PVC can be divided into soft and hard PVC PVC. The hard PVC market accounted for about 2/3, soft PVC accounted for 1/3. Soft PVC is commonly used in floors, ceilings and leather surface, but due to the soft PVC contains softeners (this is also a difference of PVC soft and rigid PVC) easy to become brittle, is not easy to save, so the use range limited. Hard PVC does not contain softeners, therefore has good flexibility, easy molding, not brittle, non-toxic and pollution-free, save for a long time, so the development and application of great value. PVC is the essence of a vacuum membrane, the surface panel used in various types of packaging, it is also known as the decorative film, with film, used in building materials, packaging, pharmaceutical and other industries. The building materials industry accounted for the largest proportion, 60%, followed by the packaging industry, there are a number of other small application industry.

The chlorine atoms in molecules containing polyvinyl chloride. Due to the dipole C - CL bond, it is a kind of strong polar material. PVC has good acid and alkali resistance, wear resistance, flame resistance and insulation resistance, but poor stability to light and heat. Preparation of PVC business, there are four kinds of methods: suspension method, bulk polymerization, emulsion polymerization and solution method. Suspension method is the most common, most of which is used PVC resin resin. The products according to the containing plasticizing dose (usually dibutyl phthalate, phthalic acid dioctyl) is divided into three kinds of materials of hard, half hard and soft. Hard PVC containing plasticizer for 10 - 25%, semi - rigid PVC for 30 ~ 40%, soft PVC for 40-70%. All PVC products must contain a certain amount of stabilizer in order to avoid degradation during processing. The plasticizer in soft PVC products is to soften the polymer. The choice of plasticizer or mixed plasticizer, the final performance to the desired product is determined by. Most of the plasticizer also plays the role of processing aids to a certain extent. The plasticizer reduces the melting temperature and viscosity of the resin, thereby preventing the resin from adhering to the metal parts of the processing equipment.