Memory foam is called "shape memory foam" not because it retains the shape of your body, but because it takes its own when the pressure is released. Unlike the polyurethane foam, memory foam exerts no pressure on members of sleeper. "Invented by NASA," we read in advertisements. Know that the U.S. space agency has not developed this material to the beds of astronauts, but rather to provide them with comfortable seating for takeoff.
Foam shape memory finally found his way to bedding throughout the medical field. Thanks to its ability to eliminate pressure points, it is a very effective and relatively inexpensive to prevent bedsores (compared to other types of hospital beds). This foam is nothing miraculous and appeal to some people as it displease others.
This material is not hotter than polyurethane foam, but as body mold more closely, it hinders further air circulation, which can cause a feeling of warmth. To correct this problem, some manufacturers have developed a viscoelastic foam with open cells.
The memory foam is temperature sensitive form, this means that it will react to the heat. It is sensitive to heat the room, but also the warmth of your body. Care must be taken to maintain a constant temperature of about 20 ° C in the room not to lie on a concrete block. Similarly, this mattress is wrapped especially for people who have hot or sweaty at night, memory foam shape will take the shape of your body, you wrap and therefore retain heat. If you tend to sweat, then the shape memory is not for you.
The memory foam shape is undoubtedly the type of suspension that offers the best support and therefore may be useful for people with back problems and in addition it reduces the need to move. This technology provides a great sleeping comfort as the muscles relax which allows the body to relax more easily, you could say that you are in a feeling of weightlessness and well-being.
Pros and cons :
+ shape fits exactly to the body, which limits the pressure, especially at the joints. They limit the pressure on the spine, allowing muscles to relax completely posture. This can be useful in the treatment of some pain. In paralytic or handicapped, they can reduce the risk of bedsores.
+ grime and dead skin particles can not penetrate into the mattress, less risk of allergies.
A mattress with a spring suspension generally has excellent resilience (the ability of a material to return to its original position) and provides a firm support and a maximum ventilation. A good spring suspension must sink but also to resist pressure. The response of spring to weight should be gradual. For spring mattresses, insulation must be placed between the suspension springs and tray packing. This insulation is a guarantee of quality spring mattress well built and provides a level of comfort to the sleeper will not feel the springs. The springs must also be fixed together to form the suspension: different systems are put in place by the brands to ensure the link between the springs as in Tréca offering a bonding system of springs between them.
The springs are manufactured using automated machinery. By means of an electric current, the machine heats the wire to make it malleable. The son then twisted hourglass shaped. Corkscrew finish prevents the wire to penetrate the mattress. From there everything takes on the nature of the spring (bonnel, biconical, multiturn, bagged) height and number of coils, the diameter and quality of the steel, the number of turns of the springs, how to place and secure the fairing, the more layers of upholstery, padding and nobility (also applies to HR foam and latex).
Compare densities provides no information to latex mattresses as density equal firmness, support is not the same because each brand has its manufacturing process. Buy without trying really dangerous! The mattress core (plate latex) crashing to fit the shape of your body surface and the same soul provides good support being compressed in depth. The role of host layers is less important for the position of the back, with the springs. This material is more accurate than the spring and closer to the body.
Aim for 16 or 18cm latex block (14cm is the minimum block compressing under the weight, the thicker it is less likely you are to feel the slats). A block of 16 cm should be finished between 17cm and 21cm maximum height, natural latex is flexible enough to not need foam comfort 40 mm, just control materials (cotton wool, silk, etc.).. The minimum for a latex that is 14 cm in 3 areas, a correct product is 16cm in 5 areas. Flexible as latex must be elastic and double-sided wear more evenly. The more one is heavier and should choose a thick block. The more one is "older", more should be natural latex with age because our body needs soft.
Starting at 35 kg/m3, these foams are called foam "High Resilience" (HR), their elasticity and comfort are superior.
Polyurethane foam can be manufactured according to the technique of continuous cutting or molding individual.
• 20 kg / m³ to 25 kg / m³: polyether foam
• 25 kg / m³ to 35 kg / m³: polyurethane foam
• 35 kg / m³ to 60 kg / m³: Polyurethane Foam High Resilience (HR)