| 摘要 |
A film layer is disclosed that is capable of shrinking when subjected to energy, such as heat. The film layer, for instance, can be formed and then stretched in one or two directions at a relatively low temperature. In particular, the film is stretched while the film layer is at a temperature near the glass transition temperature of the polymer used to form the film. Drawing the film at a relatively low temperature has been found to improve the shrink properties of the film. In one embodiment, the film layer is comprised of a non-modified polyester, such as polyethylene terephthalate. For example, the polyethylene terephthalate can be made by reacting terephthalic acid with ethylene glycol or polyethylene glycol. |
