Plastic packaging film with localised high strength areas - has co-extruded strips of different materials with higher strength material corresponding with areas of high loading stress

摘要

A plastic packaging film is extended, before location around an object, and then returns its original size, sealing the object at the same time. The film is formed into a tube by co-extrusion of two different material strips which run parallel to the tube, and at right angles to the direction of intended extension. The two materials have different tensile and recovery properties, the first having high extension and recovery, the second low friction and/or high resistance to mechanical stress. Strips are arranged such that the material with the higher mechanical resistance is located in areas which correspond with damage prone areas on objects to be covered e.g. edges.