EVA stands for ethylene-vinyl acetate. We know that sounds complicated, but in a nutshell it’s soft, lightweight, flexible and durable foam that changed footwear (and a bunch of other “cushiony” products) forever! 

It’s made through the polymerization of ethylene and vinyl acetate. When you combine these ingredients along with a foaming process to trap tiny bubbles of air (making it lightweight) you get EVA foam. 

Now that the science is out of the way we can dive into what makes EVA foam so great and why you might want it in your shoes. 

The Benefits of EVA in footwear

Proper application in EVA in your shoes make them more cushioned, shock absorbent, lightweight, flexible and durable. 

If you’ve got a pair of flip-flops, you’ve probably got a pair of EVA shoes already. While thongs (flip-flops for any non-Aussies) are great, proper application of this miraculous substance can make it even better. Let’s discover what makes it great. 

Cushioning & Shock Absorption

EVA “foam” isn’t a foam in the traditional sense. It’s more like if you mixed foam and rubber together creating a squishy hybrid that isn’t just soft, but bounces back to its original shape too. 

EVA is the combination of Ethylene and Vinyl Acetate. Ethylene is what provides strength and toughness, and Vinyl Acetate adds flexibility and increases ability to absorb impact. These ingredients can be tampered with to provide more of each attribute depending on its purpose. 

When your foot strikes the ground as you walk or run, the EVA in the sole of your shoe compresses, which reduces the impact energy sent to the rest of your body. This greatly reduces stress on your feet and joints. 

It does this, while at the same time remaining a soft base for your feet as you stand. 

Lightweight

Production of EVA foam involves a “vulcanizing process”. This simply means a blowing agent is used which releases gases which in turn expands the EVA. This traps tiny little air bubbles within the final product, making it remarkably lightweight but also increases the “cushiony” feel under foot. 

Flexibility 

EVA foam is more than just being able to bend and twist your shoes, it’s about allowing the shoe to become an extension of your foot. The “squish factor” involved with the cushioning and lightweight aspects of EVA come into their own with flexibility as well. EVA foam will mould with the contours of your foot and adapt with your movements as you make them.

This is to do with the air bubbles within the cells that act as a cushion. This allows the material to compress under pressure, but then bounce back to its original shape. Higher levels of Vinyl Acetate will generally result in a softer, more flexible material. 

Our designers have been in the lab to ensure they’ve got the mixtures right in every pair of Comfort Co shoes. 

Durability

The blend in EVA makes it both incredibly tough, but also flexible to absorb impacts without changing shape or breaking. Together, it can make an incredibly durable shoe. 

The manufacturing expertise plays a huge part in this. Upon creation EVA foam undertakes a “cross-linking process”. This bonds polymer chains together creating an almost unbreakable network. Throw bending, stretching and compression at it and those bonds are still unlikely to break down. 

It also becomes a “closed-cell structure” meaning that each of the tiny air bubbles (which makes it so light, flexible and shock absorbent) are locked in. This prevents water absorption or damage from elements (both hot and cold, often tested to extreme levels).

Conclusion 

The invention of EVA was a game changer and since then it has become a super substance in not only footwear; but sports equipment, toys, packaging, floor mats, construction, cosmetics applicators and more. If you think soft and bouncy, think EVA! And if you want your shoes to be soft and bouncy, think The Comfort Co.!