Memory Foam & Latex
Memory foam, made from a visco-elastic material, is completely pliable so it can be used on either a flat or an adjustable bed frame. This is an especially great option for anyone who has back issues as memory foam softens with heat (body temperature is enough) and conforms to the curves of the spine, thereby reducing pressure points.
Invented by NASA in the 1970's, memory foam was revised and launched into the commercial market by the Swedish company, Tempur-Pedic. Although Tempur-Pedic is still the best known brand in this category and the reigning leader of the high-end market, there are now plenty of other brands to choose from. Consumers can also purchase memory foam pillows.
firmness of the foam, (between 2 - 7 lbs) is graded with the following
2. ILD Rating (Indentation Load Deflection)
The first factor, Weight, refers to the actual density of the foam in pounds per square foot, determined by the number of chemicals used in the foam's creation.
Next, the ILD Rating, the firmness of a mattress, determined by the indentation left when "x" amount of pounds of weight is applied to a 50 square inch area. The higher the ILD number, the firmer that particular mattress.
The third factor, the Resilience, or 'H R' factor shows how fast the foam rebounds when a ball is dropped onto the surface. The faster the rebound, the more resilient the material, and the more durable the mattress.
The fourth factor, tensile, shows the ability of the foam to be stretched. However, this does not offer very relevant information, since a memory foam mattress may be compressed by the weight of the sleeper, but it is never 'stretched'.
Again, there can still be plenty of variance in these measurements; however, most consumers find that they are more comfortable in the middle, sleeping on densities between 3 - 4 lbs, although a 5 lb density is recommended for its longer lifespan.
Some common complaints about memory foam are that, initially, it takes the body some getting used to and also that new mattresses may give off an unpleasant odor for a short time. US made foam mattresses and Swedish Tempurpedic mattresses do not contain toxic chemicals like formaldehyde and generally do not cause allergies.
Latex foam, a naturally derived substance made from the milky sap of the rubber tree, Hevea brasiliensis, is flexible enough to be used on both flat and adjustable beds. Latex is a desirable product since it not only acts similarly to memory foam, conforming to your body and reducing pressure points, but is also hypo-allergenic. Mold, mildew and bacteria cannot live in latex foam and it is also very resistant to dust mites. Good news for those who are very sensitive or allergic to these factors. And no chemical smell!
Another plus to this product is its' 'breathability'. The cellular makeup of these mattresses cools in warm weather and warms in cooler weather. This is advantageous over synthetic memory foams which tend to retain body heat.
What's available? Besides 100% natural latex foam and 100 % synthetic latex, there are two other processes to create blended latex: the Talalay process and the Dunlop process. These processes use about 60% synthetic and 40% natural latex and make up the bulk of the type of latex sold in the US. Some of the synthetic latex mattresses, such as those manufactured in China, are inexpensive but do not have as long a life span and may become uncomfortable after a short time due to their inferior construction.
Environmentally, 100 % latex foam is far superior to any of the other mattresses on the market. The process of making latex mattresses does not involve the use of toxic chemicals. Since latex is derived naturally, it is biodegradable (once it reaches the end of its lifespan which can be up to 30 years). But besides being a product that doesn't clog landfills, the rubber trees themselves, once they stop producing sap, are used to manufacture furniture.