BUYING GUIDE

learn important information about mattresses & more.

History of Memory Foam

Memory Foam Defined

The Genesis of the Memory Foam Mattress Industry

How to Find Quality Memory Foam

Why Does Memory Foam Density Matter?

Memory Foam Fundamentals

Hypo-Allergenic Qualities

Mattress Comparisons

Memory Foam Pillows

Memory Foam Toppers

Basic Recommendations

When Will I Need to Replace My Mattress

HISTORY OF MEMORY FOAM

Memory Foam was first developed by NASA in the 1960s to improve seat cushioning and crash protection for airplane pilots and passengers, and later tested for use in astronaut launch couches. During lift-off, astronauts experience multiple g-forces which exert unsafe pressure on the body.  The need for a material that would create a pressure-less environment for the astronauts, spawned years of research which finally manifested in Memory Foam.  The technology sat on the shelf for years before two scientists perfected the formula into the memory foam we know today.  A few medical research companies started experimenting with the material for use in hospitals to prevent bedsores for bedridden patients.  Due to the relative low cost, these experiments led to using memory foam in a variety of clinical environments.  Through this medical research, memory foam became increasingly more adept for use as a consumer product.

MEMORY FOAM DEFINED

There is a lot of information available on the internet about memory foam.  Unfortunately however, much of it is skewed in order to favor the specific product that the online company is selling.  Here we will provide you with some basic, unbiased information to allow you to make your own decisions.  Memory foam is the fastest growing sector of the bedding industry today and millions of people have switched to memory foam to take advantage of its benefits. Memory foam, also known as visco-elastic foam, is a material that resists change and slowly returns to its original shape after molding to pressure.  We have all seen the commercial of a hand pressing down on a memory foam mattress and it slowly returning to shape, or the girl jumping on a memory foam bed without knocking over the full wine glass on the other side.  This is illustrative of memory foam’s property of absorbing pressure, instead of transferring it elsewhere.  Memory foam molds to the shape of your body to relieve pressure.  Many doctors and chiropractors recommend a memory foam mattress to those suffering from back pain, as the mold formed by your body is one of perfect posture.

Memory foam is an open celled material, which means that air is free to move from one cell to another, so when pressure is applied the affected cells collapse and you feel as if you're floating down into the material.  This collapsing of the cells allows the material to "melt away" from pressure until the entire surface of your body is evenly supported over the memory foam.  It is this ability to conform to our body's shape that makes visco-elastic foam so beneficial. This virtually eliminates pressure points.  The air in sealed foam cells has nowhere to go, so it pushes back to the same extent pressure is applied.

Another unique feature of a memory foam mattress is temperature sensitivity. Within a short time of your body lying on the mattress, your body temperature will start to cause the memory foam to soften.  Areas of the body that would have the greatest amount of pressure will also be warmer thus causing the mattress to soften even further where it is touching, making memory foam the ideal material for maximizing comfort. When you lay on a regular foam mattress, the air in compressed cells pushes back against you as well as downwards.  This causes pressure points, which constricts circulation at the area of contact.  The result is discomfort and even pain over time.  When you lay on a visco-foam mattress there is no air left in the cell to push back and cause discomfort.  The air is spread to adjoining cells and the foam simply “melts” under you to provide pressure-less support and comfort.

THE GENESIS OF THE MEMORY FOAM MATTRESS INDUSTRY

Memory foam is the fastest growing alternative to innerspring mattresses.  There are  many health benefits to a pressure relieving mattress, that is why so many medical facilities, chiropractors, doctors, and yes, even NASA, are using and recommending memory foam.  The memory foam mattress industry started slowly in the early 1990's and then shot into the mainstream in the late 1990's and early 2000's.  So much so, that it is difficult to find a magazine, newspaper, or television that doesn't have several permanent ads for memory foam products.  With that kind of demand for the product it's no wonder that a numerous companies rose to manufacture and sell to an audience with this enormous appetite.  Unfortunately as in all industries, many companies produce and market inferior products.  Their strategy lies with the relative obscurity of information; hence they are able to successfully manipulate the average consumer into believing that their products are comparable to the rest or better!

HOW TO FIND QUALITY MEMORY FOAM

So here you are shopping around for a memory foam mattress!  You have seen so much repetitive information and you still don’t really know what is good and what is not.  You have seen many options but be forewarned there are a few important things to consider! The sleep experts here at Astrabeds.com have developed a list of what to look for when choosing the right memory foam mattress.  We have access to ALL available memory foam densities due to our huge purchasing power in the foam industry.

3lb memory foam is not practical for daily use.  The lower densities form indentations after a short period of time and if used in a mattress require constant maintenance.  Also, the inferior densities do not provide a pressure-less environment as it has properties similar to regular foam:  they are noticeably “springy” and do not contour to the body to an appreciable level.  A number of online companies are marketing 3lb memory foam products as 5.3lb density.  These companies do not manufacture their own products yet they purport themselves to be leaders in online retail of memory foam. These companies also do not match our 120 day in home trial period.  There are also several documented cases of online companies who have virtually disappeared to avoid warranty issues and refunds.  This is unacceptable.

WHY DOES DENSITY MATTER?

Memory foam is graded by its density.  Imagine cutting a one foot square cube out of memory foam and weighing it.  The weight of that large cube gives you the density. For example, if your cube weighed 5.3 lbs. it's considered to have a density of 5.3, or if it weighs 3.2 lbs. the density is rated as 3.2. Fairly simple arithmetic really…  You now know more about memory foam density than most of the sales people in your local mattress store!  It's also a fact that the less dense foams are made of mostly air, not foam. Less foam, less cost to manufacture... they can sell it cheaper.  For most memory foam mattresses, it's proven that the human body is best supported by a density of 5.3 lbs. to 5.9 lbs.  Any firmer than this and it tends to be too dense to allow for prime cell collapse which will compromise the contouring of the mattress to your body.  Lighter memory foams will not give proper support in the hip and shoulder areas and thus compromise the pressure-less environment that is so beneficial to the body.  Another significant issue with lighter foams is the compromise of structural integrity, i.e. they will not continue to return to their original shape after a relatively
short lifespan. 

Remember, too, that we discussed temperature sensitivity.  Not all foam being advertised as "memory foam" is temperature sensitive. Make sure it has this feature so you get that detailed comfort.  A quality memory foam mattress will contain three inches or more, of memory foam as a top layer.  Anything less will not give you enough material to sink into and you will find yourself supported by the underlying base layers of foam.

Just remember density and temperature sensitivity when you are shopping for your memory foam mattress and you will be a smart shopper!  Stay away from memory foam with less than 5.3 lbs density, as it will not last more than a few years and will not give healthy support.  It may be tempting to go with 3.0 - 4.0 lb density memory foam to save a few hundred dollars, but understand it will cost you more money in the long run and cost you comfort!  This means ignoring mattresses found at wholesale online retailers and superstores like Costco, Wal-mart and etc. 

The second main criterion to consider is firmness.  If you are buying in a store, try out all the mattresses to select whichever feels best. To be safe, make sure the company you purchase from has experience manufacturing mattresses and that there is at least a 20 year warranty attached to the mattress.   

FOAM FUNDAMENTALS

The unique open cell structure of visco elastic foam dampens shock and absorbs motion which is why it responds with stiffness when you quickly lie down or throw yourself onto the mattress like you would do when you were a kid.  This stiffness is the way memory foam reacts at time of impact and does not necessarily indicate a hard mattress.

Increased firmness in a memory foam mattress may also result from the cooler environment it's kept in.  When you first lie down on it, it seems firm but after a few minutes of body contact, it softens and flows around your body. The mattress becomes softer at the top but deeper down, where it's cooler, the mattress is firm and supportive.

Good quality, high density visco foam mattresses are firm to begin with due to their high resilience core and need a few weeks to break in, so take that into account when buying. 

HYPOALLERGENIC QUALITIES

Statistics tell us that 70% of environmentally provoked asthma is caused by an allergen associated with house mites.  The number of people, especially children, who are affected by this allergen, rises significantly each year.  The structure of any spring mattress is an inviting host for dust mites, (even if the fibers inside are not a source of food nor do they promote nesting, they still are a closed, sometimes warm and humid environment for the tiny creatures to live comfortably in).  Unfortunately, it is not practical to clean or vacuum the inside of the mattress, so the only option is to use dust-mite resistant encasings and covers.  Open-cell memory foam mattresses do not promote dust mite nesting, nor are they a food source in themselves and consequently reduce the presence of dust mites and allergens by up to 90%!

MATTRESS COMPARISONS

Inner Spring Mattress
Inner spring mattresses are the most commonly used mattresses. Unfortunately these mattresses do not provide adequate support.  When you sleep on your side, there's more pressure on shoulders and hips, cutting off circulation at key pressure points on your body. Typical innerspring mattresses resist the weight of these pressure points; they "push up" when they should be letting you sink in. Or else they just sag all over, still not providing the right support at these points. These pressure points and sags can put the body into positions where musco-skeletal stresses can undo the benefits
of sleep.

Water Beds
Water beds exert less pressures on the body than traditional inner spring mattresses.  Waterbeds were actually the originally coveted for pressure reduced sleep as it has significantly less pressure points than inner spring mattresses.  Unfortunately the less pressure is merely a side effect of water displacement.  This displacement creates what is known as a hammock effect.  This creates unsafe stress on the spine and causes chronic back pain if used for a long period
of time.

Air Mattress
Air mattresses are available in multiple firmness settings based on your choice. Each side of the mattress can be adjusted from very soft to very firm. The Sleep Number bed is the first of this kind; they are very expensive.  In lieu of springs, the Sleep Number uses inflatable air chambers to adjust firmness with a remote control.  A mattress review done by Consumer Reports found that there are complaints in owner reviews that this bed is not as comfortable as expected, and that it is too expensive. Reviews say an in-store test is essential before you buy one of these.

Some airbed manufacturers claim that since they baffle (separate) the air into multiple chambers that these mattresses have a great ability to conform to the shape of the human body.  However, it is obvious that manufacturing an air mattress with many chambers will only create more pressure points.  The only benefit of baffling an air mattress is that it reduces the hammock effect. The latest trend with premium airbeds is to incorporate a top layer of memory foam which just proves that an airbed is not a smart way to sleep.

The other apparent benefit of an airbed would be the ability to adjust one's side of the bed differently than a partner's side. Although this would be a nice feature, it allows one to adjust to one's perceived comfort, which in our experience is often not consistent with proper support. This is similar to the common finding that a lot of folks will take comfort in the thought of falling into a big overstuffed easy chair, although most of us now know that this type of chair is not supportive and can be destructive to our spine.

Additionally, we have found that adjusting the pressure an airbed to mid or lower values allows the hammock effect to be applied to the spine. This makes any appeal in having an adjustable air bed completely useless in terms of overall back support and benefit.

Latex Mattresses
Latex mattresses conform to pressure in a level almost as good as memory foam.  Talalay and Dunlop are the most common forms of a latex mattress. Talalay is the more involved process and provides the best resilience. It is also washed to remove any impurities. Latex gives you a bouncy feel, after all it is rubber. All latex is not alike and quality levels vary greatly between the different latex options. Be careful and ensure that you purchase the best possible quality latex available.

MEMORY FOAM PILLOWS

You have a few options when it comes to pillows: The ubiquitous contour pillow, comfort pillow (shaped like a regular pillow) and various luxury pillows.  The contour pillow is a favorite among back sleepers and some side sleepers.  Luxury pillows come in a couple different types.  Some have a satin side for cool sleeping and others are ornate which make a handsome addition to any bed. 

Consumers beware!  You will find “memory foam” pillows everywhere; from wal-mart and other big retailers to online retailers, specialty magazines and etc.  The pillows these companies sell are actually more foam than memory foam, so support and comfort are greatly compromised.

MEMORY FOAM TOPPERS

Only purchase when the underlying mattress is in good condition, as memory foam will contour to the shape of the mattress. Generally 4 pound density memory foam will be sufficient, although with very heavy people or those looking for a product that is going to last longer than five years 5.3 pound memory foam is be better.

BASIC RECOMMENDATIONS

We also recommend going with a mattress that has at least 3" of memory foam. A memory foam mattress is made up of layers of different material. On the bottom is some sort of base layer. This can be anything from inner spring to latex foam. Usually memory foam mattresses have a 5 - 6" base of a fairly dense polyurethane foam as the base layer. On top of the bed you find the memory foam layer. And we recommend 3" of memory foam on the top since this gives you a real luxurious feel on top of the bed.

These basic recommendations should help you narrow the field of memory foam mattresses a bit, but there are plenty out there that still fit these general criteria. So how do you choose? Well, unfortunately one of the problems with memory foam mattresses is that they are temperature sensitive - which means the memory foam layer softens up over time with your body's heat. And different memory foams react differently to body heat; that is, they take different amounts of time to soften and they soften to different degrees. So unlike standard mattresses, you may not get a very good idea of the comfort of a particular memory foam mattress by trying it out in a store. You just don't have the time in a store test to see what the mattress will feel like over a whole night's sleep of having the foam interact with your body's particular body temperature (some people sleep warm, others don't, etc.).

WHEN WILL I NEED TO REPLACE MY MATTRESS?

Many years of use will undoubtedly compromise the original shape of the mattress.  Indentations become permanent and reduce the quality of support. The focus then, becomes on how much use a mattress can undergo before deteriorating.

Consider this:  Lower density memory foams break down within several years because there are less visco elastic cells.  Each mattress is consists of billions of cells however since lower density has less visco elastic cells there is relatively more stress on each cell thus greatly reducing the life of the mattress. With more air than substance, wear in low density visco elastic foam may become visible in as early as 3 years.