Performance of PVC resin
1. PVC resin (PVC): It is one of the important organic synthetic materials. English name: Polyvinyl Chloride, chemical structural formula: (CH2-CHCL) n, its products have good physical and chemical properties, and are widely used in industrial, construction, agricultural, daily life, packaging, power, utilities and other fields.
2. Properties of PVC resin: Physical appearance is white powder, non-toxic and odorless. The relative density is 1.35-1.46, and the refractive index is 1.544 (20 ° C). It is insoluble in water, gasoline, alcohol and vinyl chloride, and soluble in acetone, dichloroethane, xylene and other solvents. It has high chemical stability and good plasticity.
Except for a few organic solvents, it can withstand any concentration of hydrochloric acid, sulfuric acid below 90%, nitric acid 50-60%, and caustic soda below 20% at room temperature. In addition, it is quite stable to salts; PVC can burn on flame HCl is released, but it self-extinguishes when it leaves the flame. It is a "self-extinguishing" and "flammable" substance; PVC begins to decompose above 100 ℃ and slowly releases HCl. As the temperature rises, the decomposition and release of HCl accelerates Discoloration of PVC.
PVC is synthesized from vinyl chloride by free radical polymerization. The suspension polymerization method, emulsion polymerization method and bulk polymerization method are mainly suspension polymerization methods, accounting for about 80% of the total PVC production. In the industry, the PVC production process is generally distinguished according to the method of obtaining vinyl chloride monomer, which can be divided into calcium carbide method, ethylene method and imported (EDC, VCM) monomer method (the ethylene method and imported monomer method are commonly referred to as ethylene law).
3. Classification of PVC resin: According to different production methods, pure PVC powder is divided into: general-purpose PVC resin, highly polymerized PVC resin, and cross-linked PVC resin. General-purpose PVC resin is formed by the polymerization of vinyl chloride monomer under the action of an initiator; high-polymerization PVC resin refers to the resin polymerized by adding a chain extender in the vinyl chloride monomer polymerization system; crosslinked PVC resin is A resin polymerized by adding a crosslinking agent containing diene and polyene to a vinyl chloride monomer polymerization system.
The main uses of PVC resin
01
PVC general soft products
It can be extruded into hoses, cables, wires, etc. by using an extruder; it can be made into plastic sandals, soles, slippers, toys, auto parts, etc. by using injection molding machines with various molds.
02
PVC film
After PVC is mixed with additives and plasticized, a three-roller or four-roller calender is used to make a transparent or colored film with a specified thickness. The film is processed by this method to become a rolled film. It can also be processed by cutting and heat-sealing packaging bags, raincoats, tablecloths, curtains, inflatable toys, etc. Wide transparent films can be used for greenhouses, plastic greenhouses and mulch films. The biaxially stretched film is heat shrinkable and can be used for shrink packaging.
03
PVC coated products
Substrate-made artificial leather is made by coating PVC paste on cloth or paper, and then plasticizing it above 100 degrees Celsius. It can also be rolled by rolling PVC and auxiliary into a film, and then laminated with a substrate. The artificial leather without substrate is directly rolled into a soft sheet of a certain thickness by a calender, and then pressed into a pattern. Artificial leather can be used to make suitcases, bags, book covers, sofas and car cushions, etc., as well as floor leather, which is used as flooring materials for buildings.
04
PVC Foam Products
When soft PVC is mixed, a suitable 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 shock-absorbing cushioning packaging materials. It can also be used to form low-foam rigid PVC sheets and profiles based on extruder, which can be used as a substitute for wood and is a new type of building material.
05
PVC transparent sheet
PVC is added with impact modifier and organotin stabilizer. After mixing, plasticizing and calendering, it becomes a transparent sheet. It can be made into thin-walled transparent containers or used in vacuum blister packaging by thermoforming. It is an excellent packaging material and decorative material.
06
PVC rigid board and sheet
Stabilizers, lubricants, and fillers are added to PVC. After mixing, rigid pipes, special-shaped pipes, and corrugated pipes of various calibers can be extruded with an extruder for use as sewer pipes, drinking pipes, wire sleeves, or stair handrails. . The rolled sheets are laminated and hot-pressed to produce hard boards of various thicknesses. The plate can be cut into the desired shape, and then welded with hot air using PVC welding rods to a variety of chemically resistant storage tanks, air ducts and containers.
07
PVC other
Doors and windows are assembled from hard shaped materials. In some countries, it has occupied the door and window market together with wooden doors, windows, aluminum windows, etc .; imitation wood materials, steel building materials (north, seaside); hollow containers.