Rainwater grate is made of flat steel and twisted square steel or flat steel welded with flat steel. Rainwater grate has the advantages of beautiful appearance, convenient drainage, high strength, many specifications and low cost. With the development of science and technology, a new composite water grate is formed by using resin or plastic reinforcement as reinforcement and inorganic filler. The advantage is that the self weight is lighter than cast iron water grate and the cost is low.
SMC and BMC are composite materials.
BMC (DMC) material is the abbreviation of bulk (dough) molding compounds, i.e. lump molding compounds. It is often called unsaturated polyester group molding compound in China. The main raw materials are GF (chopped glass fiber), up (unsaturated resin), MD (filler) and various additives, which are fully mixed into a pellet like prepreg. DMC materials were first used in the former West Germany and Britain in the 1960s, and then developed greatly in the United States and Japan in the 1970s and 1980s, respectively. Due to its excellent electrical properties, mechanical properties, heat resistance, chemical corrosion resistance, and adaptability to various molding processes, BMC can meet the performance requirements of various products, and is widely used in automobile manufacturing, railway transportation, building accessories, mechanical and electrical products and other fields.
SMC composite is the abbreviation of sheet molding compound, namely sheet molding compound. The main raw materials are GF (special yarn), up (unsaturated resin), low shrinkage additive, MD (filler) and various additives. It first appeared in Europe in the early 1960s. Around 1965, the United States and Japan developed this technology one after another. In the late 1980s, China introduced advanced SMC production lines and processes from abroad. SMC composite materials and SMC molded products have excellent electrical insulation, mechanical properties, thermal stability, chemical corrosion resistance. So SMC products are widely used.
