MEHRSCHICHTIGER VORFORMLING ZUM BLASFORMEN UND VERFAHREN ZU DESSEN HERSTELLUNG

摘要

A multi-layer preform (26a,26b,26c) used for plastic blow molding and a method for making the preform provides an inner layer (28) of polyethylene naphthalate and an injection molded outer layer (30) of 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 (28) of polyethylene naphthalate by itself or along with a further inner layer (32) of virgin polyethylene terephthalate is thermoformed prior to the injection molding of the outer layer (30) of polyethylene terephthalate. A minimal amount of the polyethylene naphthalate which is relatively expensive can be utilized due to the thermoforming and injection molding as disclosed.