The order of mixing heat has some influence on the quality of mixture and the abrasion of mixing tank.
Feeding sequence is usually:
1.At low speed,adding PVC resin and heat stabilizer.
2.At high speed and 60℃,is added with impact modifier, processing aid and inner lubricant.
3.At high speed and the temperature of 80℃ filler, titanium dioxide, ultramarine, external lubricant, UV-531,color masterbatch,antioxidant, etc..
1.The addition of heat stabilizer can give full play to its thermal stability of PVC resin.
2.Addition of internal lubricants is beneficial to the initial gelation of PVC materials.
3.Early addition of titanium dioxide will affect the surface finish and color products, and the mixing tank wear a larger;
4.Early addition of calcium carbonate is not only a greater wear on the mixing tank, and will give priority to absorb the lubricant;
5.Early addition of processing aids will preferentially absorb lead salt stabilizers to reduce the amount of PVC absorbed lead salt stabilizers, resulting in decreased material stability
6.Early addition of external lubricants will reduce the friction heat and shear heat, affecting the mixing effect and the stability of the stabilizer;
7.Early addition masterbatch will affect the color of PVC profiles.