In a previous post we started a conversation about foam, and when we start talking about foam, all sorts of new ideas just start bubbling up (sorry). This time, we thought we’d talk about the difference between open-cell polyurethane foam and closed-cell polyethylene foam.

Before you get overwhelmed by complicated names, let’s make it simple.

Closed-cell polyethylene foam – Think of pool noodles. And for this conversation, let’s call it PE foam.

Open-cell polyurethane foam – Think of the padding inside vehicle seats or chair cushions.  We’ll shorten this one to PU foam.

So what’s the difference, and why should you care?

You should care because you encounter these products all the time, but in the context of packaging, the effective use of these products can greatly impact the cost and availability of most of the products around you. As a participant in the packaging industry, effectively protecting products during storage and transport is how we serve our clients. If we used the wrong products or used products in an inefficient way, products from oil well equipment to medical supplies would be saddled with higher-than-necessary transport and storage costs, and eventually you, the consumer, would end up eating the bill. So yeah, foam is kind of a big deal.

So let’s dive into the foam pit and see what we’ve got!

PE Foam

*PU foam is baked like bread, PE foam is extruded. This stuff is baked like bread, so you can get it in almost any shape possible. You can have the aforementioned pool noodle, or you can get sheets, planks, or whatever extruded shape your foam-loving heart desires. 

Strengths – PE foam can be fairly dense and while it offers support, it doesn’t crush down like super-soft foams, so it’s great for protecting heavier objects or when you need consistent compression performance. You’ll find it inside boxes supporting larger electronics like TVs or computers. A little PE foam goes a long way, so you don’t need a lot of it to offer protection against impact. It can also be water-resistant, so it’s great for use in flotation devices like life jackets or, you guessed it, pool noodles.

What is it not good for? – Because it’s dense and not real spongey, it’s not great in applications designed for human comfort. It wouldn’t make a great seat cushion in a chair, and it would really chafe if it was used in padded straps on a backpack. PE foam (or another closed cell foam) is used in backpack straps because it doesn’t break down as easily over time. 

How about recycling PE foam? – PE foam is extremely recyclable. You can melt it down, pour it into a mold and make whole new sheets of foam that can have a fully productive second or even third life. 

PU Foam

PU foam is made by mixing two components together that expands into huge blocks that can be cut and shaped into almost any form. You can check out this video for a pretty good explanation of the process.

What it’s good for? – PU foam is great for cushioning objects, or for offering comfort where people are concerned. You might find PU foam incorporated into the packaging for very delicate pieces, but you’re most likely to find it used in products you touch every day like seat cushions, padded straps on all sorts of backpacks and bags, even the sponge next to your kitchen sink. There’s a good chance that you’re enjoying the comfort of PU foam almost all day long.

What is it not good for? – PU foam isn’t very practical if the object you’re protecting is very heavy or if you’re in a wet environment. It can compact pretty quickly, so using it to protect a piece of cast-iron oil drilling equipment may not be the best fit. It also absorbs and retains water, so it wouldn’t be ideal if you’re trying to protect equipment in a humid or rainy environment or if the product was prone to moisture damage.

Can you recycle PU foam? – Yes, but your recycling options are limited. Unlike PE foam, you can’t melt PU foam down and reform it. Your only options are to shred it up and use that mulched foam for something else like a carpet pad or insulation. That being said, a LOT of PE foam gets recycled this way, so saying it’s sustainably problematic really isn’t the case.

Have the wheels started turning? What sort of applications could foam be used for in your operation?

Give WIC a call and let’s talk about making something that really moves your business forward.