Rubber Transfer Molding
The rubber transfer molding process is ideal to produce both solid rubber parts, rubber part with inserts and parts that require bonding rubber to metal. Rubber transfer molding combines the advantages of injection rubber molding with the ease of compression molding. This process is ideal for forming rubber products that require:
- Exact positioning
- Bonding rubber to fragile metal parts – such as wire
- Mold designs that contain multiple cavities and can trap air
- Intricate parts with lower volume requirements
The Qualiform process of transfer molding involves pushing unvulcanized rubber through sprues into a heated mold. Similar to compression molding, transfer molding requires raw material preparation into pellets and/or pre-forms.
Rather than placing the preform in the mold cavity, the rubber pre-form is placed in a chamber “pot” at the top of the mold then placed in a press. In the pot, the material is compressed by a heated plunger and transferred through sprues into the cavity below. During this, the plunger is kept in place until the preform takes on the shape of the mold and the rubber is vulcanized. Once the part cures, hardens, cools, it is then ejected. Any excess cured rubber left in the pot is removed and the mold cavities are cleaned for the next molding cycle to begin.
