About SMC/BMC composite materials

1. SMC: Sheet molding compound, SMC belongs to the FRP category. FRP is the abbreviation of English Fiber Reinforced Polymer Plastic, which is literally translated as: fiber reinforced composite plastic. FRP was first commonly known as fiberglass in China (taking its light weight and high strength), and now it refers to the hand lay-up molding process.

The main FRP molding processes include:

          1. Hand lay-up and solidify at room temperature.

          2. Molding (SMC/BMC), molding.

          3. RTM, injection type.

          4. Wrapping, pultruding and spraying.

SMC composite material is the abbreviation of Sheet Molding Compound, which is sheet molding compound. The main raw materials are composed of GF (special yarn), UP (unsaturated resin), low shrinkage additives, MD (filler calcium carbonate) and various additives.   

Since its inception, SMC has been mainly used in the automotive manufacturing industry. In the United States, all truck cabs are made of composite materials, primarily SMC. Many cars have components made of SMC, and even the entire exterior is made of SMC. In Europe, because the mass production of SMC parts is more competitive than metal, many luxury vehicles use SMC parts. 

The emergence of new SMC composite materials has completely broken the low threshold and mixed situation in the traditional industry. With its good surface gloss, zero shrinkage, excellent flame retardancy, aging resistance, pollution resistance, and excellent product performance stability, it has become the future ceiling material market. new generation products. 

The unique properties of SMC composite materials solve the shortcomings of wood, steel, plastic and other materials that are easy to age, corrode, have poor insulation, poor cold resistance, poor flame retardancy, and short lifespan. The excellent properties of SMC composite materials include absolute sealing and waterproofing It has excellent performance, anti-corrosion performance, anti-electricity theft performance, beautiful appearance, and long service life. It is widely used in home decoration and building materials, communications, and construction. 

Common SMC products: automobile parts, train interior parts, building templates, water tanks, electrical components, sanitary ware parts, etc.

SMC composite materials include flat panel series and sound-absorbing panel series.

2. BMC is the abbreviation of English Bulk Molding Compound, and its Chinese name is Bulk Molding Compound.

BMC (DMC) composite material is the abbreviation of Bulk (Dough) Molding Compounds, which is bulk molding compound. It is often called unsaturated polyester bulk molding compound in China. Its main raw materials are GF (chopped glass fiber), UP (unsaturated resin), MD (filler calcium carbonate) and various additives that are fully mixed to form a dough-shaped prepreg.          

BMC is a molding intermediate material for semi-dry manufacturing of glass fiber reinforced thermosetting products. It is pre-mixed into a paste from unsaturated polyester resin, low shrinkage/low profile additives, initiators, internal release agents, mineral fillers, etc. Add thickeners, colorants, etc., and glass fibers of different lengths, stir in a special kettle, carry out the thickening process, and finally form a ball-shaped intermediate material, which can be used for molding and injection molding. 

BMC bulk molding compound has excellent electrical properties, mechanical properties, heat resistance, chemical corrosion resistance, and is adaptable to various molding processes to meet the performance requirements of various products. Therefore, it is increasingly popular to the majority of users.