Method for making floor fan seal plug with thermoexpanding seal ring and axial guide members

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 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 nylon thermoplastic material into a first mold cavity defined by said molding die;
• using said temperature control system during a second time period, cooling said fluid cooled molding die from a second temperature of about 540 degrees Fahrenheit and above a first temperature range to a first temperature of about 180 degrees Fahrenheit 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.

A method of making a seal plug, the method comprising the steps of:

• providing a beryllium copper molding die;
• providing a molding die temperature control system;
• during a first time period, forming a resilient cover cap member portion of the seal plug 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 to a first predetermined temperature;
• and,
• during a third time period, forming a seal ring portion of the seal plug on the resilient cover cap member by injecting a foamable material into a second mold cavity defined by said molding die.

A method of making a seal plug in a two-shot injection molding machine, the method comprising the steps of:

• providing a molding apparatus including a molding die and a molding die temperature control system;
• during a first time period, forming a resilient cover cap member by injecting a nylon 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 of about 540 degrees Fahrenheit and above a temperature range to a first predetermined temperature of about 180 degrees Fahrenheit within said temperature range;
• and,
• during a third time period, forming a seal ring on the resilient cover cap member by injecting a thermoexpandable heat responsive foamable material into a second mold cavity defined by said molding die, the foamable material being adapted to expand to about one and a half times its original size when above said first temperature range.