How to Buy Memory Foam Pillow or What You Need to Know
Have you noticed that some memory foam rebounds quickly, while others rebound slowly? Some are very hard, and some are very soft.
Memory foam is indeed a black technology discovered by American aerospace astronauts. It has a rebounding effect.
Memory foam and regular sponge are the same thing, both are the result of polyurethane foaming.
The ones that rebound quickly have larger gaps during the foaming process. The ones that rebound slowly have smaller gaps. The hard ones are made with the old technology, temperature-sensitive memory foam. It gets very hard when the temperature is low.
However, nowadays they are all non-temperature-sensitive memory foams, which are less affected by temperature. Memory foam cannot be washed with water. It has strong water absorption, once it absorbs water it can't get out. Getting into water will make it turn yellow, moldy, and hard. Definitely do not use a dryer, hair dryer, and do not expose it to the sun. Doing this causes the polyurethane to break down.
Advantages: quiet, slow rebound. People prone to stiff necks and cervical spondylosis should not use it. Action and reaction are equal. There is a kind of pushing force.
