Glossary

• Memory Foam

  Memory Foam was invented by NASA in 1966. The idea was to improve the safety of aircraft cushions, but it was not long before th material was developed further and used in more and more products. Memory Foam is an open cell construction, which reacts to body heat and weight. The more heat applied, the softer the material gets. This, in turn, allows the weight applied to sink deeper. Memory Foam can be made at various densities to result in different tensions/firmnesses.

  The crucial element of Memory Foam is that it softens and moulds to the body shape. This ability allows for very accurate contour support and weight distribution. This ability makes Memory Foam a desirable material for mattresses. Some mattresses are completely Memory Foam, perhaps using different layers of various densities. Some mattresses use Memory Foam to compliment a Spring Unit.

  As Memory Foam requires heat to achieve its desired state, the heat is stored. Some people are not keen on Memory Foam as this heat can gradually build, resulting in a warm bed. However, this stereotype can be seen as outdated, as many manufacturers have solved the issue by applying new techniques to compliment the Foam. Techniques such as Outlast and Coolmax. Memory Foam is also Hypoallergenic and is therefore very popular with Asthma and Allergy sufferers.

• Pressure Points

  Pressure Points are created in the body when lying on a mattress which is not suitable for a persons physique. The Pressure Points are caused by putting stresses through the body. When the spine is not aligned correctly (i.e, straight), it can cause pressure to build up in the back, hips or shoulders (etc).
  
  When a bed is too soft, the body sinks in, causing certain areas to be under the strain of the rest of the body. When a mattress is too hard/firm, then the weight applied can cause the body to flex/bend in the opposite way - causing a similar problem. Hips, shoulders and so on, are requried to be sunken into the mattress slightly more than the surrounding areas, as they carry the weight. When this is not the case, the lower back may be bent to compensate. The ideal mattress is one which will keep the spine straight.

• Turn / No Turn

  Some mattresses require turning over, to aid even settlement. Others do not require turning, but will still require rotating.

• Zoning The idea behind Zoning is to offer support where it is needed. The body has certain areas under pressure when lying flat. Zones are designed to split the mattress into sections and offer some areas more support than others. The end result will be a straight spine and pressure relieved. Some mattresses are split into 3 Zones, some into 5 Zones and some into 7 Zones and so on. The principle areas requiring support (and therefore their own individual Zones) are the head, shoulders, hips and feet.  The spine should remain level as much as possible when lying on a mattress, therefore the areas with the most weight applied should be slightly firmer to allow for the extra loading. At the same time, the surrounding areas need to compensate for this and will not be as firm to allow the spine to remain straight. The Zoning may be created by simply adding more layers of fibres where needed, or a different type of spring in certain areas. In latex or foam mattresses, it is possible to vary the density of the foam or latex to create different tensions where required. Latex mattresses can also be sculpted in certain areas to remove latex and therefore make certain areas softer.