A Brief History of Latex Rubber:
Latex is a natural product derived from a tree. The first rubber trees
came from Brazil, Hevea Brasiliensis, but that country no longer plays any significant role in the world natural rubber trade. Seeds were
exported to the United Kingdom in 1876.
The seeds were germinated later that year. From there seedlings were exported to Sri Lanka. In 1877, seedlings were sent from Sri Lanka to
Singapore, where they multiplied and techniques of tapping were developed. Prior to this, the trees had to be felled before the latex
could be extracted.
By the early 1900s, most of the techniques and agricultural practices required to establish large plantations had been developed. One key
technique was bud grafting. This is essentially a cloning technique which ensures that genetically identical trees can be produced in
Over the next 40 years or so, the British in Malaysia and the Dutch in Indonesia cleared large areas of rainforest to create rubber
plantations. Simultaneously, local farmers saw the opportunities of rubber cultivation, and planted small groves of trees to supplement
their own income. This gave rise to two types of rubber plantations in most producing countries: the estates/plantations and the small
holdings. Small holdings tend to produce solid rubber while estates are essentially large-scale farms, with professional management. Most
latex comes from professionally managed estates. Today most all latex comes from Thailand, Indonesia, Malaysia and Sri Lanka which are all
located in South-east Asia.
Latex is NOT made from Sap:
A common misconception is that latex comes from the sap of the tree; however, this is not so. Sap runs
deeper inside the tree. Latex runs in ducts which are in a layer immediately below the bark of the tree above the cambium, the layer were
the sap resides and all tree growth takes place. Tapping these ducts requires some skill. If the cambium is cut, then the tree is damaged.
Too much damage to the cambium, and the tree stops growing and stops producing latex.
Methods of Latex Rubber Tapping:
All natural rubber originates in the Hevea tree, and it starts its journey when the tree is tapped.
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 leaves 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 stabilising 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 finishes at in the early afternoon.
Processing of Latex:
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, it is usually referred to as either TSR (technically specified rubber) or sheet rubber.
When latex is required—which covers about 10 percent of all natural rubber produced—the material is gathered on the tapper's return journey,
poured into containers and delivered to a processing station where it is strained and concentrated. At no stage in the process is the latex
heated. This means most of the proteins remain in the latex. More stabiliser is added and the latex goes into a centrifuge to remove some of
the water, and increase the rubber content of the latex. After centrifuging, the material is known as latex concentrate, and contains
roughly 60 percent solid rubber and 40 percent other stuff (water, proteins etc.). This (latex concentrate) is what is used in the dipping
process when making gloves, finger cots, latex sheaths and of course our latex leg bags.
Latex does have a distinct odor which varies from batch to batch. At times, usually during the hot summer months, this
odor can become strong. Urocare has listened to requests to reduce or eliminate this odor. Since this odor can not be entirely eliminated
at present, Urocare is developing and testing latex bags that are scented which greatly reduces the odor to minimal levels that are virtually
undetectable leaving behind only a mild fresch scent. If this process is successful, it may be applied to all our latex products. As we
progress with our prototype testing phase.
As testing comes to a close it appears that the scented latex will become a permanent part of Uroare's latex products line. We expect that
testing will be completed by mid year 2014. As futher developments become available they will be posted here.