abstract |
A method of activating the shrink characteristic of a film comprises two steps. First, a film comprising one or more thermoplastic polymers and at least about 0.01 weight % photothermic material is provided. Second, the film is exposed to an amount of non-ionizing radiation effective for the photothermic material to generate heat to cause an effect selected from one or more of: 1) shrinking the film by at least about 5% in at least one direction, and 2) increasing the tension in the film by at least about 50 pounds per square inch in at least one direction. |