Polyolefin-based stretch films incorporating mechanochromic dyes and method for using them

摘要

The present disclosure relates to a multilayer stretch film comprising at least one first layer, said first layer comprising a polyolefin resin. The film of this aspect of the disclosure further includes at least a second layer and a mechanochromic dye which may be in any or all layers of the film. Another aspect of the development is a method for promoting optimal extension of the stretch film during a wrapping operation, the method comprising at least the following steps. A polyolefin resin having a certain density is selected. select a mechanochromic dye based on its ability to agglomerate into an unstretched film produced from the polyolefin resin having the given density, so that when the dye is included in the film, the unstretched film exhibits a first color . mix by adding the mechanochromic dye to a polyolefin resin melt. form a film from the mixture by adding the previous step. Pack an object using the film from the previous step, while extending the film to a level where a change from the first color to a second color can be observed.