FoamentingIdeas: The MDI Products Blog

5 Favorite Injection Molded (EVA and Polyolefin) Foam Products

Nancy Grossbart — Fri, 20 Aug 2010 17:36:00 GMT

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.

Crocs 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.

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.

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.

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."

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. This 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

Nancy Grossbart — Wed, 28 Jul 2010 15:00:00 GMT

I love this story, even if we didn't make the “One World” 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?

Nancy Grossbart — Wed, 21 Jul 2010 15:25:00 GMT

People 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.

Actually, 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.

How, 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.)

Take 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!

Nancy Grossbart — Mon, 12 Jul 2010 16:47:00 GMT

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.

Finally, 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.)

Obviously, 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??

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

Nancy Grossbart — Tue, 04 May 2010 19:05:00 GMT

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.

How to Choose between Compression & Injection Molded Foam

Nancy Grossbart — Wed, 21 Apr 2010 17:44:00 GMT

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.

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.

Dimension 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.

How Flexible Foam Is Made

Nancy Grossbart — Tue, 13 Apr 2010 19:36:00 GMT

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.

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

Nancy Grossbart — Tue, 15 Sep 2009 14:00:00 GMT

Lately, 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.

As 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...

I 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.

Are Goals Really Important?

Nancy Grossbart — Mon, 17 Aug 2009 13:30:00 GMT

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.

The Slow Death of Product Development...Again?

Nancy Grossbart — Mon, 03 Aug 2009 13:30:00 GMT

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.

Can The Curse of Knowledge Stunt Product Innovation?

Nancy Grossbart — Mon, 27 Jul 2009 17:00:00 GMT

Years ago I was visiting with the wisest person I know where I met this amazing man. He was a doctor, a lawyer, a Julliard educated violinist and an artist. Later, my wise friend asked me if I thought having all these achievements was a blessing or a curse. Of course, I said it was "a blessing." It seemed to me to be the epitome of a "successful life." But was it, really?

It turned out that with all this achievement, all this knowledge, his life was really miserable. It was one of those mind-opening experiences where you realize that what you think you see is not what is really happening.

Over the weekend, I was reading a Harvard Business blog by Scott Anthony about How Knowledge Can Hurt Innovation which brought me back the story of this man. Anthony describes a basic problem in product innovation as:

"Managers who have spent their entire lives working in an industry often suffer from the curse of knowledge. ...This curse can blind managers to opportunities and threats."

Obviously, I saw the parallels and thought about this man who I had only met that one day. I wondered if he ever grew, which seemed like a strange thought. I realized that this can happen to anyone of us if we don't continue to create "open spaces" in our lives for growth.

Anthony goes on to say:

How do you break free from the curse of knowledge? Spending a lot of time with customers helps. The more you listen to what the customer says and doesn't say, the more you can make sure that your intuition is attuned to the customer's knowledge base. Recognizing the curse helps as well. Make a regular habit of asking questions such as, "Is this our view, or the view of our target customer?"

No matter what your age, no matter how many years of experience you have in a particular field, you need to remind yourself every day that it is possible you know very little. That humility will help ensure you are ready to recognize that next great innovative idea.

As Anthony concludes:

Don't let your own knowledge blind you to threats and opportunities.

It's good advice for product innovation in business. Maybe even better advice for innovation in your personal life.

It Could Have Been Made from Foam

Nancy Grossbart — Wed, 22 Jul 2009 13:30:00 GMT

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.

Introducing Eco-Friendly Biodegradable Crosslinked Polyolefin Foam

Nancy Grossbart — Tue, 21 Jul 2009 15:22:00 GMT

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-Link^TM 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-Link^TM 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".

Why Would People Think I'm A Polymer Chemist?

Nancy Grossbart — Fri, 10 Jul 2009 16:28:00 GMT

It's amazing how much you can learn about subjects that you thought you had no interest in.

I majored in anthropology in college and never used any of it after I was graduated. My career had been exclusively in the marketing, advertising and graphic design area until 1999, when we came up with the idea to manufacture Injection Molded Foam parts with this incredibly unique process.

In the past 10 years on the job, I have gained a deep understanding of 3D geometry, production, quality, testing and standards, distribution/shipping and foaming materials.

Gaining this kind of knowledge is good for business because it allows you to walk and talk the talk. And if you are the least bit verbally adept, you will find potential customers asking you questions about your background that can shock you.

I have been asked more times than I can count if I am an engineer. This question has always made me laugh. Me? An engineer? Obviously, the answer is no but I must be doing and saying something right or why would people ask.

My favorite, however, is when Ron Snyder (Croc's CEO) asked me if I was a Polymer Chemist. OMG. That one really made me roar with laughter (on the inside). We were sitting on a boat in a Miami harbor beginning our relationship with Crocs. I was trying to remain professional so I didn't laugh out loud. At this point, I guess I had learned a lot about foaming materials, enough to "convince" a highly experienced and intelligent person to believe that I knew what I was talking about.

It's a perfect example that, if you want to, you can always step out of your comfort zone to learn the most complicated things.

I'd love to hear about the job you have that you were not qualified for when you started!

Understanding the Injection Molded Foam Process - pt. 1

Nancy Grossbart — Wed, 08 Jul 2009 16:01:00 GMT

When my company (MDI Products) first began to work with product designers who wanted to create a foam product and had lots of plastic molding experience, it was very difficult to get them to "think differently" about how to design a product that took advantage of our injection molded foam process. There are only some things about both processes that are similar. Both plasticize raw materials in a hot barrel. Both inject in the materials into a closed mold. Pretty much the similarity stops there.

Understanding the fundamentals is key to designing a great part. To really comprehend what is happening, you need to first know that injection molded foam is actually a foam manufacturing process which manufactures foam in the shape of your part.

The next area to understand that, unlike the single mold plastic process, the machines used in the injection molded foam process are multi-station presses, which utilize multi-molds.

Again, unlike plastic injection, the mold cavities are designed smaller than the final part size. The parts expand rather than shrink. The amount of expansion is dependant on the material softness you require.

The material remains in the heated mold during the cross-linking or cooking process. The cooking time is dependent on the thickness of the part. The mold opens very quickly when the cooking is complete. The part expands and explosively self ejects from the mold cavity. The part is removed from the mold station and set to cool.

Learn more about self-ejection, draft, corners, edges, and undercuts later.

Polyolefin Foam Makes Kid Friendly Products

Nancy Grossbart — Mon, 06 Jul 2009 15:59:00 GMT

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 PolyCell^TM 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".