Foam mattresses are seen as bad. However, nowadays there is a great variety that differences them because of the way they are made. It depends on the quality of the materials, of their properties, and of the manufacturing process to know if the mattress will work or not. The hardness of the foams is measured depending on its density. For example, a foam mattress made of polyurethane with a density of 40 kg/m3 will be hard as a rock, while a latex one with a density of 65 kg/m3 will be soft and lovely at touch.
Types of foam mattresses:
1) Polyurethane foams, composed by polymerics, last more and have more firmness than the old ones.
It is a synthetic material, soft and resistant, that conserve better its original form. Its quality and duration are proportional to its price. For a good result, it must have a minimum density of 25 kg/m3. The problem they have is that they do not regulate very well the temperature and that they lose firmness with use.
2) Cutting-edge foams.
They do not have a defined name and each manufacturer sale those with a proper name like Bultex, for upmarket product of Pikolin or Aivex, upmarket product of Flex. They are more hygienic, they allow a better transpiration than other synthetic materials and have a greater elasticity, but they are much more expensive and, even if they have improved its resistance to subsidence, they don’t reach the firmness of a sprung mattress.
Its manufacturing process is different from the rest of the foams and mucho more flexible, which gives greater support surface. It is a good option for those who want to sleep on a soft mattress or for those who like to sleep on a soft mattress and are a bit overweight.