Eye Protection for Antennas | Transfer Molded

Eye Protection for Antennas | Transfer Molded

Eye protection for Antennas made from transfer molds

• Industry: Material Handling Industry
• Application: Used on top of antenna
• Process: Transfer Molded
• Material: Neoprene Compound

Neoprene Compound Rubber Molding

Molded neoprene rubber is an all-purpose resilient polymer/elastomer because it provides resistance to corrosion from chemicals. Neoprene demonstrates resilience, tear resistance and tensile strength. Additionally, it is abrasion resistant and has admirable compression set properties.

Although Neoprene is resistant to oil, gasoline, sunlight, the ozone and oxidation, other polymers have better resistance to these same elements.

The Rubber Transfer Molding Process

The 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.  The plunger is kept in place until the preform takes on the shape of the mold and the rubber is vulcanized.  The part cures, hardens, cools, then is ejected. Excess cured rubber left in the pot, is removed, mold cavities are cleaned and the next molding cycle begins.

When transfer molding is used for rubber to metal bonding or over molding, the components are loaded into a heated mold either by hand or using a loading fixture.  Material is loaded into the well pot of the transfer mold.  The mold closes and the heated rubber is then transferred through the runner and gate sprues into the mold cavities and around the metal insert.  Under pressure and elevated temperatures, the rubber cures/vulcanizes and parts are removed.

The rubber transfer mold consists of a piston, well pot, sprue plate, cavity plate, and a base plate with a knock-out system used to eject the parts after molding.

Advantages of the Rubber Transfer Molding Process

Transfer molding offers several advantages over other methods by providing:

• Shorter production cycles
• Maintains closer dimensional tolerances than compression molding
• Provides uniformity
• Fast mold setup
• Economical process with high cavity count per mold per cycle
• Cost effective tooling
• Allows for rubber to metal bonding
• Allows for rubber overmolding
• Allows for  design flexibility, sharp edges and intricate parts