In the production process of PVC pipe production equipment, since PVC is a heat sensitive material, even if a heat stabilizer is added, the decomposition temperature can be increased, and the stabilization time can be prolonged without decomposition, which requires that the molding temperature of PVC should be strictly controlled. Therefore, the extrusion temperature should be determined according to factors such as formulation, extruder characteristics, head structure, screw speed, temperature measurement point position, error of temperature measuring instrument and depth of temperature measurement point. The details are as follows: (1) Temperature control Temperature is an important factor affecting the quality of plasticization and product quality. The temperature is too low, the plasticization is poor, and the appearance and mechanical properties of the pipe are poor. After the shunt bracket, the weld line is obvious or the strength of the weld is low. Due to the poor thermal stability of PVC, the temperature will be too high to decompose, causing discoloration and scorching, which will make the operation impossible. (2) Screw cooling Because RPVC melt has large viscosity and poor fluidity, in order to prevent the screw from heating up due to friction and overheating, causing the screw material to decompose or roughen the inner wall of the pipe, the screw temperature must be reduced, so that the material can be plasticized, and the inner surface of the pipe Bright, improve the quality of the inside and outside of the pipe. The screw temperature is generally controlled between 80 and 100 ° C. If the temperature is too low, the back pressure increases, the output decreases, and even the accident that the material cannot be squeezed out and the screw bearing is damaged may occur. Therefore, the screw cooling should control the outlet water temperature to be no less than 70~80 °C. The cooling method is to perform water cooling by using a copper tube inside the screw. (3) Sizing pressure and vacuum When the tube blank is extruded into the die, the temperature is still high. In order for the tube to achieve a lower roughness, the correct size and geometry, the tube blank must be sized and cooled as it exits the die. (4) Screw speed The speed of the screw is related to the quality and output of the pipe. The adjustment of the screw speed is determined by the extruder specifications and pipe specifications. In principle, the large machine squeezes the small tube and the rotation speed is low: the small machine squeezes the large tube and the rotation speed is high. Generally ф45 single-screw extruder, screw speed is 20~40r/min, ф90 single-screw extruder, screw speed is 10~20r/min; twin-screw extruder 15~30r/min. Although increasing the screw speed can increase the output on a regular basis, if the output is too high, and the material and the screw structure are not changed, the plasticization of the material is poor, the pipe wall is rough, and the pipe strength is lowered. (5) Traction rate Traction rate directly affects the production of pipe production, and affects the wall thickness of the pipe. The instability of the traction rate will cause the pipe diameter to appear large and small. The traction speed should be closely matched to the extrusion rate of the pipe. In normal production, the traction rate should be slightly faster than the extrusion line speed by 1% to 10%. The slower the traction rate, the thicker the pipe wall, the faster the traction rate, and the thinner the pipe wall, the longer the longitudinal shrinkage of the pipe will be, and the internal stress will increase, which will affect the pipe size, pass rate and use effect. Adjusting the traction rate in production The following simple method can be used to place the extruded pipe in the traction track, but the track does not clamp the pipe, observe the difference between the track and the pipe line speed, if the traction rate is slower than the extrusion rate, it should be adjusted to accelerate to the wall. Thick enough to meet the requirements. Qingdao Huarunde Plastic Machinery Co., Ltd. Email @qq.com Plastic Material Cpu Stand,Plastic Stand With Wheels,Plastic Cpu Stand,Plastic Cpu Stand With Wheels Cixi Dujia Electronic Appliance Co., Ltd. , https://www.cixidujia.com