Foam is everywhere, but it's not all the same.
Flexible polyurethane foam is one of the most versatile materials ever created. We are literally surrounded by it. It is used in cushioning material for almost all furniture and bedding applications, for carpet underlay, packaging materials, insulation, sound proofing and so many other applications.
What does the foam's Density refer to and why is it important?
Density, in pounds per cubic feet, is found by weighing a 12″ cube of foam. Higher density foams will be more resilient and durable than lower density foams. Two foams may feel similar if they have the same compression or ILD, but there is no doubt the higher density foam will last longer before sagging.
Frequently Asked Foam Questions
ILD stands for Indentation Load Deflection, and by knowing the ILD you can tell how firm the foam is. The ILD tells you how many pounds per cubic foot it takes to compress a 4″ sample by 25% of its overall thickness. The lower the ILD the softer the foam, the higher the ILD, or the last two numbers of the grade’s part number, the firmer the foam. Foams with similar ILD’s will feel similar even if their density is different.
Yes, memory foam is a temperature sensitive material. Memory Foam is the only grade of foam where firmness is affected by room temperature. If the memory foam is used in a room that is colder than 60 degrees, it will feel firmer but will soften up when the body heats the foam during sleep.
The main differences are in price and performance. Higher density memory foam equates to higher performance at a higher price. Lower density memory foam is still good for some pressure relief at a lower price. However, a denser Memory Foam will give you get more support and conform to your body more. Higher density memory foams are designed for premium mattresses and a longer comfort life.
Most people seem to think that firmer foam will not sag as fast as softer foam. However, this is not necessarily true. To a large degree the density of the foam (its weight) is more important than its compression or firmness when it comes to determining foam’s durability. In other words, light firm foam will not last as long as a heavy soft foam.
The foam you choose for your application depends on your required thickness, budget, weight and preference. Thicker foam will feel firmer than thinner foam. In order to avoid bottoming out on a thinner piece of foam, you should go with a firmer compression which is represented by the last 2 numbers of the foam grade. There are numerous densities to suit various budgets. As for the firmness, it is entirely up to you, based on your weight, back condition, and preference.
Most foam grades are identified by a two-part numbering system (i.e. 2132). The first two numbers identify the Density of the foam (2.1 pounds per cubic foot). While the last two numbers identify the compression or the firmness of the foam (32 lbs, medium firm). A higher density equates to a better piece of foam. Similarly, a higher compression means the firmer the foam will feel.
Polyester Fibre is mainly used as a comfort layer on top of foam, or by itself, as stuffing in furniture backs. The most common and default thickness, when you order fibre wrap, is 1.25″ thick. It is cut to the size of the cushion and joined, using foam adhesive, to the top, bottom and front of a seat cushion. The fibre fills in all the gaps in the fabric and gives the finished cushion a more rounded look. Without the fibre the foam alone will look flat, and the fabric may appear loose and saggy.
High Resiliency (HR) foam is commonly used in commercial applications. In the past HR foam was fire retardant, but not anymore. The standards changed in 2013. The old standards focussed on filling materials, where fires didn’t start. It was a component test where each of the components was individually tested.
The current standards focus on where fires begin, the cover fabric, and on the interactions of the cover fabric and filling materials. It is now a composite test where foam and fabric are combined and tested together. There is no longer a need to add flame retardant chemicals to foam for it to pass the new standard.
All foam is not fire retardant. Our premium grades like NeoCell, Koosh® and Qualux all comply with the California 117 fire specification requirements. The CAL 117 fire spec is the most stringent fire retardant requirement for foam. It is mandatory for hospitals, hotels and other commercial applications. It costs a little more to produce but we believe it should be mandatory for all bedding and furniture applications.
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