Introduction to EVA Materials

Posted by zhou on April 24th, 2019

Ethylene-vinyl acetate copolymer (EVA sheet) EVA resin is ethylene-vinyl acetate copolymers, the general vinyl acetate (VA) content in 5 ~ 40. Compared with polyethylene, eva foam sheets suppliers 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. Is a relatively common midsole material, usually called foaming has a certain buffering effect, but this material is very slippery, so it is usually mixed with hard rubber EVA is a common material that is available on many sneakers.

The hardness of foamy eva materials is divided into 0 type, initial type, 2 type, 3 type, 4 type and mass production type. Six 0 types are the most basic experimental type, and the elasticity and hardness are not as good as the latter. Initial elasticity, hardness is the best after the addition of S2 additive, but S2 additives are expensive, do not recommend use.

The flexibility and performance of Model 2 are generally recognized, but mixed with mass production will have some adverse consequences.

The third model has the best elasticity and average hardness. The performance of Model 4 is similar to that of No.3, but long periods of time in the air will decompose spontaneous combustion. The flexibility and performance of the mass-produced model are not very good, and can not be mixed with the 2-size model.

The sole of EVA is especially soft and elastic. Of course, the cost of PVC is high. Compared with EVA, the hardness of PVC is large, the elasticity is poor, and the cost is low.

This article come from: http://hnarts.freeblog.biz/2019/01/22/introduction-to-eva-materials/