METHOD AND SYSTEM FOR MAKING MULTI-LAYER PREFORM

摘要

A method for making a multi-layer plastic preform (12) employs blow molding air into the multi-layer parison until an outer layer of the multi-layer parison rests against the preform mold (14) and thereafter inserting a compression core (47) sized to fit the pre-blown preform to smooth the inner layer of the blown parison and finish the preform. A system for making a multi-layer plastic preform includes a blow stem assembly having a device for introducing air into a multi-layer parison captured by a preform mold in a blow-mold operation, and a compression preform core attached to an end of a compression rod wherein when the compression preform core is retracted into the device, air can be blown into the preform mold and when, the compression rod (46) extends in a stroke through the device, the compression preform core extends out of the device into the preform mold.