Patent ID: 6319436
Filing Date: 2001-11-20
Classification: B29C,B62D

Abstract:
A method of making a seal plug in a two-shot injection molding machine, the method comprising the steps of:providing a molding apparatus, the molding apparatus including a molding die temperature control system and a fluid cooled beryllium copper molding die adapted to be cooled by a working fluid flowing through a closed loop path defined in the molding die;during a first time period, forming a resilient cover cap member by injecting a thermoplastic material into a first mold cavity defined by said molding die;using said temperature control system during a second time period, cooling said molding die from a second temperature above a first temperature range to a first temperature within said first temperature range by passing said working fluid through said closed path defined in the fluid cooled molding die; and,during a third time period, forming a seal ring on the resilient cover cap member by providing a heat responsive foamable material that is flowable when within said first temperature range and thermoexpanding when above said first temperature range, and injecting said heat responsive foamable material into a second mold cavity defined by said molding die after said molding die reaches said first predetermined temperature.