Compression molding is a manufacturing method in which the molding material, commonly referred to as molding compound, is placed in an open, heated and matched metal mold cavity. The mold is typically made from machined steel that will ensure a long service life. The mold is then closed with extreme pressure to force the fiber and resin compound into contact with all areas of the mold cavity. Heat and pressure are maintained until the molding material has cured. The process employs thermosetting resins with short or long chopped fibers, known as random mat and/or preforms of continuous fiber for added component strength.

Compression molding is a high-volume, high-pressure method suitable for manufacturing complex, high-strength fiber reinforcements. A distinct advantage of compression molding is its' ability to mold small to large intricate parts with features such as holes that would otherwise have to be post-machined with other processes. Compression molding produces fewer knit lines and less fiber-length degradation than injection molding. Carbon, aramids and fiberglass are all suitable fibers for this composite process.

ACI uses compression molding for prosthetics, bicycle components, oar blades and countless other complex geometries for a variety of industries.

Some examples of compression molded work manufactured by ACI are pictured below: