SNS College of Technology,Coimbatore-35. (Autonomous) B.E/B.Tech- Internal Assessment -I Academic Year 2019-2020 (Odd) B Seventh Semester Agriculture Engineering 16AG412–Packaging Technology

PART – A 1 Brand attitude defines what the brand thinks about the consumer by the consumer 2 Brand extension concept involves the use of a successful brand name to launch new or modified products in a new category or range 3 Trademark helps in preventing others copying in marketing 4 Which of the following defects can be found on retort pouches? Flex cracks 5 Formal statement by manufacturer of product regarding its performance is classified as warranties PART - B 6 In your opinion how is packaging useful to you. Prevents or reduces product damage and food spoilage, thereby saving energy and vital nutrients, and protecting the health of the consumer Eliminates the risk of tampering and adulteration Promotes goods in a competitive marketplace and increases consumer choice 7 What are the extrinsic parameters that can cause damage to the product? environment in which physical damage can be caused to the product. It includes shocks from drops, falls and bumps, damage from arising from transportation modes including road, rail, sea and air and compression and crushing damage arising from stacking during transportation or storage in warehouses, retail outlets and the home. 8 What are the grades of packaging? Primary packaging Secondary packaging Tertiary packaging 9 What is shrink wrapping? , also shrink wrap or shrink film, is a material made up of polymer film. When heat is applied, it shrinks tightly over whatever it is covering. Heat can be applied with a hand held heat gun (electric or gas) or the product and film can pass through a heat tunnel on a conveyor. 10 What is retort pack?

Retortable pouches can be either preformed or in-line formed using form/fill/seal equipment. Common pouch structures are PET/nylon/foil/PP and PET/nylon/EVOH or PVDC/PP. Retortable pouches are used by hotels, restaurants, and other institutions. Retortable pouches must be inert, heat sealable,

1

dimensionally stable and heat resistant to at least 121°C for typical process times. They should have low oxygen and water vapor permeability, be physically strong and have good ageing properties. Retail consumer products such as tuna, salmon, chicken patties, chipped beef, chili, and ground beef in retortable pouches have become available. PART – C 11 (a) Write in detail about the bubble packaging ➢ is used to protect items during shipment. and during shipment and loading/unloading are controlled by cushioning to reduce the chance of product damage. ➢ Cushioning is usually inside a shipping such as a corrugated . It is designed to absorb shock by crushing and deforming, and to dampen vibration, rather than transmitting the shock and vibration to the protected item. Depending on the specific situation, package cushioning is often between 50 and 75 millimeters (two to three inches) thick. ➢ Internal packaging materials are also used for functions other than cushioning, such as to immobilize the products in the box and lock them in place, or to fill a void. ▪ When designing packaging the choice of cushioning depends on many factors, including but not limited to: ▪ effective protection of product from shock and vibration ▪ resilience (whether it performs for multiple impacts) ▪ resistance to creep – cushion deformation under static load ▪ material costs ▪ labour costs and productivity ▪ effects of temperature,[1] humidity, and air pressure on cushioning ▪ cleanliness of cushioning (dust, insects, etc.) ▪ effect on size of external ▪ environmental and issues ▪ sensitivity of product to static electricity

Common types of cushioning

• Loose fill – Some cushion products are flowable and are packed loosely around the items in the box. The box is closed to tighten the pack. This includes expanded pieces (Foam peanuts), similar pieces made of starch-based , and common popcorn. The amount of loose fill material required and the transmitted shock levels vary with the specific type of material. • – Paper can be manually or mechanically wadded up and used as a cushioning material. Heavier grades of paper provide more weight-bearing ability than old newspapers. Creped cellulose wadding is also available. (Movers often wrap objects with several layers of or embossed pulp before putting them into .) • pads – Multi-layer or cut-and-folded shapes of corrugated board can be used as cushions. These structures are designed to crush and deform under shock stress and provide some degree of cushioning. composite honeycomb structures are also used for cushioning. • Foam structures – Several types of polymeric foams are used for cushioning. The most common are: Expanded Polystyrene (also Styrofoam), , , and . These can be molded engineered shapes or sheets which are cut and glued into cushion structures. Convoluted (or finger) foams sometimes used. Some degradable foams are also available. Foam-in-place is another method of using polyurethane foams. These fill the box, fully encapsulating the product to immobilize it. It is also used to form engineered structures. • – Pulp can be molded into shapes suitable for cushioning and for immobilizing

2

products in a package. Molded pulp is made from recycled and is recyclable. • Inflated products – consists of sheets of with enclosed “bubbles” of air. These sheets can be layered or wrapped around items to be shipped. A variety of engineered inflatable air cushions are also available. Note that inflated air pillows used for void-fill are not suited for cushioning. • Other – Several other types of cushioning are available including suspension cushions, thermoformed end caps[7] [8] , and various types of shock mounts.

Design for shock protection

• Drop test of cushioned package to measure the transmitted shock • Proper performance of cushioning is dependent on its proper design and use. It is often best to use a trained packaging engineer, reputable vendor, consultant, or independent laboratory. An engineer needs to know the severity of shock (drop height, etc.) to protect against. This can be based on an existing specification, published industry standards and publications, field studies, etc. • Knowledge of the product to be packaged is critical. Field experience may indicate the types of damage previously experienced. Laboratory analysis can help quantify the fragility of the item, often reported in g's. Engineering judgment can also be an excellent starting point. Sometimes a product can be made more rugged or can be supported to make it less susceptible to breakage. • The amount of shock transmitted by a particular cushioning material is largely dependent on the thickness of the cushion, the drop height, and the load-bearing area of the cushion (static loading). A cushion must deform under shock for it to function. If a product is on a large load-bearing area, the cushion may not deform and will not cushion the shock. If the load-bearing area is too small, the product may “bottom out” during a shock; the shock is not cushioned. Engineers use “cushion curves” to choose the best thickness and load-bearing area for a cushioning material. Often two to three inches (50 – 75 mm) of cushioning are needed to protect fragile items. • Cushion design requires care to prevent shock amplification caused by the cushioned shock pulse duration being close to the natural frequency of the cushioned item.

Design for vibration protection

The process for vibration protection (or isolation) involves similar considerations as that for shock. Cushions can be thought of as performing like springs. Depending on cushion thickness and load-bearing area and on the forcing vibration frequency, the cushion may

1) not have any influence on input vibration 2) amplify the input vibration at resonance, or 3) isolate the product from the vibration. Proper design is critical for cushion performance.

Evaluation of finished package

Verification and validation of prototype designs are required. The design of a package and its cushioning is often an iterative process involving several designs, evaluations, redesigns, etc. Several (ASTM {American Society for Testing and Materials}, ISTA {International Safe Transit Association Standards. International Safe Transit Association (ISTA)}, and others) published protocols are available to evaluate the performance of a proposed package. Field performance should be monitored for feedback into the design process.

3

CUSHIONING MATERIAL (b) Explain in detail about retort pack

Introduction

The is a rectangular, flexible, laminated plastic, four-side hermetically sealed pouch in which food is thermally processed. It is a lightweight, high-quality, durable, convenient and shelf stable packs. Foods packed and processed in retort pouches are in successful commercial use for a wide variety of foodstuffs in several countries, particularly Japan. The materials from which retort pouches are made are either aluminum foil bearing/plastic laminates or foil-free plastic laminate films. Retortable pouches can be either preformed or in-line formed using form/fill/seal equipment. Common pouch structures are PET/nylon/foil/PP and PET/nylon/EVOH or PVDC/PP. Retortable pouches are used by hotels, restaurants, and other institutions.

Retortable pouches must be inert, heat sealable, dimensionally stable and heat resistant to at least 121°C for typical process times. They should have low oxygen and water vapor permeability, be physically strong and have good ageing properties. Retail consumer products such as tuna, salmon, chicken patties, chipped beef, chili, and ground beef in retortable pouches have become available. Pouches are reverse printed in a wide range of graphics on the PET film before , so that the print cannot come into contact with the food. All laminates are required to meet very stringent requirements to ensure no undesirable substances can be extracted into the packaged food.

Manufacturing of pouches

Pouches can either be formed from reels of laminated material either on in-line form/fill/seal machines in the packer’s plant or they may be obtained as preformed individual pouches sealed on three sides, cut and notched. Forming consists of folding the laminate material in the middle, (or PA) side out, heat sealing the bottom and side seals and cutting to present a completed pouch. Alternatively two webs can be joined, heat seal surfaces face to face, sealed, cut and separated. Hot bar sealing is the most common practice. Notches are made in the side seal at the top or bottom to facilitate opening by the consumer. Modern pouches have cut rounded corners which reduce the possibility of perforation caused by pouch to pouch contact. Rounded corner seals can also be incorporated.

The four-seal flat shape and thin cross section of the pouch is designed to take advantage of rapid heat penetration during sterilization and on reheating, prior to consumption, saving energy

4

and providing convenience. The flat shape also enables ease of heat sealing and promotes high seal integrity. Fin seal design and certain gusset features permit the design of upright standing pouches although they create multiple seal junctions with increased possibility of seal defects. Several of these upstanding pouches are, however, available commercially. A wide range is possible in the size and capacity of pouches.

Filling and sealing

The premade pouches are filled vertically in-line. Vertical form/fill/seal machines can be used for liquid products. Another method employs a web of pouch material which is formed on a horizontal bed into several adjacent cavities. The cavities are filled whilst the seal areas are shielded. This method is especially useful for filling placeable products. Thereafter the filled cavities are simultaneously sealed from the top using a second web fed from the reel. The essential requirements for filling are:

• Pouch should be cleaned, fully opened to the filling station, solids are filled first followed by the liquid food at a second station • Matching fill-nozzle design and proportioning to the product • Non-drip nozzles are used for filling • Shielding of the sealing surfaces • Bottom to top filling • Specification and control of weight consistent with the maximum pouch thickness requirement • Product consistency in formulation, temperature and viscosity • Deaeration prior to filling.

Sealing machines like fillers are constantly being refined and speed has improved from 30 to 60 pouches per minute to the current production rate of 120–150 pouches per minute. Sealers incorporate either one of two common satisfactory sealing methods namely hot bar and impulse sealing. Both methods create a fused seal whilst the pouch material is clamped between opposing jaws, thereby welding the opposing seal surfaces by applying heat and pressure. Exact pouch-sealing conditions depend on the materials and machinery used.

Quality assurance

A successful pouch packaging quality system requires:

• Selection and continued monitoring of the most suitable laminate materials. • Regular testing of formed pouches for seal strength, product resistance and freedom from taint. • Careful selection, maintenance and control of filling, sealing, processing and handling machinery. • Specifications for the control of product formulation, preparation (viscosity, aeration, fill temperature etc.) and filling (ingoing mass and absence of seal contamination). • Post sealing inspection and testing of seals to confirm fusion, absence of defects and contamination. • Control of critical parameters influencing processing lethality such as maximum pouch thickness and residual air content. • Standardized retorting procedures applying only recommended process times and temperatures confirmed to achieve adequate lethality. • Regular inspection and testing of retort equipment and controls to ensure uniform heat distribution. • Visual inspection of all pouches to check sealing after processing. • Handling only of dry pouches and packing into collective or individual outer packaging specially tested to provide adequate, subsequent, abuse resistance. 5

• It should be routine that all stocks are held 10–14 days prior to distribution and these should be free of blown spoilage on dispatch. • Careful staff selection and training at all levels.

Shelf life

Whilst is determined by many factors such as storage temperature and the barrier properties of the particular film used, in general, satisfactory shelf stability in excess of two years is easily obtained for a wide range of products in foil bearing pouches. US military rations tested over two years at 20°C showed no significant change in product quality ratings. Some products have been successfully stored for as long as seven years and found to be safe and edible.

Foil-free laminates will demonstrate shelf stability commensurate with oxygen permeability of the particular laminate used and the sensitivity of the product. Commercial experience confirms, however, that product stability from four weeks to six months is obtainable. Nitrogen flushing of the outer container has been successful in extending the shelf life of product in foil-free pouches. .

Layers of retort pouch 12 (a) Give a detailed note on biodegradable packaging is the process in which substances are broken down by the action of microorganisms. The term is often associated with ecology, , and plastic materials (due to their long lifespan). Nowadays, the complex nature of biodegradation is better understood. It involves several steps like: biodeteriration, biofragmentation, assimilation, and mineralisation.

Biodeterioration proceeds on the surface of the polymer where its mechanical, physical and chemical properties are changed. Generally, the term refers to the activity of microorganisms growing on a given material. Bacteria, protozoa, algae, fungi, and lichenaceae are organisms, which are involved in the biodeterioration.

They cause the changes on the surface of a material. While microbial species are developing on the polymer, the biodeterioration increases, facilitating the production of simple molecules. Polymers are the carbon and nitrogen sources and growth stimulators for microorganisms. Microbial species can secrete a kind of glue (made of polymers like polysaccharides and proteins) and adhere to polymer surfaces. This

6 substance penetrates into porous structures and alters moisture amount and thermal transfers.

The microorganism’s growth in the material increases the size of pores and provokes cracks. As a result, the structure of the material is destabilized. The microbial species that are developing on the polymer surface also contribute to the chemical biodeteriration. Chemolithotrophic bacteria release inorganic compounds like ammonia, nitrites, hydrogen sulphide, thiosulphates, and elementary sulphur, whereas chemoorganotrophic microorganisms liberate organic acids as oxalic, citric, gluconic, glutaric, glyoxalic, oxaloacetic, and fumaric acids. These compounds can alter material surface.

Biofragmentation is an important phenomenon necessary for the following assimilation of the molecules. During this process a high molecular weight polymer is fragmented into a mixture of oligomers and/or . The energy needed for scissions may be of diverse origin as thermal, light, mechanical, chemical, and/or biological. The abiotic involvement was described previously. Microorganisms secrete specific enzymes or generate free radicals to cleave polymers. Oxidoreductases and hydrolases are mainly concerned in the biofragmentation process. Cellulases and amylases belong to hydrolases group and are synthesized by soil microorganisms. They hydrolyse renewable polymers like cellulose and starch. Starch in some commercial composites is co-extruded with (e.g. Mater-Bi®) to enhance the biodegradability. If low molecular weight molecules can be identified within degradation media, the polymer is considered as fragmented. A lot of analytical techniques, which are useful to separate oligomers with different molecular weights, like GPC, HPLC for liquid phase or GC for gaseous phase, are currently available.

Biodegradable Polymers for

Polyethylene and polypropylene, which are conventional polymers, last in the environment for many hundred years after disposal. Mainly, they are applied for production of plastic , which are disposed after one single use. Furthermore, food and other biological substances often stain packaging materials, which makes physical recycling of these materials impractical and generally undesirable. On the contrary, the science offers biodegradable polymers, capable of degrading after disposal in bioactive environments by the enzymatic action of microorganisms such as bacteria, fungi, and algae.

Polyhydroxylalkanoates are produced from renewable resources by bacterial fermentation of sugar and lipids. They are or elastomeric polymers, depending on the used in the synthesis. These materials, alone or in a blend with synthetic polymer or starch, give packaging films. The polyhydroxybutyrate (PHB) is the most common type of polyester, which is obtained in the polymerization of 3- hydroxybutyrate monomer, with properties similar to polypropylene although more stiffer and brittle. Scientists from China produced several PHA polymers from food wastes used as carbon source. The produced materials had various physical and mechanical properties, like flexibility, tensile strength, and melting viscosity. Such production of polyhydroxylalkanoates is rather inexpensive, but until now the project has not found commercial application.

Starch Based Polymers

Starch is an abundant, inexpensive, and annually renewable material available from potatoes as well as corn and other crops. It is composed of amylose, a mostly linear alpha-D-(1-4)-glucan and amylopectin, a branched alpha- D-(1-4)-glucan, which has alpha-D-(1-6) linkages at the branch point. Ratios of amylase and amylopectin vary with the starch source

Starch can be thermoplastic (TPS), which is obtained by technology similar to extrusion cooking. It has destructurized, noncrystalline form, produced by various heat application. From pure thermoplastic starch, traditional plastic goods can be obtained. However its sensitivity to humidity makes it unsuitable for most

7 applications.

Starch-based biopolymers can be obtained by blending or mixing starch with synthetic polymers. The properties and morphology of these blends can be adjusted easily and efficiently. Full advantage of this phenomenon was taken by Novamount Company to produce Mater-Bi® material. It is mainly formed into films and sheets, which found application in agriculture, waste management, packaging, personal care & hygiene, accessories for animals.

Poly(Lactic Acid)

Poly(lactic acid) can be synthesized by biological and chemical methods. The first one is more environmentally friendly, due to its renewable character. It is based on starch and other polysaccharides fermentation. It can be produced from corn, sugar beet, sugar cane, potatoes, and other biomasses.The second one was developed by industrial sector.

Lactic acid (2-hydroxy propanoic acid) contains an asymmetric carbon in its structure, which gives two optically active configurations. D- and L-enantiomers can be produced by bacteria and the amount of bot is adjustable, but some bacteria can produce only one isomer, whereas the chemical process gives the racemic mixture of both D- and L-enantiomers.

Poly(lactic acid) is totally biodegradable when composted at 333 K and above. The first step of the degradation is proceeding by hydrolysis to water-soluble compounds and lactic acid. Then microorganisms are able to metabolize these products into carbon dioxide, water and Biomass.

The biodegradation mechanisms of PLA are influenced by numerous factors, including the structure and hydrolysis media. The diffusion coefficients of the soluble oligomers depend mainly on molar mass, degree of swelling of the matrix, macromolecular conformation, rigidity, chemical structure, molecular weight distribution, impurity/monomer residue, stereochemistry, chain mobility, and crystallinity. The amorphous domain is more susceptible to biodegradation process.

Various route of PLA synthesis

8

Lifecycle of poly(lactic acid)

(b) Elaborate about the steps involved in two piece metal can 1Two-piece single drawn and multiple drawn (DRD) cans

• Pre-coated, laminated and printed tinplate or TFS is fed in sheet or coil form in a reciprocating press that may have single or multiple tools. • At each tool station the press cycle cuts a circular disc (blank) from the metal and whilst in the same station draws this in to a shallow can (cup). • During the drawing process the metal is reformed from flat metal into a three- dimensional can without changing the metal thickness at any point. • After this single draw, the can may be already at its finished dimension. • However, by passing this cup through a similar process with different tooling, it may

9

be re-drawn into a can of smaller diameter and greater height to make a draw–redraw can (DRD). • This process may be repeated once more to achieve the maximum height can. • At each of these steps, the can base and wall thickness remain effectively unchanged from that of the original flat metal. • Following this body-forming operation, necking, flanging and beading operations follow according to the end use and height-to-diameter ratio of the can (as for three- piece welded cans). • For all two-piece cans pinhole and crack detection on finished cans is carried out in a light-testing machine. This measures the amount of light passing across the can wall using high levels of external illumination. • One advantage of two-piece cans is that there is only one can end instead of two, meaning that one major critical control hazard point is eliminated. • The single drawing process is also used to make aluminium- or steel-tapered shallow trays for eventual heat-sealing with coated metal foil. • The container bodies are constructed from metal laminated with organic film. • The single drawing processes are also used for the manufacture of folded aluminium baking trays and take away . • In this process the aluminium is allowed to fold, as the metal is converted from a flat sheet into a shaped container.

13 (a) Write in detail about double seaming Double Seaming After the side seam has been welded, the bodies are transferred to a flanger for the final metal forming operation: necking and flanging for beverage cans, and beading and flanging for food cans. The can rim is flanged outward to enable ends to be seamed on. The top of beverage cans is necked to reduce the overall diameter across the seamed end to below that of the can body wall, yielding savings in the cost of metal through the use of smaller diameter ends. This allows more effective packing and stacking methods to be adopted, and prevents damage to the seams from rubbing against each other. Simultaneous creation of the neck and flange using a spin process is used. Double-, triple- and quadruple-neckings are now quite common, the latter reducing the end diameter from 68 to 54 mm for the common beverage can.

For food products where the cans may be subjected to external pressure during retorting or where they remain under high internal vacuum during storage, the cylinder wall may be beaded or ribbed for radial strength. There are many bead designs and arrangements, all of which are attempts to meet certain performance criteria. In essence, circumferential beading produces shorter can segments that are more resistant to paneling (implosion), but such beads reduce the axial load resistance by acting as failure rings.

The end is then mechanically joined to the cylinder by a double seaming operation. This involves mechanically interlocking the two flanges or hooks of the body cylinder and end. It is carried out in two stages. In the first operation, the end curl is gradually rolled inward radially so that its flange is well tucked up underneath the body hook, the final contour being governed by the shape of the seaming roll. In the second operation, the seam is tightened (closed up) by a shallower seaming roll. The final quality of the is defined by its length, thickness and the extent of the overlap of the end hook with the body hook. Rigid standards are laid down for an acceptable degree of overlap and seam tightness. The

10 main components of a double seam. Finally, the cans are tested for leakage using air pressure in large wheel-type testers; leaking cans are automatically rejected.

Double seaming of metal ends on to meet containers (a) end body are brought together (b) first seaming operation (c) second seaming operation (d) section through final seam

(b) Elaborate in detail about end and body manufacture END MAKING PROCESSES

• Can ends for mechanical double seaming are constructed from aluminium, tinplate or TFS. Aluminium and TFS are always coated on both sides with organic lacquer or film laminate whilst the metal is still in coil or flat sheet form. • For tinplate these are optional, depending upon the product being packed in the container and the specified external environmental conditions. • The base of a three-piece can will always be a plain end (non-easy-open). • For food cans, the top may be either plain (requiring an opening tool) or full aperture

11

easy-open (FAEO). Rectangular solid meat cans employ a key opening device to detach both the scored body section and ME. • For drink cans, the top is usually referred to as a Stay-on Tab (SOT), enabling the opening tab and pierce-open end section to be retained on the can. The SOT end has largely superseded the traditional ring-pull end. • All ends for processed food cans have a number of circular beads in the centre panel area to provide flexibility. These allow the panel to move outwards, as internal pressure is generated in the can during the heating cycle of the process and so reduce the ultimate pressure achieved in the can. • During the cooling process, this flexibility permits the centre panel to return to its original position.

12