Method for making multi-layer plastic preform for blow molding

摘要

A method for making a multi-layer plastic preform 14 with an inner layer 28 that is extrusion blow molded from a resin having an intrinsic viscosity greater than 0.90, and an outer layer 44 that is injection molded around the inner layer from a resin having an intrinsic viscosity that is at least 0.10 less than the intrinsic viscosity of the inner layer. The inner layer 28 is no greater than 200 (preferably no greater than 15%) by weight of the total weight of the preform and the outer layer 44 is at least 80% (preferably at least 85%) by weight of the total weight of the preform.