Furthermore, all thermoplastic materials contract as they solidify, which means that the molding wilt shrink on to the core which forms it. This shrinkage makes the molding difficult to remove.

• 此外，所有的热塑性塑料在固化的时候会收缩，意味着塑件将包紧在成型的型芯上。这种包紧使得塑件难以脱下。