| 摘要 |
The present invention provides a film of an oriented material which exhibits the property of expansion in at least one of its machine and transverse directions at a first temperature and of shrinkage at a second, higher, shrink onset temperature, the film having been annealed after orientation at a temperature above the first temperature and selected with reference to an intended recycling wash-off process to promote expansion of the film at the selected temperature of the wash-off process. |
