Monroe Seals is a direct manufacturer and supplier of custom molded rubber parts. Monroe Seals molding processes include:

Compression Molding: Uncured rubber compound is made into what is called preforms. They are the same size and weight as the finished part. A preform is placed into each cavity of the mold. The mold is compressed and under heat, pressure and time, the parts take form and the rubber is cured. The mold is opened and the parts are removed in a web of rubber and flash. The parts are then removed from the webbing and the flash is trimmed. Some compounds may require a post cure in addition to the time in the mold in order to achieve all of its properties.

This is by far the most popular type of rubber molding. The molds are low cost. The lead time to produce a tool is the shortest and you can produce the widest range of part sizes.

Transfer Molding: The mold is closed up and under hydraulic pressure, uncured rubber is forced into the mold cavities through small holes. The mold is heated so the rubber flows and takes the shape of the cavity. The mold remains closed until the rubber cures. The plunger is then raised and the transfer pad material is removed. The mold is then opened and parts are removed. Parts are then trimmed to remove any flash.

This process works well for rubber bonded to metal parts and rubber bonded to plastic parts.

Injection Molding: Uncured rubber compound is injected into a mold with a ram or screw-type plunger. The exact amount of material required for each part is injected into each cavity through a gate or runner system. The mold remains heated until the parts are cured. Once the parts are cured the mold can be opened and parts removed.

This process allows for tighter tolerances on the parts and cycle times are much quicker. The downside is the initial startup costs are much higher than compression or transfer molding.

We work with a wide variety of materials, including: Buna-N, EPDM, Viton, Neoprene, Silicone, Fluorosilicone, Vamac, and others.

Monroe Seals has over 40 years in the industry means we have the experience to supply you with exactly what you're looking for. We take pride in providing only the finest product possible, and that has led to an industry-leading quality control. We are proud to continue to serve many different industries around the world. Contact us with your design specifications.

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N/A Prop 65 Warning: This product may contain chemicals known to the State of California to cause cancer, and birth defects or other reproductive harm.

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Over 150 years of combined knowledge for our customers

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A full complement of rubber, machined plastics and standard materials.

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We are ISO 9001:2008 certified and have a customer base in many diverse industries