EVA Foam – 3 Things to Know (Cheat Sheet)
Get the lowdown on the world’s most remarkable moldable material—ethylene vinyl acetate
Here at CCG, EVA foam (otherwise known as ethylene vinyl acetate) material is in high demand. And for good reason. This space-age stuff is probably the most versatile moldable material in the world. It’s soft, resilient and has compression-recovery characteristics that are second to none.
For the most part, EVA plastic is converted into foam (“foamed”) by either injection or compression molding processes. In both processes, bubbles and high heat are added to the mix, creating the closed-cell structure that makes EVA foam so very usable. Read on for the top three things to know about this incredible material.
1. WHAT MAKES IT AMAZING – THE FEATURES
Below, we’ve listed the top features that make EVA foam amazing. There are more we could add, but, in the interest of space, we figured we’d give you those characteristics that our engineers love most.
- Incredible flexibility and versatility – EVA foam can be made stiff or floppy, which makes it exceedingly easy to customize.
- High friction coefficient – That means objects placed inside one of our cases with an EVA foam interior won’t slip and slide around.
- Good low temperature toughness – Like, really EVA foam will remain flexible at temperatures as low as -94°F. Because of this, it’s often included in cases designed for things like Antarctic expeditions.
- Stress-crack resistance – This is related to its flexibility. Basically, it means EVA foam is very hard to break.
- Good weather, ozone and UVA radiation resistance – This means EVA foam can take pretty much whatever the environment throws its way.
- Sulphur free and low odor – These are great features because they mean you’re not going to get a migraine every time you get too close.
- High chemical resistance – This feature makes EVA foam awesome for all kinds of toxic situations. It’s highly resistant to dilute acids, dilute alkalis, oils and greases, aliphatic hydrocarbons and alcohols. However, it does have poor resistance to aromatic and halogenated hydrocarbons (nobody’s perfect, right?).
- Superior impact and vibration absorption – We (and our customers) love this feature because it provides incredible protection for even the most fragile cargo.
- Buoyant and low water absorption –Not only does it float, it protects whatever’s inside it from water damage.
2. THREE FORMS
EVA is a copolymer, which means it’s created by combining two different plastics—vinyl acetate and ethylene. The ratio of those plastics in an EVA product is what create its rigidity. The lower the amount of vinyl acetate in the mix, the more brittle the product. There are three formulations:
Low percentage vinyl acetate. When an EVA copolymer has a low percentage of vinyl acetate (usually up to 4%), it’s sometimes referred to as vinyl acetate modified polyethylene. This formulation is the most brittle.
Medium percentage vinyl acetate. When the copolymer has a medium percentage of vinyl acetate (typically between 4% and 30%), it’s sometimes referred to as thermoplastic ethylene-vinyl acetate copolymer. This formulation is more flexible than low percentage vinyl acetate.
High percentage vinyl acetate. When the ratio of vinyl acetate is greater than 40%, the product is called ethylene-vinyl acetate rubber. This is the most flexible and versatile formulation.
3. WHAT YOU CAN MAKE WITH EVA FOAM
The outstanding versatility of EVA foam is, of course, our favorite of its features. For years, it’s been used to make everything from top-quality Nike running shoes to fishing rods. Here’s a list of some of the other things made from this material (and this is just the tip of the iceberg).
- Handle grips for just about anything that needs them
- Flexible tubing for vacuum cleaners, industrial machines, beer brewing (you name it)
- Cling wrap (the stuff in your refrigerator)
- Kids’ foam stickers
- Costumes (everything from Halloween costumes to special effects for high-budget films)
- Biomedical drug delivery devices
- All kinds of sports equipment, such as ski boots, bike seats, hockey pads, mixed martial arts gloves and helmets
- Floating eyewear (or all kinds of other things that need to float)
- Encapsulation material for crystalline silicon solar cells
- Tons of different sandals
- Substitute material for cork
- Interior waterborne paints
Last, but most certainly not least, EVA foam is a fantastic material for custom reusable case interiors. You’ll find it in all our Shell-Case products and in many of our custom OEM cases. Click on the links below to see the amazing things we do every day at CCG with this awesome material.
More From Custom Case Group:
Shell-Case – Top Manufacturer of EVA Cases