Do you know PVC? If you don't know, let's get to know it together!
In our daily life, there is absolutely no shortage of places where plastics are used and touched, but plastics also have many categories. Commonly used products are similar and different. How to judge and choose? How to use these materials correctly to facilitate our lives? The following content will explain and answer questions for everyone and understand the world of PVC materials.
1). What is the difference between PVC and PC materials?
1. PC is polycarbonate plastic, which belongs to the category of engineering plastics. It has good transparency, high strength, and good weather resistance. It is often used in optical products, optical discs, solar panels, etc.
2. PVC is polyvinyl chloride plastic, which belongs to the category of general plastics. Hard (without plasticizer) PVC products are often used as plastic doors and windows, water pipes, threading pipes, plates, etc. Soft (with plasticizer) PVC products are often used for films, soft boards, flexible films, hoses, medical products (such as infusion bags, etc.).
3. PVC is one of the largest plastic products in the world, with a low price and a wide range of uses. PVC resin is white or light yellow powder. Different additives can be added according to different uses, and PVC plastics can show different physical and mechanical properties.
4. PC is the three major application areas of engineering plastics: glass assembly industry, automotive industry and electronic and electrical industry, followed by industrial machinery parts, optical discs, packaging, office equipment such as computers, medical care, film, leisure and protective products, etc. PC can be used as door and window glass, and PC laminates are widely used as protective windows in banks, embassies, detention centers and public places, as well as aircraft cabin covers, lighting equipment, industrial safety baffles and bulletproof glass.
2). Characteristics and applications of soft and hard PVC materials
1. Characteristics and applications of soft polyvinyl chloride
Soft PVC is mostly produced with high molecular weight PVC resin, that is, SG4 and above resins are mostly used. Soft polyvinyl chloride contains more plasticizers, and its softness, elongation at break and cold resistance increase. It is soft and has good air tightness and impermeability. Although the electrical insulation is reduced due to the addition of plasticizers, it still maintains very high electrical insulation. Brittleness, hardness and tensile strength are reduced. Soft PVC is mainly used for wires and cables, agricultural films, packaging films, industrial films, hoses, artificial leather, plastic shoes, etc. Due to the advantages of PE film over PVC film in processing and aging resistance, as well as the development of resin technology and processing technology, PVC agricultural film is gradually withdrawing from the market. The processing of soft PVC mainly adopts processing methods such as extrusion and calendering, and a few adopt injection molding.
2. Characteristics and applications of rigid polyvinyl chloride
Rigid PVC is mostly produced by low molecular weight PVC, and basically uses SG5 and below grade PVC resin. Rigid PVC contains no or a small amount of plasticizer, has good tensile, bending and compression properties, and can be used alone as a structural material. Such as corrugated cardboard, doors and windows, wall decorations, etc. PVC has excellent chemical resistance and can be used as a chemical anti-corrosion material. It is mainly used for anti-corrosion pipes, pipe fittings, oil pipelines, centrifugal pumps, blowers, etc. PVC cardboard is widely used in the chemical industry to make linings for various storage tanks. Excellent electrical insulation properties, suitable for insulating materials; therefore, it can be used in plugs, switches and sockets.
Low fluid resistance. Experiments show that the wall of PVC-U pipe is very smooth, with little resistance to fluid, and its roughness coefficient is only 0.009. Its water delivery capacity is 20% higher than that of cast iron pipes of the same caliber and 40% higher than that of concrete pipes. Therefore, PVC pipes and accessories are all the rage. However, due to the high and low temperature resistance of PVC pipes, with the development and use of pipes such as PPR, PEX, and aluminum-plastic composite pipes, the current consumption of rigid PVC accounts for about 70% of the total PVC production, but most of it is processed by extrusion technology. Due to the poor fluidity of PVC, it cannot be used for injection molding of large products, which also limits some application areas of PVC.
The development and contribution of PVC are definitely not limited to the above. When we know more about it, we can use it better. I hope that reading this will help you understand.