For us amateurs, when it comes to eva, we should all be at a loss. We don't know what it is or what it is used for. In fact, it is very common around us, as long as we pay attention to it, we will see it, but when we see its finished product, we don't know what eva is, and it is inevitable that we will feel shallow. Today, Bian Xiao will take you to know what eva is and its use and function. I hope everyone can learn something.

What is the material of 1.eva?

Eva is a rubber elastic material at room temperature and can melt and flow at high temperature. Eva is made of ethylene and acetic acid. Eva has a wide range of applications, and the annual market consumption in China is also increasing, especially in the shoemaking industry, which is used in the soles of middle and high-grade travel shoes, hiking shoes, slippers and sandals and interior materials.

Eva is characterized by good softness, rubber-like elasticity, good flexibility, transparency and surface gloss at -50℃, good chemical stability, good anti-aging and ozone resistance, and no toxicity. Good miscibility with filler, coloring and molding processability. Eva is widely used in foam shoes, functional shed films, packaging molds, hot melt adhesives, wires and cables, toys and other fields.

Second, the main role of eva

1, eva materials generally have very good flexibility and strong chemical corrosion resistance, and eva materials also have strong elasticity, so eva materials can be used to make various footwear products, which can make us feel more comfortable in the process of using eva products and increase the service life accordingly.

2.eva material has good inclusiveness and cross-linking, which other materials do not have, so it can be used in industrial fields and some production supplies.

Third, the use of Eva materials.

1, eva material can be used to make household appliances and daily necessities such as pipes, gas pipes, civil building plates and containers of household refrigerators.

2.eva material can be used as packaging film, gasket, medical instrument, hot melt adhesive, cable insulation layer, etc.

3.eva materials are widely used in wireless binding of books, shell structural parts of digital products, edge sealing of furniture, assembly of automobiles and household appliances, shoemaking, carpet coating and metal anti-corrosion coating.

What material is EVA?

Eva material is an extremely common material and a common midsole material in daily life. The finished products made of it have good flexibility, shockproof, anti-slip and strong compression resistance, such as our common EVA slippers, cotton shoes, EVA mobile phone protective cover, EVAipad protective cover and so on.

Polymerization methods include high pressure bulk polymerization, solution polymerization, emulsion polymerization and suspension polymerization. If the vinyl acetate content is higher than 30%, emulsion polymerization will be used, and if the vinyl acetate content is low, high pressure bulk polymerization will be used.

EVA sole refers to the sole made of EVA material. EVA sole has high resilience and tensile strength, high toughness, good shock-proof and cushioning properties, excellent heat insulation, heat preservation, cold resistance and low temperature performance, cold resistance and exposure resistance, closed-cell structure, good sound insulation effect, no water absorption, moisture resistance, good water resistance, corrosion resistance to chemicals such as seawater, grease, acid and alkali, and antibacterial, non-toxic, tasteless and pollution-free.

Extended data:

Application fields of EVA:

1, and EVA products with vinyl acetate content of 5%~ 10% are elastic films.

2. EVA with vinyl acetate content of 20~28% is mainly used for hot melt adhesives and coated products;

3. The content of vinyl acetate is 5%~45%, and the main products are films and sheets, injection molded products, foamed products, hot melt adhesives, etc.

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.

Movies. The main purpose of EVA film is to produce functional greenhouse film. 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, its antifogging performance can only last 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 produce packaging films, medical films, composite films and cast films.

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%.

Toys. Ethylene-vinyl acetate copolymer also has many applications in toys, such as children's wheels and cushions.

Hot melt adhesive Hot melt adhesive with ethylene-vinyl acetate copolymer as the main component is very suitable for auto production line production 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 and metal anti-corrosion coating.

References:

Baidu encyclopedia -eva plastic

What material is eva?

Eva is neither foam nor rubber. Eva is a plastic material made of ethylene and acetic acid.

When the material is polymerized, it is made by high-pressure bulk polymerization, pvc additives, adhesives and other processes.

If the content of vinyl acetate in eva material is above 30%, it is made by emulsion polymerization. If the content of this material is relatively low, high pressure bulk polymerization is used.

However, if the content of vinyl acetate in eva material is below 20%, it can be used as plastic. Moreover, eva has good low temperature resistance, and its thermal decomposition temperature is about 230 degrees, which is relatively low. Moreover, with the increase of its molecular weight, its softening point will also increase.

Features of Eva material:

1, eva material contains good water resistance, has closed pore structure, does not absorb moisture, and can bring good moisture resistance.

2.Eva material has strong corrosion resistance and can avoid chemical reaction with oil, acid, alkali, seawater and other substances. At the same time, it is non-toxic and tasteless, and is very safe to use.

3.Eva material has good resilience, tension resistance and toughness, which can play the role of shock absorption. In addition, because it is closed, the sound insulation function is also good.