POLYMER-COATED HEAT-SEALABLE PACKAGING MATERIAL, METHOD FOR MANUFACTURING THE SAME AND A SEALED PACKAGE MADE THEREOF

摘要

The invention relates to a polymer-coated heat-sealable packaging material, its manufacturing method and a sealed package manufactured thereof. The material comprises a fibre base (3), which is a packaging paper or packaging board, an outer polymeric heat sealing layer (1, 8), which is, for example, LDPE, and an inner polymeric water vapour barrier layer (2, 7), which according to the invention is partly or totally formed of cycloolefin copolymer (COC). The COC water vapour barrier and the heat sealing layers are brought onto the fibre base by extrusion, and they can be placed on one side or on both sides of the fibre base for achieving a moisture barrier on both sides of the package. Also polymeric oxygen barrier layers, such as EVOH or polyamide layers can be incorporated in the packaging material. COC is amorphous, and by using it as an extruded water vapour barrier layer, curling of the packaging material is prevented. The packages according to the invention comprise carton, box and bag packages for dry and liquid foods.