1. Rigid PVC is one of the most widely used plastic materials.
2. The melting temperature of PVC during processing is a very important process parameter. If this parameter is improper, it will lead to the problem of material decomposition. The flow characteristics of PVC are quite poor, and its process range is very narrow. In particular, PVC materials with large molecular weight are more difficult to process (such materials usually need to add lubricant to improve flow characteristics), so PVC materials with small molecular weight are usually used. The shrinkage of PVC is quite low, generally 0.2~0.6%.
3. PVC can be divided into hard PVC and soft PVC. Among them, hard PVC accounts for about 2/3 of the market and soft PVC accounts for 1/3. Soft PVC is generally used for floor, ceiling and leather surface. However, because soft PVC contains softener (which is also the difference between soft PVC and hard PVC), it is easy to become brittle and difficult to preserve, so its scope of use is limited. Hard PVC does not contain softener, so it is flexible, easy to form, not fragile, non-toxic and pollution-free, and has a long storage time, so it has great development and application value. Soft PVC is mostly used to make vacuum plastic film for surface packaging of various panels, so it is also called decorative film and adhesive film, and is used in building materials, packaging, medicine and many other industries. Among them, the building materials industry accounts for the largest proportion, 60%, followed by the packaging industry, as well as a number of other small-scale applications.
4. PVC is actually a vinyl polymer, and its material is an amorphous material. In actual use, PVC materials are often added with stabilizers, lubricants, auxiliary processing agents, pigments, impact agents and other additives. It has non flammability, high strength, weather resistance and excellent geometric stability. PVC has strong resistance to oxidants, reducing agents and strong acids. However, it can be corroded by concentrated oxidizing acids, such as concentrated sulfuric acid and concentrated nitric acid, and is not suitable for contacting aromatic hydrocarbons and chlorinated hydrocarbons.
