HEAT-SHRINKABLE THERMOPLASTIC PACKAGING FILM AND RECEPTACLES FORMED THEREFROM

摘要

The invention provides a multi-layer, heat-shrinkable, thermoplastic packaging film which can be heat-sealed to itself to provide strong seals at pasteurizing temperatures. The preferred film has four layers including, in order, a sealing surface layer comprising a blend of propylene-ethylene copolymer and (butene-1)-ethylene copolymer, a layer comprising ethylene-vinyl acetate copolymer which may be cross-linked to further increase high temperature strength of the film as desired; a relatively gas-impermeable layer comprising a copolymer of vinylidene chloride; and a surface layer of the same blend as the sealing layer. Receptacles such as end seal and side seal bags can be made from the film at a faster rate than with prior art films and these receptacles have the high temperature seal qualities of propylene polymers and the hot water shrink capabilities of ethylene polymers.