Multilayered barrier

Table 17. Physical Properties of a Multilayer Barrier Film and a Polyethylene Film ...

Multihydroxy surfactants, 24 148 Multijunction (MJ) stack arrays, 22 137-138, 139-140 Multilayer adsorption, 1 591 Multilayer barrier film, properties of,... 

Packaging and multilayer barrier films produced from COC materials exhibit improved moisture and thermal resistance. Thus, they are suitable for... 

Table 17. Physical Properties 1 of a Multilayer Barrier Filmb and a Polyethylene Film0...

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. 

An oxygen-sensitive product is packaged in a multilayer barrier pouch containing an inner EVOH layer, tie layers on either side of the EVOH, and outer layers of PR The total thickness of the PP in the film is 3 mils. Does it matter whether the structure is ... 

To come back to the question of hiding. The reason why better hiding is achieved with smaller metallic pigments is because they form more of a multilayered barrier. This barrier allows less light to penetrate than when formed by large particles. 

MAJOR APPLICATIONS Homopolymer and copolymers—usually with vinyl chloride (VC), or methyl acrylate (MA)—used in solvent-based or latex barrier coatings on cellophane, paperboard, plastic film, and rigid food containers. Films of copolymer used as household cling wrap. Also used with other polymers in multilayer barrier films or containers mostly in packaging applications. Also used in fibers and adhesives. 

High barrier plastic containers are currently made from multiple layers of a relatively thick economical polymer such as polyethylene terephthalate (PET) or polyethylene, combined with a thin layer of a barrier polymer such as ethylene vinyl alcohol (EVOH). In a similar way, multilayer barrier containers can be made with a thin layer of liquid crystal polymer (LCP), as an excellent barrier to oxygen, water vapor, and other gases. 

Formed multilayer barrier packages, eg, trays, bowls, and cans from coextruded PP/PVDC/ PP, are being developed for soups and entrees that can be stored at ambient temperatures and heated to serving temperature in a microwave oven. Coextrusions of high performance, high temperature polymers, such as polyether-imide and polysulfone, for dual-oven containers capable of withstanding conventional bake-oven temperatures of 204-232°C are being tested. 

S.I. Allen, M. Ferguson, and H. Tung, Multilayer barrier film for transdermal drug delivery system and ostomy applications, U.S. Patent 5567488 A, 22 Oct 1996. 

Applications include multilayer barrier films with PA6 (polyamide 6)/ethylene-vinyl alcohol (EVOH)/ PA6 for the highest barrier applications especially for medical products, co-extruded cast films based on PP or PE with fillers such as calcium carbonate monoaxially stretched to achieve breathability to provide a water barrier but enabling water vapour to permeate the film, used in domestic wrapping, roof underlay applications, hygiene products, for example, nappies and feminine care. 

Gu, C.-H., Wang, J.-L, Yu, Y., Sun, H., Shuai, N., Wei, B. Biodegradable multilayer barrier films based on alginate/polyethyleneimine and biaxially oriented poly(lactic acid). Carbohydr. Polym. 92, 1579-1585 (2013)... 

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