Method to adjust the elongation required to effect a color change in polymeric stretch films incorporating mechanochromic dyes

A method to match the amount of elongation required to effect a color change in a polymer stretch film comprising at least a first layer comprising a polyolefin resin and an AIE mechanochromic dye dispersed within the first layer with a desired amount of elongation for an intended application for the stretch film, the method comprising the following steps:

• a. determining the level of elongation needed to effect a color change in the resulting film based on the intended application for the film;
• b. selecting a polyolefin resin for use in the first layer, said polyolefin resin having a given density based on expected level of elongation needed to effect a color change in the resulting film;
• c. admixing a given amount of the AIE mechanochromic dye into a melt of the polyolefin resin;
• d. making a film comprising at least a first layer which is made from the polyolefin resin containing the mechanochromic dye;
• e. optionally, if color change does not occur at the desired level of elongation for the resulting film, adjusting the density of the polyolefin resin in the first layer to change the level of elongation needed to effect the color change to the desired level.