| 摘要 |
The invention is concerned with a multilayer packing film having improved properties of oxygen permeability, transparency, flexibility and toughness and capable of being converted into pouches and bags upon conventional packaging machinery without distortion under heat-sealing conditions. The film comprises a surface layer of a heat-sealable polymer, preferably a linear low density polyethylene, an oxygen barrier layer, of an ethylene/vinyl alcohol copolymer and a layer of polypropylene having an atactic content of 10% to 25% by weight which has a melting point substantially greater than the heat-sealable polymer. The layers may be bonded by a polymeric adhesive and the whole film is preferably manufactured by coextrusion. The multilayer film is particularly useful for packaging liquids where a high degree of resistance to cracking is required. |
