3RUBBER

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Unformatted text preview: contains little channels called lactiferous vessels because they contain latex. This layer is next to the cambium. Knife used to make long diagonal Knife used to make long diagonal grooves in the trees to collect latex milk. A rubber tree just after TAPPING, the latex flowing through the A rubber tree just after TAPPING, the latex flowing through the tapping channel will be collected in the coconut shell or similar collection vessel. Heavea with cup lump. Drying Drying rubber Drying Rubber Drying Rubber Latex Is Not Made From Sap Latex Is Not Made From Sap Latex is often described as the sap of the Hevea tree. This is not an accurate description. The sap runs deeper inside the tree, beneath the cambium. Latex runs in the latex ducts which are in a layer immediately outside the cambium. This highlights the skill of the tapper. If the cambium is cut, then the tree is damaged, because the cambium is where all the growth takes place. Too much damage to the cambium, and the tree stops growing and stops making latex. Methods Of Latex Rubber Tapping All natural rubber originates in the Hevea All natural rubber originates in the tree, and it starts its journey when the tree is tapped. Trees are rarely tapped more often than once every two days. A tapper starts the trek around the plantation before dawn. At each tree a sharp knife is used to shave off the thinnest possible layer from the intact section of bark. The cut must be neither too deep, nor too thick. Either will reduce the productive life of the tree. This starts the latex flowing, and the tapper This starts the latex flowing, and the tapper leaves a little cup underneath the cut. In ordinary circumstances, this latex will normally coagulate into a lump in the bottom of the cup, called 'cup lump.' If the plantation manager wants to make latex, then the tapper must add a stabilizing agent to the cup. Usually this is ammonia, which prevents the latex from coagulating. The tapper returns a few hours later and collects the stuff in the cup ­­ either cup lump or latex. The double round trip usually Processing Of Latex ­ Cup Lump or Processing Of Latex ­ Cup Lump or Liquid Concentrate If solid rubber is required, the cup lump, together with tree lace (the remnants of the latex flow from the cut down to the cup) and other bits and pieces are collected together and processed. That processing involves quite a lot of heat, which destroys many (but not necessarily all) of the proteins. It ends up as solid rubber. Depending on the method of processing and the final purity of the material, the industry refers to it either as technically specified rubber, or sometimes sheet rubber. When latex is required­­which covers about 10 % of all When latex is required­­which covers about 10 % of all natural rubber produced­­the material is g...
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This document was uploaded on 03/10/2014 for the course AGRO 1001 at LSU.

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