Selection of plastic additives in the hottest UPVC

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Selection of plastic additives in UPVC core foaming pipe

plastic additives must be added in the processing of UPVC. The processing temperature of UPVC is also its decomposition temperature. 5. Displacement measurement accuracy: 0.5% indicating value (the whole process is not divided into grades). In order to inhibit the decomposition of UPVC resin at the processing temperature, a certain amount of heat stabilizer must be added. At present, the stabilizers used in the production of drainage pipes are mostly lead salts, such as tribasic lead sulfate (tribasic salt) and dibasic lead phosphite (dibasic salt), and rare earth composite heat stabilizers (REC) are also used

in comparison, the latter is better than the former in terms of thermal stability effect, synergistic effect, brightening effect, internal lubrication, etc. In addition, the composite lead salt stabilizer, which is developing rapidly at present, has thermal stability and lubricity at the same time, uses less than ordinary powdered lead salt, is convenient and dust-free, and is very suitable for the use of PVC drainage pipe in research metallographic microscope

in order to make the surface of the pipe smooth and the bubbles uniform and fine, resin modifiers such as ABS, EVA and other resins are often added; The commonly used AC blowing agent (Azodicarbonamide) is selected as the blowing agent, which has small dosage and large gas evolution. The above two kinds of heat stabilizers have the function of activating foaming agent. It can reduce the decomposition temperature of AC foaming agent from 200 ℃ to 160-180 ℃, which is close to the melting temperature of resin, and can decompose rapidly within a narrow temperature range, which can make foaming efficiency high and product quality good

in the processing of PVC, it is often necessary to add an appropriate amount of fillers. When processing u and keeping clear PVC pipes for a long time, CaC03 filler is generally added, which is good and cheap, has a wide range of sources, and the dosage is generally no more than 30 parts. In addition, in the deep processing of UPVC, the PVC resin turns yellow due to the degradation reaction of PVC, and the whiteness of the UPVC products produced is not good

in order to improve the appearance of products, it is often necessary to add some pigments to the UPVC core foaming pipe to increase the whiteness of materials, such as titanium dioxide, fluorescent brightener, etc. The choice of other additives, such as lubricants, is the same as the production of ordinary pipes on November 28

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