There are three types of foam that dominate the packaging market because they stand out for their performance and for their lower costs – Polyethylene Foam (PE), Polyurethane Foam (PU), and Expanded Polystyrene Foam (EPS), also called Styrofoam TM. We will discuss the advantages and disadvantages of each type.
Polyethylene Foam is the most common for good reason. It is flexible, absorbs shock and vibration, is lightweight and strong, is easy to cut, resists moisture and chemicals, is non-abrasive, and one of the lowest priced flexible packaging foams available. PE Foam is available in rolls or sheets.
Rolled PE Foam, is sold in rolls and is white, and is commonly available from 1/32” to 1/4” thick in roll widths from 6” to 72” wide and also in premade pouches. Because it is so thin, PE Rolled Foam is more used to protect surfaces from scratching, not so much for shock absorption or holding an item in place.
PE Foam Sheets are sold in 1/2” increments from ½ “ thick to 4” thick. It can be specially ordered up to 6” in depth. In the United States, the most common sheet size is 4 feet x 9 feet. Since PE Sheets are more commonly used than Rolled PE and more versatile, the remaining discussion will be about the PE Foam Sheets.
In the United States, PE Foam is most commonly sold in 1.7 lb density , which means a cubic foot of material weights 1.7 lbs, or 27.2 kg/m3. The second most common density is 2.2 lb per cu foot, or 35.2 kg/m3, but there can be a significant price increase. This density is used when shipping very heavy products or to comply with government or military specs.
PE Foam is available in many colors, but black, also called charcoal, dominates for packaging as it is the least expensive, most available, better looking foam, and the black color is partially made from recycled materials with almost no difference in performance. The other common color for PE Foam is white, also called natural, but it can be significantly more expensive than the black. White PE Foam is used when specs require it or the color is critical, such as in medical, military or cosmetic packaging.
PE foam can be cut with a simple hand knife, but for production, is most commonly cut with saws, die punches, water jets, and CNC reciprocating knife machines. There can be upfront tooling costs when die punching, but the savings from production costs can more than offset the investment in tooling.
The disadvantage of PE Foam is the limitation of thickness and the cost if filling a large void since Polyethylene Foam is only commonly available in sheets with thicknesses up to 4”. Multiple layers of PE Foam can be glued or heat bonded together.
Expanded Polystyrene Foam (EPS), sometimes called Styrofoam TM, has some distinct advantages and disadvantages over PE and PU Foam.
The big advantages of EPS Foam are its cost, its insulating properties, and it lightness. EPS Foam is the least expensive foam to custom shape, especially on larger packaging requiring a lot of foam. Unlike PE Foam, where sheets are cut into packaging shapes and sometimes laminated together, EPS Foam is cut from large blocks, or billets, generally around 4′ x 4′ x 8′, so even large shapes can be cut from one solid piece, reducing labor.
EPS foam is cut from hot wires, and multiple wires cutting multiple blocks at the same time make production costs low and there are no tooling costs.
If you are shipping temperature controlled products, then EPS Foam coolers or Insulated Box Liners are the logical choice.
EPS Foam is actually more environmentally friendly than the other foams as the foam is 98% air, the amount of energy and greenhouse gases it takes to produce and transport is much less, and it is easily available in up to 40% recycled material.
The disadvantage of EPS Foam is cushioning against shock and vibration is not as good as the other flexible foams, and the aesthetics can be less desirable.
Expanded Polystyrene Foam in the United States is available in what is commonly referred to as 1 lb, 1.5 lb, and 2 lb densities. 1 lb EPS Foam is available in both virgin and recycled versions. For packaging, both 1 lb recycled and 1 lb virgin foams are the most commonly used.
EPS Foam can be glued using the appropriate hot melt adhesives.
Polyurethane Foam (PU) can be referred to as Charcoal PU Foam because of its color. PU Packaging Foam comes in three types, soft, medium and firm. Polyurethane is the foam that commonly comes in a camera or gun case or used as seat cushions. Density can affect the price significantly.
The advantages of PU Foam is that is can be extremely soft and non-abrasive. If you are shipping very delicate equipment, or you want a certain type of aesthetic, PU Foam may be the best for performance or looks.
Another advantage of PU Foam, is like EPS Foam, it is made in large blocks, or buns, so the size of your packaging is not restricted to 4” thick sheets, for example.
Like PE Foam, PU Foam can be cut using steel ruled dies, saws, water jest and CNC knife machines. PU Foam cannot be easily hand cut.
Polyurethane Foam can be used for making Convoluted Foam, commonly called Egg Crate Foam, which can be used for packaging. IPS Foam produces all of its convoluted foam in-house.
PE Foam cannot be heat bonded but can be glued using special hot melt adhesives.
Which foam is the best?
Here is my strategy when choosing foam for packaging.
Most of the time, I’m concerned about costs, so I’m thinking what is the least expensive foam that will sufficiently protect my product when shipping.
I first see if EPS Foam will work. Will EPS Foam cushion enough and will it look okay. The price advantage of EPS Foam is too great to not first consider it, and it has less of an environmental impact compared to other foams.
If I need more cushioning, or a different look or color, than both PE and PU Foam are options. PE foam is more commonly used in general because it is less expensive than PU Foam and looks and works fine.
Of course if I am trying to control the shipping temperature, than I would use EPS Foam.
There are other foams that can used, such as Cross-linked Foam (XLPE), Expanded Polyethylene Foam (EPE), Expanded Polypropylene Foam (EPP), Ethylene Vinyl Acetate Foam (EVA) and a few others, but these are not so common like the “Big 3” because they are more expensive. IPS Foam carries all of these foams.
IPS Foam is one of the few companies that produces EPS Foam, PU Foam, PE Foam, Egg Crate Foam, and more which gives you more options.
