How Is Memory Foam Made?
Memory Foam Developed by NASA
The very first memory foam material was developed by NASA in the 1970s. Their intention was to try to improve seat cushioning and crash protection for airline pilots and passengers. Memory foam has widespread commercial applications, in addition to the popular mattresses and pillows you are familiar with today.
Anybody who has gone shopping for a bed, a new pillow, or even a new bicycle seat or mouse pad wrist rest in the last two decades will have encountered memory foam. This new material has been applied to a huge range of uses since its introduction to the US in 1991—from revolutionary medical uses to gimmicky new product designs. But what is it, who came up with it, and how does it work?
Though it is a relatively recent phenomenon in the US, memory foam has been around in various forms since the midpoint of the century—the first work on the polyurethane polymers that go into memory foam was actually begun in 1937 by Otto Bayer and his coworkers In 1965 the nursing staff at Lankenau Hospital tested “inert polyurethane porous foam” pads for use as bedding material, and found that they prevented “decubitus ulcers” (also known as pressure ulcers, sustained by patients who spend long amounts of time lying down), and found them to be hypoallergenic and resistant to bacteria (Kraus 1965). In the 1960s, NASA did work on materials that would serve as better cushions, and would also keep astronauts comfortable and protected from the extreme g-forces of lift off. It was then that memory foam as we know it came into being.
Memory Foam vs. Polyurethane Foam
Memory foam starts its life as polyurethane foam—a material first manufactured in the 1950s by adding water, halocarbons, or hydrocarbons to a polyurethane mix. Depending on the chemicals added and the way it is processed, polyurethane can form anything from car parts to spray liner, or in this case, one of the most comfortable sleeping surfaces the world has ever seen.
In the modern production of memory foam, a polyol is mixed with a diisocyanate and water. The foam rises like bread, with an open cell structure that helps give it its unique ability to spring back slowly from pressure. The introduction of gases into the initial solution creates a bubble matrix; vary the application of chemicals, and the size of the bubbles changes. A more open cell structure will have more give, and allow more airflow through the material.
Memory Foam Firmness
The firmness of memory foam is rated by the IFD (Indention Force Deflection), also known as ILD (Indentation Load Deflection) measuring the force in pounds required to make a 25% indentation in a 4 inch thick foam square. Also important in measuring the “softness” of a foam is the density. Foam densities range from 1-7 lbs, but a good-quality foam will usually be at least 4 and usually 5 lbs. A foam with a high density, but low ILD may still feel firm when compressed, especially in a lower room temperature. The density together with the IFD/ILD and the resilience will determine the softness, firmness, and life-span of the foam. Foam that is lower density will more readily conform to pressure, whereas higher density foam (usually 5-lb. or above) molds itself to contours when warmed by body heat.
Major production of memory foam did not begin until NASA released it into the public domain in the 1980s.Fagerdala World Foamstook up the challenge of producing this somewhat difficult product, and in 1991 produced the “Tempur-Pedic Swedish Mattress.” Today numerous companies around the world produce visco-elastic memory foam, which gives consumers increased variety and price range. Unfortunately, it also increases the risk of purchasing cheaply-made foams that may deteriorate over time. Not all memory foam is made equal, as many of the overseas manufacturers work at reducing the cost of memory foam by adding in other “filler” type ingredients that reduce the quality and potentially add toxicity to the formulation. The real problem with overseas foam is the lack of quality standards that have been created in the United States.
Memory Foam: Pros and Cons
Considering a memory foam mattress or similar product? Read what sleep experts say about it.
Few things feel as good as a good night’s sleep. That’s especially true if sleep seems to escape you, night after night after night.
If you’ve heard about memory foam, you may wonder if it could improve the quality ofyoursleep. Some people swear by it. Others are less enthusiastic.
What exactly is memory foam? And what are its pros and cons? Here’s information to help you decide whether memory foam is worth a try.
What Is Memory Foam?
First designed in the mid-1960s for NASA airplane seats, memory foam is made from a substance called viscoelastic. It is both highly energy absorbent and soft.
Memory foam molds to the body in response to heat and pressure, evenly distributing body weight. It then returns to its original shape once you remove the pressure.
In addition to protecting against impact, these properties make memory foam very comfortable. After its "virgin flight" for NASA, memory foam made a foray into other applications. For example, it was used as cushioning in helmets and shoes. Medicine found a use for it in prosthetics and products to prevent pressure ulcers such as seating pads for people who are severely disabled.
Then, memory foam really took off. It’s now well known for its use in pillows, mattress pads, and mattresses, which come in different densities and depths.
What Are the Benefits of Memory Foam?
Could the special properties of memory foam enhance your sleep? Sleep specialist Donna L. Arand, PhD, says that objective studies supporting the claimed benefits of memory foam — or the effects of any particular type of sleeping surface — are lacking.
This is true for a variety of reasons, she says. This type of sleep study can be expensive, if conducted independently. Or it is "chased" by a shadow of bias, if supported by industry.
Also, some sleep technology, such as memory foam, is relatively new, so it hasn’t been well studied. But perhaps one of the more difficult stumbling blocks to testing the health benefits of mattresses such as memory foam is the subjective nature of sleep. It is simply difficult to measure.
Sometimes the brain’s electrical activity, measured with an electroencephalogram (EEG), and other findings recorded during a sleep test don’t always match up perfectly with a person’s subjective experience, says Arand, who is the clinical director of the Kettering Sleep Disorders Center in Dayton, Ohio. "They might say, вЂI had a great night’s sleep,’ but the EEG parameters might not really indicate that."
Sleep is not only subjective, but preferences for sleep surfaces are individual, Arand says. "There’s quite a bit of variability between individuals in terms of what type of surface — whether it’s firm, hard, or soft — they prefer when they’re sleeping," she says. "As far as we know, there is no rhyme or reason for that."
Many of Arand’s patients who use memory foam have offered unsolicited glowing reports like these about memory foam: "I’m sleeping great." "Best sleep I’ve ever had." "I love going to bed at night." Arand says these anecdotal responses may be one-sided. That’s because she and other staff don’t ask all their patients about their sleep surfaces. "We may only be hearing the good stuff," Arand says.
Kathy R. Gromer, MD, sleep specialist with the Minnesota Sleep Institute in Minneapolis, agrees that memory foam may improve sleep. "It can, if it relieves painful pressure points," she says. But Gromer adds that memory foam doesn’t do anything for sleep apnea or other sleep-breathing disorders — and sleep disorders are the primary complaint of most her patients.
"When you lie on the memory foam, the heat from your body softens it in appropriate points," Arand says, "so this helps to support your body along the curves and natural lines of the body." Memory foam manufacturers claim this helps relieve pain and thereby promotes more restful sleep. And, though consumers often believe that very firm mattresses are best, more "giving" mattresses like these may lead to better sleep in people with back pain, according to the National Sleep Foundation.
Although there aren’t scientific data to support the hypothesis, Arand wonders whether memory foam sleep surfaces might be especially helpful for older people. For them, minimizing extra movement could reduce the number of times they awaken during the night. Being less aware of a bed partner’s movements might be an extra benefit, she adds. "Without the coiled springs, you feel your sleep partner’s movement less, and that might help, too."
What Are the Disadvantages of Memory Foam?
Gromer says that memory foam products may retain body heat, which could make them less comfortable in warm weather. However, Arand has not heard this complaint from her patients. "In our culture, most people can adjust their thermostats or blankets for the appropriate season," Arand says.
When new, memory foam can produce an odd chemical smell — a phenomenon called offgassing. To minimize this problem, the Sleep Products Safety Council, a sleep products trade group, recommends airing out the mattress or pad for at least 24 hours before putting sheets on it. "If you follow directions, the smell dissipates quickly," Arand says, "But I’ve never heard of anyone having reactions to it."
Are Memory Foam Products Safe for Young Children?
"I would strongly recommend avoiding this and similar very soft materials for use in infants’ beds," Gromer says. "That’s because soft bedding traps [carbon dioxide] and increases the risk of sudden infant death syndrome (SIDS) deaths."
NASA Scientific and Technical Information: "Forty-Year-Old Foam Springs Back With Newer Benefits."
Donna L. Arand, PhD, clinical director, Kettering Medical Sleep Disorders Center, Dayton, Ohio; research associate professor, Wright State University Boonshoft School of Medicine.
Kathy R. Gromer, MD, sleep specialist, Minnesota Sleep Institute; medical director, Respiratory Care Program, Saint Paul Technical College.
National Sleep Foundation: "Buying the Right Mattress for You."
Sleep Products Safety Council: "Mattress Odors" and "Sudden Infant Death Syndrome."
How is memory foam manufactured?
The first memory foam material was invented in the 1970s by NASA. At that time, NASA was trying to come up with a material that could cushion the astronauts when taking off due to the high G levels.
The material was invented yet never made it to any space program. Instead, several medical companies saw the potential of memory foam material and adapted it to be used in the medical industry to help relive bedsores.
Memory foam, a viscoelastic material that first appeared on the market in mattresses in 1991, is a mixture of chemical compounds. It is primarily made of polyurethane with combination of other chemicals. The combination of chemicals with polyurethane varies with the manufacturers. The formulation of memory foam has been copyrighted and maintained as a trade secret by the manufacturers. This is due to the fact that different combinations of chemicals with polyurethane deliver different viscoelasticity and density of memory foam. One of the chemicals used with polyurethane is silicone additives.
As the chemical composition of the foam is mainly polyurethane, it is combustible. If the foam gets ignited accidentally, it can spread the flame rapidly and also emits toxic gases. Hence some of the manufacturers in America treat them with flame-retardants like Polybrominated diphenyl ethers (PBDE). Some of the studies of PBDE have shown that they are causes for the impairment of nervous and reproductive systems in animals. Memory foam keeps away the dust mites and mildew due to its chemical composition, as these mites feed on natural fibers like cotton.
There are misconceptions that the foam contains residues of diisocyante. Diisocyanate is completely consumed in the polymerization reaction with polyol. So any product made of genuine memory foam will not contain residues of diisocyanate. There are replicas of memory foam made of cheaper constituents, which may be hazardous.
Memory foam is produced in a complex multi-step process that takes a full workday. Memory foam mattresses differ from conventional innerspring mattresses by molding to the sleeper’s body shape and slowly springing back to their original shape. Memory foam has an open-cell structure, where the foam cells have holes that allow them to pass their air to adjoining cells when under pressure from a user’s body. Also, memory foam cells are temperature-sensitive; the warmer they get, the more they compress. This body molding process reduces discomfort from pressure points where bony body parts contact the mattress.
The process starts with polyurethane plastic, to which the maker adds a proprietary chemical blend from families of petrochemicals known as monols and polyols to impart the correct type of slow flexibility, and fillers such as calcium carbonate to add body and reduce tackiness. The mixture is heated until the ingredients melt together, then whips and churns the hot mixture to introduce the air that makes it foamy.
To go deeper in the system experts say that the main constituent of memory foam is polyurethane. They are chemical substances with linear polymers which are made of carbamate groups (-NHCO2). These groups are called urethane, formed by the chemical reaction between a polyol and a diisocyanate. Polyol is a multiple hydroxyl group bearing alcohol and diisocyanate has two isocyanate groups. Isocyanate is a functional group with a single nitrogen, carbon and oxygen molecule. The ratio of polyol and diisocyanate used for the process is 1:2. When these compounds react with water, in the presence of catalysts like tin and amines, it forms cells which are very similar to bubbles. The size of the bubbles is controlled by surfactants, which lowers the liquid surface tension.
This reaction is an exothermic reaction and the product formed is a liquid. The foam, about the consistency of soft dough or ice cream, is poured into a slab mold at a precise rate and temperature. The hot mixture is agitated within the mold as the air is pumped out, forming the open cell structure. The mold is dried very quickly to form the foam or polyurethane. The slab mold is cooled again and the foam is removed, washed, dried and inspected. The foam slab is then clipped into mattress-size sections that are stored until they’re assembled into a memory foam mattress. The reaction takes about 5 minutes but the whole foam manufacturing process takes about eight hours.
How Is Memory Foam Made
How Is Memory Foam Made
Most of us know that memory foam was originally created by NASA to help absorb the extreme G-force pressure placed on astronauts at take-off and landing, but few of us know how they actually make memory foam. It’s really a very cool process!
While the exact recipe for memory foam is kept secret, we know that memory Foam, or visco-elastic polyurethane foam (as scientists like to call it), is made primarily from polyurethane with some additional chemicals added to increase its density and viscosity. This increased density and viscosity in turn creates a foam that’s more supportive than other foams and also allows it to mold to our bodies.
All of the memory foam ingredients are kept in liquid form in separate tanks. When it’s time to make a batch of memory foam, metered pumps release the proper amount of each ingredient into a smaller tank. In this tank, the ingredients are all mixed together and heated so that the chemicals can combine and react. This liquid is then sprayed onto a conveyor belt, where it begins to rise.
The conveyor belt is very long and typically with raised sides. The foam begins to undergo a chemical change, which causes a raise in temperature, which in turn causes the foam to expand and rise. As the foam rises, the raised sides on the conveyor belt keep the memory foam contained, so as to create a square shape. Once the memory foam has cooled and is finished expanding, it is cut into uniform lengths. Since the foam is not ready to be stacked yet, it is then set to be cured. Once cured, the memory foam is ready to be trimmed down even further to create mattresses, mattress toppers, pillows, etc.
When memory foam is used in a mattress, the memory foam is stacked upon other layers of thicker, more firm foam that help support the heavier layer of memory foam. And you’re probably wondering what happens to those scraps of memory foam back at the factory? Nothing goes to waste! The scraps of memory foam are either broken down and used in pillows or other consumer items, or used as carpet padding!
Now that you know where memory foam comes from, what are you waiting for? Go buy your Mattress or Mattress Topper today!
How to Compress (Deflate) & Roll Up a Memory Foam Bed at Home
One of the biggest pains of moving is transporting a mattress.
They are big, bulky, and require two people to move. They take up a ton of room in a moving van, and if you’ve only got a car, then you’re probably wracking your brain trying to figure out the best way to strap that sucker onto the roof.
But, wait a second.
If you have a memory foam bed, if you may remember that it came in a fairly compact box. Surely there must be a way to compress the bed back down to a size similar to the factory’s package.
The bad news is that those factories have giant machines that exert tons of force onto the mattress to fold it into the nice, little bundle that gets delivered to your doorstep. The good news is that there’s a relatively easy and inexpensive way tocompress a memory foam mattressDIY-style, so you can move to a new house without having to bribe your friends with bottomless pitchers of margaritas.