Compression Molding involves placing the uncured rubber compound into a heated, open mold cavity, then closing the mold under pressure (usually in a hydraulic press) to initiate vulcanization (curing). Transfer Molding requires the uncured rubber compound to be placed in a transfer chamber, heated, then forced into the mold cavity under pressure until cured. Injection Molding entails preheating uncured rubber in a chamber, then injecting it into a closed, heated mold.