Lets talk about latex.
Latex used to be made primarily by two methods, Dunlop or Talalay. The difference lies in the process by which the liquid latex is transformed to a solid; different processes result in different feels.
Traditional molded Dunlop vulcanizes the latex in molds until the foam becomes solid. Talalay has a more extensive (and more resource intensive) process of vacuum sealing, flash freezing and then baking its molds. The attributes of each process are reliably consistent, yet produce different feeling latex foams. Dunlop molded latex foam is known for its solid support, with the least variation in firmness. The Talalay mold results in a latex foam that is considered to be a “bouncier” latex that is less dense, or more flexible, with a greater variation in softness and hardness.
A third process came along in the 1980s called Dunlop Continuous Pour. That’s what we use for all our Spindle mattresses and it’s manufactured in Pennsylvania by Mountain Top Foam. This latex is what we call an “in-betweener” latex foam, with a feel somewhere between Dunlop and Talalay, but leaning slightly more in the molded Dunlop direction.
"100%" Natural Latex
Our latex is what is referred to as 100% natural. Latex is only natural in a liquid state. Liquid latex is the tapped sap of the hevea brasiliensis rubber tree, much like maple sap is tapped from a maple tree. The finished/manufactured foam rubber we use is natural liquid latex mixed with a proprietary formula of zinc oxide, fatty acid soaps, sulfur, sodium and other compounds that are essential for the vulcanization, foaming, and curing process. This added formula is the only way to turn the pure liquid into foam. All 100% natural latex is made this way — 95% of the final foam is pure liquid latex, while 5% of the final latex foam is the curing package. The curing package is made of the same ingredients across the board, but what varies are the exact proportions of each ingredient from manufacturer to manufacturer.
After it is cooked (vulcanized) the finished natural latex foam core is then washed a minimum of three times to remove all residuals and proteins that may be left over after curing. In the end, it is the most pure, natural latex available; free of any man made synthetic latex. Please note that all “100% Natural Latex” on the market is made this way. Even certified organic latex is produced in this fashion.
The raw liquid latex is sourced globally because the hevea brasiliensis, rubber tree, is not found in the US. It is typically brought in from Guatemala and occasionally from India. The latex is certified to Oeko-Tex 100 – Class I, which is the most stringent standard. The certificate — available here as a PDF — can be verified by entering the certification number 16.HUS.00338 on the Oeko-Tex website.
ILD + Density
|ILD @ 25%||ILD @ 40%||Density [kg/m3]||Density [lb/ft3]|
|Medium Latex||17.5 – 20.5||27 – 33||73||4.6|
|Firm Latex||29.5 – 32.5||44 – 54||90||5.6|