Mattress

Mattress  directory

A mattress is a mat or pad, usually placed on top of a bed, upon which to sleep or lie.

The word mattress is derived from Arabic words meaning "to throw" and "place where something is thrown" or "mat, cushion." During the Crusades, Europeans adopted the Arabic method of sleeping on cushions thrown on the floor, and the word materas eventually descended into Middle English through the Romance languages.

Though a mattress may be placed directly on the floor, it is usually placed on top of a platform (such as a platform bed or a metal box spring or a slatted foundation) to be further from the ground. Historically, mattresses have been filled with a variety of natural materials, including straw and feathers. Modern mattresses usually contain either an inner spring core or materials such as latex, viscoelastic, or other polyurethane-type foams. Mattresses may also be filled with air or water, or a variety of natural fibres, such as in futons.

Spring mattress core
The core of the mattress supports the sleeper’s body. Modern spring mattress cores, often called "innersprings," are made up of steel coil springs, or "coils."

The gauge of the coils is another factor which determines firmness and support. Coils are measured in quarter increments. The lower the number, the thicker the spring. In general, higher-quality mattress coils have a 14-gauge (1.63 mm) diameter. Coils of 14 to 15.5-gauge (1.63 to 1.37 mm) give more easily under pressure, while a 12.5-gauge (1.94 mm) coil, the thickest typically available, feels quite firm.

Connections between the coils help the mattress retain its shape. Most coils are connected by interconnecting wires; encased coils are not connected, but the fabric encasement helps preserve the mattress shape.

There are four different types of mattress coils:

Bonnell coils are the oldest and most common. First adapted from buggy seat springs of the 19th century, they are still prevalent in less expensive mattresses. Bonnell coils are hourglass-shaped, and the ends of the wire are knotted or wrapped around the top and bottom circular portion of the coil and self-tied.
Marshall coils are each wrapped in a fabric encasement and usually are tempered. In the case of Beautyrest, high carbon magnesium is added while the steel itself remains untempered. Some manufacturers pre-compress these coils, which makes the mattress firmer and allows for motion separation between the sides of the bed.
Encased Coils or encased springs, are a component part of a mattress in which each coil is separately wrapped in a textile material. Encased coils may also be generically referred to as Marshall coils or wrapped coils.
Offset coils are designed to hinge, thus conforming to body shape. They are very sturdy, stable innersprings that provide great support. An example of this type of coil design is the Sealy Posturepedic coil system.
Continuous coils Or Mira-coils, Work by a hinging effect, similar to that of offset coils. In a basic sense a continuous coil is simply that, one continuous coil in an up and down fashion forming one row (usually from head to toe) of what appear to be individual coils. The advantages of how firm a support the continuous coil provides it is somewhat tempered with the 'noise' associated from a typical mira coil unit. The largest company using a Mira-coil design, is Serta Mattress Company, though their coil units are supplied from Leggett & Platt.

Air mattresses
Air mattresses use one or more air chambers instead of springs to provide support. Quality and price can range from inexpensive ones used occasionally for camping, all the way up to high-end luxury beds. Air mattresses designed for typical bedroom use cost about the same as inner-spring mattresses with comparable features.

Several companies currently produce adjustable firmness air mattresses. In 1981, Comfortaire began manufacturing and marketing air mattresses that looked conventional but allowed users to adjust the firmness. Select Comfort patented a variant and began marketing them in 1987.

Adjustable air mattresses come in a variety of models from basic, no-frills ones that measure about 7" in height, to high-profile, 15" tall hybrids that contain several types of foam, pillow tops, and digital pumps with memory, for individual pressure settings.

Air bladder construction varies from a simple polyethylene bag to internally baffled, multiple chambers of latex (vulcanized rubber) with bonded cotton exteriors. Mattresses have a layer of foam above the air chambers for added cushioning. The air chambers, top and sidewall foam all sit inside a removable two piece cover that looks like the outside of a standard innerspring mattress. These high-end luxury Air Beds are also known as soft sided Air Beds.

Medical versions of these adjustable firmness mattresses have even greater control mechanisms which include features like frequently changing pressure to prevent bed sores.

Foam mattresses
Foam mattresses use shape-conforming latex or viscoelastic memory foam rather than springs to provide support. Mattresses manufactured using memory foam or latex are generally hypoallergenic.[citation needed] Since foam varies in quality, prices can vary widely. Most mattress manufacturers offer a line of memory foam mattresses.

Foundation
There are three main types of foundations.

Box-springs consist of a rigid frame which contains extra-heavy-duty springs. This type of foundation contributes to softer support and a bouncier mattress. Because box-springs can cause mattresses to sag, many manufacturers add high-density block foam underneath the coils or provide a rigid foundation instead.
Traditional wood foundations are usually made of soft woods, such as pine, or hard woods. They usually consist of seven or eight support slats covered with cardboard or beaverboard. This type of foundation, called a zero deflection unit or an "Ortho Box" in the bed industry, increases the feeling of firmness and stability.
Grid foundations are a combination of steel and wood.

Upholstery layers
Upholstery layers cover the mattress and provide cushioning and comfort. Some manufacturers call the mattress core the "support layer" and the upholstery layer the "comfort layer." The upholstery layer consists of three parts: the insulator, the middle upholstery, and the quilt.

The insulator separates the mattress core from the middle upholstery. It is usually made of fiber or mesh and is intended to keep the middle upholstery in place.

The middle upholstery comprises all the material between the insulator and the quilt. It is usually made from materials which are intended to provide comfort to the sleeper, including regular foam, viscoelastic foam, felt, polyester fibers, cotton fibers, convoluted (“egg-crate”) foam, and non-woven fiber pads.

The quilt is the top layer of the mattress. Made of light foam or fibers stitched to the underside of the ticking, it provides a soft surface texture to the mattress and can be found in varying degrees of firmness. The protective fabric cover which encases the mattress is called ticking. It is usually made to match the foundation and comes in a wide variety of colors and styles. Most ticking is made of synthetic fibers like polyester, or acrylic; or of natural materials such as latex, cotton, silk, and wool.