Rubber Compression Molding

Compression molding is the oldest and most simple rubber molding process available. It is a good manufacturing choice for large parts, and low to medium production quantities. Tooling is less expensive than other processes, but is a labor-intensive process due to method of loading the mold; and cure times. With this method it requires a preform of uncured rubber to be placed on top of the mold cavities, or individually into each of the cavities.  The mold is then closed, and the press squeezes the mold plates together forcing the preform to take the shape of the cavity, or cavities, and form a finished part. The mold remains closed until the rubber is cured, completing the process. Producing parts in this method requires more press time, labor, and yields the most inconsistent results however, than either Transfer or Injection molding.

Our molding press capabilities, for our compression line, range from 12” x 12” up to and including 85” x 108”, with various press sizes in between.

Advantages of Compression Molding

  • Less expensive tooling
  • Good choice for small to large parts
  • Good for parts with inserts
  • Good for low to medium production quantities
  • Good for high durometer parts

Disadvantages of Compression Molding

  • Longer loading and process time
  • Labor intensive beginning to end
  • Yields the most inconsistent results than either transfer or injection molding processes

To get started on a compression molding process, request a quote from Minor Rubber today.