When it comes to shopping for a new mattress, most people aren't aware that "foam" and "memory foam" are not necessarily the same thing. Although you may have heard these words being used interchangeably, there are actually a variety of differences between traditional foam (also known as polyurethane foam) versus memory foam. These differences can have a huge impact on the quality, cost, and overall comfort of the mattress...
It's because of this assumption that memory foam sometimes gets a bad reputation... unrightfully so! For instance, there are a lot of people under the assumption that all "foam" absorbs heat. This is simply not true. Although there is still traditional, old-fashioned foam on the market that does absorb heat, authentic memory foam does not!
So how does one differentiate?
Closed Cell vs. Open Cell Foam
Closed cell foam has a tendency to trap air. As temperatures in the mattress's environment rise, the air absorbed by the traditional foam mattress becomes stuck within these closed cells and the mattress is more likely to over heat as a result. This can cause a very unpleasant, hot, and sweaty sleeping surface.
On the contrast, real memory foam (also known as Visco elastic or visco-foam) that contains open cells does exactly the opposite. Visco elastic foam is temperature sensitive as it resists change and slowly returns to its original shape when forced upon. The open cells within this foam allow the foam to "breathe" easier, disallowing heat to be trapped within its fibers, hence providing an overall more comfortable and cool sleep experience.
How can I tell if it's open or closed?
If you have recently purchased or are looking at an authentic Visco elastic memory foam mattress, you are in luck. All Visco elastic memory foam is open cell, which means that the air travels from cell to cell as varying degrees of pressure are applied to the mattress. Heat is much less likely to be trapped within the cells as traditional foam mattresses, made by polyurethane material, have a tendency to do.
Note: keep in mind that there are varying degrees of Visco-foam out there. Density and thickness can have an affect on the overall mattress's temperature sensitivity, even if it is Visco elastic.
Another way to tell if your foam is open or closed: do your research on the manufacturer! Find out where the mattress was made and start hunting. There are tons of websites out there that provide user and industry reviews. It really depends on a case-by-case basis.
The Recovery of the Foam
Another difference between traditional foam and memory foam is the recovery time. Traditional, or polyurethane, foam recovers much quicker than Visco elastic memory foam. When polyurethane recovers, it quickly takes its shape back in a "bouncy" manner that is much less comfortable. When Visco elastic recovers, it reacts more slowly and conforms to irregularities in shape (such as body parts!).
Perhaps the most telling sign of quality, Visco elastic memory foam is the ability of it to soften under the places where your body heat affects it. If you are to experience an injury, you will notice that the softness underneath your injury normally convey fevered heat. The additional heat may cause the mattress material to soften even more, providing more comfort and alleviation to that respective area. Specifically, memory foam has worked wonders for alleviating chronic back pain, a common problem among older adults.
So the next time you are in the market for a mattress, remember the differences between polyurethane and Visco elastic. Polyurethane contains closed cells and is regarded as a traditional foam mattress, whereas authentic memory foam consists of open cells and is much less likely to absorb heat... not to mention it's a lot more comfortable!