All There is to Know About Memory Foam
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Memory foam, viscoelastic foam or thermoregulated foam. So many names and technical specificities for a material that is nevertheless simple. Faced with the large number of mattresses for sale in stores and online, it is difficult to find a single source of knowledge for this comfort-creating material. What is memory foam, is there a version that is best-suited to me & my sleep partner? how long will it deliver the same support as day one? there's now gel in it? why does density matter? what thickness would suit me best?
We've all asked ourselves these questions at one time or another. Choosing a product made of memory foam may be a little intimidating, but after reading this, you'll be able to select your memory foam mattress or topper with confidence!
Summary
What is memory foam?
How memory foam adjusts to pressure
What is a good density for a mattress topper?
How tall should the mattress be?
Types of memory foam
Alternatives to memory foam
How is a memory foam mattress constructed?
The benefits of memory foam
WHAT IS MEMORY FOAM?
Memory foam is mainly composed of a polymer called polyurethane. Polyurethane is a popular and versatile material that is used to produce a wide range of products in many fields.
Memory foam, also known as “viscoelastic” foam, is made by adding various compounds and elements to the polyurethane, which change depending on the type of foam created.
These elements are important because they are the ones that affect the quality of the two main properties of memory foam: viscosity and elasticity. Viscosity is the fact that matter forms and deforms in a slow and controlled manner - think of honey. Elasticity is the ability of material to return to its original shape or size after being stretched or deformed.
Manufacturers have different "recipes" for the elements they add to the foam and the processes they use to create the foam. These recipes and this process affect the feel and function of memory foam and are often trade secrets.
However, as a general rule, the viscoelastic foam used in most foam toppers and mattresses contains a compound called a polyol which helps give the foam both elasticity and viscosity.
HOW MEMORY FOAM ADJUSTS TO PRESSURE
Memory foam is both highly absorbent and soft. It adjusts to body heat and pressure, evenly distributing weight across its surface. When pressure is removed, the memory foam rebounds and returns to its original shape. Properties of isolating movement, absorbing impact and supporting the body, contribute to making memory foam extremely comfortable.
BACK PAIN RELIEF
One of the most appealing qualities of memory foam mattresses and toppers is the their ability to relieve pressure points. As mentioned earlier, memory foam does an exceptional job of evenly distributing body weight over a larger surface area rather than concentrating support for the entire body in a few small areas such as the pelvis, hips, back or shoulders. These locations create uncomfortable pressure points and are often the object of various ailments because such a large percentage of the body's weight is concentrated on a regular basis.
When viscoelastic foam is used in mattresses and toppers, the foam evenly cushions and cradles the entire body by absorbing your weight and pleasantly distributing across the sleep surface.
Another aspect of memory foam is that its viscosity is temperature dependent. This means that it becomes less rigid and more flexible as temperature increases. This is why memory foam products are initially softer in the summer as well as after you lay on them for a while.
DENSITY: IDEAL LEVELS FOR A GOOD MATTRESS / TOPPER?
When considering a memory foam mattress topper density is an important consideration, and one that is specific to the person or persons that will be sleeping on the foam.
Foam density is expressed in units of pounds per cubic foot (lbs / ft3) , the higher this value is, the more weight can be supported. And, regardless of weight, if you prefer a firmer sleep surface you'll want to consider foams with a higher density. A foam density above 3 will create a well-supported sleep surface.
IS THERE AN IDEAL HEIGHT (THICKNESS)?
It is important not to confuse density and thickness, a 10" mattress can have a very low density, while a 3" mattress topper can have a much higher density.
The choice of the thickness of the mattress or mattress topper will also depend on size and body composition of the sleeper. The rule is the same as for density, i.e. the bigger the person, the thicker the mattress should be.
So, what thickness of mattress to choose? In general, a memory foam mattress should be at least 10" thick. A quality mattress with multiple layers of memory foam will usually be 12"-13" and wrapped in a textile cover. The thicker the mattress, the more padding there is. It is also important to pay attention to the ratio of of memory foam to 'classic' foam. A mattress made up of 85-90% classic foam, will not be comfortable for most people and should be avoided!
VARIOUS TYPES OF MEMORY FOAM
Beyond the differences specific to each manufacture and the compound used, there are multiple types of memory foam used in mattresses and mattress toppers. There are generally three main types of viscoelastic memory foam:
TRADITIONAL MEMORY FOAM
This is the "original" memory foam . It is the first memory foam to enter the market for consumer use. This traditional foam initially developed by NASA for astronauts is designed to mold to the body and absorb impacts as explained previously.
While supportive and relaxing, the major disadvantage of this traditional material is that it tends to retain heat and reduce air circulation. This can cause the sleeping surface to become hot and uncomfortable. Two newer versions of viscoelastic foam were created in part to solve this problem.
OPEN CELL FOAM
Open cell memory foam is made with the same elements as traditional memory foam, but the material has a honeycomb construction and structure that makes it more airy . Open cells are like air pockets partially connected to each other. Conversely, closed cells do not have these air bubbles and are isolated from each other. Thanks to these internal bubbles, open-cell memory foam mattresses allow better ventilation and air circulation to dissipate body heat.
Initially it was difficult to make open cell memory foam with a high density. As a result the mattresses were too soft and lacked support. The latest manufacturing technologies make it possible to produce higher densities thus solving this problem.
GEL MEMORY FOAM
This type of memory foam incorporates gel beads into its construction. The gel has natural cooling properties that help regulate body temperature while you sleep. Injecting gel-based microbeads into the foam has allowed manufacturers to create products that help hot-sleepers get a better night of rest.
ALTERNATIVES TO MEMORY FOAM
There are alternatives to memory foam which are sometimes combined to provide different sleeping options.
LATEX FOAM
Latex mattress toppers and mattresses are a sustainable and environmentally friendly option especially when it comes to natural latex. Latex foam also conforms to the shape of the body but with a more bouncy and invigorating feel than the more enveloping and flexible memory foam. Latex can also provide a cooler sleeping surface than memory foam. However, a mattress composed solely of latex may have comfort drawbacks for some linked to the flexibility of the product's structure.
SPRING MATTRESS
Single spring mattresses contain one or more layers of less resistant springs of different sizes. The new generations of springs are individually pocketed, that is to say that each spring is wrapped in a fabric to make it more stable and resistant. Spring mattresses are wrapped in a quilting or fabric cover. These mattresses are generally inexpensive but less durable over time; with the exception being hybrid products combining springs and foam.
HYBRID MATTRESSES
Hybrid mattresses are a combination of several materials and manufacturing processes. These mattresses made in several layers combining, for example, the cooling advantages of latex, the unique properties of polyurethane foams and pocket springs. Usually the mattress will consist of a top layer of memory foam or latex foam supported by a pocketed spring structure and polyurethane foam. These mattresses provide a good foundation, bounce and extra ventilation.
WHICH PRODUCT SHOULD YOU CHOOSE?
A memory-foam topper is a good option if you want to improve the comfort of your current mattress without the expense of replacing it completely. Most mattress toppers fall within a spectrum of being 1.5" to 4" thick. Thicker options will deliver more comfort and support, significantly improving the feel of the sleep surface when compared to the mattress below. Because mattress toppers use the existing mattress as the foundation, they require less material, are smaller and easier to ship and thus have the advantage of being less expensive than a new mattress!
HOW ARE MEMORY FOAM MATTRESSES CONSTRUCTED?
Memory foam mattresses are often made in layers according to a basic pattern:
HOME LAYERS
Top layers of the mattress are made up of one or more layers of foam designed to provide first-touch comfort with cushioning and enveloping feel depending on the level of firmness. The best mattresses use breathable foams (gel, open-cell) in these first layers to dissipate heat from the sleep surface.
TRANSITION LAYER
This section of the mattress is made up of a layer of foam intended to link the home layers to the core. Some mattresses use this layer to further increase comfort with high density memory foam that provides a plush and enveloping feeling without being in direct contact with the sleeper. The foam actively responds to input from your weight minimizing motion transfer and providing support to your body.
CORE
The structural base of the mattress. This thick layer is made of a much firmer and more robust polyurethane foam. This guarantees the overall stability and support of the mattress.
THE BENEFITS OF MEMORY FOAM
WEIGHT DISTRIBUTION AND PRESSURE POINT RELIEF
Memory foam envelops your body evenly distributing weight and reducing pressure points. This relieves the hips, shoulders and neck which experience more pressure during sleep.
PROMOTES SPINAL ALIGNMENT
The enveloping and modular properties of memory foam allow your hips and shoulders to sink slightly re-creating the natural alignment of your spine while you sleep. Promoting proper spinal alignment and lumbar support dramatically improves the quality of sleep, reducing restlessness at night as well as the likelihood of back pain in the morning.
REDUCES MOTION TRANSFER
The viscoelastic memory foam prevents movement from one part of the bed to be felt on the other part of the bed thanks to the high density, weight distribution and impact absorption qualities. For couples and co-sleepers who are light sleepers, memory foam has a significant advantage for a peaceful night's sleep.
NOISE REDUCTION
Memory foam mattresses are also known to be quiet. Thanks to impact absorption, foam reduces or eliminates squeaking, shifting and other bed noises.
You are now knowledgeable about memory foam and its derivatives. Questions like: what foam density should I look for? how thick should my mattress be? what type of memory foam to choose? and are their alternatives to memory foam? will no longer hold any secrets for you!
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