What is a mountaineer's insole?

EVA sports insoles are generally used by athletes. Ethylene-vinyl acetate copolymer

Ethylene-vinyl acetate polymer is abbreviated as EVA, and the content of vinyl acetate (VA) is generally 5% ~ 40%. Compared with polyethylene, EVA is widely used in foam shoes, functional shed films, packaging films, hot melt adhesives, wires and cables, toys and other fields because of the introduction of vinyl acetate monomer in the molecular chain, which reduces the high crystallinity and improves the flexibility, impact resistance, filler compatibility and heat sealing performance.

Generally speaking, the properties of ethylene-vinyl acetate copolymer mainly depend on the content of vinyl acetate in the molecular chain. The market consumption of 200 1 ethylene-vinyl acetate copolymer is about 290 kt. With the development of China's footwear industry and the increase in the amount of functional films, the demand for ethylene-vinyl acetate copolymer in China will increase year by year.

(1) Foamed shoe material

Shoe material is the most important application field of ethylene-vinyl acetate copolymer. In the ethylene-vinyl acetate copolymer used for shoe materials, the content of vinyl acetate is generally 15% ~ 22%. Ethylene-vinyl acetate copolymer * * * mixed foam products have the properties of softness, good elasticity and chemical corrosion resistance, and are widely used in the soles of middle and high-grade travel shoes, hiking shoes, slippers and sandals and interior materials. In addition, the material is also used in sound insulation board, gymnastics mat, sealing material and other fields. Shunde, Zhongshan in Guangdong, Jinjiang, Quanzhou in Fujian and Wenzhou in Zhejiang are the main production bases of China's footwear industry, which consume a lot of ethylene-vinyl acetate copolymer products every year. 1999 In the field of foamed shoe materials and shock absorption in China, the consumption of ethylene-vinyl acetate copolymer is about 150 kt.

(2) Movies

extravehicular activity

The main purpose of the film is to produce functional greenhouse films. Functional greenhouse film has high weatherability, anti-fog and heat preservation. Because polyethylene has no polarity, even if a certain amount of antifogging agent is added, it can only maintain its antifogging performance.

About 2 months; The shed film made by adding a certain amount of ethylene-vinyl acetate copolymer not only has high light transmittance, but also greatly improves the anti-fog performance, which can generally exceed 4 months. In addition, EVA can also be used to make packaging.

Film, medical film, composite film, cast film, etc.

From 65438 to 0999, more than 50 enterprises in China used ethylene-vinyl acetate copolymer to process films. 1999, China * * * produced 800 kt of greenhouse film, including 220 kt of functional greenhouse film, and consumed about 30 kt of ethylene-vinyl acetate copolymer. In addition, in the field of packaging film and medical film, China * * consumed 37 kt in ethylene-vinyl acetate copolymer.

(3) Wires and cables

With the continuous development of computer and network engineering, halogen-free flame retardant cables and silane crosslinked cables are used more and more for the safety of computer rooms. Ethylene-vinyl acetate copolymer is widely used in halogen-free flame retardant cables, semiconductor shielded cables and two-step silane crosslinked cables because of its good filler inclusiveness and crosslinking. In addition, ethylene-vinyl acetate copolymer is also used to manufacture some special cable sheaths. The vinyl acetate content of ethylene-vinyl acetate copolymer for wire and cable is generally 12% ~ 24%. From 65438 to 0999, the wire and cable industry consumed about 6000t EVA.

(4) toys

Ethylene-vinyl acetate copolymer also has many applications in toys, such as children's wheels and cushions. In recent years, China's toy processing industry has developed rapidly, and its production is mostly concentrated in Dongguan, Shenzhen, Shantou and other coastal areas, mainly for export and foreign processing. According to analysis, these manufacturers consume about 5,000 tons of ethylene-vinyl acetate copolymer every year, and the brands used are basically the same as the materials used in shoe materials.

(5) Hot melt adhesive

Hot melt adhesive with ethylene-vinyl acetate copolymer as the main component is very suitable for production in auto production line because it contains no solvent, does not pollute the environment and has high safety. Therefore, it is widely used in wireless binding of books, edge sealing of furniture, assembly of automobiles and household appliances, shoemaking, carpet coating, metal anti-corrosion coating and so on.

Hot melt adhesives mainly use varieties with vinyl acetate content of 25% ~ 40%. Although there are products of this brand in China, they have not been arranged for production for a long time, so they are all imported materials. 1999, China hot melt adhesive industry is expected to consume ethylene-vinyl acetate copolymer 17 kt.

(6) Others

Ethylene-vinyl acetate copolymer is also widely used in ink, luggage, wine bottle cushion cover and other fields. It is estimated that the consumption of ethylene-vinyl acetate copolymer in these areas is not less than 15 kt.

Of course, Eva is still as high as

PVC is polyvinyl chloride. This is the most used plastic in buildings. Rigid PVC has a density of 1.38 ~ 1.43g/cm3, high mechanical strength and good chemical stability, and its service temperature is generally between-15 ~+55℃, so it is suitable for manufacturing plastic doors and windows, sewer pipes, trunking, etc.

ABS is a polymer of acrylonitrile, butadiene and styrene. ABS plastic can be used to make plastic decorative boards with patterns.