Posted by Nancy Grossbart
The most interesting products can be made from the injection molded EVA foam process. The process was originally created to manufacture midsoles but over the last 20 years, it has become so much more. Even when we don't make the part, we love to see great design using our process.
My favorites this week are some of the latest designs from the footwear company, Native Shoes. (I also love fun shoes.) They are made 100% injection molded EVA foam; that means both the sole and the colorful uppers. EVA foam is closed cell which means they are washable, antimicrobial, and odor resistant. It is really lightweight which could be plus depending on where you're walking.
From a designer’s perspective, molded EVA foam can be ideal when a design needs to be expressed in really vibrant colors. The foam's ability to create saturated colors gives a designer the confidence to really "break out" when using this foam. Obviously, that's what makes Native Shoes so dynamic looking.
Whether you’re wearing the slip-on (one-third Vans and two-thirds Crocs) or the hiking boots, these shoes are really made for walking as the molded EVA foam will contour to your feet as the foam warms up, making them extra comfortable.
As far as I’m concerned it’s another fantastic design utilizing a process that I have grown to love. Visit our product gallery if you want to see some other fantastic designs.
I been looking on the web to buy the boots but they don't seem to be available yet. When they do become available, someone let me know so I can get a pair. Which color should I get? Hmmmmm.
Posted by Nancy Grossbart
Almost any resin can be foamed. The world of foam is made from many different resins yet the injection molded foam process uses EVA, in combination with polyolefin elastomers. Why is that? Because it makes soft foam parts!
Hard or Soft Foam? There are many other polymers like polypropylene, polyethylene, or polystyrene which can easily be foamed creating a lower density, lighter product. However the results will stiff and hard as they are hard and stiff resins to begin with.
EVA produces flexible foam. EVA is a polymer that is similar to an elastomer because it can be made to be soft and flexible. That's the origin of the term flexible foam. This means that when soft EVA is manufactured, the resulting foam will also be even softer and pliable, allowing the production of varied soft foam parts to be used in industries such as juvenile, outdoor, sporting goods, kitchen and bath to name a few.
How does it work? In a simplistic sense, any formula combining EVA and polyolefins will have a linear chemical makeup. Under normal circumstances, having a linear chain creates a harder material. However, because of the specific chemical makeup of EVA it won't crystallize easily, helping it to retain its softness. In addition, EVA foam can be crosslinked, which will both help to stabilize the foam as well as produce soft foam final parts.
Crosslinking creates stable soft foam. Basically crosslinked foams, like EVA foam, are more stable than similar highly expanded un-crosslinked foams. This means it can retain its foam structure at temperatures approaching the melting point of the polymer used and, in some cases, exceed it. One of the additional benefits of parts made from EVA foam, and other crosslinked foams, is the ability to create parts by compression molding methods, including the injection molded foam process.
Why EVA foam is a perfect resin for our injection molding manufacturing process? It produces soft EVA molded parts that are stable, durable, closed cell, and chemically resistant.
Learn more about "Understanding Injection Molded Flexible Foam". Download our 8-page white paper.
Posted by Nancy Grossbart
When a gas is captured inside another material or resin, you get foam. Because the resin is filled with gas, it makes it expand like a balloon filled with air. This creates many beneficial characteristics such as being lightweight and, sometimes, soft with cushioning capacity. Foams that are made from a plastic resin, start as a solid and then are turned into foam by creating a "gas phase" with a foaming (blowing) agent.
The foaming process begins by creating thousands and thousands of gas bubbles in the melted plastic resin. These thousands of bubbles cause the cubic volume of the base plastic resin to expand as the bubbles increase in size and number. The resulting foam can be open cell foam or closed cell foam.
The next step is for the plastic resin to begin the process of hardening, fixing the shape and size of the bubbles. Foams may be soft and flexible (flexible foam) or hard and rigid, depending on the base resin that is used to make the foam.
When a foam shell wall forms from a rigid material like most metals, plastics, or ceramics, it acts like a tiny ping-pong ball providing lighter weight material. In other words, it has a higher volume-to-weight relationship (lower density) than the same material without a foam shell. This lower density is an important property that plays a key role in many industrial applications such as floatation and insulation, which currently are substantial markets. However, when a shell wall forms from flexible material like rubber or elastomer, it acts like party balloons and provides extra cushioning or softness to the material as well as more volume-to-weight ratio. It can be used in the athletic and furniture industries. Other industries also benefited by the usage of flexible polymeric foams are automotive interiors, seals and gaskets, footwear, medical aid devices and packaging.
You can foam almost anything, if you can find an application that needs it: metal foam, polymeric foam, paper foam, wood foam, and ceramic foam have been developed and used in a variety of products for unique advantages to enrich our lives or to explore the mysterious universe.
In terms of practical perspective, foams can be viewed in three categories; properties, technologies and ingredients.
In general, foam properties can be defined by dimensions, density, softness, cell size, number of cells per cubic volume, shape, and other properties such as surface appearance.
As for technology, it is basically classified as three types of manufacturing: soluble foaming, reactive foaming and melt/solution quenching.
When producing flexible molded foams you will find huge benefits in using some ingredients like polyolefin elastomers (POE). They are known for their flexible characteristics with benefits such as:
- High Durability and Abrasion/Scratch Resistant:
- Chemical Resistance
- High Weathering and UV Stability
Flexible foam can be created in sheet form or by an injection foam molding process. The main difference is that the injection foam molding process produces a "finished part" at the end of the foaming process. The foam molding process that produces a sheet still needs a secondary "fabricating" process to turn it into a usable part.
Learn more about "Understanding Injection Molded Flexible Foam". Download our 8-page white paper.
Posted by Nancy Grossbart
Part of my daily web meanderings take me down the path of looking at new product designs and concepts. If you follow me on Twitter (@foamentingideas) you will see that I am apt to share these "finds." Yesterday I came across a unique bathroom tile with the towel hook built in. 
It was designed by Czech designer Vadim Kibardin. I liked it immediately as it was both innovative and very practical. How many times have you been in the shower and wish you had easy access to a towel? It's a thoughtful, beautiful design as is but (being in the foam business) I suddenly realized "this design could have been made of injection molded foam."
I know this sounds like a commercial but, I swear, it's not. Don't you agree that foam tiles on the shower walls wouldn't be a great idea?
Imagine it could be both colorful and protective at the same time. Because this foam is closed cell it wouldn't absorb any of the water. Plus the base resin is chemically resistant, allowing you to keep it clean with any regular household cleaner.You could even mold logos and textures into it.
I will probably come across lots of products that fit the "It Could Have Been Made From Foam" description. When I find them, I'll talk about them. If it feels like a commercial then I'll, at least, try to make it a commercial worth watching.
Posted by Nancy Grossbart
I am particularly excited to hear that a US sheet foam manufacturer has created an additive for polyolefin foam that makes it biodegrable. This is an incredible breakthrough.
Bio-Tec Environmental LLC and the M.H. Stallman Company, a global leader in the development and manufacture of specialty fabricated crosslinked polyolefin foams for use in a wide variety of industrial and consumer markets, announce the first commercial production of the B-LinkTM line of biodegradable crosslinked foam, using the proprietary additive EcoPure® from Bio-Tec Environmental LLC. The EcoPure® additive enables microorganisms in a landfill disposal site to metabolize the molecular structure of most common plastics into an inert humus-like form that is harmless to the environment. This process takes organic compounds, mixed with nutrients, a scissoring agent and a carrier resin to enable biodegradation while not affecting the normal use performance of the polymers.
Polyolefin foam has many benefits. It's closed-cell, durable, and chemically resistant. In it's injection molded form, it creates products with incredible detail and unusual geometric features. What it hasn't been is biodegrable. President of the M.H. Stallman Company, said,
"This advancement in green technology will have a major impact on our industry. Until today crosslinked polyolefins could not be recycled and would not break down once thrown away. Now with our B-LinkTM products we are able to provide our customers with crosslinked foams that meet all of their performance requirements during normal use but will safely biodegrade once disposed of in a landfill."
I'm hoping this is an indication of more developments to come to help the foam manufacturing industry expand it's product offering as well as resolve environmental issues at the same time.
Download 8-page white paper on
"Understanding Flexible Foam".
Posted by Nancy Grossbart
Polyolefin foam is a great material for kid's products. It works well in lots of applications from padding for sporting goods to sandals (Crocs) and now, products for kids.
To begin with, it's closed-cell. That means it's waterproof and won't absorb bodily fluids. It also means it resists mold and mildew because the bacteria has no place to reside.
It's so light that it floats and can be used for bath or pool toys and has no adverse chemicals so when kids put the toy in their mouths, there is no need to worry.
Polyolefin foam has a high tear and tensile strength so it can't easily rip and won't crack or peel. This means it will not only last a long time but, when kids put it in their mouths, it will pass the bite test.
The chemistry of polyolefin foam makes it resistant to most chemicals. This allows you to clean and disinfect it with any household cleaner keeping it safe from any surface bacteria.
Parts can be also designed with lots of features and benefits including molded-in logos and graphics. And can be made in extremely bright, attractive to kids, colors.
If you're wondering if it will pass the new CPSIA standards, it will!
MDI Products' offering of formulas known as PolyCellTM are phthalate free, PVC free, AZO dye free, with insignificant metal content. In addition to all the other reasons why it is great for kid's products, you can also be confident of its safety.
I'd love to get your feedback on what other specifications might be important for kid's products.
Download 8-page white paper on
"Understanding Flexible Foam".