What is EVA foam insole? Everything you need to know

What is EVA?

EVA is a foam commonly used in the midsole of athletic shoes to provide excellent shock absorption when you walk or run.EVA is considered a more comfortable insole material than materials such as cork, leather, and rubber. Still, of course, that's just most people's opinion, and some people may feel differently because different people have different ideas of what "comfort" is. The definition of "comfort" is not the same.

In the 1970s, Nike pioneered the popularization of ethylene vinyl acetate (EVA) foam to add more cushioning to the midsole of running shoes, fundamentally changing the look and feel of footwear.

Although EVA foam material was initially used in athletic shoes, it gained recognition for its comfort, so EVA foam insoles are increasingly used in formal shoes and boots, as well as other shoe types.

Why use EVA foam for insoles?

EVA foam works well as a shock absorber in the midsole. If you go to a store and try on a pair of shoes made of traditional materials and then try on a pair with EVA foam insoles, you can feel the comfort that EVA insoles provide. Of course, we can't say 100% that EVA insoles are more comfortable than insoles made of ordinary materials.

EVA vs. traditional materials

Traditional materials used to make soles and midsoles, such as cork, rubber, and leather, can also provide shock absorption. However, these materials have limitations. For example, cork compresses after repeated use, and once compressed, it stays compressed. It still absorbs some shock but is much stiffer.

While soft compared to some rubbers, leather outsoles wear relatively quickly and don't do much in shock absorption.

Many rubber forms can also act as shock absorbers - they contract like a spring when weight is applied and expand when weight is reduced. However, rubber is still relatively stiff, so it doesn't provide a lot of absorption.

EVA has unique physical properties. It's not so soft that it loses its shape, but it's soft enough to absorb many impacts. That's why EVA has sometimes been considered a "Goldilocks" material; it provides more shock absorption than rubber and recovers its shape better than cork while providing plenty of cushioning.

Is EVA durable?

The durability of EVA foam insoles is relatively poor, and in athletic shoes and hiking boots, the EVA midsole is often the first component to wear out. After a period of use, EVA compresses and loses its ability to absorb shock.

In insole production, we usually use "compression deflection" to measure the midsole's durability, which is the percentage of the midsole that bounces back after wear. Rubber has a very low compression deflection because it will spring back close to its original height and not compress much, to begin with. Low-quality EVA has a high permanent deflection in compression and does not bounce back too much. High-quality EVA foam insoles have higher durability, such as Foamwell's EVA foam insoles.

With the advancement of technology, the technology and materials used in the production of insoles are also evolving, in addition to EVA foam, many other materials can be used in the production of insoles, and each has its strengths. If you want to know more types of insoles products can browse through our product categories, custom insoles welcome to contact Foamwell.