• Latex
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    Latex can be used to make mattresses and pillows. Raw materials' transformation usually occurs in Asia. Institutes are in charge of controlling the raw materials' origins and their 100% natural latex certification.

    Latex is an elastic material, either made from the hevea tree's natural latex or artificially synthetized by polymerization. It's harvested by undercutting the hevea tree's truck. Latex can also be found in banana trees and other plants, but only the hevea tree's bears the industrial qualities needed for mattresses. Using a special knife, cutters periodically bleed the trunk by cutting a small incision going down a half or a third of the way around its circonference. It usually begins at 1,5 meters high, while the trees are about 50cm in circonference. Each bloodletting cuts about 2mm deep on the old incision, as deep as the bark, but shallow enough in order not to damage the cambium (where the timber is generated), because that would leave scars. Some systems are more or less intensive, going from every two or three days to weekly undercuts, while the more common system is to cut every two days.

    When one whole side of the bark has been used, they switch to the other side. This usually happens after 6 years. When all the lower side has been used, they start practising a higher undercut, going upwards. This one, albeit more delicate, is very productive. It is practised in quarter spirals and can last at least 4 years. After that, it will be possible to start over again on the lower side, which in the meantime will be regenerated. This way, the tree can start producing latex by the age of 5 years, and will produce for around 30 years. In many regions, especially in Thailand (the number one latex producer), the cycles tend to be shortened, for less than 20 years.

    Latex, while exiting the incision, oozes into a cup during a few hours. It then coagulates, thus closing the wound and stopping the dripping. It can be harvested in a liquid form (we call this a latex harvest) if we proceed right after the undercut, or in a solid form (called coagulum) if we leave the latex to coagulate in the cup. If harvesting in a liquid form, we may add a bit of ammonia to preventit from coagulating too soon. The post-harvest transformation process calls to add a bit of acid (generally formic acid) to coagulate the latex.

    By the end of its exploitation cycle, the hevea tree is cut down in order to be replanted. Research progress in this field has allowed to replant much more performant trees.