Compression molding is the process of manufacturing by using a mold to produce goods. The mold has two parts that form the complete product shape when they are closed. Materials, which are usually pre-heated, are placed on one of the molds. The two halves are then compressed to spread the material around them. High pressure from the compression distributes the material evenly around the mold cavity.
Heating the material enables it to conform to the mold better. Molds can also be heated to keep the material from cooling too quickly. After the molds are pressed, they are left to cure. The curing process ensures that the material will not change its shape when it is removed from the mold. This process can usually take from several hours to days, depending on the materials used.
The materials generally used for compression molding are made from plastic compounds, rubber, and metal alloys. Compression molding plastic is commonly made from vinyl or polyester compounds. Before molding, they are usually in the form of pellet, paste, or sheet to ease handling. Additives and fillers may be added to the compound to reduce cost and prevent shrinkage after the molding process.
Read more: What is Compression Molding?