such as oven-ready foods and pharmaceutical packages. An often misunderstood but very obvious purpose of packaging is its use in marketing and recognition, through which, by application of careful tactical and market opportunity surveillance, a specific design that means market-leading capability can be crafted. Brand- ing and brand identity have very powerful roles in marketing of the product (food, medicine, device) and an assurance to engage the customer. Where this is not done successfully, the best an organisation can hope for is simply market-leader following. Consequently, all suc- cessful design considerations take into account product uniqueness, distinctiveness, and functionality; without the last a customer purchases the product only once and is discour- aged by the awkwardness of the product. For pharmaceuticals and medical devices pack- aging is a fundamental and key part of current good manufacturing practice (cGMP) and also part of good distribution practice (GDP); cGMP and GDP are enshrined in the interna- tional standard British Standard (BS)-European Norm (EN)-International Organization for Standardization (ISO) 9001:2008 and are intimately associated with the assurance of quality and, by implication, safety. The stringent requirements of packaging serve to ‘protect and inform’ the recipient with the provision of important information, such as dosing and dosage strength, adverse effects, and allergenicity, reinforced by the legal aspects ofcom- mercial activity. The form of the pack and its performance, such as ease of bottle opening or ease of dispensing of a tablet from a push-out pack or blister pack, need to be consis- tent with mass manufacture and distribution, but this is not achieved without appropriate production testing and the associated higher cost of producing consistently high quality.

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1.2 Survey of Packaging Use 11

Role of packaging

Technological

Legal and political Social and cultural

Economic

Easily sourced Demographic

Environmental

Figure 1.2 Survey of packaging use: the needs fulfilled by packaging.

Figure 1.2 shows that the role of packaging is associated with a cluster of needs. The k packaging needs include technological requirements that fit societal or speciality require- k ments, such as multiple opening and resealing. Legal requirements and political compli- ance include wastage and guidelines; social and cultural requirements are also important, often mapping to creeds and cultures such as halal or kosher foods (and the guarantee of freedom from animal-derived materials, e.g. gelatin or dairy produce). Fur- ther needs for most packaging also involve cost minimisation, which is linked to finan- cial accessibility and economic drivers [3], and ubiquitously sourced materials with no restrictions on availability. Demographic requirements, which might include easy access or restriction-to-access packaging for the elderly and infants, often define the needs for some high-risk products. Finally, and of increasingly important decision-informing status, concerns about environmental impact, issues covering material sustainability, and efforts to recycle and reuse without impact on the anthrosphere, geosphere, or biosphere have a powerful role in product engineering and composition. All these needs amalgamate to dic- tate the overall requirements placed on packaging materials and their routine use in the commercial sector. Central to the use of various types of packaging are the pivotal notions of their role (pri- mary, secondary, and tertiary) and what type of environment might be appropriate for the packaging (Figure 1.2). For example, plastic may be the best first choice but then, given the informing nature of the container, use of printed paperboard may present the best financial choice. The selection of packaging use is modelled against maintenance of standards, con- veyance of identity, mechanical strength, product quality (both required and obtainable), and the purity required of the contained goods (particularly true of medicines). A good pack, therefore, needs to provide full information, be familiar or instantly recognisable, be

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based on a design for frequent or intermittent use (as required), and demonstrate suitabil- ity for its intended use. Additionally, where portioning of the product is required, such as multi-vitamins, infant formula, dietary or meal replacements, or traditional pharmaceuti- cals, careful control of doses leads to medical and therapeutic compliance. Marketing and identity, aligned with matching product trends in pack volume, size, and form, are often indicators of product success. Because of the nature of the commercial sector packages need to be able to conform to high-output manufacturing but also need some thought embedded in the design as a ‘superior’ quality product can have an associated cost. Reliable packaging universally prevents water and humidity breach and demonstrates mechanical resistance (shock, strength), chemical resistance (absorption; corrosion; air and gas exclusion; chem- ical, sterilant, or pH resistivity), microbial resistance, ease of handling, ease of repeated processing, and light exclusion. Regulation adherence of the materials used and framed pragmatically within the commercial goals of high-numbered product sales must consider materials, product manufacture, and logistical cost – this usually means the pack should be lightweight, easily packed, and yet physically robust. The unit cost of the product given its manufacturing and shipping costs gives rise to the idea of lean manufacturing and cost trim- ming, some of which might arise from contact with a regular supplier and specific business approaches, such as just-in-time manufacturing. In order to satisfy the requirements of intimate contact with the contents, all pack- aging should ideally be chemically inert, unreactive, non-additive, non-absorptive, and, therefore, does not add to or corrupt the pack contents. Additionally, the package is k required by the manufacturer and customer alike to offer protection against deterioration k and contamination during handling and transport. Storage and transport conditions are likely to vary considerably and will include alterations in freezer conditions, cold-room conditions, and ambient or room temperature handling. Strict control of the physical and spatial separation of packs is needed during storage as this may encourage temperature and pressure gradients in the pack, possibly leading to weaknesses, pinholes, tears, and cracks. A regular part of the development of commercial products will, therefore, consist of inspections, history-marking steps, label scrutiny, sampling procedures, establishment of non-conformance or rejection criteria, record-keeping for shipments, and product security during transportation and the distribution chain. As a ‘protector’ of the product within, the packaging has a key role in resisting physical impacts, such as is seen with perishables in the squashing, wetting, and bruising of shipped fruit. Packaging, therefore, allows for the product to reach the consumer in the most economical and ideal way possible despite the transit time and variable conditions experienced during shipment and storage. As a result of modern societal changes, including changes in family dynamics and time spent in traditional activities, such as cooking, there have been a number of changes required for commercial products, such as foods. Highly packaged goods are often preferred in modern times because people have less time to pursue ‘traditional’ preparatory activities in the household and there is a higher need for convenience but with the guarantee of safety and hygiene. Consequently, packaging consumption is higher in developed than in developing countries, the latter of which in turn consume more packaging than underdeveloped countries. This must be balanced against sociopolitical notions, such as global warming (from incineration and refining), recycling, and environmental pollution, which are more evident and higher on the political agenda in the developed world.

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1.2 Survey of Packaging Use 13

1.2.1 Primary, Secondary, and Tertiary Packaging

Packaging type is classified into three rather subjective categories based entirely on their areas of use. Primary packaging (cf. sales packaging) is defined as the packaging that sur- rounds the product when sold to and received by the final consumer. In essence, it includes the packaging material substance or product that is in direct contact with the fill prod- uct and the other packaging components (i.e. , instructions). Secondary packaging, also referred to as group or grouping packaging, is packaging used to collate or hold together the primary packaging or units being sold and is used for ease of transportation. In modern times of global trade this can involve shipments back and forth across the globe. This pro- cess is undertaken by collecting the products together (e.g. a paperboard box holding blister trays of pharmaceutical pills or a corrugated cardboard box holding plastic laminated car- tons of milk). Tertiary packaging is occasionally referred to as transport packaging and is needed to make convenient bundles of secondary packaged goods for mass transport or ultimate delivery of units or secondary packaging; it is used specifically to prevent physical damage that may occur during delivery (e.g. high-density polyethylene [HDPE] skip or pal- let). Recent studies based on damage to all transported foods, estimated at approximately 5–10% of all foods transported, demonstrate the value of primary and secondary packag- ing [4]. The term ‘’ is often used to represent the packaging group consisting of the compounding together of more than one type of packaging for delivery processes and can be exemplified as the unit repackaged with stretch film on the palette. Consumer pack- aging is a term used to describe the packaging of a unit that reaches the final consumer k k from a retail outlet and this represents the received goods that make an impression on the consumer. Identification of materials, such as plastics, that can be reutilised is an important partof the push for improved recycling. The three types of basic packaging – primary, secondary, and tertiary – encompass virtually all forms of containment (Table 1.1), which often how- ever possess different degrees of reusability. Primary packaging has a role in containing and protecting the commodity directly and is generally based on high-purity materials;

Table 1.1 Packaging: contains, protects, preserves, transports, ‘informs’, and ‘sells’.

Types of use/function Risk Example

Primary: protects and directly envelops the drug Could Can, pouch, (pharmacy shelf or home) compromise and blister, , contaminate the bottle, or product Secondary: protects the packaging that protects Misleading Carton or box the drug (for warehousing); used to group information on primary packages together the pack Tertiary: protects the secondary packaging. , hopper, Purpose: bulk handling, warehouse storage, and skip, or transport shipping. The most common form is a over-wrap palletised unit load that packs tightly into shipping/haulage containers

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secondary packaging protects the integrity of the primary; and tertiary protects the sec- ondary packaging and permits shipping and transportation of the primary and secondary products within the tertiary packaging. Consequently, secondary and tertiary packaging need lower levels of material purity and, therefore, may be more open to incorporation of recycled material. Occasionally, primary and secondary packaging are combined but they may also not have the same physical presence, for example shrink-wrap (secondary) cover- ing of a carton (primary); this is often used when the product cannot be easily corrupted by the carton. Primary packaging may be something like a , a bottle, or a blister, which are often not accessible to current recycling practices. Secondary packaging is typified by a carton or a box and tertiary packaging is typified by a carton with an outer wrap. Tertiary packaging is typically a skip, , crate, etc. and represents containers that can make use of mixed aggregated recycled materials. The risk of primary packaging lies in its intimate contact with the product, which could be seen as a risk of product compromise and contam- ination. Typically this could involve the increasing loading of plasticiser or toxic materials in product contact packaging resulting from recycling. Chemical risk is less important in secondary packaging but significant risk arises from misleading information on thepack that could potentially cause injury to the recipient. The international identity code (Table 1.2) ascribed to the recycling of materials used was devised in combination by the bodies concerned with packaging use but fell under the remit of the American Society for the Testing of Materials (ASTM), which encompasses the International Resin Identification Code (RIC); the American National Standards Institute; k and the European Commission (based on decision 97/127/EC – ID System for Packaging k Materials, which is underpinned by council directive 94/62/EC). These bodies and nomen- clature systems together have helped group materials into six usable categories (Table 1.2). The categories of plastics, paper, metals, glass, and the seldom used category ‘organic mate- rials’ in addition to composite materials are now marked on most products to aid recycling and clarify chemical make-up. The codes range from 01 for PET plastic, 22 for paper, 41 for aluminium, and 79 for glass through to 80 and higher numbers for composite or mixed materials. The table also indicates the main uses of the listed material, which includes, for example, in the case of iron (number 40), its use in aerosol cans, tin-plated cans, lids, and staples but that might also include fittings and hinges in wooden . Indexed labelling of packaging materials in this manner has been hugely valuable and is responsible for much of the improvement in worldwide recycling and local municipality recycling practice.

1.2.2 Types of Packaging: An Overview and the Basics

The primary types of packaging are tinplate, aluminium, plastics, paper and paperboard, glass, and biopolymers but can also extend to wood and wicker or ‘raffia’ materials. The robustness and purity along with costs associated with transport and shipping have a large bearing on selection. Shipping costs are by no means trivial as there is an addi- tional carbon footprint associated with the pollution caused by freighting goods around the globe in addition to the direct paid costs. Division of packaging materials is often performed on a convenient chemical basis; for example, organic and inorganic, natural and artificial/synthetic, porous and solid, or wettable and water repellent. Other suitable

k k

1.2 Survey of Packaging Use 15

classifications might include flexible and rigid, degradable and non-degradable, orrecy- clable and non-recyclable. Yet other relevant definitions could also include the malleability or ductility or the and thermosetting formulation. In reality, most packag- ing materials fit into a number of categories and so the classification is by no means straight- forward. For example, paper is generally porous, malleable, wettable, and both natural and artificial in terms of its processing history. A representation of the complexity involved in any classification and the diversity of firms or organisations, material, size, and contentis given by the vessels shown in Figure 1.1. Packaging used for pharmaceuticals [5, 6], foods [7], and devices has different requirements and yet fulfils the identical overall goal.

Table 1.2 Accepted international identity and recycling codes from the American Society for the Testing of Materials D7611 International Resin Identification Coding system, the recycling symbols of the American National Standards Institute, and the European Commission/Union identification of packaging materials for recycling (94/62/EC and 2008/98/EC).

Numerical Abbreviation Packaging Category code code materials(s) Use

Plastics 01 PET, Polyethylene terephthalate Drinks bottles, PETE trays, fibres 02 HDPE High-density polyethylene Tough bottles, 03 PVC, Polyvinyl chloride Bottles of corrosives k V k 04 LDPE Low-density polyethylene Polythene bags, containers 05 PP Polypropylene Shampoo, syringes 06 PS Cases, Styrofoam 07 OTHER, All other plastics (PC, PA, Bottles, O PAN, SAN, ) biodegradables 08 Reserved for new materials 09 ABS Acrylonitrile– Tough coverings, butadiene–styrene cases Paper 20 C PAP, Cardboard Secondary PCB packaging 21 PAP Other paper Leaflets 22 PAP Paper 23 PBD Paperboard Boxes Metal 40 FE Steel (low-carbon iron) Aerosol cans, tin-plated steel, lids, staples 41 ALU Aluminium Cans, closures, tubes Organic 50 FOR Wood Crates, , mate- boxes rial (Continued)

k k

16 1 Historical Perspective and Evolution

Table 1.2 (Continued)

Numerical Abbreviation Packaging Category code code materials(s) Use

51 FOR Cork Bottle stoppers 60 COT Cotton Insulation 61 TEX Jute, hemp Sacks, packing 62–69 TEX Other textiles Glass 70 GLS Mixed glass, multi-part glass Glass bottles, food, medicines 71 GLS Clear glass 72 GLS Green (chrome oxide) glass 73 GLS Dark sort glass 74 GLS Light sort glass 77–79 GLS Metal-backed glass (Cu, Ag, Au, respectively) Composites 81 Ca Mixed media: paper/plastic Chilled grocery, drinks cartons 82 Ca Paper and fibreboard with Pack liners aluminium k 90–92 Ca Plastic and metals Retortable pouches k 95–98 Ca Glass and metals Reinforced glass 99 Ca Other

a) LDPE, LD polyethylene; PA, polyamide; PAN, polyacrylonitrile; PAP, paper; PC, polycarbonate; PET, polyethylene terephthalate; SAN, styrene–acrylonitrile. Numerical and abbreviation codes are also shown in Figure 8.2a(iv).

1.2.2.1 The Meaning of Symbols on Packaging A single cyclical arrow ( ), a circle based on an arrowed ‘ying-yang’ symbol ( ) found on the product packaging, and the more common centre-filled codified three-arrowed uni- versal recycling symbol ( ) represent an assurance that the producer of that packaging recognises the potential for the material to be reused or reworked (see Table 8.2 and Figure 8.1). The colour, exact form, and size of this triangular symbol ( )aswellasthe colour of the background may vary according to the packaging. The meaning of the sym- bols is given in Table 1.2. The symbols were initially used by the Society of the Plastics Industry (SPI) of the USA (founded in 1937) until it ceased activities under this name in 2010, when the body was renamed. The organisation was rebranded in 2016 as the Plas- tics Industry Association (PIA) and now sits as the authority on plastic materials, pro- moting the use of the eight ‘plastics’ symbols that have been adopted globally to aid recy- cling and recyclability. The RIC and international packaging material codes highlight that the packaging product is made from materials that can be recycled or indicate that any recycling of this material is not available at present. Recyclable plastics with RIC codes

k k

1.2 Survey of Packaging Use 17

of 1/2/4/5 (mostly polyolefins) are habitually recycled. However, plastics assigned 3/6/7 are rarely recycled, possibly because of the evolution of toxic waste, with category 7 indi- cating the use of a mixed-medium material (other than polymeric materials 1–6), which is currently inaccessible to recycling practices. Other common groupings of materials are 20–39 for paper and cardboard material, 40–49 for metal material, and 70–79 for (Table 1.2). Other information shown on the pack in recent times can include ‘made from recycled …’ or shows the packaging origins by bearing the caption ‘is made in part or in full from recycled material’. Where only part of the material of the product is based on recycled mate- rials this is often indicated in a manner such as ‘label made from’ or ‘core made from’ in the case of white-lined paperboard. Packaging manufacturers or companies that have a code number from the relevant body such as the Department for Environment, Food and Rural Affairs in the UK or the Ministry of Commerce and Industry in India may use thesymbol in the way it is allocated to the product varying by the country holding the licence. Some products also bear on the pack or on the label an indication of other properties of the con- tents. These can include pictorial indications if the product contains flammable products such as butane, contains pressurised gas, contains toxic products ( ), or may cause infection or irritation. The product packaging also indicates if it is made from compostable materi- als and therefore is a recognised compostable product, such as the compressed paper egg boxes used in the UK (according to EN 13432). The complex variety of packaging materi- als [8] used for consumable and non-consumable products serves a multitude of functions, k but the primary importance is chemical, microbiological, and physical protection. Current k awareness of packaging use, design, and resource utilisation and ultimately of sustainabil- ity [9–11] is an important issue and one that defines current, and will increasingly define future, use.

1.2.2.2 Glass Packaging Washed sand is the main ingredient needed for the fabrication of most types of glass. How- ever, glassy materials produced using only pure silica result in a glass that is too fragile for commercial handling. Consequently, soda (sodium oxide) is added to increase the durability and simultaneously decrease the melting point temperature, making the product easier to handle. Limestone minerals, such as dolomite (calcium carbonate), are incorporated into the sample to increase the chemical resistance of the glass and confer an inertness to a corrosive product. Secondary additions, such as broken pieces of preformed glass (cullet), are further added to this ‘combination’ during production; this is then heated to approxi- mately 1500 ∘C and shaped into the desired glass packaging. Using broken cullet that has been through certain recycling processes provides technical, environmental, and economic advantages over virgin materials. Glass packaging has a natural gloss and sheen and is smooth and easy to clean or rinse and dry, so it represents a convenient material for many applications. It is also aesthetically pleasing to the eye because it is optically transparent and can be fine-tuned to possess a range of optical properties. Given the high amount of energy required for original manu- facture it is convenient that glasses can be both reused and recycled. Many pharmaceutical

k k

18 1 Historical Perspective and Evolution

and liquor producers prefer the material because of its inertness and non-reactivity to chem- icals but also because of its high gas and water barrier properties, combined with its ability to withstand very high pasteurisation and sterilisation temperatures. The technical proper- ties of glass have also increased as a result of new techniques discovered for cutting, carving, moulding, and surface engraving. Using computer-programmed cutting to form numerous designs, including same strength but lightweight versions of vessels, is now possible. Glass beer bottles account for nearly 55% of glass packaging usage followed by 18% for food, 12% for wine, alcoholic drinks, and liquor, 7% for soft drinks, and others, including pharma- ceuticals, which account for only 5%. In the past stoneware, ceramic vessels, or pottery were used for pharmaceuticals, chemicals of medical use (e.g. opium elixir, Epsom salts, cold cream, quicksilver [mercury]), and foods (honey, beers, spirits, ginger beer). However, stoneware is now used as a value-adding tool and to aid product marketing but there are no current forms of medicines making use of pottery. Part of the downfall of ceramics and their replacement with glass is a result of its lower cost in earlier times, e.g. Victorian and pre-Victorian periods. In recent times, the return of stoneware has been used to infer a traditional basis for the manufacture of products (typically beverages and food) and thus extra value. Stoneware-mimicking glasses have now also been made possible by frosting and compounding or pigmenting of the glass, and these have replaced nearly all food uses of ceramic containers.

1.2.2.3 Metal Packaging k Two materials, namely steel sheeting (or aluminium sheeting) and metallic ends, are k used to make tinplate metal packaging. Higher grade iron, with less carbon, known as steel, forms the scaffold in the form of sheets that are electroplated with metallic tinto prevent oxidation. A further layer of organic or resinous lacquer is applied to the tin-plated steel; therefore, any direct contact of steel with can contents (usually food) is removed. In this manner, corrosion-resistant metal packages can be mass produced. Can bodies and ends are produced for various types of product such as high-acid, low-acid, and high-sulfur-resistant metal packaging. Other than food products, metal packaging is also used for the packaging of pigments, oils, waxes, paints, and chemical materials. The metal packaging forms a physical barrier, which is resistant to pests (insects and rodents) and also to humidity, light, and air. The thermal resistance of lacquered tin or aluminium cans favours sterilisation and is consequently used as a standard form of packaging. This is certainly the case for foods, where use is common because the can and contents can be heated and simultaneously cooled during retort sterilisation without contamination of the contents. In the modern era, the important factors determining the preference of metal packag- ing are related to cost, metal abundance, environmental concerns, health concerns, and payments or levies. These have shaped modern production techniques and advances in the sophistication of manufacturing and handling machines used for various forms of con- tainer and formats of accessing the contents. As such, the development and wide-scale use of easy-to-open lids, various surface designs, high structural robustness, and the tightness of seams assuring sterility are areas of considerable interest among manufacturers. Probably the most common form of making tin cans (tin-plated steel; cans) is the drawn and redrawn process for steel or aluminium cans, with a ubiquitous example being the standard food can.

k k

1.2 Survey of Packaging Use 19

The second most common form of making cans involves a DWI process for aluminium or steel cans, with a common example being the thin-walled soft drink or beer can. Other pro- cesses include the drawn and ironed (DI) steel can; the shaped aluminium or steel can, e.g. the sardine or pilchard can; the stretch-drawn ironed aluminium or steel can (Toyo ULtimate Can; TULC); and the welded side wall tin-plated steel can. However, because of concerns over toxicity and lack of assurance in seam integrity, ‘soldered’ cans are rarely used in modern times. Additionally, combinations of the above forms of canning vessel may be used to create hybrid products. The frequency of use of the tin can as a routine form of preservation over the last 10–15 years for foods and beverages has seen an observable increase of roughly two times.

1.2.2.4 Paper and Cardboard Packaging Paper at first appears to be a simple material but this is an underestimation of a complex polymeric resource that has a colourful and extensive history, with the material undergoing many processing revisions and refinements across the centuries. The first paper was con- structed from woven and intertwined papyrus reeds and this even pre-dates the well-known originators of wood-pulp paper in north-eastern China. The process of making the ‘mod- ern’ form of paper is thought to date back to the Han Dynasty (200 BCE to 200 CE). A Chinese court official, called Ts’ai Lun, in north-eastern China fabricated fine-grade paper sheet- ing by improving on an existing process dating from a century prior to his technological advancement. This paper was fabricated from fine-fibre materials, such as mulberry, and k the bark from nettles, hemp, and flax. The first recorded use of wrapping paper dates back k to 100 BCE with paper made from hemp. The first paper book was dated at 256 CE and by 300 CE paper use was widespread in China and Japan. From about 750 CE paper use was seen to move from China via the ‘silk route’ to the Middle East. At approximately 900 CE paper was found ubiquitously in Egypt with an early form of paper packaging being used for wrapping spices and fruit dating back to 1035. From this point in time, paper use spread to Europe through the Spanish courts in 1085 and then on to the rest of Europe via France. By the late sixteenth century paper production in Europe was well established and there was a more formalised form of paper mill-based production of paper in England, Denmark, the Netherlands, and Russia. In 1844 Friedrich Gottlob Keller and Charles Fenerty began undertaking experiments replacing cotton fabrics and substituting with an exclusive paper made only from wood pulp. Importantly, Henry Fourdrinier, a British engineer, and his brother, Sealy, invented and improved on a prototype of the casting Fourdrinier machine. The paper-making machine changed the process from one of batch fabrication to one where continuous variable sized rolls of paper could be made with ease. The basic raw material for making paper and cardboard packages is the polymer cellu- lose. Cellulose for paper pulp is usually obtained from specific species of trees and plants, which grow quickly, are easily replaced, and allow the material to be easily mechanically or chemically pulped. Favoured species include the cotton plant, which produces fine-grade paper, and cellulose-rich softwood trees, such as larch, pine, and spruce, or hardwoods, such as birch and poplar. Paper pulp may also be used to create cardboard that does not require the fine-grained structure of refined paper. Both paper and paperboard boxes and cartons are among the most cost-effective ways of packaging goods and have the added advan- tage of excellent recyclability. Commercial paper and cardboard for packaging applications

k k

20 1 Historical Perspective and Evolution

require sound puncture or tear resistance and need to offer the pack contents protection from humidity and light. Corrugated cardboards are produced by two flat paper liners bonded to one another by a corrugated layer called fluting. The three or more layers are glued by a material usually made from maize or polymeric water-based . This gluing function provides the material with strength and unity and enables the material to provide cushioned pro- tection of the encased product against impact from the corrugated layer. Secondary pack- aging made of corrugated cardboard is very popular among manufacturers. This is mainly because of the cheapness of these packages but also the low weight to high strength ratio that provides adequate protection [4]. Key performance-indicating test methods for packag- ing include puncture resistance to defy a force that will allow a tool of a specified shape and dimensions to puncture and pass completely through a test specimen. Similar test criteria can be applied to tear and bending deformation and bursting strength resistance along with crush resistance.

1.2.2.5 Wooden Packaging Commercial wooden packaging is a rarely used commodity in modern times. Despite being one of the oldest packaging materials, its use for foods, pharmaceuticals, and medical devices is now virtually non-existent. A combination of weight, fragility, risk of contam- ination during transport or reuse, and durability mean its only use is for luxury goods and some fruit or vegetable shipments. Wood used for packaging material is customarily k treated with pesticides and insecticides to avoid infestation and to protect its contents. k Examples of the persistent use of wood include pallets (for heavy goods), boxes (often for valued products such as tea and coffee), crates (fruit or wine), and (beer, wine,and liquors).

1.2.2.6 Plastic Packaging The plastic packaging used across the globe is made from processing various products from crude oil and gas. However, only about 5% of global oil resources are used in the production of plastic and an astonishing mere 3.5% of this small amount is lavished on the production of plastic packaging. Plastic can be used for both packaging body and closures and, with the aid of designer input with ever less material, to produce even more packaging. As a conse- quence of their ductility, malleability (plasticity), and ease of shaping, ‘plastics’ remain one of the most popular classes of materials for universal packaging needs. Plastic use as a ubiq- uitous packaging material did not start until the 1950s; it gained momentum up to the 1970s and is now globally a matter of prime concern with respect to its ineffective disposal and frequent single use. Acrylonitrile (AN) and its related family of packaging materials are often used when pliability is required. There are many different types of AN-based plastics and synthetic rubbers. Materials in this grouping include acrylonitrile–butadiene–styrene, a terpolymer (three different monomers) with extremely good chemical resistance and flexibility, orthe copolymers styrene–acrylonitrile, which is more thermally resistant than polystyrene (PS) alone, and polyacrylonitrile or Creslan 61, which is thermally resistant but also possesses some unique metal-binding properties. On combustion, as part of the energy-recovery processes of waste plastics or thermal recycling because of the acrylonitrile (AN) group

k k

1.2 Survey of Packaging Use 21

≡ (CH2=CH–C N), the compounds are known to liberate cyanide gas and carbon monoxide. In opposition to AN, polycarbonate (PC) packaging is easy to process, cover, and shape with heat-forming capability. These types of plastic have a wide area of usage in the modern production sector, where toughness and a durable character with respect to impact are required. Consequently, PC plastic is now used for and ‘plastic glass’ mimics. This polymer is very transparent and light transmitting – actually being better than most types of glass. Water bottles used in homes and babies’ bottles populating nurseries around the globe are made from PC material. The best property of PC lies in its durability to impact, which is why it is also used for prefilled syringes and industrial safety glasses. The PE group of packaging materials represents the single biggest category of plastic used in packaging but also universally across all sectors. Recycled PE is used for milk bottles, medicine bottles, and many general containers and can account for up to 61% of all plastics in the recycling stream. HDPE is a tough, malleable, abundant, and cheap material but its natural opacity due to light scattering means it cannot be used in products where trans- parency is needed. Nevertheless, it is one of the most widely used plastics of all those that are currently available to manufacturers. HDPE, which is a particularly tough version of PE, is also utilised for tubs used for cheeses and butter and boil-in-the- food products and may account for as much as 29% of all plastics. Low-density polyethylene (LDPE) is a semi-opaque, tough, durable plastic but with an elastic, easy-to-cut character. LDPE plas- tics are used mostly in pack-film materials by virtue of being smooth, elastic, and relatively transparent. LDPE plastics are also routinely used in the manufacture of bags and in the k elastic lids of many types of jars. This type of plastic may account for an incredible 32% k of all plastics and, along with HDPE, accounts for a significant portion of environmental plastics and micro-plastics. PET packaging, depending on the thermal treatment, is an amorphous (transparent), semi-crystalline (opaque), flexible, and valuable packaging material (representing 9% ofall plastics used). Depending on PET film thickness it may be rigid or semi-rigid and this can dictate its possibilities for end use. At a density of around 1.39 g/cm3 (cf. 2.7 g/cm3 for alu- minium and about 2.8 g/cm3 for glass) it is a lightweight material that has excellent gas and humidity barrier properties. Simultaneously, it is mechanically tough and highly resistant to impact, making it ideal for bottles such as liquid pharmaceutical containers and car- bonated drinks bottles as well as jars and trays. The semi-crystalline form of PET, known as CPET, is used almost exclusively for oven-ready meal trays because of its high thermal resis- tance. The now common PET bottle was first invented in 1973 but has since spread touse in some ‘plastic cans’ that consist of a transparent or printed PET body and aluminium lid, often with a pull-ring (Minuman, Invento, Lino, and Sino Packaging). The most important advantage of PET usage is that it possesses sound multiple recycling characteristics; con- sequently, greater use of this plastic presents greater possibilities for more routine . Some recently discovered species of bacteria are thought to be able to digest PET as a food source; this opens up more avenues for improved recycling or disposal by species found in the natural environment that degrade the waxy and wax-like materials. The next cluster of packaging materials includes PP, PS, and polyvinyl chloride (PVC). PP as a packaging material is resistant to chemicals, heat, and moisture. It is a plastic that has moderate rigidity, being used for ketchup bottles, medicine bottles, yogurt pots, and lids. It has the lowest density among plastics used in packaging and accounts for up to

k k

22 1 Historical Perspective and Evolution

11% of all plastics. PS packaging can be seen in rigid containers and in expanded insulat- ing foam. In a non-expanded form it is a very tough, highly transparent, and bright plastic used for protective packaging (egg cartons and meat trays) and may account for up to 10% of all plastics. PVC packaging exists in two forms – hard and elastic varieties (constituting 5% of all plastics) – and is often used to make bottles for vegetable oil and shampoo; it is also used in pharmaceutical push-out-packs. PVC was initially discovered by Henri Victor Regnault and later refined for potential use by Eugen Baumann. Approximately 40 years later in 1926 Waldo Semon mixed different additives into PVC to make it more pliable; this resulted in an easier-to-process material and allowed its widespread use (5% of all plas-

tics). Concerns in the 1970s over the vinyl chloride (C2H3Cl) monomer (frequently referred to as VCM), bisphenol A ((CH3)2C(C6H4OH)2), and dioxin (dioxin-like compounds, e.g. 1,4-dioxin) present in the material have somewhat spoilt the reputation of PVC as the super- packaging material that it is. From the 1970s, VCM exposure was linked to a rare form of liver cancer, known as angiosarcoma. The US Environmental Protection Agency classified VCM as a known human carcinogen from this time onwards, with factory workers being the most common victims of VCM over-exposure.

1.2.2.7 Composite Packaging Composite packaging is made from combining at least two different and often physically distinct materials. The goal in combining various materials is to increase the mechanical and chemical properties of the materials over those observed in any single material. k Sometimes composite materials also demonstrate unique properties not seen with either k individual material through an effective synergism in the physical properties of each material. Commonly used examples include plastic–aluminium composite packaging used for steam retortable pouches; cardboard–PE composite packaging used for cartons; paper–PE composite packaging, frequently used for medical sachet pouches;® plastic–paper–aluminium composite packaging used for UHT sterilised product cartons; and paper–aluminium composite packaging used as the webbing for pharmaceutical push-out packs. In some more modern combinations hemp and flax woven materials are embedded within plastic to produce more rigid materials and a range of contemporary ‘bioplastics’ make use of this composite structure.

1.2.2.8 Novel Materials: Bioplastics and Oxo-Degradable Polymers In recent times, the term ‘’ has become increasingly prevalent in packaging industry circles. These substances are innovative polymeric materials that can mimic the properties of conventional plastics. However, these materials are made from products or by-products of raw materials from renewable sources. In many applications, bioplastics can be used as a like-for-like substitute for hydrocarbon-derived plastics. Bioplastics can also be produced from many plant-originated raw materials; notably, starch has a very significant place among them. Cellulose and simple sugars are the other important raw materials for a range of polymers. Bioplastics can be thought of as a viable alternative for a wide range of renewable raw materials derived from simple species for potential packaging uses. At present, and most probably because of societal uptake, their cost

k k

1.2 Survey of Packaging Use 23

remains two to three times higher than that of conventional materials [12]. Biopolymers currently gathering much interest as alternatives to polyolefins include polycaprolactone, polyamide, polylactic–glycolic acid, polycaprolactone (PCL), and polylactic acid (PLA). Importantly, with regard to the persistence of plastics in the environment and according to European standard EN 13432, these materials can be degraded under particular conditions and reduced to a compost. Although it is currently considered impossible to produce sufficient raw materials to supply the current global need for plastics, even if all possible efforts were put into bioplas- tics production, their use alongside better recycling could achieve this end. Other materials called oxo-(bio)degradables are produced by methods such as adding biological materials to those polymer materials obtained from petrochemical products. Oxo- is a type of degradation resulting from oxidative- and microbe-mediated processes or phenomena in combination or in succession. The emergence of packaging materials made from composites and complex blends of fats and waxes with proteins such as zein (maize) or gluten (wheat) along with starch [13] and chemically modified hydroxypropyl- or hydroxyethyl-cellulose is becoming commonplace [14] for sheeting and adsorbent hydrogel uses in packaged products. Foam ‘peanut’ insulation (Envirofill) and cushioning transport materials (see Figure 8.6) fabricated from thermoplastic starch for applications where expanded PS was previously used have provided good opportunities for growth as more than 220 million tonnes of plastic are used worldwide each year for these purposes. Starch-based packaging that is often used for secondary packaging includes Bio4Pack k (Germany). These bioplastics include starch (corn, pea, and potato) and natural fats k (hemp oil, soya oil, etc.). They often make use of blends such as PLA and PCL or on occasion PET and mix this with starch. Starch-based plastics routinely contain sorbitol or glycerol as plasticisers to increase flexibility [15]. Bioplastics still account for a very small proportion of the total plastics market share – approximately 2% of plastic use. Currently obtainable materials include bioplastics such as starch–PLA, called Biotec (Germany); a starch–PET/PE blend, called Plantic ES (Australia); starch–PCL, called Mater-Bi (Italy); starch–(polybutylene adipate-co-terephthalate), called Ecoflex (BASF, Germany); a starch polyester (Bayer-Wolff Walsrode, Germany); a starch polyolefin (Roquette, France); kenaf (Deccan hemp); and a fibre–PLA material (NEC Corp., Japan). Routine use of PET is hoped to be replaced with a sugar cane-derived monoethylene glycol–PET material used for the soft drinks industries called PlantBottle (Dasani/Coca-Cola Company, USA). Thermoplastic called Chisso (Japan) and another variant called Envirofill based on an expanded product (DuPont, USA) represent promising new candidate materials. Unfortunately, biopolymers of this type tend to degrade easily at 180 ∘C and consequently, at present, many are combined with oil-derived plastics from a performance point of view and this informs design strongly [16]. European standard EN 13432 and ASTM 6954 describe the criteria and precisely controlled conditions used in prescribed tests for degradation at 60 ∘C in order for a material to be considered as biodegradable. The biopolymers suitable for packaging applications [15], including starch, chitin/chitosan, cellulose derivatives, PLA, PCL, poly(butylene succinate), and polyhydroxybutyrate, are discussed in detail in other publications.

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24 1 Historical Perspective and Evolution

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