Insulated modular injection nozzle system

Abstract

A modular injection nozzle system for use with hot runner injection machines employs a thermal insulating element between the tip of the injection nozzle and a removable mold gate insert. This thermal insulating element limits the heat loss from the tip to the gate insert, assists in sealing the gate area and provides assistance in aligning the gate and the nozzle during assembly. The removable mold gate insert allows for eased servicing and assembling/dis-assembling of the injection nozzle system and has limited contact with the mold plate. In one embodiment, the removable gate insert is mounted to the nozzle via the insulating member, which is in the form of a sleeve with exterior threads which are complementary to interior threads on the gate insert. The sleeve can either be press-fit onto the nozzle or can have interior threads which are complementary to exterior threads on the nozzle. In either case, the sleeve can assist in the alignment of the components of the nozzle system. In another embodiment, the insulating element also includes an gap between the nozzle tip and the gate insert, the gap having a suitable insulating gas or vacuum therein to provide additional insulation. In another embodiment, the insulating element comprises a layer of insulating material on the nozzle tip and the gate insert can either be press fit with the layer or the layer can have exterior threads can into it to engage complementary threads on the gate insert. In another embodiment, the insulating element is molded in place on the nozzle tip.