EVA sole material analysis!

The material used for EVA soles is ethylene/vinyl acetate * * * polymer (also called ethylene-vinyl acetate * * * polymer), which is composed of ethylene (E) and vinyl acetate (VA)***, which is called EthyleneVinylAcetate in English. EVA for short, the content is 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.

Features of EVA sole:

EVA soles are characterized by good flexibility, rubber-like elasticity, good flexibility below 0℃, good transparency and surface gloss, good chemical stability, good anti-aging and ozone resistance, and no toxicity. Good miscibility with filler, good coloring and molding processability.

It has a great relationship with vinyl acetate content, molecular weight and melting index. When the melt index (MI) is fixed and the content of vinyl acetate (VA) is increased, its elasticity, flexibility, compatibility and transparency are also improved. When the content of VA decreases, its properties are close to those of polyethylene, its rigidity increases, and its wear resistance and electrical insulation improve.

If the content of VA remains unchanged, the melt index will increase, the softening point will decrease, the processability and surface gloss will improve but the strength will decrease. Otherwise, with the decrease of MI, the molecular weight will increase, and the impact resistance and environmental stress cracking resistance will improve. The polarity of acetate increases elasticity and viscosity, but decreases crystallinity and electrical properties. It is soluble in hydrocarbon solvents and oils.

Extended data:

Describe the advantages and disadvantages of EVA soles in detail.

Is EVA sole made of EVA material? There must be something good and something bad, so it's hard to say. EVA sole material is a polymer material, which is often used for jogging, walking, casual shoes and foot training soles. The EVA sole made of EVA sole material is light and elastic, but the elasticity decreases after wearing for a long time.

Advantages: EVA sole is light, elastic, flexible, not easy to wrinkle, excellent in coloring, and suitable for all kinds of climates.

Disadvantages: EVA soles are easy to absorb water, not easy to corrode, not conducive to environmental protection, easy to get dirty, hard and equal after a long time.

Because the ethylene-vinyl acetate copolymer * * * mixed foam products have the properties of softness, good elasticity and chemical corrosion resistance, EVA soles are widely used in the soles of middle and high-grade travel shoes, hiking shoes, slippers and sandals and in interior materials.

Baidu encyclopedia -—EVA sole