Blow molding process for the manufacture of polyethylene terephthalate containers

摘要

Blow molding processes for the manufacture of polyethylene terephthalate (PET) containers are disclosed. The containers are capable of withstanding, without appreciable deformation, relatively severe thermal conditions encountered during processing by filling with a hot liquid or pasteurization of the contents of the container. A representative process includes the steps of blow molding the heated body of an amorphous PET preform comprising a body and a neck section having a body with dimensions greater than the dimensions of the final PET container to be formed; heating only the body of the intermediate container under specified conditions to rapidly shrink the body, thus forming a contracted body; heating the neck section to effect crystallization thereof; slowly cooling the neck section alone while heating of the contracted intermediate body continues; and blow molding the heated contracted body of the intermediate container in a second mold to its final shape and dimensions.