What is the process condition of RPVC injection molding

RPVC is the main class of PVC, also known as rigid polyvinyl chloride, and the following main research on its technological conditions.(1) the forming performance of RPVC small 1) moisture absorption of RPVC, but in order to improve the liquidity, improve the quality of plastic parts, appropriate to the dry processing, 2) the poor thermal stability of RPVC, extremely easy degradation, is one of the worst thermal stability in the plastic, 200 ℃ will decompose, decomposition release corrosive and irritant gas, so the heat stabilizer must be added.3) the melt viscosity of RPVC is high, which requires high molding pressure, but the pressure is too large and it is easy to cause the melt fracture. Therefore, it is advisable to use middle and low speed in injection molding, so as to avoid high speed filling.4) the viscous flow temperature of RPVC is very close to the thermal decomposition temperature, and the forming temperature range is very narrow. Therefore, it is necessary to strictly control the material temperature.5) the RPVC melt will release hydrogen chloride gas during decomposition, which has a strong corrosive effect. Therefore, the equipment and molds of the processed RPVC should have good anti-corrosion measures to ensure that it is not corroded.6) the mold casting system of RPVC should be coarse and short, and the feed inlet section should be as large as possible, and there should be no dead Angle in the runner.7) the molding temperature range of RPVC0 is narrow, and the retention time of the molten material should be reduced as soon as possible.8) the temperature should be as uniform as possible in all parts of the RPVC mold, and the temperature difference should not exceed 5, otherwise the internal stress will be too large.9) the cooling speed of RPVC melt is fast, and the molding cycle should be as short as possible, and the general molding cycle is 40~80.10) screw injection molding machine is suitable for RPVC body, and the nozzle should be used in straight line.(2) main injection molding condition of RPVC 1) temperature of the material cylinder.RPVC is strict to the temperature, it is heat sensitive plastic, the temperature is too high easy to cause decomposition;It is also less liquid and less liquid.Usually, the cylinder temperature control in 170 ~ 190 ℃ is good, do not exceed 200 ℃.2) mold temperature.Have a great relationship die temperature on forming quality, mold temperature is too high will promote the decomposition of low is harder to fill, usually, mold temperature control in 30 to 60 ℃ advisable.3) injection pressure.Due to the high viscosity of the RPVC melt, the injection pressure should be on the high side, and the injection pressure is usually controlled at 80~130MPa.