all began with Brazil, the country that gave rubber to the world
The country which introduced rubber to the world was Brazil,
and that tree is called Hevea Brasiliensis. Unfortunately,
longer plays any significant part in the world as far as natural
rubber trade is concerned. Everything began with the export of
Seeds, from the lower Amazon area of Brazil to London UK
by Henry Wickham, a local planter acting for the British
Government in 1876.
These seeds were germinated at the Tropical Herbarium in
Kew Gardens, London later that year. From there seedlings
were exported to present Sri Lanka. In 1877, 22 seedlings
were sent from Ceylon to Singapore, where they grew strongly,
and the technique of tapping was developed. Prior to this, the trees
had to be felled before the latex could be extracted.
During early years of 20th Century, most of the techniques
and practices, which were required to establish large plantations
had been developed. Bud grafting, that is essentially a cloning
technique which ensures that genetically identical trees can be
produced in unlimited numbers, became one of the key techniques
in rubber plantation. 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. Opportunities
of rubber cultivation, seem very bright and as a result, local farmers
planted small groves of trees to supplement their own income.
Gradually two types of rubber plantations came into existence
in most of the producing countries : the estate plantations and
the smallholdings. Smallholdings tend to produce solid rubber
while estates are essentially large-scale farms, with professional
management. Most latex comes from professionally managed
Though latex is often described as the sap of the Hevea
tree, but in reality it is not made from sap latex. Sap is a liquid
that 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.
All natural rubber originates in the Hevea tree, and it
starts its journey when the tree is tapped, which are rarely tapped
more often than once every two days. The procedure of tapping begin
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 which are made on the trees must be neither too
deep, nor too thick. In either cases it will reduce the productive
life of the tree. From these cuts, starts the latex flowing, and
the tapper leaves, which flow to 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.' In case
of making latex, the tapper must add a stabilizing agent to the
cup. Usually ammonia is used, 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.
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, TSR, or sometimes sheet rubber. When latex
is required--which covers about 10 percent of all NR 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.