This article is part one of a multi-series on foam compression by our account manager, Jordan. He shares his insights to help customers better understand the variables that factor into the purchase of a compression machine. We hope it helps guide your discussions and allows you to make educated decisions when packaging your products.
Foam compression is an exciting concept that has recently gained a lot of traction within the foam industry. The reasons are obvious – a smaller package has the potential for some substantial benefits. We’ve talked a lot about these benefits, so we’d like to focus on factors that you need to be aware of before you start compressing your foam products.
Characteristics of Foam that Affect Compression
The properties of your foam are the foundation for a conversation about compression. All foams are not created equally and they all respond differently to being compressed. There are a number of reasons for this, but the four main characteristics of foam that factor into its ability to be compressed and recover are type, density, ILD, and quality.
Visco, Conventional, and HR (High Resiliency) foam are the three main foam types being compressed today. Visco foam (also called memory foam) is a durable, dense, soft foam that lends itself well to compression. It’s known to handle significant volume reductions for extended periods of time without compromising the foam. For conventional foams, they vary in density and firmness so their ability to compress differs. This is because density and firmness play a large roll in compression (more to come on this). HR foams are the most difficult to compress. These foams place a higher stress on the compression machine and often experience recovery issues. This is not to say that HR foams can’t be compressed, but you should consider the potential issues. With conventional and HR foam, plan on doing ample testing before reaching any conclusions.
Foam density ranges from around 1 lb/ft3 on the light side, up to 5-6 lb/ft3 or more on the heavy side. In general, the lighter the foam, the less resilient it is to compression. The biggest concern with lighter foams is that often they will not recover to their original volume after compression. This volume loss exaggerates even more when the foam stays compressed for a long time. We can control the volume loss by reducing the amount of compression. Yet it is often more cost-effective to go with a heavier foam that handles compression than with a lighter foam that can’t handle compression.
ILD (Indentation Load Deflection)
ILD is a measurement of firmness. The higher the number, the firmer the foam. Compression may cause some ILD loss, as the pressure softens the cell structure of the foam. We can avoid this by starting with a higher ILD, knowing that with compression the ILD will drop into a range that is acceptable. Testing will determine if your product may need to move to a higher ILD.
While a slight ILD loss may not be the best news, there might be a silver lining. End consumers may find that foam that has been conditioned from compression packaging does not soften with use as much as unconditioned foam (think of the “break-in period” for a mattress). This could result in fewer warranty and comfort issues later in life.
Finding a high-quality foam from a trusted foam pourer is vital for consistent compression recovery. To increase foam’s weight (and command a higher price), some foam pourers might be tempted to add excessive fillers to their foam. These fillers can have a detrimental effect on a foam’s ability to recover. Using a high-quality foam, regardless of density and ILD, will ensure that you experience repeatable post-compression performance.
Understanding your foam’s characteristics is a big step in moving toward a compressed package. Taking these characteristics into account will provide you with a framework for assessing your foam. Next, you’ll look at realistic expectations, packaging options, and machinery. Knowing what you’re working with and where your flexibility is with the product gives you a great head start.
Questions? Contact us to see if your products are suitable for compression.