Compression molding, used for compression mold, is a molding method according to the characteristics of each stage in plastic curing reaction, and often used to produce high-quality composite parts. Compression molding materials are usually powder, granular or fibrous plastic, such as thermoplastic(LFT, GMT,LWRT), rubber and thermosetting plastic(SMC, BMC), Or new composites(SymaLITE,carbon fiber).
What is compression molding process?
Firstly, plastic is put into the cavity at the molding temperature, then close the mold, the material inside the cavity becomes a molten state under the high heat and high pressure, and then fills in the whole cavity. After curing, the product is ejected by ejector, repairing the flash. For compression molding, material, shape, compression, temperature, part thickness, cycle time must be considered. You must analyze the characteristics of the materials to ensure the product perfectly. Molding cycle time is something with material, part feature, mold design, temperature, pressure, etc.
What are the advantages and disadvantages of compression mold?
Advantages of compression mold:
(1)The loss of raw materials, the wear of the mold cavity is small, and the maintenance cost of the mold is low.
(2)It can be used to form large flat products. High dimensional accuracy, small shrinkage, low internal stress, the mechanical properties are relatively stable. The surface is smooth without secondary modification.
(3)The cost of the molding machine is lower, the mold structure is simpler, multiple cavities can be produced at lower cost, and the manufacturing cost is usually lower than that of the injection mold.
Disadvantages of compression mold:
(1)At present, it is not suitable for molding complex products with depressions, side slopes or small holes.
(2)Burrs must be trimmed manually
(3)For thermosetting plastics, when the molded products have slight defects, they are often unable to be recycled.
What is compression molding used for?
Compression molding is widely used in industry, agriculture, automotive industry, electricity, chemical industry, construction and other fields. MDC has developed compression molds such as spoiler templates, fenders, bumpers, front panel on trucks, engine covers, doors, bottom fenders, car ceilings, seat backs, electric boxes and bathroom door panel basin, etc.