PVC can be divided into ordinary level ( toxic PVC) and Health Level ' ( non-toxic PVC). Sanitary requirements of vinyl chloride (VC) content of less than lOXl0-6, can be used for Processing aidfood and medicine. Different synthesis , PVC can be divided into suspension and emulsion PVC PVC. According to national standards GB/T5761-93 " universal suspension PVC resin test" requirements , suspension PVC into PVC-SGl to PVC-SG8Jk resins , where the smaller the number , the greater the degree of polymerization , the molecular weight of the more large, higher strength, but the more difficult the melt flow , processing is more difficult . The specific choice when doing soft products , generally use PVC-SGl, PVC-SG2, PVC-SG3 type , you need a lot of added plasticizer . Such as polyvinyl chloride resin Flame retardantfilm for SG-2 , 50 to 80 parts of a plasticizer . While processing hardware products , generally with little or no amount of plasticizer added , so use PVC-SG4, VC-SG5, PVC-SG6, PVC-SG7, PVC-SG8 type . Such as rigid PVC pipes using SG-4 resin, plastic window profiles using the SG-5 resin , hard transparent resin sheet using the SG-6 , rigid foam profiles using the SG-7, SG-8 resin . The paste is mainly used for emulsion PVC artificial leather , wallpaper and floor covering and dipped in plastic products. Some manufacturers factory PVC resin by polymerization degree of PVC resin ( polymerization degree is the number of the link unit , the degree of polymerization multiplied by the molecular weight of PEG molecular weight equal ) Classification
PVC powder as a white powder , the density between 1.35-1.45g/cm3, an apparent density of 0.4-0.5g/cm3. Depending on the size of the plasticizer content for software and hardware products , general plasticizer content of 0-5 parts of hardware products , 5-25 parts of semi-rigid products, more than 25 parts of soft products .