The compression molding process is used for temperature activated thermosetting polymers. Compression molding basically involves the pressing of a deformable material charge between the two halves of a heated mold, and its transformation into a solid product under the effect of the elevated mold temperature. Compression molding temperatures are often in the range 140-200 0C; mold pressures can vary from 35 atm to 700 atm. Material charges are often pre-heated to speed up the initial softening stage. Compression molding is characterized by the show and moderate flow of the very viscous material charge to fill the cavity, and it is not normally suitable for making complicated parts, or parts featuring fragile inserts.