1. Rigid PVC is one of the widely used plastic materials.
2. The melting temperature during the processing of PVC is a crucial process parameter, as an improper setting can lead to material decomposition issues. PVC has poor flow characteristics and a narrow processing range. Particularly, PVC materials with high molecular weights are more difficult to process, hence small molecular weight PVC materials are typically used. PVC has a relatively low shrinkage rate, generally ranging from 0.2% to 0.6%.
3. PVC is categorized into hard PVC and soft PVC. Hard PVC accounts for approximately two-thirds of the market, while soft PVC makes up one-third. Soft PVC is commonly used for flooring, ceilings, and leather surfaces. However, due to the presence of softening agents, it tends to become brittle and is not easy to preserve, thus limiting its range of use. Hard PVC, being free of softening agents, offers good flexibility, is easy to mold, is not brittle, is non-toxic and environmentally friendly, and has a long shelf life, making it highly valuable for development and applications. Soft PVC is often used to create vacuum-formed films for surface packaging on various panels, hence its alternate names of decorative film and adhesive film, and is applied in industries such as building materials and packaging. The building materials sector holds the largest share at 60%, followed by the packaging industry, with several other niche applications.
4. PVC, in fact, is a vinyl polymer, a non-crystalline material. In practical use, PVC is often enhanced with stabilizers, lubricants, auxiliary processing agents, colorants, impact modifiers, and other additives. It boasts non-flammability, high strength, resistance to climatic changes, and excellent geometric stability. PVC is highly resistant to oxidizers, reducers, 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 contact with aromatic hydrocarbons or chlorinated hydrocarbons.
