Posted March 22nd, 2014
By: Wesley Vaughn

Mattresses, Beds, and How We Sleep

by Wesley Vaughn

 

Sealy Gel Memory Foam Mattress

Sealy Mattress and Box Spring

 

It is common knowledge that we need sleep, and that—for the most part—several factors determine whether and how we sleep. Among these factors are time of day, how tired we are, physical condition, medication, diet, amount of light, noise, vibration and motion, warmth and cold, pain and comfort.

Even knowing this much, it is easy for many people to take their beds and mattresses for granted. For example, I used the same steel framed bed from late pre-teen years through high school. It had a “sheet spring,”* and the mattress was only 3-4 inches thick. What was suitable for a runty fifth grader was not good for a late teen approaching 130 lbs. Oh yes, I slept. But I became tired during the day. I also thought that the “morning backache” was normal for everyone. When I got to college, I had a firmer bed. The morning backaches faded away. I didn’t make the connection then between the bed and how I felt, but now I do.

The point of this testimonial is that our beds, mattresses and bedding do make a difference in how we sleep, and how we sleep makes a difference throughout the day. A ton of research bears this out, even though an occasional article downplays the role of beds and mattresses in poor sleep (to be fair, the intent of a 2011 NY Times article was to not blame everything on the bed or mattress, but also consider sleep disorders).

The last three pairs of factors in the opening paragraph are all influenced by what we sleep on, under and in: our bed frame/foundation, mattress, pillows, covers & sheets and nightclothes. The mattress and bed support and cushion us.

When people used sleeping mats on the floor or a raised earthen platform, they had plenty of support. The mats were for cushioning, to reduce the pain of lying on a hard surface. With the introduction of couches and beds standing above the floor, the bed had to also provide support. Ultra firm support was supplied by a solid surface or a grate, so the role of early mattresses remained cushioning.

In the mid 1800′s coil springs were invented for wagon seats. These were modified for box springs and innerspring mattresses as Bonnell coils. Now a mattress both supported and cushioned the sleeper. Heavy springs were the norm, and innerspring mattresses provided firm support. Padding cushioned the user and evened out the impact of individual coils. From Bonnell coils, offset coils and continuous coils were developed.

In the mid 1960s memory foam was invented by NASA contractors for airplane and space ship seats. It was developed for commercial use, and Tempur-Pedic introduced the first memory foam mattress. Memory foam is more conforming than Bonnell, offset or continuous coils. It responds to the heat and weight of a sleeper’s body. If you push your hand into memory foam then lift it, an impression of your hand will show for several seconds. The comforming provides support for the body between the big parts such as hips and shoulders. This way it reduces pain from pressure points.

How can a mattress affect our sleep? It can be too firm or too soft. It can transfer motion from one person to another or dampen motion transfer. It can be noisy if coils or other components squeak. It can be too hot or not warm enough. The surface can be smooth and relaxing or rough. Some mattresses can emit unpleasant odors. Others may cause allergic reactions, contain irritants or harbor harmful microbes.

Support & cushioning- pain and comfort

How a mattress supports the sleeper determines how well you sleep and how you feel after getting up. The first mattresses were supported by the floor or by a solid bed, so the support was external. After the invention of the innerspring, the mattress itself provided support. Now there are several types of innersprings: Bonnell coils, offset coil, continuous coils, wrapped (pocket) coils, and dual coils. These different kinds of springs have been developed to tailor support for proper spinal posture, relief from pressure points, preventing motion transfer, and adjustment to different sleepers.

Bonnell coils are the least costly, but also the ones better suited for supporting heavy weight. However, they also transfer motion from one sleeper to another. This means that when one sleeper moves, the other can be disturbed.

Offset coils cost more to make than Bonnells, but they are about as supportive. However, motion transfer is lessened, making them better for couples. Continuous coils are somewhere between Bonnell and offset coils in support. Each of these three types has variations.

Wrapped or pocket coils, also called Marshall coils after their inventor, are more conforming than the previous types. This reduces pressure points and virtually eliminates motion transfer. However, since the coils do not support each other, as the previous kinds do, they are more subject to coil failure unless made of heavier gauge wire.

The last type, dual coils (also known as coil-in-coil design), is a development of pocket coils. Each pair of coils is wound from one piece of wire with a shorter coil inside a larger one. With a dual response, dual coils can cushion a light person and support a heavier one. This should make both members of a couple comfortable, even if they differ widely on size and weight.

Specialty sleep mattresses (those without an innerspring) have been gaining in popularity. There are three types: foams, waterbeds, and air beds and now gel. There are three basic kinds of foam mattresses: polyurethane, memory foam and latex. Polyurethane mattresses are usually made for institutions like college dormitories, such as those made by University Sleep Products.

Waterbeds use liquid-filled bag to support the sleeper. Water offers viscose support, meaning that the medium moves out of the way (is displaced) to make room for the supported weight. Waterbeds were popular for a while. A major advantage is that water provides even support for the whole body. However, as an adult sinks into the water, it becomes hard to move around or get out of bed. Also, when two people are using a waterbed at the same time, they tend to roll together, and one person’s motion moves the other.

Air beds use three or more air-filled chambers to support the sleeper. An advantage air has over water is that the level of support can be adjusted by changing the air pressure in the mattress. This is the concept used to promote Select Comfort beds, hence their brand name Sleep Number. Now even Tempur-Pedic, the original memory foam mattress maker, has an airbed. Modern air beds have two sets of air chambers with separate controls. Each sleeper in the bed can select his or her level of support.

Gel beds, with a gel-only top layer, are relatively new, and there are a few manufacturers, such as Technogel. Gel is described as supportive, cushioning, conforming, and cooling. Time and customer reviews will tell.

Foundations also affect sleep by how they support the mattress. A good box spring makes a firm Bonnell, offset or continuous coil innerspring mattress more responsive and cushioning. On the other hand, foam mattresses need more consistent support to keep from sagging. For them a solid platform or closely space slats are more suitable for supporting both the mattress and the sleepers. Therefore, it is important to have the right foundation for your mattress.

While the right kind of support is needed for a good night’s sleep, so is the right level of cushioning. Very few of us can sleep comfortable on a concrete floor with no padding. At the same time, too soft a sleeping surface makes many people uncomfortable. The right level of firmness is a Goldilocks preference. What’s just right for one person may be too hard for a second person, yet too soft for a third. Only by trying mattresses can you know which combination of support and cushioning is right for you.

Comfort layers began with fiber paddings over the innerspring, such as cotton and wool. Modern padding fibers now include polyester. Then foams were used, such as foam rubber (latex), polyurethane and memory foam. Now comfort layers can include microcoils. Then there are hybrid mattresses, a combination of two kinds of mattress into one. Usually these are innerspring mattresses with a significant thickness of specialty material. However, it is not clear when a mattress becomes a “hybrid.” Some retailers and reviewers are trying to draw the line.

Temperature

When Goldilocks sampled the three bears’ porridge, one bowl was too hot, one too cold, and one just right. So it is with sleeping. We sleep better if it is neither too warm nor too cool. The right temperature begins, of course, with the room temperature, and continues with the covers and nightclothes. But the mattress itself can influence our temperature, affecting the quality of our sleep. Memory foam introduced conformability, but it also absorbed and built up body heat, becoming too warm for many people. Innerspring mattresses are inherently cooler, since air can circulate through the mattress, even with fiber padding on top, but with the introduction of memory foam in the cushioning, they can get too warm for comfort.

Manufacturers are using various means to make memory foam cooler. These include open-cell structure, porosity, ventilation and gel-infusion. Now several mattress makers are using phase change materials to regulate temperature. These are added to cover materials and foams ot keep temperatures within a desired range—not too hot, not too cold.

Allergies and Irritants

It can be hard to sleep well if we are allergic to the mattress or the bedding. Stuffy sinuses, runny noses, congestion, and itchy or burning skin can make us uncomfortable and restless. More serious allergies can interfere with body systems. Allergic reactions can be caused by laundry detergents and fabric softeners in pillowcases and sheets. Bedbugs, fleas, lice, dust mites and mosquitos can carry allergens. Some of us are also allergic to some materials used in mattresses. Outgassing from certain foams and adhesives can trigger allergies. Some fabrics and chemical fire retardants are irritants. Even if we are not allergic to released gasses, the odors can disturb us.

Texture

The texture of the sheets or the mattress cover may or may not keep you awake, but it is easier to sleep on a smooth surface.

Noise

One of the most recognized factors leading to sleeplessness or poor quality of sleep is noise. It is hard to sleep when there is too much noise, unless one is deaf. On the other hand, stone silence (negative noise) can keep some of us awake. We can control most of the unwanted sounds—even snoring—but what if your bed and/or mattress are making noise? Some innerspring mattresses and some beds squeak. Not loud, but when your ear is on the mattress it can be too much. And if you have an air bed or an adjustable base, pumps and motors are not totally soundless, but some are quieter than others. This is not a problem if you sleep alone, but what if this is a dual control bed or base, and your partner makes an adjustment while you are asleep?

Preparing for Quality Sleep

We can prepare for quality sleep in the selection of our beds and mattresses. Read the reviews, including those on Beds.org. Visit several retailers and try their mattresses. If you get a good night’s sleep in a hotel or a friend or relative’s house, find out what the make and model are, including the comfort rating. Check out not only mattresses, but also foundations. Would an adjustable base work for you? How about a platform bed? Or European style wood slats?

Find out what bothers you, and screen the mattress and base for these. Do you have allergies? What is your sleeping position? Do you have back or hip problems? Take these into consideration. Hopefully, your choices will lead you to quality sleep.
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* A sheet spring was a wire grid attached to the bed frame by coil springs at the ends or around the edge
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Posted March 12th, 2014
By: Wesley Vaughn

Quality Sleep: How to Get a Night of Rest and Restoration

by Wesley G. Vaughn

Sine Wave

If someone tells you, “It’s not how long you sleep, but how well you sleep,” they’re half right.  It’s both.  Research studies show us that quantity and quality of sleep are correlated and work together.  We cannot have quality sleep unless we have enough sleep.  On the other hand, staying in bed for a certain amount of time does not automatically provide us with much needed rest, relaxation and restoration.  Sleeping long but not sleeping well may be called “Empty Sleep Calories.”

So, what makes quality sleep?  What factors contribute to sleep quality?  A lot of sleep research results are available on these questions.  Experts may differ on some points or have separate emphases, but there is a great deal of consensus in their conclusions and recommendations.  Among factors affecting the quality of sleep are our beds, especially mattresses.

Sleep is not shut-down time for the brain, though it is a suspension of conscious activity.  The brain still functions during sleep, but its functions differ from those of waking hours.  And sleep is not just “sleep.”  There are actually two stages of sleep in a sleep cycle:  deep sleep and REM (rapid eye movement) sleep.  Each has its own primary function.  A person normally has two or three full cycles in a night of sleep of 6 to 9 hours, more often 2½ cycles.

What do these cycles have to do with the quality of sleep?  Here is where quality intersects with quantity.  Most people require at least two full cycles.  Each stage has to run its course, which is about 1½ hours long, especially deep sleep, making a cycle about 3 hours long.  This adds up to about six hours for two cycles, which is why most persons need at least six hours of sleep.

During REM, the brain is setting memory, sorting things out, resetting parameters, etc.  This is the stage when we dream. Most dreams we don’t remember, a few we do.  If they seem crazy, it’s because the brains is putting pieces in our memories together to see if they fit, much as we might do with a jigsaw puzzle.  Studies show that students who have REM sleep stages do better than those who don’t.

Deep sleep is when the rest of the body is refreshed and restored, which includes building muscles, tendons and bones and repairing tissues.  This is why rest is so important for healing.

What factors contribute to quality sleep or impair it?  First, since it is so important to complete the sleep cycles, it is vital that they are uninterrupted.  Quality sleep is uninterrupted sleep.

Three words seem to summarize all the suggestions for quality sleep:  precaution, consistency and comfort.  Precaution is what we do or don’t do before bedtime to prevent interruptions or other hindrances to sleep.  Consistency is setting and abiding by schedules and routines.  Comfort is making yourself comfortable while sleeping and avoiding discomfort.

Precaution begins with adjusting the sleeping environment—the bedroom itself, lighting, sound and distractions.  The space itself will affect some people and how easily they fall asleep.  This is personal, for some can’t sleep when they feel crowded, while others need to feel cozy.  We don’t all have the option of remodeling the bedroom, especially if we are renting, but how we furnish and arrange the bedroom can make it feel roomier or cozier.

Light can interfere with sleep, especially natural light, which our bodies are programmed treat as a signal to awaken.  Preparation for sleep may include shades, blinds and drapes to block outside light, especially for night shift workers or if in a well-lighted neighborhood, such as in many cities.  We also need to dim, hide or turn off bedroom devices which emit light.  One exception is a night light, which may provide a feeling of security for some sleepers, as long as it is neither too bright nor shining directly into the eyes.

Sounds can awaken us or otherwise degrade sleep.  Try to close out sounds or use white noise to counter them.  Soft music may detract from noises.  Some people may have to use earplugs.

Distractions are not always making noise or shining lights.  Just having and using some items such as a computer or TV in the bedroom may be a distraction, since the bedroom is associated with related activities.  A bedroom is more restful if associated with sleep.

Precaution also includes avoiding things or activities which make it more difficult to sleep.  Among these are caffeine and other stimulants too close to bedtime. Since they tend to keep us awake, these should not be taken or consumed within three to five hours of going to bed, depending on your sensitivity.  Heavy meals should be eaten earlier in the day, but a light snack may make us more relaxed.  A sip of water at bedtime may be OK, but a full glass should be an hour to an hour-and-a-half earlier. Cease activities which keep us stirred up early enough to relax.  A common hindrance to falling asleep is the mind that can’t quit.

Consistency sets a pattern which leads us into sleep.  Set regular times for going to bed and for getting up.  Choose pre-bedtime activities which relax us, such as light reading, soft music, a shower or warm bath.  Lower the light levels earlier in the evening.  Do whatever it you can to tune yourself to sleep.  The sooner we fall asleep, the more time we have to complete our sleep cycles. Briefly, consistency means establishing habits which lead to quality sleep.

Comfort is more important than some might think.  More than a luxury, a certain degree of comfort is necessary for needed quality sleep.  If for any reason we become uncomfortable while sleeping, it may interfere with the stages of sleep.  Several factors are involved with comfort.  Among these are position, temperature, disturbances, pain & soreness, skin irritations, and the feel of the bed and bedding.

The easiest and least expensive means of adjusting ones comfort is the sleeping position, but that belies its importance.  Our position influences how we feel by affecting our breathing, our spinal posture, our circulation, etc.

How we breathe determines the oxygen level in our bodies, and the body needs oxygen to function, to build and to repair itself.  If we struggle to breathe, the struggle interferes with relaxation and can break or degrade a sleep stage. Generally, for most people breathing is easier when sleeping on one side or the other than on the back.  One drawback is that pressure points are more acute sleeping on ones side. Another is that many persons tend to curl up when sleeping on their sides, and this can result in a stiff back in the morning, so stretching out is recommended for side sleepers.

Many people sleep on their backs.  Ideally, this requires some elevation of the head.  the spine has a natural “S” curve, and lying on ones back on a flat surface can be hard on the back,  However, if the knees are elevated slightly, this will keep the spine in its normal posture.  Sleeping on the back is not recommended if snoring or sleep apnea are problems.  However, nose strips are now available to keep the nasal passages open.

A few people have to sleep on their stomachs to breathe easily.  This is especially so if one is struggling with nasal allergies or a cold, because the face-down position diverts fluids away from the throat.  But stomach sleeping is hard on the back without proper support and an open space for the nose and mouth.  Pillows can be arranged to provide for this.

A moderate temperature is neeedful for comfortable sleep, not too hot nor too cold.  Our metabolism level drops when we fall asleep, so the room temperature should be a little lower at night than during the day, but not too cool. Some, such as those with asthma, may need cooler air to breathe, so they need warm nightclothes and bedding to keep the body warm while the room temperature is cool.  If the house temperature is kept low for economic reasons, insulating covers are a necessity.

Being too warm also disturbs sleep.  Air circulation helps sleepers cool off.  But so does mattress design.  Some mattress materials may keep us too warm, even hot.  Memory foam, for instance, naturally absorbs heat, and accumulated body heat makes it hot.  Memory foam is valued for its conforming support, which relieves pressure points, so manufacturers have found ways to keep it cool.  First, the foam is structured or ventilated to let air flow through it.  Also, gel and/or other heat conducting substances are added to the foam to carry heat away from the sleeping surface.

Another method of temperature control now being used is Phase Change Materials (PCMs).  Developed for NASA to use in space suits, PCMs absorb heat when it’s too hot and release heat when it’s too cold.  Now they are used in some types of outerwear, sleeping bags and mattress covers.

Discomfort is also caused by feeling “clammy.” Some clothing and mattress cover materials wick moisture away to evaporate.  This both keeps the sleeper dry and has a cooling effect.  Controlling moisture also controls other moisture related problems, such as the growth of bacteria, mold and mildew.

Allergic reactions cause irritations and discomfort, which disturb sleep. Allergens may be items in the bedroom, clothing and bedding materials, soaps we wash and shower with, fragrances, even laundry detergents and fabric softeners. If we have allergies, we will sleep better by ridding our sleeping environment, including beds and bedding, of allergens.

We may not be able to control everything, there are ways we can improve the quality of our sleep through taking precaution, establishing consistent sleep promoting patterns, and doing what we can to provide comfort for sleep.

The next article focuses on how mattresses, bedding and adjustable beds influence our quality of sleep.

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Resource links

Help Guide Organization:  http://www.helpguide.org/life/sleeping.htm

Sleep Cycle:  http://www.sleepcycle.com/faq/how-is-sleep-quality-calculated/

Healthy Sleep:
http://healthysleep.med.harvard.edu/healthy/getting/overcoming/tips

Sleep Medicine Institute, University of Pittsburgh:
http://www.sleep.pitt.edu/content.asp?id=1484&subid=2316

WebMD:  http://www.webmd.com/sleep-disorders/features/sleep-position-and-sleep-quality

Mayo Clinic:
http://www.mayoclinic.org/healthy-living/adult-health/in-depth/sleep/art-20048379

Nat’l Sleep Foundation, Study: Physical Activity Impacts Overall Quality of Sleep:
http://sleepfoundation.org/sleep-news/study-physical-activity-impacts-overall-quality-sleep

NIH,  The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research:
http://www.ncbi.nlm.nih.gov/pubmed/2748771

Sleep Number (Select Comfort):
http://www.sleepnumber.com/eng/individualNeeds/sleepQuality.cfm

NIH, Sleep Disorders:
http://www.nlm.nih.gov/medlineplus/sleepdisorders.html

 

Posted March 8th, 2014
By: Wesley Vaughn

Benefits of Sleep: The Importance of Rest

zzzzz

Proper rest, including quality sleep, is vital to our health and well-being. It is not only an issue of personal health, but one of safety. The Department of Transportation has regulations limiting the amount of time commercial drivers can operate their vehicles without time off for rest. Numerous airline, maritime and industrial accidents have been blamed on operator fatigue. Lack of rest also affects workplace efficiency. Office workers sometimes nod at the desk, with a long string of one keyboard character on the screen, or missing a step in procedures, forgetting to save vital information, pulling the wrong file, etc.

An overwhelming volume of information about the benefits and vital importance of sleep is available online and in print, much of it from medical and scientific sources. For some persons, this may give the appearance of being a new discovery, but this is concept was recognized for thousands of years. Modern research actually verifies and explains it. As an example from ancient literature, almost 3,000 years ago Solomon wrote, “In vain you rise early and stay up late, toiling for food to eat—for he grants sleep to those he loves” (Psalm 127:2 [NIV]). Sleep was viewed as a divine gift for those who work.

Simple observation reveals that all life, including plant life, goes through diurnal (daily) cycles. Animals sleep. So do people. Even famous people reputed to never sleep actually slept, though it was not several hours at a time but multiple short periods throughout the 24-hour day. Also, most animals lie down when sleeping, and so do people. And almost all have preferences for what they lie on. We will get to that subject farther down.

What are the benefits of sleep? R. Morgan Griffin describes 9 benefits of sleep in an article for WebMD. These benefits are: Better health, better sex life, less pain, lower risk of injury, better mood, better weight control, clearer thinking, better memory, and stronger immunity. The first benefit listed, better health, is also the most important. In fact, almost all of the remaining benefits are either part of better health or contributing factors. Surveys and studies cited by various health organizations, such as Harvard Medical School, National Institutes of Health and WebMD, show that experiencing enough restful sleep (depending on age, development, and individual condition) is necessary for digestion, immunity, both long- and short-tem memory, proper growth, and many other health factors. Degradation or inadequacy in these areas results from sleep deprivation (for college students this averages less than six hours of sleep per night).

How much sleep is enough? Newborn babies sleep most of the time. By the First Grade, most children sleep about 8 to 10 hours a night. Adolescents need about 7 to 8 hours a night, although there is some disagreement with several experts calling for 9 hours. As stated above, studies suggest that young adults (including college students) need at least six hours of sleep per day, a requirement which continues up to the senior years. However, the amount of sleep needed by individuals varies. The amount needed is affected by personal physiology, one’s state of health, occupational demands, and lifestyle. Lifestyle and occupation can also hinder of enable sufficient sleep time.

The question is not just how much we sleep, but also how we sleep. There are different stages or levels of sleep. The two most significant are slow wave sleep (SWS) and rapid eye movement (REM). These stages tend to alternate through the sleep cycle. Some sleep researchers credit one of these two stages with setting and coördinating short-term memory, the other with long-term memory. What they agree on is that students with adequate sleep, a full cycle which includes both stages, have better memory.

Most of us sleep in one several-hour span per day-night cycle. This is called monophasic sleep. Before the invention of electric lighting, most people experienced bi-phasic sleep, waking up about midway through the night for a while then going back to sleep. Many persons today, especially those with short nights, take a short nap during the afternoon. A few individuals, including some well-known historical figures, slept mostly in several short naps throughout the day (multiphasic sleep). Some have/had a short night sleep time of about 3 hours, making up the difference with naps. Some research seems to indicate that these individuals are able to experience both stages of sleep in separate sleep periods. This may be a trait of select individuals—in other words, “Not everyone can so this.”

Inadequate sleep, whether in quantity or quality, is a negative safety factor. We are all aware of drowsiness and falling asleep being a factor in accidents. But impaired alertness is also a factor. When we think someone is “just not paying attention,” their alertness may be impaired by sleep deprivation. This is usually not just one short night, but several, often over a long period of time. Lack of alertness also factors into poor academic performance. Alertness is necessary to perceive vital details in an article, book or other document. It is also needed in editing one’s own work, catching errors of all sorts from spelling to format to facts.

The most perceived benefit of sufficient sleep is feeling well. If we sleep enough and sleep well, we will feel better, physically and emotionally. The obvious exception to this are the persons who always feels guilty when they “sleep too much,” meaning more than an unreasonably short sleep time to which they had been conditioned.

As to physical health, many studies highlight the correlation between sleep (or the lack thereof) and circulation, immunity, digestion and other physiological functions.

As to sleeping positions, the “mat” in “mattress” is for sleeping mats. Throughout history people have had various kinds of cushioning between their bodies and the hard ground or floor. For many this was a sleeping mat, usually woven, which could be, rolled out at night to sleep on, and rolled up and put out of the way in the daytime. Later on, these mats were filled with various cushioning materials and called “mattresses.”

Sleeping mats and mattresses have a lot to do with the benefits of sleep. Sleep is more restful when it is comfortable—or at least not uncomfortable. The first role of cushioning is to relieve pressure points, a concept predating the term. The first solution was to soften the interface between prominent points of a sleeper’s body and the ground. Modern mattresses try to support the body’s weight evenly so these points do not bear more of the burden than other parts of the body.

Another role for the mat/mattress is insulation. When the ground or floor is cold, we need to keep warm. From the beginning, mats and mattress fillings—for instance as cotton, wool, down, and straw—have been insulating materials. But comfortable, restful sleep depends not only on keeping warm, but on not being too warm, so mattresses manufacturers try to make their products breathable.

Overall, ancient wisdom from many cultures on the value of good sleep has been borne out by modern scientific and medical research. Many persons and companies aim to promote beneficial sleep through their products and services:   bedroom design, beds, adjustable beds , mattresses, bedding and accessories.

Our next article focuses on the quality of sleep
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Resources
American Academy of Sleep Medicine, “College Students: Getting Enough Sleep is Vital to Academic Success,” Friday, November 30, 2007, http://www.aasmnet.org/articles.aspx?id=659, accessed 03/05/2014.

Division of Sleep Medicine, Harvard Medical School, “Healthy Sleep: Benefits of Sleep,” http://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep, accessed 03/05/2014.

Griffin, R. Morgan, “9 Surprising Reasons to Get More Sleep,” WebMD Feature, WebMD http://www.webmd.com/sleep-disorders/features/9-reasons-to-sleep-more, accessed 03/05/2014.

National Sleep Foundation, “Napping,” http://sleepfoundation.org/sleep-topics/napping, accessed 03/06/2014.

National Sleep Foundation, “Teens and Sleep,” http://sleepfoundation.org/sleep-topics/teens-and-sleep, accessed 03/05/2014.

Posted February 28th, 2014
By: Wesley Vaughn

Adjustable Beds: Adjusting for Health and Comfort

By Wesley Vaughn

Adjustable Bed Selection

When adjustable beds became available for home use, they were commonly called “hospital beds.”  This was only natural, since until that time adjustable beds were primarily used in hospitals.

The first adjustable beds were beds with adjustable side rails, first used in English hospitals in the early 1800s.  Then beds could be tilted with either the foot high (Trendelenburg position) or the head high (anti-Trendelenburg).  In 1874 the first articulated bed was patented by Andrew Wurst & Son, a Cincinnati mattress manufacturer.  This bed was hinged in the middle so the head could be raised.  Then the 3-part hospital bed was developed at the Indiana University School of Medicine in the early 1900s.

Up to this time, all beds were adjusted manually.  At first, the elevated part was lifted by hand and fixed in place.  Later, they were adjusted with cranks and gears.  Then motors were added for lifting and lowering the bed and tilting its sections.  In 1945 a motorized hospital bed with push-button controls was patented.

Care of patients was the original reason for adjustable beds.  Side rails were for safety, as well as an aid for a patient trying to sit up.  The Trendelenburg position was for abdominal surgery.  Raising the head and torso to a sitting position eased stress on the abdomen. More available positions meant better positions for the patient’s health and comfort.  And raising or lowering the bed as a whole made caring for patients easier.

The first adjustable beds sold for home use were hospital beds, intended for home care of patients.  For some people, this was the only way they could be at home. My grandfather spent the last couple of years of his life at home in a hospital bed after suffering massive strokes.

In 1974, 100 years after the invention of the articulated bed, Craftmatic began selling adjustable beds designed specifically for home use.  These were not hospital beds, but were designed to be used for one’s health.  Customers bought them not only for their backs and necks and for better breathing, but also for comfort.  My parents had a Craftmatic bed.

Following this, a number of manufacturers began making and marketing adjustable beds for the home.  Some were already producing hospital beds.  Some started with the home market.  Now there are at least a dozen manufacturers of home use adjustable beds.  Among the leading producers are Craftmatic, Leggett & Platt, Reverie, and Ergomotion.

Beyond health and comfort, manufacturers and retailers are now marketing adjustable beds for convenience and lifestyle.  Even the term is often changed to adjustable “base” or “foundation.”  They can be used for more than sleeping or therapy.  “Your bedroom is now your den,” they say.  “The positions of the bed make it suitable for reading, watching TV, writing, working on your laptop or tablet, or just visiting.”  The sides of many adjustable bases have pockets for various items, outlets for your devices, USB ports, under-the-bed night lights, etc.  And style—today’s adjustable foundations are upholstered to match the mattress and/or coördinate with the room décor.

As the market for adjustable beds/bases/foundations has increased, so has the number of features. Many models now have massage functions, operating in pulses, waves or combinations.  Some have heaters.  Remote control handsets were wired at first.  Some still are, but now most are wireless, many programmable.  The newest remotes are digital, even wi-fi and Bluetooth capable, controlling room functions such as lights and fans.  With available apps, users can control their adjustables from their smart phones or tablets.

The bottom line is that adjustable beds are still beds.  That is their primary function, however they are otherwise used or marketed.  So when you consider buying an adjustable foundation for your new mattress (or a complete adjustable bed), first look at how it functions as a bed.  Will the positions help me sleep?  Would this really help with my back?  My asthma?  My acid reflux?  What are the safety features?  And, of course, the multi-thousand-dollar question:  Is this worth the cost?  If with these features you will really be adjusting for health and comfort, and you can afford the price, it may be.
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Select Adjustable Bed Manufacturers
(Ones reviewed on Beds colored blue)
Flex-A-Bedhttp://www.flexabed.com/
Med-Lift – http://www.medlift.com/
Reverie (Ascion)http://www.reverie.com/
Leggett and Platthttp://www.lpadjustablebeds.com/
Mantua (Rize)http://bedframes.com/rize
Ergomotionhttp://www.ergomotion.com/
Craftmatichttp://www.craftmatic.com/
Tempur-Ergo [designed by Tempur-Pedic]http://www.tempurpedic.com/tempur-ergo-adjustable-bases/tempur-ergo-adjustable-bases.asp
Electropedichttp://www.electropedicbeds.com/
Customatic – http://www.customaticbeds.com/
Christeli - http://www.christeli.com/adjustable-beds
Sleep Science - http://www.southbayinternational.com/index.php
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Posted February 25th, 2014
By: Wesley Vaughn

The Great Mattress Cover-up

By Wesley Vaughn

WJS Archetype_TT_Mattress_large top-cover

Cover of WJ Southard Archetype mattress

Ever since the transition from woven sleeping mats, mattresses have been covered. Whether filled with sawdust, straw, or feathers, a cover—also called ticking—defined the shapes and dimensions of the earliest mattresses. The role of the cover was to hold the loose materials in place.

The first cover materials were whatever was available where the mattresses were made, whether linen, wool, cotton, or some other fiber. The first requirement was durability. The fabric had to be strong enough to hold the fill under the sleeper without rupturing, spilling the contents and losing its support. The grain of the fabric had to be close enough to keep the cushioning materials from leaking through. With small caliber loose fill material, a tight weave was preferred over knit. With the invention of innerspring mattresses, the cover held padding against the springs to cushion sleepers against the ends of the coils.

In the United States, mattresses were first made locally. Thanks to the U.S. cotton industry, the almost universal mattress cover material was heavy cotton canvas. Some luxury mattresses were covered with linen. Early commercial cushioning materials were cotton or wool batting and horsehair. Then, toward the end of the 19th Century, wagon seat springs were modified for the first innerspring mattresses as Bonnell coils, and padding served as cushioning over the springs. Mattresses still needed covers, and sturdy cotton continued to be the expected material.

When synthetic fibers became more widely used in clothing, they also began to be used in covering mattresses, usually polyester in a blend with cotton. Polyester increased durability, reduced shrinkage, and lowered the cost.

Mattress cover fabrics were generally woven, though the contents were no longer loose materials. But with the introduction of memory foam mattresses by Tempur-Pedic with memory foam’s conformability, knit fabrics were preferred because they could stretch with the surface of the foam. Several fabric forms are available now: damask, jacquard, terry, velour, microsuede, flocked, and others.

Beginning with manufacturers of luxury mattresses, such as ES Kluft and Aireloom, silk and cashmere joined linen as luxury mattress cover fabrics. Then the quest for healthier and environmentally responsible materials led to new mattress coverings, such as bamboo, wool. Wool is advertised as coming from several sources. OMI stresses its use of domestic wool, while others cite wool from France, New Zealand or some other country. For some of its models, Carolina Mattress Guild uses Repreve, fibers made from recycled plastics, such as beverage bottles.

Rayon is used in covers, too, not only as the cover fabric, but more often as the fire barrier just below the fabric. Since rayon naturally impedes the spread of flames, mattresses can meet federal flammability standards without using chemicals. Several mattress makers are using organic materials as much as possible. These include organic cotton, grown without pesticides, and untreated wool. There are several blends of fibers in cover fabrics. The most used are polyester-cotton, silk & wool, and bamboo & cotton.

On early mattresses, the entire cover was of the same material. Now the sides are covered differently. And with one-sided mattresses, the bottom panel differs from the top panel.

Temperature control also produces new mattress coverings. The first applications are for breathability. The use of foams made mattresses warmer, sometimes too hot. The initial solution was airflow. When the cover is breathable, air flows through it better, carrying heat away. The Space Age produced Outlast, a material developed for use in space suits. Outlast uses phase change materials to absorb extra heat when too hot and releases heat when it is too cool. Now several mattress models by different manufacturers are covered around the border (the sides) with mesh to allow grater airflow for cooling.

Other fabric materials such as CoolMax are profiled to channel moisture away from the surface, keeping it both cool and dry. This brings about an irony. Horsehair was among the early mattress cushioning materials. Now Stearns & Foster uses Mongolian horsehair in the covers of its Golden Elegance mattresses for moisture wicking.

Fabrics are often treated to make them more healthful or aesthetically pleasing. Some of the treatments are aloe vera, lavender, gel, silver, and vitamins.

Mattress covers can be quilted or non-quilted, tufted or non-tufted. In quilted covers, the quilting materials share billing with the cover fabric. Quilting foams may be polyurethane, memory foam or latex. Sometimes these are gel-infused to enhance cooling. Quilting fibers are also used, such as polyester, Dacron, rayon, cotton, various kinds of wool, cashmere, etc. The functions of quilting materials can be cushioning, softness, warmth, coolness, and breathability. In SpringAir’s reintroduced Four Seasons line, the quilted topper is reversible. One side has a Joma wool quilted cover for warmth. The other is quilted with silk & fibers for cooling. Whatever the firmness level of a mattress, a quilted cover is perceived as luxurious, even though it is fairly common now.

There are several considerations used by mattress designers in selecting cover materials. Among these are comfort areas such as surface texture, conformity, breathability, and how warm the underlying material gets. Health issues include allergies, mold & mildew, pathogenic microbes, and pests (such as bedbugs). There are also the economic issues of durability and cost. Besides these are considerations of environmental impact, aesthetics, and class appeal. The goal of designing the cover of a mattress is to optimize the balance of these considerations for the best mattresses in the designated price range.
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Sample list of cover materials by source

Plant origin –

  • Linen (from flax)
  • Cotton
  • Bamboo
  • - extracted fibers
  • - viscose for rayon
  • Wood fibers
  • Aloe vera fibers (added to other fibers)

Animal origin –

  • Silk
  • Wool
  • - Lamb’s (fr. France)
  • - Jomma/Joma
  • - Merino
  • - “Eco-Wool” – from U.S. raised sheep without chemical baths
  • - New Zealand
  • Cashmere
  • Horsehair

Synthetic –

  • Rayon (from plant cellulose, such as bamboo)
  • Nylon
  • Dacron
  • Polyester
  • Recycled plastics
  • CoolMax® fibers for moisture control
  • Botany Wool®, wooly fiber made from plant materials
  • Maize fibers, synthesized from corn stalk cellulose

Mineral/metallic –

  • Silver fibers
  • Gold fibers

Treatments and other materials –

  • Outlast® (temperature control)
  • Silver coatings (anti-microbial, anti-static)
  • Aloe vera gel or extract (skin soothing)
  • Lavender (scent, relaxation, hygenic)
  • Vitamin treatments
  • Fire Retardants (several manufacturers are now replacing chemical treatments with naturally flame-resistant materials such as wool and rayon)
Posted February 21st, 2014
By: Wesley Vaughn

Memory Foam Mattresses – Good or Bad?

By Scott Braddam

Hand Impression in Memory Foam

Hand Impression in Memory Foam

Since about 2004, when I bought my current memory foam bed, I’ve been sold on the benefits of memory foam. There is truly no other feeling in the world which is close to sleeping on memory foam. Memory foam is like sleeping on silk sheets, unless you’ve done it, you can’t possibly understand why people rave about it. My bed is a pure foam bed, meaning no springs or framework of any kind, just layers of foam bonded together to create the mattress. I believe this is the best format, but memory foam on top of a spring base or adjustable air chamber can be good too. The bottom line is that if you have the option to use memory foam, I recommend that you do it.

I have had a lot of questions about memory foam over the years, first from friends and family and now from our readers, and the most common has to be about the most popular name brand. Tempur-Pedic was the first to introduce a memory foam bed in the United States, and has spent millions of dollars in research and development to refine their beds into the models available today. This is why they are the standard for memory foam beds, the benchmark by which all other companies are judged.

When I look at a mattress, I see so much more than just a name brand. With Tempur-Pedic, I see premium grade foams which excellent craftsmanship and durability. What I also see is room for improvement. One area for improvement is the cover used on most, if not all, of their beds. The cover is designed to be water resistant, which also means that it will not transfer air as well as a more breathable material. Basically, the cover material is woven onto a plastic sheet. This can create an overwhelming hot feel as you sleep. Tempur-Pedic does employ an airflow system which is actually two different ventilation areas in the base foam layers of the bed. This can help air circulation in the mattress itself.

Other mattress makers combat this in many ways. One way that I have seen which seems really attractive to me is the TempFlow. The TempFlow uses a breathable, non-water-resistant cover over a dual airflow system. Basically the top layers have a series of tiny holes which are vertical, and then the base foam is eggcrate which promotes horizontal airflow. This should increase the overall airflow in the mattress greatly.

Now, I do want to take a moment and let you know that I am not here to plug any mattress. I simply used these two brands to illustrate some concerns with memory foam beds. There are dozens of mattress manufacturers which use memory foam in their products. Which is the best?

Here are some things to think about if you plan to look at if you plan to shop for a memory foam bed.

Consider the foam density – Density is usually measured in the weight of the foam per cubic foot (in pounds).  Tempur-Pedic uses a 5.3-lb density foam.  Memory foam used in mattresses can be found in almost any increment from  about 3-lb to 8-lb.  The manufacturing process of the foam generally dictates that the heavier the foam is, the more expensive the mattress will be.  A budget memory foam bed will have an average density of 3.5-lbs to 4-lbs.  High quality memory foam mattress manufacturers will use the 5-lb to 8-lb memory foams more often, and the 8-lb foam is usually found on their top-of-the-line mattress models.

Consider the foam source – Memory foam is primarily produced overseas.  Very few mattress manufacturers produce their own memory foam, but the number is growing.  Tempur-Pedic makes their own foam.  Some imported foams are very poor quality and suffer from irregularities, such as lumpy hard spots.  These poor quality memory foams can vary in density from one area of the mattress to another.  These mattresses may even state that the memory foam density is an “average” density.  Foams made in the U.S.A. and the foams used by Tempur-Pedic are the best quality I have personally seen.

Consider the cover – Covers vary wildly.  Look for cover options which give you breathability and durability.  Exotic materials, like bamboo and silk may be the best, but good ole cotton and wool is a great place to start.  Don’t be fooled by waterproof covers, they may add to the heat of the foam.

Consider the price – There’s an old adage which says “If something sounds too good to be true, it usually is”.  A memory foam bed which boasts all of the features I have listed for $299 in a queen size is likely to be hiding something.  The other side of the shopper adage above is, “You get what you pay for”.  If you want to get a quality memory foam bed, make sure to plan on spending $700-$1,000 or more.

Consider the customer service – I preach on warranty and return period heavily.  In my mind, if I am going to write a check with a comma, I need to know about what to do to get that money back if I am not satisfied.  Sleep trial duration and qualifications, warranty coverage, terms, and requirements are all things that I will know well before I even consider the purchase.  This ain’t no pack of gum here kids, you can’t just throw it away if you don’t like it.

Consider the usage – Ever seen a movie where the kid has an ultra tiny apartment and a huge TV or stereo?  Well, I have seen it too many times in reference to a bed in a bedroom. Here’s a great rule of thumb for you – try to shop for the smallest size which will suit you, not the largest.  Yes, a king bed will fit into a 10×10 room, but you will have less than 2 feet on either side and less than 4 feet at the end of the bed.  This is not exactly what I would define as “practical”.

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Originally posted in 2010 by Scott Braddam 

Posted February 17th, 2014
By: Wesley Vaughn

Wooden Coils: What Will They Make Springs from Next?

By Wesley Vaughn

Vitalwood catalogue_cover-s

What are innerspring coils made of?  “Steel,” we say.  Other options are: Stainless steel, titanium steel, titanium alloy, or some other metal alloy.  That is it!  Or it was—until now.  Among the new mattress companies at the Winter Las Vegas Market in January 2014 is VitalWOOD USA, the U.S. distributor for VitalWOOD, a  division of Hungarian manufacturer Bio-Textima.

This family-owned firm developed the wooden coil as an alternative to metal springs, releasing it in 2011.  VitalWOOD touts their “metal-free mattress” as not contributing to electromagnetic pollution, because the wood does not resonate with electromagnetic radiation (otherwise known as radio waves).  I remember the stories of old-style steel beds and springs acting as AM radio receivers, so there must be something to this claim.

Besides being free of electromagnetic pollution, VitalWOOD’s wooden springs are also made from a sustainable, renewable resource.  There is also less environmental impact processing wood than in the making of steel (even recycled steel).

When I first read about springs made of wood, my question was, “How do they do that?”  VitalWOOD has a video on their site showing how this is done.  Knowing a little about woodworking, it did not surprise me. First of all, if someone doubts that wood can be a spring, point them to wood archery bows.  Then in the mattress industry, European wood slat foundations work like box springs, because the carefully selected and crafted wooden slats are resilient.  So the real question is, “How do they make the wood into coils?”  Heat and moisture make the wood pliable enough to wind into coils.  Watch the video, and see for yourself.

If selling mattresses and box springs with wooden coils is successful in the United States, especially if it cuts deeply into the mattress market, look for other manufacturers to develop their own alternative material coils.  One or more domestic manufacturers will develop their own wood coil manufacturing process  (or license it from VitalWOOD).

I have one more question:  “What Will They Make Springs from Next?”  If wooden innerspring coils prove a successful alternative to metal, expect other non-metal coils for mattresses to be developed.  Already, spring coils for very light applications are being made of synthetic materials, such as nylon.

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Resources:

VitalWOOD – www.vitalwood.com
“This is how wooden-spring is made” – http://vitalwood.com/download/this-is-how-wooden-spring-is-made-vitalwood.avi

Bio-Textima – http://www.bio-textima.hu/en/

“Bio-Textima , the only mattresses in a metal-free design,” Sleep Tech Magazine, May 8, 2013 – http://www.sleeptechmagazine.com/bio-textima-the-only-mattresses-in-a-metal-free-design/

Bedroom Retailers –  http://bedroomretailers.com/mattress-update/bio-textima-brings-its-vitalwood-wooden-coil-spring-system-to-the-us/6885

Perry, David, “Prana, Juel, SensorPedic lead Vegas newcomer list,” Furniture Today, Jan 24, 2014 – http://www.furnituretoday.com/blog/Bedding_Today/43878-Prana_Juel_SensorPedic_lead_Vegas_newcomer_list.php

“New Exhibitors At Specialty Sleep Association Las Vegas Market Showroom,” Furniture World, December 26, 2013 – http://new.furninfo.com/Furniture%20Industry%20News/2602

Posted February 10th, 2014
By: Wesley Vaughn

Microcoils

Leggett & Platt “Softouch” Microcoil

Definition

Microcoils (or minicoils) are coils which are smaller than standard innerspring coils.  Innersprings are usually 6” to 8” high.  Some microcoils are 4” high, but most are much shorter, usually 1” to 2½” high. They are also narrower and made with lighter gauge wire.  Some microcoils are only ¾” tall.  At least one supplier calls the shorter ones mini-microcoils.

Purpose

Innersprings are designed for primary support, but microcoils are designed for comfort.  The lighter wire gives them a softer feel, and more coils in a given area make them feel smoother.

Design

Microcoils are the latest major development in mattress springs, but there is already a great deal of variety.  Among their developers and manufacturers are major players such as Leggett & Platt, Hickory Springs Manufacturing and Spinks Springs.

Microcoils are sometimes called “micro-pocket coils,” because they are usually pocket coils, individual coils wrapped in fabric pockets, a design now often found in innersprings.  Because each coil responds independently, a pocket coil layer conforms to body contours, helping to relieve pressure and dampen motion transfer. The pockets are sewn, glued or “welded” together.  Welding at one point on a seam allows the coils to move sideways as well as up-and-down.  Mattress makers call this “three-way stretch.”  It makes the microcoil layer even more conforming.

Microcoils are sold to mattress manufacturers in sheets or layers covered top and bottom.  The major advantage of microcoils is that since they are thinner than innersprings, they can be placed higher in the mattress, among the comfort layers.  Several mattresses alternate layers of foam and microcoils.

One benefit of microcoils is that they are cooler than foam.  They are open, allowing air to flow through, making them much cooler than memory foam.  Some microcoil layers are covered with mesh to let even more air through.

Coil or Non-Coil?

Mattresses without coils are specialty sleep beds. Therapedic a manufacturer of specialty sleep products, now has a mattress collection with springs.  Ágility models have microcoils and mini-microcoils, with heights of ¾, 1 ½ and 4 inches.   The trend seem to be that more foam mattresses will also include microcoils.

Therapedic Agility 2

The Future

Because of their flexibility and versatility, the use of microcoils in mattresses will grow.  The advantages are durability, conformability and coolness.  As microcoils and mini-microcoils are developed further, there will be a greater variety of design as well as sizes, yielding additional benefits.  In this sense, smaller will be bigger.

Posted February 9th, 2014
By: Wesley Vaughn

Mattress Foams – Part 2

Polyurethane Foam

Polyurethane (PU) foam is made by linking large molecules, usually isocyanates, to each other with modified oil molecules called polyols, usually petroleum-derived. Polyurethane foam is very durable and supportive.

320px-Polyurethane

Most of the issues with polyurethane foam are related to its manufacture.  Isocyanates are toxic before becoming part of the PU foam.  I used to work on a line making foam-filled panels for garage doors.  Two liquids were injected between the sheet metal skins of the doors.  They immediate blended and swelled into foam, which cured to become firm.  One of the liquids was an isocyanate, and we had to be extremely cautious around it.

Another issue is outgassing.  For some time after it is made, polyurethane releases gasses with an unpleasant odor.  Careful selection of ingredients reduces the outgassing and the odor.

Many mattress manufacturers use “plant-based” polyurethane foam.  From 15% to 20% of the polyols in this foam are from plant-derived oils.  At the current level of technology. No more plant oils can be used and still have a high quality polyurethane.  With further research & development, this may change. The plant-based polyols used are most often from soy oil, but other hydrocarbons, such as coconut oil and palm oil, are sometimes used.  Further technological development may see the use of many other plant oils.

Memory Foam

Hand Impression in Memory Foam

Hand Impression in Memory Foam

As stated above, memory foam was developed from polyurethane.  It is denser than polyurethane.  Visco-elastic foam also is more sensitive to heat.  When someone sits or lies on it, the memory foam becomes softer, allowing the person to sink into it. This way it conforms to a sitter’s or sleeper’s body contours.  The memory foam can be formulated to be more or less heat sensitive, therefore more or less conforming. With memory foam beds now widely available, manufacturers are competing to make the best memory foam mattress.

One drawback of memory foam is its heat build-up.  When it absorbs heat, it becomes warmer.  For a sleeper, this can become uncomfortable.  Over time, several ways have been used to cool memory foam.

The first solution was to promote air flow to make memory foam breathable.  Ventilating the foam by perforation or by cutting channels in its surface allowed air to flow through it and by it.

Then manufacturers began to make the cells in the foam open and more connected to make the foam itself permeable to air. Open-cell memory foam is more breathable than closed cell foam.

Now it is common practice to infuse the memory foam with gel.  The gel acts as a heat sink, carrying heat away to where it can dissipate.  The most common method of gel infusion is to stir beads of microencapsulated gel into the liquid used to make the memory foam.  Variations of this are the size of the beads and the kind of gel.  Another method used by a few manufacturers is to swirl liquid gel into the memory foam mixture.  This memory foam has streaks of gel.  Additionally, a layer of gel itself may be embedded in the layer of memory foam.  Some models use this is for lumbar support.

Since memory foam is basically a kind of polyurethane, there may be some emissions.  Using more plant-derived oils reduces this.  However, memory foam has to be cut more slowly because of its “memory.”  And it has to have time to recover before the next cut.  This extra time allows the foam to air out more before being put into a mattress then packaged for shipping.

Latex Foam

Tapping Latex

Formerly called “foam rubber,” latex foam is made in a number of ways.  Foam rubber was first made by Dunlop, a tire manufacturer.  Foaming agents were used to whip liquid synthetic rubber into foam.  Then rubber tree sap (natural latex) was whipped and cured into foam.  Now there are several kinds of latex foam, depending on the proportion of natural latex and the composition of other ingredients.  All natural latex foam is (or should be) made from 100% natural latex sap. Natural latex foam is partly synthetic.  Then there is synthetic latex foam.  Synthetic ingredients can be petroleum derived or natural ingredients, such as soy oil.

Latex foam is highly resilient.  Its recovery time from pressure is virtually instantaneous.  Latex is conformable, not as much as memory foam, but it is more durable.  Its durability partly depends on the manufacturing process.  Latex is used in some mattresses for the support core.

The oldest method is the Dunlop process.  Liquid latex is mixed with the foaming agents and poured into molds to cure.  The cured latex foam then is cut to specification.

Another common manufacturing method for latex foam is the Talalay process.  The liquid latex is fed into a closed mold from which air has been removed.  Freezing and insertion of carbon dioxide are used in expanding the foam, and heat is used to cure it.  This is a more costly process, but it can be done without toxic ingredients or agents. Also, parts can be molded in their final form.

Like memory foam, latex is sometimes infused with gel for cooling.  Latex foam is naturally breathable, and it is cooler than memory foam, but the addition of gel is seen as an added value for cooling and its smoother support. Latex is naturally resistant to bacteria, mold, mildew and dust mites.  Properly washed latex foam is hypoallergenic, since allergens have been washed away.

Several mattresses on the market today use several kinds of foams, selected, sized and placed to optimize the use of their characteristics.  Gel foams are usually at or near the top of the mattress where cooling is most needed.  Firmer, more resilient foams are usually at or near the bottom to provide basic support.  Layers in between tailor the comfort level of the mattress as a whole.

Posted February 9th, 2014
By: Wesley Vaughn

Mattress Foams – Part 1

History of Mattress Foams

Most of us appreciate some cushioning when sitting or lying on a hard surface for very long.  This has been true for thousands of years, with cushions for sitting and sleeping.  Mattresses began with fiber sleeping mats laid out on a floor.  At some point, long cushions or pillows were made, filled with wool, straw, feathers, sawdust, horsehair—anything to soften a hard surface.

In the middle of the 19th Century, coiled springs were invented for buggy and wagon seats.  Later, these coiled springs were adapted for use in mattresses, what we call the Bonnell innerspring.  For most of the 20th Century, the majority of mattresses were innerspring models.

The most durable innersprings are also very firm.  Mattress manufacturers cushioned this with batting, usually cotton, sometimes wool or other fibers.  But with the introduction of polyurethane and foam rubber, foam began to be used for seat cushions, then as cushioning on innerspring mattresses.  Various configurations were introduced, including convoluted (or “egg crate”) foam.

Introduction of Memory Foam

With manned space flight, better padding was needed to cushion astronauts against high G forces at launch.  NASA contractors modified polyurethane foam to produce visco-elastic foam.  This was further developed by corporate firms for consumer use, becoming memory foam.

First used for seat cushions, memory foam began to be used in pillows, mattress toppers and mattress cushioning.  Eventually, all-foam mattresses were introduced, with high-density polyurethane foam as the support core.  These non-spring mattresses are collectively called “specialty sleep products.”

Kinds of Mattress Foams

The three major kinds of foam uses in mattresses are polyurethane foam, visco-elastic memory foam, and latex foam.  Each kind of foam has variations.  First, there are different ingredients in these foams.  Then there are different densities and firmness levels.  Now gel is infused into different foams to add desired characteristics.

Foams for bedding are rated by density and Indentation Force Deflection (IFD).  Density measures pounds per cubic foot.  IFD measures how many pounds it takes to make a 1” indentation.

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Part 2 will cover the different kinds of mattress foams

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