Compression molding material

Compression molding material types

There are many types of compression molding materials, which can be prepreg materials, pre-mixed materials, or blanks. The main types of molding materials currently used are: prepreg tape, fiber premix, BMC, DMC, HMC, SMC, XMC, TMC, and ZMC.

Synthetic resin

The molding compound used for composite molded products requires that the synthetic resin has: ① good wetting properties to the reinforcement material, so as to form a good bond at the interface between the synthetic resin and the reinforcement material; ② has an appropriate viscosity and good fluidity, in the pressing conditions, it can fill the entire cavity with the reinforcing material uniformly; ③ Under the pressing conditions, it has an appropriate curing speed, and there are no by-products or fewer by-products during the curing process, and the volume shrinkage is small; ④ It can meet the specific requirements of the molded product Performance requirements. According to the above selection requirements, commonly used synthetic resins are unsaturated polyester resins, epoxy resins, phenolic resins, vinyl resins, furan resins, silicone resins, polybutadiene resins, allyl esters, melamine resins, Polyimide resin, etc. In order to make the molded products reach specific performance indexes, after selecting the resin type and brand, the corresponding auxiliary materials, fillers, and pigments should also be selected.

Reinforced materials

The commonly used reinforcing materials in molding materials mainly include glass fiber cutting wire, untwisted roving, twisted roving, continuous glass fiber bundle, glass fiber cloth, glass fiber felt, etc., as well as a small number of special products asbestos, felt, asbestos fabric (cloth) and asbestos paper and varieties of high silica fiber, carbon fiber, organic fiber (such as aramid fiber, nylon fiber, etc.) and natural fiber (such as linen, cotton cloth, smelted cloth, non-smelted cloth, etc.). Sometimes two or more fiber mixtures are also used as reinforcement materials.

Auxiliary materials

It generally includes auxiliary materials such as curing agent (initiator), accelerator, diluent, surface treatment agent, low shrinkage additive, mold release agent, colorant (pigment), and filler.