Rubber Transfer Molding Process
Our 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.
Transfer molding is a manufacturing process used for creating various industrial products. It is done when a piece of uncured rubber called a preform is loaded into a transfer pot. The ram is then closed, pushing the preform through the runner and gate system into the part cavity. The rubber is held in the heated cavity for a specific amount of time to properly cure the rubber into its final shape. While it is more labor intensive than injection molding, transfer molding is ideal for high precision applications, as well as for using colored rubber compounds.
Custom Rubber Molding Co.