Container preform assembly and method of manufacture

摘要

A preform assembly for blow molding a container includes a molded plastic preform having a body and a neck with an external surface. The neck includes a plurality of spaced lands molded integrally with the neck and the body and defining the external surface of the neck, and a plurality of open spaces between the lands. A plastic finish ring is molded separately from the preform and is externally secured over the lands. The open spaces between the lands reduce heat transfer between the preform neck and the finish ring. In two exemplary embodiments of the invention, the lands include either spaced axial ribs or spaced circumferential ribs on the preform neck, and the open spaces include either spaced axial channels or spaced circumferential channels between the ribs.