Transfer molding

 Transfer molding

Transfer molding uses a pre-formed rubber blank that is placed into a transfer pot located between the upper platen and the plunger. Once the mold is closed and loaded into the press, the plunger compresses the rubber and forces it through runners into the mold cavity below. When the cavity is filled, excess material flows into overflow channels or remains in the transfer pot.
After the cure time, the mold opens and the part is removed. The pot is cleared of excess rubber, reloaded with a new blank, and the cycle repeats for the next part.

Advantages

• High number of cavities

• One rubber blank can fill hundreds of cavities

• Cost-effective tooling

• Tighter dimensional tolerance control

• Economical for medium-to-high precision components

• Capable of producing two-stage molded components 

Disadvantages

• Increased waste (sprues/overflow)

• More expensive tooling than compression molds

• Slower cycle time than injection molding