POM GC-25宝理

POM GC-25宝理--POM can be divided into homopolymer formaldehyde and copolymer formaldehyde according to the chemical structure of the molecular chain. Homopolymer formaldehyde is usually obtained by the polymerization of anhydrous polyformaldehyde. Copolymer formaldehyde is the product of the copolymerization of trimethylformaldehyde and a small amount of dioxane. It is precisely because of the different structure that the homopolymer and copolymer formaldehyde have different properties. The main differences between them are: the density and crystallinity of homopolymer formaldehyde are higher, the melting point and HDT are 10 degrees higher than that of copolymer formaldehyde, the strength, creep resistance and friction resistance are better, but the thermal stability is poor, the processing temperature range is narrow about 10 degrees, and the stability of acid and alkali is lower

POM melt is a kind of shear-sensitive polymer, which can be achieved by increasing the injection speed to increase the flow performance. At the same time, the cooling rate of POM crystallization will be very fast in the above applications. Surface defects such as wrinkles, speckles and weld marks will easily occur on the products, so it is necessary to improve the injection speed. When moulding products with large wall thickness, a slightly slower injection speed can be used to prevent the gas wrapped in the material from effectively discharging and producing holes due to the rapid injection speed.

POM is similar to PA in many respects, but its fatigue resistance, creep resistance, rigidity and water resistance are superior to PA. The crystallinity of POM is very high, from 73% to 86%, which depends on quenching temperature. When quenching temperature changes from 0 to 155 C, the crystallinity changes from 78% to 82%. Annealing treatment will increase the crystallinity. The higher the crystallinity, the higher the yield strength and tensile strength