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5 Favorite Injection Molded (EVA and Polyolefin) Foam Products

  
  
  
  
  
  

I was thinking back over my last ten years in the injection molded (EVA and polyolefin foam) business, and wondered which products made with this process are my favorites. It's an extremely hard question because there have been lots and lots of products made. Many products have been made by my company but other companies in our industry have also created incredible designs. If I had to narrow it down to only five, which five would it be?

It was hard to decide, but here's my list. I'm sure, however, that I will need to do another post for the runners up.

molded-eva-foam-crocsCrocs Sandals. The Crocs Sandal is the number one obvious choice. It’s not only because of the incredible (so ugly, it’s beautiful) design but because of the worldwide phenomenon it created. We were lucky enough to manufacture Crocs in our factory and it never ceased to delight me to watch them being made. After they came out of a hot mold, the sandals were cooled on a unit that looked like a ferris wheel, where each level held one cycle of production. Round and round they would go and, at the end of the cycle, they would be removed from the carousel. Straps were attached and "voila" a new pair of Crocs was born, in a rainbow selection of colors.
molded-eva-foam-backpacking

Backpack Padding. If you’ve owned a backpack, especially a high-end backpack, you probably never noticed the comfort-foam included in the product. Why? Because it was always hidden behind fabric or mesh. The ability to injection mold EVA and polyolefin foam changed all that. Here’s a backpack that is wearing its lumbar and upper back comfort-foam on the outside, as a showpiece. The detail of the injection molded foam process allowed for industrial design to not only deal with the practical, but also the beautiful.
molded-eva-foam-kayak-seat

Kayak Seat. Traditionally, kayak seats were made from compression molded foam with a fabric laminate. This product design has always had a limited life. Several years ago a few kayak companies were adventurous enough to recognize the durability and detail benefits that result from the application of the injection molding foam process. They designed kayak seats that were not only very detailed with undercuts and logos but extremely durable.
molded-eva-foam-armrest

Carseat Armrest. Check out this really creative foam carseat armrest. The carseat manufacturer designed the armrest foam to be injection molded separately and allowed the foam to "shrink" onto a plastic substrate. The subtrate has ridges on it that create a "grip" relationship between the foam and the plastic. The results ended up utilizing the benefits of EVA/polyolefin foam in an armrest application that needed to be "kid friendly."
molded-eva-foam-ridgerunner

Construction Kneeling Unit. I don't know if I like this product more because of its design or because of its function. I'll bet if you just looked at the product on the left you would never know it was used in construction. injection-molded-eva-foam-ridgerunnerThis clever kneeling pad design allows workers to stay on top of a house during roof construction as they are installing one truss after another. The time savings in crane rental is up to 40%, paying for the product almost the first time it is used. The orange support is made of durable, powder-coated aluminum. The injection molded EVA/polyolefin foam padding provides comfort for knees and legs and stays dry during use.

If you have a favorite, I'd love to hear about it. If you send me a photo, I will be happy to post it. In the meantime, visit our product solutions gallery to see a selection of products we've made over the years

 

Indestructible Soccer Ball Made from Injection Foam Molding

  
  
  
  
  
  

I love this story, even if we didn't make the “One World” soccer ball.injection-foam-molding-soccer-ball

This soccer ball took 5 years to develop. I can believe it. I, absolutely, know how hard this soccer ball was to manufacture. I've worked on lots projects in the injection foam molding process that have required extensive R&D to make the product come out just right.

It all started when a music producer and inventor, Tim Jahnigen, saw how children traumatized by their violent environment “were desperate to play with anything.” It gave him the idea to create an indestructible soccer ball.

After 5 years of development, and some help from Sting, he developed a soccer ball with the injection foam molding process like Crocs sandals.

 

   

 

The soccer ball is indestructible because this soft foam is basically indestructible. How long have you worn your Crocs sandals? The soft foam has its own, extremely durable, skin that is formed during the manufacturing process. Inside the skin is an equally tough, closed cell, foam that won’t absorb liquid.

 

See how a truck can run over it and still not destroy it.


All of these process and foam benefits mean the kids will be able play with this ball in any environment with no chance of it being flattened, and almost no chance of it ever being damaged. I understand a ball was given to a lion in the Johannesburg zoo. Even he couldn’t destroy it.

You can learn more about it in an article in the San Francisco Chronicle.

 

Do You Mean Foam Density or Do You Mean Foam Softness?

  
  
  
  
  
  

foam-softness-durometerPeople confuse foam density and foam softness all the time. They say to me, “I’m looking for a low density foam.” I always ask “Do you really mean density or do you mean softness?” They (almost always) mean softness.

So, what is the difference? The density of foam is a measurement of the weight of a cubic volume of a material, like 12lbs/ft3. On the other hand, the softness of foam is a measurement of the tension on the surface of the material when it is touched.

foam-density-formulaActually, there is not a real direct relationship between foam density and foam softness. You can have foam that is 2lb/ft3 density and is very soft or very hard. It depends on the chemicals used to make the foam.

foam-softness-durometer-2How, then, is softness measured? It’s measured with an instrument called a durometer. There are three major softness measurement scales: Shore 00 (shown right), Shore A, and Asker C. Shore 00 is the best scale to use when you want to measure something that is very soft as it has the widest scale on the soft end.

So, is there any relationship between softness and density? Not really. However, there is a direct relationship between density and Squishiness (a new term I have created.) Of course, I’ve had to also create the tool for measuring this soft foam specification…the Squishometer (seen below left.)

foam-softness-squishometerTake the difference between open cell foam and closed cell foam. Open cell foam scores extremely high on the Squishometer because it has a very low density. (A sponge is an example of open cell foam.) Closed cell foam tends to be denser and, therefore, scores low on the Squishometer.

Hopefully my short post on this (often confused) physical property of soft foam is now clear. The next customer who asks me will be the test of this theory.

Learn more about our foam. Download our 8-page white paper.

 

Injection Molded Foam. Now in Dual Color/Density!

  
  
  
  
  
  

For years, product designers and developers have been asking if the injection molded foam process could produce parts in a dual density or dual colors.

Although this foam process was invented several years ago, it wasn't really perfected. There was always some flash bleeding over into one side or the other between the densities or colors which made the parts look sloppy and not of the quality most developers need. Of course, this was most visible when the colors were different.

two-color-molded-foam-partsFinally, after lots of trials, this foam process is now perfected for simple geometry parts. This is huge progress in a growing industry that has no centralized association. It's the hard working inventive people on both the machine manufacturing and molder sides that pushed past all the obstacles that ultimately resulted in this breakthough. 

So far, we've only been able create real quality parts when the geometry is simple, like a sandal or a midsole. Look at them. Don't they look fabulous? For example the upper side is one color (and one density) and the bottom side is a second color (and denser for abrasion resistance.)

two-color-sandalObviously, it can't stop here. Those of us in this industry must continue to strive to create the ability to produce more complex geometric parts in dual density/dual color. Hopefully, this will not take several years to perfect like the initial trials.

An adventurous customer, with a vision of their complex part in dual color or dual density, will absolutely help accelerate the development.

Any takers??

  

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Why Choose EVA for Molded Foam? Because it Makes Soft Parts!

  
  
  
  
  
  

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!

eva-molded-foam-partsHard 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.

eva-foam-manufacturerHow 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.

 

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<b>How to Choose between Compression & Injection Molded Foam</b>

  
  
  
  
  
  

5 ways products manufactured by injection molded foam differ from compression molded foam, not counting the obvious...Injection molded foam products are made by a pellet to product process, injecting a melted pellet into a closed mold foaming the formula into a multi-dimensional design. Compression molding foam can't come close to creating the same complex designs. However, when injection molding produces the same, or similar, product to compression molding here's how they differ.compression-molded-foam-chest

Aesthetic Quality. When it comes to a finished look, the overall appearance of a compression molded (vacuform/thermoform) foam part cannot compare with that of an injection molded foam part. The increased density, and perfect "mold" finish of an injection mold, produces a part with far superior aesthetics. Because the foam used for compression molded parts is outsourced, the quality of the foam is also likely to be variable, affecting the final aesthetics of the part. On the other hand, because the injection molded foam is manufactured in-house with the foam and part made simultaneously, the quality is always consistent.

Specific variables that affect quality in compression parts, but not injection parts, are:

  • inconsistent cell count within the foam, variable pigmentation and density in the raw materials causing color variation
  • inconsisent part to part processing time, temperature and degree of compression causing variation in part definition.

molded-foam-partDimension Quality: The ability to produce a consistent dimensional part is based on how well the molding process can be controlled. The pellet to product process means that the manufacturing of the foam, and final part, are one and the same. Most processing conditions can be controlled and duplicated, resulting in minimal part to part variation. Compression molding, however, starts with a bun or sheet of foam that is heated and molded into a different shape, subject to far more variable processing conditions. In addition, the need for final trimming of the compression molded part can also be a major contributor to a low quality image.

Thickness Variation: If the final product has varying height profiles, a compression molded part must start with a sheet (bun) of foam that is the height of the tallest dimension of the part. If the foam chosen for the compression molding process does not come in a thick enough bun, laminating sheets together is required to form thicker buns. This can result in that some parts have a lamination line which can delaminate with time. Injection molded foam parts, however, can be made to any height, not limited by the process, without need for lamination.

Post Mold Stability: Another area where the two processes differ significantly is what happens to the part after it is processed. Injection molded parts are extremely soft and malleable when they finish their molding cycle. During the post molding phase, a cooling fixture may be required to help the part maintain its shape. Unless the part is subjected to external forces that causes it to change shape,  the final cooled part will be exactly what was expect. On the other hand, compression molded foam parts can suffer post molding shrinkage and warp, even if cooling fixtures are utilized.

Cost and Value: Compression molded foam parts will almost always cost less than injection molded foam parts. Not only is the tooling and manufacturing equipment less expensive but the parts as well. Because compression molding uses bun stock, low density (inexpensive) foams are often chosen. This results in lower quality products that are great for a give-away or other temporary product. Injection molded foam products, while more expensive, are attractive, with long lasting value.

Both compression molded foam and injection molded foam have their place in the world of manufacturing. Choose the foam process that is best for your product.

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<b>How Flexible Foam Is Made</b>

  
  
  
  
  
  

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. 

flexible-foam-closed-cellThe 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.
 

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How do you know a Great Product Design is Really Great?

  
  
  
  
  
  

i-phoneLately, I find myself waxing philosophical about great product design and what it really means. I voraciously devour articles and blogs on the subject, finding that the writings that affect some inner space inside me are the ones that make the most sense. Knowing great product design is probably more emotional than anything else.

Dan Harden's article at Fastcompany.com about the Disappearing Act of Good Design affected me that way. In his blog, he says.

When a product is so completely and rightly designed, it has aesthetic and functional elements that are clearly stated and obvious. The product itself communicates without words its utilitarian value, ease of use, and beauty, and you perceive the quality-contributing elements instantly.... When a product does all the above things well, instead of it having abundant presence like one would expect, it actually sort of disappears when you use it.

What this means to me is the best product designs are ones you love instantly and then take for granted (in a good way) after you incorporate them into your everyday life. Harden uses the examples of the iPhone, a Porsche, an Aeron Chair. All of these are great designs that we admire whether we own one or not.

foam-toilet-seatAs a manufacturer of injection molded polyolefin and EVA foam, we have worked with some really great product developers and product designers. One customer, in particular, made the development process extremely difficult by creating five different designs (five molds) over a two to three year period before settling on the final design. As you can imagine, from a manufacturer's perspective, we were both frustrated with the process and anxious to be in production. However, when the 5th design came out of the mold, it was astoundingly beautiful both in aesthetics and function. It was hard to remember ever being frustrated, which only emphasizes Harden's take on this.

There is unity and wholeness, and it is so evident that this thing will totally satisfy a physical and/or emotional need....The product becomes a subconsciously satisfying experience, not a heavy conscious thing that demands attention because it's pretty or different...

holly-hunterI recently heard a story about Holly Hunter, the Academy Award Winning Actress, who is starring in the TV series "Saving Grace". One of the directors is a friend of a friend. The director said "She is so frustrating. I have a budget to meet and every time I OK a scene, ready to move on, Holly always asks for one more take insisting that she can do it better. Reluctantly, I agree and every time she is right. She adds that something extra that makes it amazing."

Obviously, this doesn't relate directly to product design or molded foam or foam manufacturing. It does, however, relate to the truth that when creativity is right, it's just right.

 

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Are Goals Really Important?

  
  
  
  
  
  

When I went on an interview for a marketing job at a TV station, early in my career, I was asked that age-old question "What are your five-year goals?" I sat there very quietly, not answering, for way longer than was comfortable for either of us. I kept thinking what are my five year goals...what about three year...do I even have one year goals? Tick..tick..tick. What am I going to answer?

Finally, the silence was so long, so pregnant, I blurted out this long stream-of -consciousness mind-dump, "I have no goals. Well, it's not that I really have no goals. It's that my goals are always changing as I get more experience and I don't want to create a  goal for something that, six months from now, I will change my mind about."

The interviewer sat looking at me as if she had never heard anything like it before.I stared back nervously thinking I had totally screwed up my chances for this job but couldn't make up goals I didn't have. Finally, she said, "I like that answer because that's how life really works. You're hired!"

Well, that's not exactly how it happened. There was a lot more discussion before the "you're hired" part actually happened. What was most important is that I got the job because she really understood how I saw the concept of goals.

When I think about it, it's very similar to the creative process. You start your product development cycle with set goals that must be met. However, when you're actually involved in the product design itself, you can start with one concept that takes you to the next, and then the next and the one after that. And when it is all over, you end up in a place that you love, but never expected.

Look at me. I ended up in business development at an injection molded foam company. It really goes to prove that life is a creative adventure, one creation after another.

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The Slow Death of Product Development...Again?

  
  
  
  
  
  

Michael Cannell at Fast Company wrote a blog on Design's Lost Generation. It was about how many talented designers (architects, product designers and design engineers) were lost to the recession of the early 90's, wondering if the same thing is going to happen because of this recession.

I never really thought about it from that perspective. People lose their jobs in a recession but do they really lose their profession because they just give up? When you give all that time to your education and have to watch your job disappear, with little opportunity to replace it, do you actually give up your dream and move on to another industry? Michael Cannell says that's exactly what happened.

Many of those young designers left the field for good. They took their training and skills and went elsewhere--construction, real-estate development, teaching.

You have to take a deep breath before you wrap your mind around this. It's not just the loss of jobs at the time; it's the loss of talent from a whole industry. What is the net effect of this? What product development projects never came to fruition? What buildings were never built? What industrial design firms failed because it had to let talented people go that might have changed their future? Cannell says:

Over the long run, the design firms probably suffered more than their cast-off staff did. When the economy gained steam a decade later, after the tech crash and 9/11, design firms struggled to find midlevel talent to draft and manage projects. The shortage of experienced hands was one of the factors that led firms to begin outsourcing work to India and Eastern Europe over the last five years or so.

So now not only did architects, industrial designers, and product engineers lose their jobs, the whole country lost their jobs, potentially forever. You can't have a "do-over" on something like this.

Here we are in another recession, where more design talent is being laid-off every day. What affect is this going to have on the future of design? We can only hope, none.

 

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