Process of roughening thermoplastic films and roughed plastic films

Abstract

The invention relates to process for roughening thermoplastic films and roughed films. The invention further relates to process for preventing thermoplastic packaging films from slipping on each other and a suitable system for such purpose. The essence of the roughening process is that practicles consisting of the same polymer as that of the film and/or other plastic material being able to weld together with that, and having suitable size and/or abrasion resistance are brought to the surface to be roughened of semi-finished product having sufficient reserved heat content to maintain condition appropriate for welding said particles on said thermoplastic film surface to be roughened or on one or on both film surfaces being re-heated to such temperature and are dispersed in suitable closeness and configuration and that condition of the roughened surface is maintained until desired welding process is completed. Process for preventing thermoplastic packaging films from slipping on each other characterised in that a system comprising films to be stacked—at least one of which is roughed—and has protrusions of suitable closeness on its surface; a binding element having a loose fibrous structure and stability is placed on the film or on its specified parts, on the entire surface or on surface pan(s); said binding element comprises fiber of such closeness and layer thickness that between the fiber of the binding element and the protrusions of the roughed film a mechanical joint is formed.

Dependencies are inferred from the claim text.