7/31/2019 Latex Turned Into Rubber Sheet

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Tapping 2 To harvest latex, a worker shaves off a slanted strip of bark halfway around the tree and about one

third in (0.84 cm) deep. Precise skill is required for if the tree is cut too deeply, the tree will be

irreparably damaged. If the cut is too shallow, the maximum amount of latex will not flow. The latex

then bleeds out of the severed vessels, flows down along the cut until it reaches a spout, and finally

drops into a collection cup that will later be drained. 3 Tapping is repeated every other day by making thin shavings just below the previous cut. When the

last scar created by the cuts is about 1 ft (0.3 m) above the ground, the other side of the tree is tapped in

similar fashion, while the first side renews itself. Each tapping takes about three hours and produces

less than a cup of latex.

4 A tapper first collects the cut lump, which is coagulated latex in the cup, and tree lace, which is latexcoagulated along the old cut. Next, the tapper makes a new cut. The latex first flows rapidly, then

declines to a steady rate for a few hours, after which it slows again. By the next day, the flow hasnearly stopped as the severed vessel becomes plugged by coagulated latex.

5 To prevent most of the liquid latex from coagulating before it can be conveniently pooled andtransported, the tapper adds a preservative such as ammonia or formaldehyde to the collection cup.

Both the liquid and coagulated latex is sent to factories for processing.

6 To increase tree yields and reduce tapping times, chemical stimulants are used. Puncture tapping, inwhich the bark is quickly pierced with sharp needles, is another method that can improve productivity,

since it enables the same worker to tap more trees per day.

Producing liquid concentrate 7 About 10% of the latex is processed into a liquid concentrate by removing some of the water and

increasing the rubber content to 60%. This is achieved either by spinning the water out of the latex

through centrifugal force, by evaporation, or by a method known as creaming. In this method, a

chemical agent is added to the latex that causes the rubber particles to swell and rise to the liquid's

surface. The concentrate is shipped in liquid form to factories, where it is used for coatings, adhesives,and other applications.

Producing dry stock 8 Other rubber and field latex is coagulated with acid. A giant extrusion dryer that can produce up to

4,000 lbs (1,816 kg) per hour removes the water, creating a crumb-like material. The dried rubber is

then compacted into bales and crated for shipment.

Forming sheets 9 Ribbed smoked sheets are made by first diluting the latex and adding acid. The acid makes rubber

particles bunch together above the watery serum in which they are suspended. After several hours,

roughly one pound (0.45 kg) of soft, gelatinous rubber coagulates for every three pounds (1.35 kg) oflatex.

10 The rubber is allowed to stand for one to 18 hours, then the slabs are pressed into thin sheetsthrough a system of rollers that wrings out excess liquid. The final set of rollers leaves a ribbed pattern

on the sheets that increases the surface area and hastens drying. The sheets are dried for up to a week in

smoke houses before being packed and shipped.