Vinyl-vinyl acetate copolymers abbreviated as EVA foam, generally vinyl acetate (VA) content in the amount of about 40.

Cultura e Società postato da hnarts || 5 anni fa

Vinyl-vinyl acetate copolymers abbreviated as EVA foam, generally vinyl acetate (VA) content in the amount of about 40. Compared with polyethylene, eva foam sheets is widely used in foaming shoes and functional shed film because of the introduction of vinyl acetate monomer into the molecular chain, which reduces the high crystallinity, improves flexibility, impact resistance, compatibility of fillers and heat sealing properties. Packaging film, hot melt adhesive, wire and cable, toys and other areas. The main results are as follows:

(1) Foamed shoe material is the main application field of EVA resin in China. In the EVA resin used in footwear, the vinyl acetate content is generally 15% 22. Due to EVA resin The blend foaming products have the properties of softness, elasticity and chemical corrosion resistance, so they are widely used in the soles and interior materials of middle and high grade travel shoes, mountaineering shoes, slippers and sandals.

(2) The main purpose of EVA film is to produce functional shed film. The functional shed film has high weathering resistance, anti-fog droplet and heat preservation properties. Because polyethylene does not have polarity, even if a certain amount of antifogging agent is added, the anti-fogging property can only be maintained for about 2 months. The greenhouse film made by adding a certain amount of EVA resin not only has higher transmittance, but also has a great improvement of anti-fog droplet performance, which can generally exceed 4 months. Besides, EVA can also be used to produce packaging film, medical film, laminate film, casting film and so on.

(3) With the development of computer and network engineering, more and more people use halogen-free flame retardant cable and silane crosslinked cable for the safety of machine room. EVA resin is widely used in halogen-free flame retardant cables, semiconductor shielded cables and two-step silane cross-linked cables because of its good filler inclusiveness and crosslinking ability. In addition, EVA resin is also used to make some special cable sheath. EVA resin used in wire and cable, vinyl acetate content is generally 12% or 24%. In 1999, the total consumption of EVA in the wire and cable industry was about 6 000 t.

(4) Toy EVA resin is also used in toys, such as baby wheel, cushion and so on. In recent years, China's toy processing industry has developed rapidly, and its production is mainly concentrated in Dongguan, Shenzhen, Shantou and other places along the coast, mainly for export and external processing. According to analysis, these manufacturers consume about 5,000 tons of EVA resin a year, using the same number as footwear materials.

(5) Other EVA resins are also widely used in the fields of ink, bag, bottle cushion, etc. It is estimated that the consumption of EVA resin in these areas is not less than 15 kt. Of course, EVA is still as high as PVC is polyvinyl chloride. It is the largest amount of plastic in the building. The density of rigid PVC is 1.38 ~ 1.43g / cm ~ 3, the mechanical strength is high, the chemical stability is good, and the temperature range is generally -1555 ?, which is suitable for making plastic doors and windows, downwater pipes, line grooves and so on.

This article come from: http://prsync.com/hnarts/five-main-uses-of-eva-2892185/

Fonte: https://www.hnarts.com/EVA_foam_sheets/