SMC molding

SMC (sheet molding compound), the main raw material is composed of smc special yarn, unsaturated resin, low shrinkage additives, fillers and various additives. SMC has the advantages of superior electrical performance and corrosion resistance. Its mechanical properties are comparable to some metal materials, so it is widely used in transportation vehicles, construction, electronics / electricity and other industries.

SMC molding process

When the SMC enters the mold cavity, the press goes down quickly. When the upper and lower molds coincide, slowly apply the required molding pressure. After a certain curing system, the SMC molding is completed. During the molding process, various molding process parameters should be selected reasonably.

(1) SMC molding temperature

The molding temperature depends on the curing system of the resin paste, the thickness of the SMC product and the complexity of the structure. If the thickness of the product is 25 ~ 32mm, its molding temperature is 135-145 ℃. And thinner products can be formed at 171 ℃. The molding temperature should be selected between the highest curing speed and the best molding conditions. It is generally believed that the SMC molding temperature is between 120-155 ° C.

(2) SMC molding pressure

Smc molding pressure is determined by product structure, shape, size and smc material formula. Simple shape SMC products only need 5-7mpa molding pressure; complex shape products, molding pressure can reach 7-15mpa. The determination of molding pressure should consider many factors. Generally speaking, smc molding pressure is between 3-7mpa.

(3) Curing time

SMC curing time (also called holding time) is related to its material characteristics, molding temperature, product thickness and color and other factors. The curing time is generally calculated at 40s / mm. For thick products above 3mm, for each additional 4mm, the curing time increases by 1min.