What is Compression Molding?

Compression molding is a molding process in which preheated polymer is placed into an open heated mold cavity. The mold is then closed and pressure is applied so that the material contacts all areas of the mold.
Compression molding dies usually use a hydraulic press, and the upper and lower parts of the die are fixed on the press. The molding material is placed on the open mold, and the press is closed. The raw material is melted under the set temperature and pressure generated by the press and fills the cavity of the mold.
At present, compression molding has become a popular technique.
Advantages of compression molding:
1. It uses advanced composite materials, which tend to be stronger, lighter and more resistant to corrosion than metal parts, resulting in objects with better mechanical properties.
2. Another advantage of compression molding is its ability to manufacture very complex parts. Although the technology can’t quite reach the production speeds of plastic injection molding, it does offer more geometries than typical laminate composites.
3. Compared to plastic injection molding, it also allows longer fibers, making the material stronger. Therefore, compression molding can be seen as a middle ground between plastic injection molding and laminate composite manufacturing.
4. Compression molding has the ability to manufacture complex parts in a variety of applications, while prioritizing part cost and production cycle time, so for manufacturers in many industries, molding is an advantageous process.