PROCESS FOR PRODUCTION OF PLASTIC-COATED ALUMINIUM FOIL AND PACKAGING MADE FROM THIS

摘要

In a process for production of an aluminium foil (10) coated with sealable and sterlisable plastic (14) based on polypropylene (PP) or polyethylene (PE), the plastic (14) is coextruded with an adhesion-promotion agent (16) and combined with an aluminium foil (24) between two rollers (20, 22). The aluminium foil (10) coextrusion-coated in this way, to increase the adhesion strength between the aluminium foil (24) and the plastic layer (14), then passes continuously through an oven (26) with temperature (TO) set such that the temperature of the plastic layer (14) and the adhesion-promotion agent (16) lies above the crystallite melt point (TK) of the plastic. The coated aluminium foil heat-treated in this way, after emerging from the oven (26), is cooled shock-like such that the crystalline proportion at least in the surface area of the cooled plastic layer (14) and the crystallites in this area are as small as possible. A container made of a coated aluminium foil (10) produced with the process for animal feed shows a good serving behaviour on removal of the filling. Also a lid of the coated aluminium foil (10) has low adhesion of the animal feed to the lid, which leads to clean opening of the container. Thanks to the essentially suppressed after- crystallisation of the plastic layer (14), white breaks are avoided which increases the resistance to aggressive fillings.