Commonly known as the press was one of the earliest methods of molding plastic parts. Compression molding is the plastic directly added to a certain temperature within the open mold cavity, and then closed molds, plastic melt under heat and pressure into a flow state. Due to the physical and chemical effects, leaving the plastic hardens into a certain shape and size of the plastic parts of the room temperature remains the same. Compression forming main is for forming thermosetting plastic, as phenolic die plastic powder, and urea aldehyde and Melamine Formaldehyde die plastic powder, and glass fiber enhanced bakelite, and epoxy resin, and DAP resin, and organic silicon resin, and poly n Asia amine, of die plastic, also can forming processing not saturated polyester material Mission (DMC), and tablets-like die plastic (SMC), and prefabricated overall die plastic (BMC),. Under normal circumstances, often according to the compression with the structure of the upper and lower mould, compression modes into Flash, without spilling, half spilling type categories.