Packaging applications flexible

Table I shows the chemical composition limits of various aluminum alloys presently used for packaging applications (3). In general, these alloys have good corrosion resistance with most foods. However, almost without exception, processed foods require inside enameled containers to maintain an acceptable shelf life (4, 5). Moreover, when flexible foil packages are used for thermally processed foods, the foil is laminated to plastic materials that protect it from direct contact with the food and also provide heat sealability as well as other physical characteristics (6,7).

This paper discusses how tightening environmental regulations in the USA are encouraging a shift from solvent-based to waterborne adhesives for use in flexible packaging applications. It also looks at how new adhesive systems have a relatively easy path to Food Drug Administration clearance for food packaging uses. 

The physical properties and melt processing of PLA are similar to those of conventional packaging resins. It may thus be used as a commodity resin for general packaging application. In many aspects the basic properties of PLA lie between those of crystal PS and PET [ 14]. When plasticized by its own monomer lactic acid, PLA becomes increasingly flexible so that products that mimic PVC, LDPE, LLDPE, PP, and PS can be prepared [15]. Possible applications are espe-... 

Flexible packaging applications include extruded bags and nets for fresh fruit and vegetables. 

Phthalate plasticisers have historically served as the preferred plasticisers to impart flexibility to PVC and several other polar polymers. They provide a desirable balance of cost and performance properties. Their acceptable and safe use is unmatched in medical appliances, food processing and packaging applications, as well as many other end uses. Potential alternatives do not have the historical record of acceptable performance found with phthalate plasticisers. Nevertheless, the Precautionary Principle has caused certain segments of society to clamour for alternatives to phthalate plasticisers. Known non-phthalate plasticisers are reviewed, and comparisons to the traditional General Purpose (GP) phthalate plasticisers are provided General Purpose plasticisers are those that impart optimum overall performance properties in PVC at lowest cost. 6 refs. USA... 

SBC film is growing into more and more film applications. It is proving to be well suited for fresh cut produce packaging, candy twist wrap, shrink films, flexible medical and decorative films. SBC can be extruded into either cast or blown film for use in flexible packaging applications. While some applications employ a monolayer SBC film, many films are co-extruded with SBC along with several layers of other materials in order to bring a combination of properties to the final application. 

Covers prefoamed polyurethane foams, both rigid and flexible, for packaging applications. The foams described are intended for use as... 

Butyl benzyl phthalate is a plasticizer added to polymers to give flexibility and softness. It is used extensively in polyvinyl chloride and in cellulose plastics, polyvinyl acetate, polysulfides, and polyurethane. Also used in flexographic inks for food packaging applications and acrylic coatings, profile extrusions, slush moulding, film and sheeting, coated fabrics, floor and wall coverings, vinyl foams and plastisols for car sealants. 

Ethylene acid polymer is obtained by the copolymerisation of ethylene with either acrylic or methacrylic acid. These copolymers are somewhat similar to LDPE and are found as ethylene acrylic acid (EAA) and ethylene methacrylic acid (EMA). Both are used in various packaging applications, i.e. flexible packaging, adhesive laminating, hot melts, and heat seal coatings. 

For most rigid packaging applications with thick polyolefin layers, this requirement is easily met. In cases of flexible packages (film wraps, etc.), the transport limitations should be checked. 

Ethylene vinyl alcohol is also used in production of plastic bottles, thermoform film and sheet, and flexible squeeze tubes. It is being experimented with for microwave food packaging applications, but this use is not yet commercial. It could, however, provide a large new market for EVOH if the application can be successfully demonstrated. 

Blown and cast films utilized in flexible packaging applications such as cereal, cracker and snack food packaging, wraps for delicatessen products, and grocery sacks. 

Flexible PVC film is often used for packaging food products, particularly fresh red meat. The oxygen permeability of PVC film is well suited to maintain the necessary oxygen requirements of the meat, to preserve its red color and appearance of freshness. PVC films also provide good toughness and resilience. PVC is also used to wrap fresh fruits and vegetables. Almost all poultry producers in the U.S. once used PVC stretch films for chilled, tray-packed poultry parts. However, multilayer barrier films have made considerable inroads in this market. PVC is also used for a variety of other food and nonfood packaging applications, as illustrated in Table 4.8. 

EVOH can be extruded in films, blow molded, or injection molded. It can also be processed by coextrusion or lamination, in combination with PE, PP, PET, nylons, and other resins. Applications in packaging include flexible structures and rigid containers, as shown in Table 4.12. Typical applications are ketchup and barbecue sauce bottles jelly, preserves, vegetable juice, and mayonnaise containers and meat packages. Nonfood applications include packaging of solvents and chemicals. 

Flexible foams also find use is packaging applications. Die-cut flexible foam is used to package costly goods such as delicate instruments, optical products, and pharmaceuticals. Semiflexible foam lining is used for cart interiors to protect auto and machine parts during transportation. 

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