What is the ideal density of a foam for my weight?
Generally, we advise our customers not to use foams with less than 30 kg/m3 of density for mattresses. However, there are several factors that influence the choice of foam density: sleeping alone or with a partner, the thickness of the foam, the hardness of the foam and its compression set.
Do you sleep alone or with a partner?
Sleeping alone or accompanied also influences the definition of the appropriate density. If you sleep with a partner, a higher density solution is advisable, even if one of the partners is short stature or has low body density. Yet, this decision cannot be made without considering the foam’s hardness, which must be appropriate for the bedding industry.
Thickness versus density
What is better – 20cm of a 20kg/m3 or 10cm foam of a 40 kg/m3 foam? It depends entirely on the application.
In principle, the higher the density, for the same thickness, the greater the probability that the mattress is compatible with any body type and/or density. Thickness is relevant if the application is compared between foams of different densities. That is, for a foam with a 20cm thickness, it is safer to pick a 40 kg/m3 density than 20kg/m3, so that performance is not jeopardized.
However, there are applications that do not require high-density foams if the thickness compensates for the foam’s lack of ‘body’.
Another factor to consider in this equation is the compression set of the foam in question. Also called static fatigue, the compression set measures, as a percentage, the loss of thickness of a foam sample after prolonged compression, thus being an indicator of durability. For example, a foam with compression set values of 3% is more resistant to use than a foam with 6%.
Therefore, using low density (and lower thickness) foams is not always a bad option if the compression set of the foam is better.
By coordinating all these factors, you can determine the ideal density for a product – mattress, sofa, chair, etc. – that is appropriate to your needs.