If the specific gravity has a value of greater than one, then the object sinks in water and if it is less than one, then the object floats in water. If the specific gravity has a value equal to one, then the object will neither sink nor float. The specific gravity is a very important factor in different industries.
On average, your mattress should last anywhere between 8 to 10 years. However, there are a lot of elements that can increase or decrease the longevity of your mattress. Your mattress is an investment â the better you take care of it and the more money you put into it will increase the longevity of your mattress.
The main indicator of how well a piece of foam will hold up over time is the density of the foam. If you have a mattress with a 3 lb. density memory foam layer on top, that will not last as long as one with a 5 lb. density memory foam layer on top. Memory foam mattresses can last two years or they can last 15 years. Memory foam mattress just have memory foam in the comfort layer and then there is poly foam or springs in the support layer. So, the longevity of the mattress depends on more than the density of the memory foam.