processingdetails

Compression Molding

Compression molding is common processing methods using to make plastic parts, which has a long history and is developed at the very beginning of the plastics industry. It is a truth that it was widely used in the bakery industry for cookie or cake molding before plastic materials existed.
 
Although it also can be applied to thermoplastics, compression molding is commonly used in manufacturing thermoset plastic parts. The raw materials for compression molding are usually in the form of granules, putty-like masses, or perform. In the process of compression molding, the molding material if generally preheated and is first placed in an open, heated mold cavity. The mold is closed with a top force or plug member, pressure is applied to force the material into contact with all mold areas, and heat and pressure are maintained until the molding material has cured. The process employs thermosetting resins in a partially cured stage, either in the form of granules, putty-like masses, or performs. Compression molding is a high-volume, high-pressure method suitable for molding complex, high-strength fiberglass reinforcements. The advantage of compression molding is its ability to mold large, fairly intricate parts. Compression molding produces fewer knit lines and less fiber-length degradation than injection molding.