A multilayer strech film having cling properties, a method of preparation thereof and its use for strech wrapping operations

摘要

A multilayer stretch film having at least a first layer (i) with cling properties comprising an olefin (co)polymer composition, a second layer (ii) with slip properties comprising another olefin (co)polymer composition and if desired at least one core layer (iii) comprising an olefin (co)polymer composition between the first layer (i) and the second layer (ii). The outer surface of the first layer (i) with cling properties is provided with a non-stretchable thin film of one or more slip agent(s) covering at least 50 % up to 100 % of the outer surface of the first layer (i), lowering the cling properties of the unstretched composite film. The thin film of slip agent(s) is provided either by direct application of the slip agent(s) onto the outer surface or by use of slip agent(s) having limited compatibility with the (co)polymer composition as additive in the (co)polymer composition of the first layer (i). The limited compatibility of the slip agent(s) with the (co)polymer composition of the first layer (i) results in migration of the slip agent(s) to the outer surface and formation of a non-stretchable thin film at the outer surface of the first layer (i). The multilayer stretch film is preferably composed substantially entirely of ethylene or propylene (co)polymer compositions or mixtures thereof. The invention includes a method of preparing a multilayer stretch film according to the present invention by extrusion and the use of the multilayer stretch film for stretch wrapping operations of articles or groups of articles.