Memory Foam is a type of modified Visco-Elastic Polyurethane Foam used commonly in Mattresses, Toppers, and Pillows. Denser, and more viscous than most foam, Memory Foam is known for its 'bounce back' nature and ability to mould to the sleepers position, returning to the original position after use.
Memory foam is favoured for its luxurious feel, exceptional support, and moulding properties, and is a popular filling for mattresses and bedding.
Famously developed in the 1960s by space company NASA, memory foam was originally invented to improve the safety of aircraft cushions, and physical health of astronauts on long missions. It was originally named "Slow Spring Back Foam" and "Temper Foam", and years after the project went underway, the foam was commercialised, and used in a range of products, from bedding, to sporting and medical equipment.
One of Memory foam's first domestic use was in hospital beds for long-term patients laying immobile in one postion- Memory Foam Mattresses were used to increase blood flow and to reduce pressure build up.
The first memory foam mattress, the "Tempur-Pedic Swedish Mattress" was released in 1991, was the first product from Tempur World- the company who worked with NASA to produce the foam.
The structure of Memory Foam varies, from open to closed cell. The tighter the cell, the less airflow through the cell and vice versa, meaning foam with a more open cell structure will be more breathable, and allow for better airflow and quicker recovery.
The cell structure is separate to density or firmness.
Memory Foam Mattresses
Memory Foam is popular for use in Mattresses, and is ideal for a more supportive and luxurious alternative to traditional mattresses.
The most common Memory Foam Mattress is a combination of Memory Foam and Reflex Foam. The Memory Foam will make the all-important top layer to mould to the body, whilst the lower layers of Reflex Foam will support the whole body's weight, and provide a better structure to the mattress.
Some Mattresses offer a combination of Springs and Memory Foam, such as the Snuggle Ortho Memory 2000. These mattresses are often of a higher quality, as they offer the dual support of both the [Springs] and memory foam.
Memory foam can be beneficial for those suffering with various health ailments, ranging from Arthritis, to joint and tendon problems, and poor circulation. This is because the foam moulds to the body, evenly distributing weight, reduces pressure points and promotes blood flow. The supportive nature of the foam also keeps the body warm and supported, ideal for relaxing and warming muscles, and reducing tension build up.
Memory Foam Mattresses are generally more supportive, heavier and more expensive than traditional spring mattresses.
In Mattress production, the softest filling will always be on top- for this reason, the layer of memory foam will usually be on top, whether for a foam, spring, or combination mattress. The means that most Memory Foam mattresses will be one sided (no-flip), and will need seasonal rotating only.
CharCOOL is a Memory Foam based technology developed by Snuggle Beds, designed to combat the common problem of memory foam heating up whilst being slept on. Infused with Bamboo Charcoal, this alters the humidity of the air by absorbing moisture and keeping airflow throughout the foam mattress regular.
The density of a memory foam mattress is a measurement of the weight of the memory foam, in relation to the size. Standard density can range from 40-85 kg/m, with the highest density being 85kg/m produced by Tempur. Mattresses of a density this high will commonly retail for over £1000.
The density of a memory foam mattress will be measuring the top layer of memory foam- this is the part of the mattress that is most expensive to manufacture, and the part than makes the difference when it comes to comfort and support.
The higher the density, the more air cavities are in the foam. The higher the density, the smaller, and more tightly packed the air cavities in the foam will be together.
Generally speaking, it is considered best to buy the densest mattress you can afford however; keep in mind that not everyone will benefit from a highly dense mattress. Different people will need different densities; heavier people benefit more from a firm mattress, whereas lighter people may find it of no real difference or benefit. Higher density mattresses generally mean higher quality, and longer lifespan.
Density in Memory Foam mattresses is measured by the ILD (Indentation Load Deflection). This is a measurement of the amount of pressure needed to indent 4" of foam by 25%. The higher the ILD the firmer the foam; the lower the ILD, the softer.
Memory Foam is used in a range of products, ranging from Hospital Beds, Football Helmets, Wheelchair Pads, Pillows and Cushions, Furnishings and Mattresses.