PVC resin is a polar amorphous polymer, density: 1.380 g/cm3, glass transition temperature: 87 ℃, so the thermal stability is poor, difficult to process. Can not be used directly, must be modified mix, add the relevant additives and fillers to be used. As a result of the addition of the relevant additives and fillers of different types and fractions, this determines the preparation of the PVC material performance and requirements are not the same. We usually call it the PVC formula, which is strictly a modified PVC formula, and the PVC is only modified to use. This category is often classified as a polymer modified material. The modification of polymer materials mainly focuses on the high performance of general plastics, the transformation of one-component materials to multi-component material composites (alloy, blending, compounding), the function of materials, the optimization of properties and prices. The modification methods are mainly chemical modification, filler modification, enhanced modification, blending modification and nanometer compound modification. The basic principle of modification is to give the material function or improve some performance by adding things.  Therefore, the PVC formula technology, determines the technology and production capacity of a factory.