Application and characteristics of PVC

PVC is the abbreviation of polyvinyl chloride and its English name is Polyvinylchloride. The main component is polyvinyl chloride. It is bright in color, corrosion-resistant, strong and durable. It is reinforced by adding some toxic auxiliary materials such as plasticizers and anti-aging agents in the manufacturing process. Its heat resistance, toughness, ductility, etc., so its products generally do not store food and medicine.

In terms of chemical and physical properties, PVC is one of the most widely used plastic materials in terms of rigidity. PVC material is a non-crystalline material. In actual use, stabilizers, lubricants, auxiliary processing agents, pigments, anti-impact agents and other additives are often added.
PVC material has non-flammability, high strength, weather resistance and excellent geometric stability. It 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 contact with aromatic hydrocarbons and chlorinated hydrocarbons.

The melting temperature of PVC during processing is a very important process parameter. If this parameter is not appropriate, it will cause material decomposition. The flow characteristics of PVC are quite poor, and its process range is very narrow. Especially the high molecular weight PVC material is more difficult to process (this kind of material usually needs to add lubricant to improve the flow characteristics), so the PVC material with small molecular weight is usually used. The shrinkage rate of PVC is quite low, generally 0.2~0.6%.

The main use and industrial chain of PVC

1. PVC profile
Profiles and profiles are the largest area of ​​PVC consumption in my country, accounting for about 25% of total PVC consumption. They are mainly used to make doors and windows and energy-saving materials. At present, their applications are still growing nationwide. In developed countries, the market share of plastic doors and windows is also the highest, such as Germany at 50%, France at 56%, and the United States at 45%.

2. PVC pipe
Among many polyvinyl chloride products, polyvinyl chloride pipes are its second largest consumption area, accounting for about 20% of its consumption. In my country, polyvinyl chloride pipes are developed earlier than PE pipes and PP pipes, with more varieties, excellent performance, and a wide range of applications, and occupy an important position in the market.

3. PVC film
The consumption of PVC in the field of PVC film ranks third, accounting for about 10%. After PVC is mixed with additives and plasticized, a three-roll or four-roll calender is used to make a transparent or colored film with a specified thickness. The film is processed in this way to become a calendered film. It can also be cut and heat-sealed to process packaging bags, raincoats, tablecloths, curtains, inflatable toys, etc. The wide transparent film can be used for greenhouses, plastic greenhouses and mulch films. The biaxially stretched film has the characteristics of heat shrinkage and can be used for shrink packaging.

4. PVC hard materials and plates
Stabilizers, lubricants and fillers are added to PVC. After mixing, the extruder can be used to extrude hard pipes, special-shaped pipes and corrugated pipes of various calibers, which can be used as sewer pipes, drinking water pipes, wire casings or stair railings. . The calendered sheets are overlapped and hot pressed to make hard plates of various thicknesses. The plate can be cut into the required shape, and then welded with hot air with PVC welding rod to form various chemical resistant storage tanks, air ducts and containers.

5. PVC general soft product
The extruder can be used to squeeze into hoses, cables, wires, etc.; the injection molding machine can be used with various molds to make plastic sandals, shoe soles, slippers, toys, auto parts, etc.

6. PVC packaging materials
Polyvinyl chloride products are mainly used for packaging in various containers, films and rigid sheets. PVC containers mainly produce PTP packaging for mineral water, beverages, cosmetics packaging bottles, medicines, and packaging for refined oil. PVC film can be used to co-extrude with other polymers to produce low-cost laminates and transparent products with good barrier properties. Polyvinyl chloride film can also be used for stretch or heat shrink packaging for packaging mattresses, cloth, toys and industrial goods.

7. PVC siding and floor
Polyvinyl chloride wall panels are mainly used to replace aluminum wall panels. Except for a part of PVC resin, the other components of PVC floor tiles are recycled materials, adhesives, fillers and other components, which are mainly used on the ground of airport terminal buildings and other hard ground.

8. Polyvinyl chloride daily consumer goods
Luggage bags are traditional products made by processing polyvinyl chloride. Polyvinyl chloride is used to make all kinds of imitation leather, which are used in luggage bags and sports products such as basketball, football and rugby. It can also be used to make belts for uniforms and special protective equipment. Polyvinyl chloride fabrics for clothing are generally absorbent fabrics (without coating), such as ponchos, baby pants, imitation leather jackets and various rain boots. Polyvinyl chloride is used in many sports and entertainment products, such as toys, records and sports goods. At present, the growth rate of polyvinyl chloride toys is large. Due to the low production cost of polyvinyl chloride toys and sports goods, and the easy molding, it has an advantage.