Hi jdeck66,
I don’t know exactly no but most of the Polyfoam and memory foam manufacturers (although not all of them including Tempurpedic which makes their own memory foam and a few others) are listed on the CertiPur site here* along with some that aren’t American. US manufacturers that make latex of one kind or another in the US are Latex International (Talalay), Latexco (continuous pour Dunlop), and Mountaintop Foam (continuous pour Dunlop). The major brands (including Serta and Simmons and Sealy) don’t make their own foam (either polyfoam, memory foam, or latex foam) and buy it from one of the foam manufacturers.
ADMIN NOTE: *Removed 404 link|Archived Footprint: certipur.us/pages/for-industry/find-a-foam-supplier/
I would keep in mind that there are several types of foam (latex foam, polyfoam, memory foam) and all of them are very different so a “full foam” mattress can use some very different materials and of course there are tens of thousands of designs and many differences between them in terms of the quality and durability of the foam. Serta manufactures their own mattresses … not their own foam.
The first place to start your mattress research is the tutorial post here which has all the basic information, steps, and guidelines that can help you make the best choices … and learn how to avoid the worst ones (including Serta and the other major brands).
“Hybrid” doesn’t really have any specific meaning outside of the fact that it would use different types of materials in the same mattress. For example a mattress that used latex comfort layers and a polyfoam core would often be called a “latex/polyfoam hybrid”. A memory foam mattress usually uses memory foam in the top layers and polyfoam in the support core so it would be a “memory foam/polyfoam hybrid” but they are usually just called a memory foam mattress. A mattress that used a memory foam comfort layer and an innerspring support core would be a memory foam/innerspring hybrid. Even most “traditional” innerspring mattresses are really a hybrid and use polyfoam in the comfort layers and an innerspring as the support core so these would also be a polyfoam/innerspring hybrid although they are normally just called an “innerspring” mattress and don’t specify the material in the comfort layers (just like memory foam mattresses don’t specify the material in the support layers). There are also yybrid mattresses that use comfort layers with more than one type of material (such as a mix of polyfoam and memory foam or latex) so these could also be called a “hybrid” mattress regardless of what type of support core they have (generally an innerspring of some kind, latex, or polyfoam).
It’s usually more effective to focus on the specific materials rather than more generic names such as “hybrid” which could be used to describe almost any mattress that uses more than one type of material (which is most of the mattresses on the market).
Phoenix