CPVC is the chlorinated product of PVC, which is the chlorinated modification of PVC. PVC resin is the main raw material for producing CPVC resin. It must be loose and not compact. As the processing of CPVC resin mainly uses the aqueous suspension method, in this process, because the diffusion rate of chlorine gas in the PVC resin has a greater effect on the chlorination rate of PVC, it is required that the film of the PVC resin be as thin as possible and the surface area cannot be Small, so manufacturers of CPVC should choose special PVC resin synthesized by suspension with special additives to synthesize CPVC resin. CPVC resins produced by Goodrich in the United States, BASF in Germany, Sekisui in Japan and Zhongyuan Chemical Co., Ltd. are all chlorinated using special PVC resins.

　　The performance of CPVC products is mainly determined by CPVC resin, and its processing performance is determined by CPVC resin. The key to the application and development of CPVC materials lies in the improvement and improvement of the production process of CPVC resin, and the availability of special PVC resin, which can provide CPVC resin with excellent performance and good processability.

　　The processing difficulty of CPVC is greater than that of PVC. The melt processing viscosity is at least twice that of PVC. The melt processing temperature is also higher than that of PVC, especially during injection processing. Therefore, PVC resin with low polymerization degree should be used to synthesize CPVC. CPVC resin for extrusion should use P = 700 PVC resin, and CPVC resin for injection should use P = 500 PVC resin.

　　Generally, the chlorine content of PVC is 56-59% and CPVC is 64-75%. As the chlorine content increases, the melt viscosity of CPVC increases, the softening point increases, the heat resistance improves, the density increases, and the tensile strength increases. As it increases, the brittleness increases, the impact strength decreases, and the processing difficulty increases. This party does not involve the chlorination process and technology of CPVC during synthesis, but we hope that the high chlorine content CPVC resin with a chlorine content greater than 70% will have a lower chlorine content on the surface to make it easier to process.

　　With the use of special formulas and processes, the performance of the extruded products made of domestic CPVC resin has reached the international advanced level, and the processing is not difficult, but the injection products using domestic CPVC resin are difficult to process, which depends on the production of CPVC. Manufacturers can develop domestic CPVC resins that are truly suitable for injection processing.