FIELD: packaging industry; chemistry.
SUBSTANCE: invention relates to multilayer polymer materials for food packaging containers, and concerns a multilayer barrier film, laminated packaging material, container and method for the production of the film. Biaxially oriented multilayer has gas barrier properties and consisting of polymer layers, comprising a polyolefin core layer and a barrier surface layer of ethylene vinyl alcohol (EVOH) on a first side of the core layer. Invention further relates to such a vapour deposition coated film, especially a metallised such film, to a packaging laminate comprising the film or vapour deposition coated polymer film and to a packaging container produced from such a laminated packaging material. Method for the production of the film comprises the following steps: a) co-extruding a polyolefin core layer together with a surface barrier layer of ethylene vinyl alcohol (EVOH) on a first side of the core layer, surface barrier layer has an ethylene content of no more than 36 mole.%, b) simultaneously, biaxially orienting the obtained co-extruded film, while maintaining the temperature of the film during the stretching operation between a minimum level and the melt temperature of the polyolefin of the core layer, which minimum level is depending on the core layer polyolefin material of the film and is at least 105 °C.
EFFECT: invention provides cost-efficient polymer film having improved gas-barrier properties at high moisture content.
30 cl, 8 dwg, 3 tbl, 6 ex
