The Differences in
Memory Foam Mattresses
Many people get confused when shopping for mattresses.
This is especially true when it comes to shopping for
memory foam mattresses!
Memory foam is a relatively new technology
in mattresses. Perfected in the space shuttle program, the
technology was introduced to help reduce the effects of
G-force or the force of gravity, on the astronauts when
executing take-offs and re-entry. NASA discovered the joints
in the body suffered significantly during these events. Thus
they developed a cushion foam to absorb these effects and
fitted the astronauts seats with it.
Since then, it has spread to general use, much as Velcro did
before it. Mattress technology is where it is most widely
beneficial. This is a technology driven product, so the
technology must be done correctly, for the end user to gain
the most benefit from the mattress. Producing these
mattresses correctly is time consuming and more costly than
producing it incorrectly. Because of this, you see a wide
spread in memory (visco-elastic) foam mattress pricing. A
little knowledge can save you a lot of money and
disappointment in this area.
There are a lot of important features in a well made
mattress. These include:
The cell structure of the foam itself
The density of the memory foam (measured in foot pounds per
The thickness of the visco-elastic layer
What's underneath the memory foam layer
The surface covering of the mattress
The thermal sensitivity of the visco layer
In order to understand why all of these things are
important, it is best to understand how the technology is
designed to work. How it differs from more conventional
foams and latex foams is important. Conceptually, when
exposed to body heat or pressure, the foam becomes
semi-viscous (called visco-elastic) and forms around the
high pressure/temperature points in contact with it. It
supports these points alleviating the gravitational effects.
This reduces the stress on the body and allows for greater,
deeper, sleep. It also helps with the rest/rejuvenation
cycle, making you more refreshed after sleep. When the
temperatures/pressures return to normal, the foam resumes
its original form.
There are key factors that are required for this to work.
One of the most important is the thermal sensitivity of the
foam. Many low quality foam mattresses are comprised of
foams that require temperatures that are considerably higher
than that of the human body. This means that that mattress
cannot perform as designed. The foam never reaches the
visco-elastic state when you are sleeping on it. It simply
Along the same thermal lines, the heat built up by the body
needs to be dispersed. This is principally done by creating
elliptical cell structures within the foam that allow air
and thermal flow. This keeps the mattress cool to the touch
while you are sleeping on it. Poorly made foam mattresses
have a circular cell structure that does not do this.
Therefore, you get hot when sleeping on them. When you hear
people say they didn't like this style of mattress, it is
usually because they slept on one that was poorly
The visco foam itself does not provide enough structure to
support the overall weight of a human body. Therefor, this
is accomplished by putting a support layer underneath it.
This layer may be a high density base 6-10" of foam or a
type of spring set with a smooth surface in contact with the
visco. Mattresses made with ONLY visco also do not work.
What works in this regard is a top layer of visco that
performs its basic task. If the layer is too thin, it cannot
completely fulfill its job. Too thick, and the mattress
fails to provide enough overall support. Ideal thicknesses
range between 1 and 3".
This thickness layer can be determined by the density of the
visco foam. It needs to be dense enough to perform
correctly. Too dense and the mattress is too hard. the foam
never achieves visco-elasticity. Too low a density, and the
mattress does not have enough material to perform its task.
Ideal densities range from 3 to 5 lbs. Getting the right
mixture of density and thickness is important to providing
the best sleep conditions.
The last important issue to look for is the cover on the
mattress. It should allow thermal transfer of the body heat
to the foam and return airflow from within the mattress. It
should be comfortable to the touch. Ideally, it should by
hypo-allergenic and removable/washable. This will make the
sleep much more pleasurable and comfortable. If you get all
of these features in your mattress, you should have decades
of sleeping comfort.
We carry mattresses that encompass all of the requirements
for the technology to work correctly. Come sample the
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