Patent attributes
In one embodiment the invention is an article comprising at least two layers, a first or low crystallinity layer comprising a low crystallinity polymer and a second or high crystallinity layer comprising a high crystallinity polymer. The high crystallinity polymer has a melting point as determined by differential scanning calorimetry (DSC) that is about the same or within less than 25 C of the melting point of the low crystallinity polymer. The article is elongated at a temperature below the melting point of the low crystallinity polymer in at least one direction to an elongation of at least about 50% of its original length or width, to form a pre-stretched article. Preferably, the high crystallinity layer is capable of undergoing plastic deformation upon the elongation.
