Multi-layer preform used for plastic blow molding

摘要

A multi-layer preform used for plastic blow molding and a method for making the preform provides an inner layer of polyethylene naphthalate and an injection molded outer layer of homopolymeric polyethylene terephthalate which has reduced transmission of gas upon blow molding as a container due to the gas barrier provided by the inner layer of polyethylene naphthalate. The inner layer of homopolymeric polyethylene naphthalate by itself or along with a further inner layer of virgin polyethylene terephthalate is thermoformed prior to the injection molding of the outer layer of polyethylene terephthalate. A minimal amount of the homopolymeric polyethylene naphthalate which is relatively expensive can be utilized due to the thermoforming and injection molding as disclosed.