Memory Foam Pillows – The Basics
Memory foam pillows are increasingly common these days with seemingly lower and lower prices. With an overflow information, consumers are getting confused between various manufacturer claims. So what are memory foam pillows?
One of the first thing you hear or read about memory-foam pillows is that they are space-age technology. This is technically correct but not as meaningful as you might think. They were originally developed for NASA, the US space agency, in the 60's to absorb the high G-forces experience during the takeoff into space,. But they were never actually used in space flight.
So it is not cutting edge space technology, but more in the same vein, like velcro is used in space flights. Very useful, but not leading edge.
Visco-Elastic Polyurethane Foam
So what is memory foam? Memory foam, or visco-elastic polyurethane foam is made from polyurethane with additional chemicals that increase its viscosity level. Polyurethane is simply a widely available polymer that when mixed with other chemicals gives you a range of foam such as spandex and foam in your sofa couch, including memory foam.
Memory foam has two features that make them excellent materials for bed and pillow supports.
First, memory foam cells employ an open cell structure meaning the cells of foam have holes in them. These holes compress fully and spread their air pressure to adjoining cells. This feature of memory foam is what really helps to reduce pressure points.
Secondly, along with yielding underweight, the memory foam mattress cells are heat sensitive. The more heat that is applied, the more the cells compress. This temperature sensitivity helps the memory foam mattress further conform to the exact shape of the sleeper’s body. The example often used to demonstrate its properties is that a hand pressed into the foam and then removed will leave a clear impression in the foam. It is this property of variable density that led to its use for medical bed supports for long-term bed-bound patients.
Firm but not so firm
If you, like most, would have experienced fluffing up your pillow just to get the right support, wishing some parts of the pillow was firmer and the rest softer. Some manufacturers have attempted to do this by making pillows out of several different layers of materials. Unfortunately, as users of such pillows, we rarely sleep at the same spot or hold still for the entire period of sleep. We move throughout the night, making the decision to place the different materials within the pillow an almost impossible task. Memory foam pillows solve this problem.
With memory foam, we only need one material throughout the entire pillow. The material itself adjusts to where we need more support. Our body heat warms the pillow at the areas where we are in contact. This softens the memory foam and allows us to sink in and support the specific body part.
The property of firmness (hard to soft) of memory foam is used to determine comfort. Firmness is measured by a foam's IFD (Indentation Force Deflection) rating. Not all memory foam pillows are made the same. IFD ratings for memory foams range between super soft (IFD 10) and semi-rigid (IFD 120).
Other variations beside firmess is the contoured shape of the pillows.
Which to choose?
As always, we strongly recommend trying out any pillow for a period of time before making a purchase. Note that generally cheaper memory foam pillows tend to be of the lower IFD firmess variety. If the pillow's density is too low, it has very few genuine memory foam qualities. The recovery time is also so slow that the foam does not actually conform to the body's shape. So try, before you buy.
- Memory Foam Material Safety Data Sheet (MSDS)
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