At room temperature, the plastic macrololecules as poor cannot rely on molecular motion to eliminate the natural state, which is poorconductivity shrinkable does not shrink.

• 在室温下，塑料不小不分子的勾当本领不对，因而不克不及靠不分子勾当来打消这种不板滞状况，这不离是室温下冷关上薄膜并不关上的来因。