r, > (
Polyoxymethylene: r, >) (Saigang~Trane)
<:rr, , English name:)
<:rr, , (polyoxymethylene resin) Definition: Polyoxymethylene is a linear polymer with no side chains, high density and high crystallinity. According to the different chemical structures in its molecular chain, it can be divided into two types: homopolymer and copolymer. The important difference between the two is that homopolyoxymethylene has high density, crystallinity and melting point, but poor thermal stability, narrow processing temperature range (about ℃), and slightly lower stability to acids and alkalis, while copolymer has high density, crystallinity, melting point, The strength is low, but it has good thermal stability, is not easy to decompose, has a wide processing temperature range (about ℃), and has good stability against acids and alkalis. It is an engineering plastic with excellent comprehensive properties. It has good physical, mechanical and chemical properties, especially excellent friction resistance. Commonly known as Saigang or Duugang, it is the third largest general-purpose plastic. Suitable for making wear-reducing and wear-resistant parts, transmission parts, chemical industry, instrumentation and other parts.
: r, >Polyoxymethylene is a hard and dense material with a smooth and shiny surface, light yellow or white, and the thin wall part is translucent. The combustion characteristics are that it burns easily and continues to burn after leaving the fire: r, >. The upper end of the flame is yellow and the lower end is blue. It melts and drips, and has a strong pungent formaldehyde smell and fishy smell. Polyformaldehyde is a white powder, generally opaque, with good colorability, specific gravity: g/cubic centimeter, molding shrinkage rate: molding temperature ℃, drying conditions: ℃ hours. The long-term heat resistance is not high, but it can reach ℃ in the short term. The short-term heat resistance of homopolymerization is more than ℃ higher than that of copolymerization, but the long-term heat resistance of copolymerization is about ℃ higher than that of homopolymerization. It can be used for a long time in the temperature range of ℃ to ℃. It is extremely easy to decompose, with a decomposition temperature of 10°C. During decomposition, irritating and corrosive gases are produced. Therefore, mold steel should be made of corrosion-resistant materials.
: r, >High strength, stiffness, good elasticity, good wear reduction and wear resistance. Its mechanical properties are excellent, its specific strength can reach ., and its specific stiffness can reach ., which is very close to metal. The mechanical properties of copolymer change little with temperature, and the change of copolymerization is slightly larger than that of homopolymerization. The impact strength is higher, but the conventional impact is not as sensitive as B: r, > and C. The impact strength can be reduced significantly if there are gaps. The fatigue strength of The creep property is similar to that of , it is only . at ℃,, and is little affected by temperature. The friction coefficient is small, the wear resistance is good (
: r, >
: r, >B), the limit value is large, and the self-lubricating property is good. When products are ground against each other, a squealing noise is easily produced when high loads are applied.
: r, >The electrical
insulation: r, >has good resistance and is almost unaffected by temperature and humidity. The dielectric constant and dielectric loss are within a wide range of temperature, humidity and frequency
br/>: r, > Electrical insulation: r, > has good resistance and is almost unaffected by temperature and humidity. The dielectric constant and dielectric loss vary widely over a wide range of temperature, humidity and frequency. The arc resistance is excellent and can be maintained at high temperatures. The dielectric strength of is related to the thickness, when the thickness is ./, it is ./, when the thickness is ./.
: r, >
Blue POM stick//4102 manufacturer wholesale blue POM stick