Polyfoam/reticulated foam

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I am writing up an article on what types of foam to use (not just for muppet-types so if you have other suggestions, let me know!). However, I'm really confused on "reticulated" vs "polyfoam". It seems they are two different things, based on the conversation on this site; but when I checked my enquiries to a foam supplier, they used "reticulated" to refer to EVA foam, when some people use EVA foam to refer to polyfoam.

Can someone please give me a succinct explanation as to what they are called by the manufacturer and what the differences between the two are?


PS. Continually amazed at the amount of info that is here for all to find. :)

Shawn Sorrell:
I don't think you are going to get a solid answer on this one. :)  Seems as if ever seller has different names.  Here is how I see it.

Polyfoam is what I use when I am refering to the foam sheets you get at hobby and craft stores. As a rule it is what you find in chair cushions.

Reticulated foam looks a bit like air conditioning filter in that it is very open almost like a sea sponge.

EVA foam is very dense foam and most commonly used to make cushions on boats and docks because it is "water proof". It is often refereed to as close celled foam.

I think really that they all kind of fall under the heading of Polyfoam but that each is a different process and I am sure mix of chemicals and agents.

Billy D. Fuller:
I ordered some foam that was close to reticulated from Albany foam http://albanyfoam.com/ It was called E-Z dry and is used for cushions in outdoor furniture. As Shawn said the reticulated I think is primarily used to make filters in air conditioning and heating systems. There are some craft products made from eva foam as well.


Shawn Sorrell:
Good link Billy!  The "Closed Cell Foam" that is shown on that page is what my supplier calls EVA foam.

This confused me for years, but after learning from some chemists and talking to companies that actually manufacture foam, I think I can give you a pretty definitive answer. Really, there are only two types of foam - open cell foam and closed cell foam. Every type and brand of foam fits under one of those two categories.

Open cell foam has an "open" structure and is usually very soft and pliable. One characteristic of it is that it contains pores that can be filled with a liquid (like water) or gas (like air). For example, synthetic dish sponges are made from open cell foam, which is why they can absorb water. Open cell foams are reticulated, which just means they are structured like a web or a net. What is commonly called "reticulated foam" in puppet building circles is actually industrial filter foam that is usually manufactured to make filters for air conditioners as mentioned above. What's often called "Polyfoam" (short for polyurethane foam) is the type of foam rubber that couch cushions and mattresses get made from. Technically speaking they are both open cell foam and therefore reticulated foam.

Closed cell foam does not have pores and is usually stronger and harder than open cell foam. An example of a closed cell foam is L200/400/600 foam, which is known to many people as "craft foam" or "Foamie" when it's sold in thin sheets. As I think Shawn mentioned, closed cell foams are typically used for marine applications because it floats and does not absorb water because of it's "closed cell" structure. Pool noodles are manufactured from closed cell foam and it's also used to make life jackets.

EVA stands for Ethylene-vinyl acetate, which is used to make lots of things like wetsuits, hot glue, and even body bags. It's a type of polymer (technically, it's a copolymer) that can be used to make foam, so all "EVA foam" means is that it's a foam made from EVA. All of the EVA foams I've ever seen are closed cell foams, although it's probably possible to manufacture an open cell foam using EVA, which might explain the confusion.

Does that make sense?


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