BUYING A MATTRESS: SUPPORT
Correct support is an essential ingredient for a healthy body. It is mainly delivered through the “core” of the mattress, which can be innerspring, foam, air or water. It is also delivered through the box spring or foundation under the mattress.
A good mattress and box spring will gently support your body at all points and keep your spine in the same shape as a person with good standing posture. When trying a mattress, pay special attention to the heaviest parts of your body; your hips, shoulders and lower back. If there is inadequate support, you may develop back pain. However, if a mattress is too rigid, you may experience uncomfortable pressure.
Innersprings are the most common type of support system used to make mattresses. These units are comprised of metal coils that are either pocketed or open and laced. Innersprings conform to and support your body by allowing your hips and shoulders to penetrate the surface while allowing the back to be supported in its proper position.
When shopping for an innerspring mattress, there are a few things to consider:
1 - Coil Count:
The number of coils in the unit. Counts are usually quoted in full or queen sizes. The number of coils alone has little bearing on the quality of the unit. The coil design, wire gauge and number of turns must also be considered!
2 - Wire Gauge:
The thickness of a wire. The lower the number, the thicker and more durable the wire. For example, a 12 ¾ gauge wire is thicker than a 15 gauge wire.
3 - Number of Turns or Rotations:
A coil turn is defined as a complete rotation in the coil. More turns equates to more coil resiliency and longer coil life. In addition, more turns allow the sleeper’s weight to be distributed across more wire, resulting in less wire fatigue in the coil.
4 - Unit Size:
An innerspring unit can be standard size or foam encased. In the former, the coils extend from edge to edge, providing uniform support. Some standard size units also have a border rod around the perimeter for additional edge support. In a foam encased unit, which is smaller in size, coils are removed and replaced with a foam edge. All innerspring units used by The Original Mattress Factory are standard size units with a border rod construction.
5 - Design of the Coil:
There are five basic types of innerspring coil designs: Marshall, Bonnell, LFK, Offset and Continuous.
Marshall Coil – A straight barrel, unknotted coil that is encased in fabric. It is sometimes made with non-tempered steel, which reduces the long term resiliency of the springs. (Also known as a pocketed coil.)
Tempering: Tempered innersprings are stronger, more resilient and therefore more durable. The tempering process, which involves heating the wire or innerspring unit to a high temperature, can be done electronically or in a tempering oven. The term “double tempered” or “twice tempered” is often used in the industry, but once a coil has been heated to the optimum temperature to achieve tempering, it cannot be tempered twice. All coils used by The Original Mattress Factory are tempered for maximum durability.
Bonnell Coil - An hourglass shaped coil with a round, knotted head. It is made with tempered steel and is commonly used in most national brand entry level products as well as some promotional products. The Bonnell coil unit is used in The Original Mattress Factory’s Classic mattresses.
LFK Coil - A straight barrel coil with an offset, squared and unknotted head. It is made with tempered steel and is a premium innerspring unit utilized in the flagship product lines of several brands. The LFK coil unit is used in The Original Mattress Factory’s Regency & Silhouette mattresses.
Offset Coil - An hourglass shaped coil with a square head that can be knotted (as shown below) or unknotted. It is made of tempered steel and is used in premium quality innerspring units found in high end luxury brands. Our best Offset knotted coil unit is used in The Original Mattress Factory’s Orthopedic mattresses.
Knotted Coils: The end of a coil is either knotted or unknotted. Knotting utilizes more steel and gives the coil more stability.
Continuous Coil - A strip of coils that runs either vertically or horizontally with each head representing the end and beginning of consecutive coils. It is made of one piece of tempered wire and commonly has a high coil count, but uses less steel and a much thinner gauge of wire with a low number of turns.
Foam mattresses are becoming increasingly popular in today’s market. Like an innerspring mattress, foam conforms to and supports your body by allowing your hips and shoulders to penetrate the surface while allowing the back to be supported in its proper position.
If you are interested in a mattress with a foam core, there are a few different kinds of foam available. It is important to consider the type of foam as well as its density and Indentation Load Deflection (ILD). ILD is a measure of a foam’s load bearing capacity and is indicative of the foam’s feel (hardness/softness).
Polyurethane foam is a synthetic material that is produced by a reaction between two chemicals, a few minor ingredients and water. It is then solidified into foam via one of two processes: the Slabstock Process or the Molded Process. In the former, a chemical mix is poured onto a moving conveyor belt, where it is allowed to react and expand. The slab is then cut, stored and allowed to cure for 24 hours. The Molded Process differs only in that the chemical mix is poured into specially shaped molds as opposed to an open conveyor.
The resulting product of either process is polyurethane foam, which is made up of a network of tiny interlocking support cells consisting of “struts” and “windows”. The “struts” form the support structure of the foam while the “windows” or voids allow it to circulate air and “breathe.” As such, polyurethane foam is both durable and lightweight. It conforms comfortably to an individual’s body shape and is also available in a range of densities. A higher density of foam means that there is more “strut” material, which gives the foam an increased amount of support and durability. Density is a measure of weight per unit of volume (i.e. lbs/ft3).
Latex literally means “polymers suspended in water” and can be 100% natural, 100% synthetic or a blend of the two. It is manufactured via one of two processes: the Dunlop process or the Talalay process.
The Dunlop Process is the most commonly used method of production for latex foam. It is a four-step process that begins by blending natural and synthetic latex with soaps and curing agents. In the second step, the mixture is poured into molds on a conveyor belt. The introduction of sodium silicaflouride (SSF) then gels the mixture into foam. Finally, the foam is sent into a steam chamber, where it sets and cures. This process, although much quicker than the alternative Talalay process, tends to create denser foams that are less consistent with a limited range of firmness.
The Talalay process is a highly controlled and precise process that produces the highest quality, most resilient and most consistent latex foam. It consists of six steps.
Step One: A mixture of natural and synthetic latex is blended with soaps and rubber curing agents in a temperature-controlled stainless steel tank. The soaps stabilize the mix, prevent it from coagulating and helps it “foam” up. The curing agents strengthen the polymer or rubber bond of the latex particles.
Step Two: The compound is transferred to the pressroom, where it is whipped into a frothy liquid form. It is then injected into an aluminum pin core mold by a robotic arm. The mold, which is fixed, is filled partially to allow for the production of a wider range of ILDs. More compound is used to create a firmer foam, while less compound results in a plusher feel.
Step Three: The mold is sealed and a vacuum is used to extract air and evenly distribute the liquid inside. This gives the latex a consistent, round and open cell structure.
Step Four: The latex is chilled to -20 degrees Fahrenheit. Freezing allows for a more consistent cell structure as it prevents particles from settling. It also allows for the production of softer ILDs.Step Five: Carbon dioxide is introduced to gel or solidify the foam.
Step Six: The mold is heated to 220 degrees Fahrenheit to cure the core as it is baked into a solid state. The large number of pins in the Talalay mold allow for consistent heat transfer to the entire product.
The resulting product of either process is latex foam, which is a naturally resilient and breathable cushioning foam that instantly conforms to the body to provide comfort and support.
Viscoelastic Foam (Memory Foam):
Viscoelastic foam is a type of polyurethane foam and is therefore synthetic. Its name is derived from the word “visco,” which means “resistant to change of shape” and “elastic,” which means “the ability of something to return to its original shape after being forced to change.” Viscoelastic foam, which is commonly known today as memory foam, was originally developed in the late 1960s by NASA. The result was a very dense, open cell variety of polyurethane foam that molded to the weight and shape and temperature of an individual. Unlike latex or standard polyurethane foam, it is a slow-response foam and gradually conforms to your body and temperature. It also takes a certain amount of time to recover and resume its original shape. Due to its high density, it helps to reduce pressure points as well as minimize motion transfer. However, it is not asbreathable as other mattresses and has a tendency to become hot while you sleep.
Air and Water:
Some mattresses use air or water as the support component. These alternatives provide support through displacement, allowing the heavier part of the body to force the air or water into areas with less weight (like a balloon that is squeezed in the middle.) The Original Mattress Factory does not manufacture air or water beds.