B2b. screw transfer molding - is a further refinement of the transfer molding process. The material is heated and mixed with a plasticizing screw in the molding machine and is dropped in the pot of the mold. A plunger then forces the material into the mold cavity. Fig. 4B2b illustrates the process, which is useful when the molding material is difficult to preform.

Fig. 4B2b Screw transfer molding.

B3. cold molding - is regular compressionmolding with no use of heat during the compression phase. The thermosetting material, including binders, is pressed to shape in the mold, then removed, and cured in a separate oven. The pressing operation is thus quicker than with hot molding, and the full molding sequence is more economical. However, the dimensional accuracy and surface finish of the molded part are usually inferior to that achieved with conventional compressionmolding. A number of parts can be cured simultaneously in the oven. The process can be useful for limited quantity production. The term cold molding is also used to identify the molding of reinforced thermosetting plastics that have been formulated to polymerize and cross-link at room temperature.