Transfer Molding

Transfer Molding

Transfer Molding involves having a “piston and cylinder”-like device built into the mold so that the rubber may be injected into the cavity through small holes.

1.  A piece of uncured rubber is placed into a portion of the mold called the “pot.” The plunger (on the top-most part of the mold) fits snugly into the “pot.”

Transfer Molding

2.  The mold is closed up and under hydraulic pressure the rubber is forced through the small hole (the “gate”) into the cavity. The mold is held closed while the rubber cures.

* Cycle times are shorter than compression molding

* Better than compression molding for rubber-to-metal bonding

3.  The plunger is raised up and the “transfer pad” material may be removed and thrown away.

4.  Mold is opened and the part can be removed. The flash and the gate may need to be trimmed.

Advantages of Transfer Molding
* Cycle times are shorter than compression molding

* Better than compression molding for rubber-to-metal bonding

Disadvantages of Transfer Molding

* The transfer pad is scrap

* Cycle time is longer than injection molding

* Product consistency is less than injection molding