High density foam is a very firm foam that generally makes up the bottom layer of popular memory foam mattresses. Other types of mattresses such as innerspring or hybrid may also use high density foam to support the spring systems.
High density foams generally are not used to create the entire mattress because they are just too firm. So, generally they are used as a foundation for the bed or to provide edge support.
High density foam is made of a blend of polyurethane and has a tendency to off-gas. If you are susceptible to lung issues, please do additional research on the quality of foams before purchasing.
Pros: Structural firm foam used by many mattresses to provide foundation and shape.
Cons: Off-gassing problems with lower quality foams and it is too firm to make a mattress in its entirety.
Overall Score: 8.9/10
General Support: 9.3/10
Price Value: 9.4/10
High density foam is a polymer created during a chemical reaction between polyol and diisocyanate (two chemicals created from organic compounds). The ratio of polyol to diisocyanate is 2:1 to form polyurethane, though there may be other compounds that are added to create just the right amount of density for each piece of foam. The foam is synthesized, poured into molds, and cooled before cutting into mattress layers.
High density foam is generally used as the base layer of popular memory foam mattresses and some innerspring models.