A natural rubber mattress, also known as a natural latex mattress, is made by extracting latex sap and then baking it, where it turns into rubber.
Natural latex is harvested from the rubber tree, also known as Hevea brasiliensis, which grow in regions near the equator.
An angled incision about three feet long is made on the tree allowing the milky latex sap to drain out. The latex is collected by hand as it flows out of the tree. The harvesters rig buckets up to collect the latex as it drains out.
This will happen for about an hour and as the tree heals itself the incision will close up and the latex will stop flowing. The collection of the latex does not kill the tree, allowing for repeated harvesting year after year. This makes latex a sustainable resource that can be harvested indefinitely.
The collected latex is then poured into a large vat and filtered to remove any small particles. At this stage it is approximatley two thirds water, yet still very thick.
The milky latex is turned into solid rubber by a process called vulcanization. The raw serum is poured into large moulds and then baked becoming the solid yet slightly flexible material we know as rubber.
So latex is the raw material, rubber is the finished product. However mattresses are commonly referred to as either latex or rubber.
After being vulcanized the rubber is washed with clean water only. It is then passed through a heavy roller in order to squeeze all the water out.
Every natural rubber mattress needs a binding agent to hold the cells of the mattress together. Without the binding agent the mattress would not be able to hold its shape and would end up as a big blob.
When a merchant advertises a 100% natural rubber mattress they don't mean that the mattress is made out of nothing else but rubber. They mean that the rubber component - between 95% and 99% of the mattress - is 100% natural, with no synthetic blends.
However the issue of the binding agent is negligible compared to the amount of toxic material in a standard polyester mattress or one made from synthetic latex.
Despite the binding agent it is still an all natural latex mattress with 100% natural latex and 0% synthetic. The phrase "100% natural" refers to the fact that there is no synthetic rubber blended into the mixture.
There are two different methods of vulcanizing natural latex and turning it into a natural rubber mattress. These are the Dunlop and the Talalay methods. The oldest method is known as the Dunlop method. When the raw latex is collected and filtered it is whipped in a centrifuge and then poured into mould. During the baking of the mould the sediments in the serum naturally settle at the bottom. This means the bottom of the mattress is slightly firmer than the top.
The Talalay method adds an extra step. After the serum has been poured into the mould it is flash frozen. This traps any air bubbles and sediment at a consistent distribution throughout the product. The latex is then baked and turned into rubber without sediment settling on the bottom.
Dunlop is quicker and less expensive to make than Talalay. The Talalay process is more effective at transferring heat evenly across the mattress when it is baked so there is more consistency in the firmness, resulting in a comfortable springy feel.
Talalay is widely regarded as the premium method for the highest quality natural rubber mattress. Many people claim that it is the best natural latex and makes the best latex mattress.
However others argue that when it comes to a natural latex mattress Talalay and Dunlop are neither better nor worse than each other.
I agree that Talalay is the superior choice. A natural Talalay latex mattress is slightly softer with a bit more give, while a Dunlop one is slightly firmer. The extra softness and give of Talalay is what makes it first choice for most people.
Having said that every person is unique and responds differently to different things. Nobody can claim to say that Talalay latex will be better for every person in every case. Some people are always going to prefer Dunlop.
Yet a high quality natural rubber or natural latex mattress will be luxurious regardless of whether it is Talalay or Dunlop.