A former sand, constitute the main body of the original sand-coated sand, sand the original requirements are: high refractoriness coated sand, less volatile matter, high strength particles themselves, usually made from natural silica sand, mainly because of its rich reserves, cheap, to meet the casting requirements. Only the special requirements of the casting was made of special sand (such as zircon sand, chromite, ceramic sand, magnetic iron ore, etc.) as the original sand coated sand: General requirements for silica sand is: A.SiO2: cast iron and non-ferrous casting require more than 90% sand, castings require more than 98%. B. acidic than alkaline sand sand. C. clay content <0.3%. D. Particle size distribution: 3 screen should adopt centralized, 5 sieve dispersion. E. grain shape: round good choice as silica sand, angular coefficient should generally be less than 1.3. Usually by two sand scrub to meet the requirements, but in order to improve the performance of coated sand, silica sand can be pickled or active treatment temperature (900-1200 ℃ roasting). Ordinary coated sand: its composition usually consists of quartz sand thermoplastic phenolic resin, methenamine and calcium stearate constitute resin sand regeneration equipment, without concerning additives. The resin is usually relatively high amount at a certain strength requirements, do not have high temperature, low inflation, low gas and other characteristics suitable for some less demanding, simpler structure of cast iron production. High strength, low gas coated sand: is based on ordinary coated sand by adding the relevant characteristics of "additive" and the adoption of a new preparation process, so that the amount of resin dropped significantly, significantly reduce gas evolution resin sand reclamation manufacturers, and can delay the hair air speed. The coated sand with high strength, low inflation, low gas, gas and other characteristics of slow hair, especially for iron castings, steel castings in small and medium volume requirements for low-fat sand core resin sand recycling machine, such as sand and other core body High temperature coated sand: This generally refers to a large sand coated sand thermal strength, heat long time, high temperature deformation sand resin regeneration, rather than its high refractoriness. It is through a special process recipe technology (usually when a certain amount of inert materials such as silica sand coated sand milling, high chromium ore, carbonaceous material or other inert materials, etc.), to produce a superior high temperature performance and integrated casting The new coated sand properties. High temperature, high strength, low inflation, low gas, gas, etc. slow hair. Especially for complex thin-walled precision iron castings (such as automobile engine block, cylinder head, etc.) as well as the high demand of castings (such as container train horn and brakes buffer housing, etc.) production, which can effectively eliminate the sticky sand, deformation, thermal cracking and porosity and other renewable resin sand casting defects production line, resin sand regeneration, provided by Qingdao Heng Heng Machinery Co., Ltd. Qingdao. Qingdao Heng Machinery Co., Ltd. (www.thjidian.com) strong, credible, Shandong Qingdao Cleaning equipment industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Qingdao Heng and you hand into the brilliant, for a better future!