LAYERED THERMOCONTRACTABLE FILM AND SAC MANUFACTURED FROM IT Russian patent published in 1998 - IPC

FIELD: packaging materials. SUBSTANCE: film includes: first layer of copolymer with acid, copolymer of ethylene with alpha-olefin or their mixture; and second layer containing copolymer of ethylene with 9-20 wt % vinylacetate with narrow molecular weight distribution determined by polydispersity index α from 5 to 10, where M_z/M_n = 15000-30000. Copolymer of ethylene with vinylacetate has high content of short- chain branching. Film can also have third layer of barrier polymer, fourth layer of copolymer of ethylene with 9-20 wt % vinylacetate with narrow molecular weight distribution and high content of short-chain branching, and fifth layer. Layered film hose is used to fabricate bottomed sacs. Films are easily welded and have improved insulation strength, especially in presence of fats. EFFECT: improved packaging properties. 12 cl, 1 dwg, 4 ex