PVC (Polyvinyl chloride) is a polymer obtained by polymerizing vinyl chloride monomer (VCM) with initiators such as peroxides, azo compounds, etc., or by radical polymerization reaction mechanism under the action of light and heat. Vinyl chloride homopolymers and vinyl chloride copolymers are collectively referred to as vinyl chloride resins.
PVC is a white powder with an amorphous structure, small branching degree, relative density of about 1.4, glass temperature 77~90 ℃, 170 ℃ starts to decompose, poor stability to light and heat, above 100 ℃ or after long exposure to sunlight, it will decompose to produce hydrogen chloride, and further automatic catalytic decomposition, cause discoloration, physical and mechanical properties also decline rapidly, must be added stability in practical application agent to improve stability to heat and light.
Industrial production of PVC molecular weight is generally in the range of 50,000 to 110,000, has a large polydispersity, molecular weight increases with the decrease of polymerization temperature; no fixed melting point, 80~85 ℃ begins to soften, 130 ℃ becomes viscoelastic, 160 ~ 180 ℃ begins to change to viscous fluid state; has good mechanical properties, the tensile strength of about 60MPa, impact strength 5 ~ 10kJ/m2; excellent intermediate electrical performance.
PVC was once the world’s largest general-purpose plastic, and it was widely used. It is widely used in building materials, industrial products, daily necessities, floor leather, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, fibers, etc.
1 PVC profile
Profiles and profiles are the areas with the largest consumption of PVC, accounting for about 25% of the total consumption of PVC. They are mainly used to make doors, windows, and energy-saving materials. In developed countries, plastic doors and windows also have the highest market share, such as 50% in Germany, 56% in France, and 45% in the United States.
2 PVC pipe
Among the many PVC products, PVC pipes are the second largest consumer sector, accounting for about 20% of their consumption. In China, PVC pipes were developed earlier than PE pipes and PP pipes, with many varieties, excellent performance and wide range of use, 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 and plasticized with additives, a three-roll or four-roll calender is used to form a transparent or colored film of a specified thickness. It can also be cut and heat-sealed to process bags, raincoats, tablecloths, curtains, inflatable toys, etc. The wide transparent film can be used in greenhouses, plastic greenhouses and mulching films. Bidirectionally stretched films are subject to heat shrinkage and can be used for shrink packaging.
4 PVC hardwood and board
Stabilizers, lubricants, and fillers are added to PVC. After mixing, the extruder can extrude hard pipes, special-shaped pipes and corrugated pipes of various calibers for sewer pipes, drinking water pipes, wire sleeves or stair handrails. The rolled sheet is superimposed and hot pressed to form rigid plates of various thicknesses. The plates can be cut into the desired shape and then welded with hot air using PVC electrodes to form various chemical-resistant tanks, air ducts, containers, etc.
5 PVC general soft products
PVC soft sheet extrusion line can be used to extrude hoses, cables, wires, etc.; plastic sandals, soles, slippers, toys, auto parts, etc. can be made by using injection molding machines with various molds.
6 PVC packaging materials
PVC products are mainly used for packaging various containers, films, and hard sheets. PVC containers mainly produce bottles of mineral water, beverages, cosmetics, and are also used as packaging for refined oils. PVC film can be used to co-extrude laminated products with other polymers at low production costs, as well as transparent products with good barrier properties. PVC film can also be used in stretch or shrink-wrap for packing mattresses, fabrics, toys, and industrial goods.
7 PVC wall panels and flooring
PVC wall panels are mainly used to replace aluminum wall panels. In addition to 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 hard ground of airport terminal floors and other places.
8 PVC consumer goods
Luggage bags are traditional products made of PVC. PVC is used to make various faux leather, used for luggage bags, sports products such as basketball, soccer, and rugby. It can also be used to make belts for uniforms and special protective equipment. PVC fabrics for clothing are generally absorbent fabrics (no coating is required), such as ponchos, baby pants, faux leather jackets, and various rain boots. PVC is used in many sports and entertainment products, such as toys, records, and sporting goods. PVC toys and sporting goods have grown significantly and have an advantage due to their low production cost and ease of molding.
9 PVC coated products
Artificial leather with a substrate is made by applying PVC paste to cloth or paper, and then plasticizing it above 100℃. It can also be made by rolling PVC and additives into a film and then pressing it with the substrate. Artificial leather without a substrate is directly rolled into soft sheets of a certain thickness by a calendar and then pressed with a pattern. Artificial leather can be used to make suitcases, bags, book covers, sofas, car cushions, etc., as well as floor leather as flooring materials for buildings.
10 PVC foam products
When soft PVC is mixed, an appropriate amount of foaming agent is added to form a sheet, which is foamed into foam plastic, which can be used as foam slippers, sandals, insoles, and shockproof cushioning packaging materials. Can also be used as an extruder base for low hair.