Every year, during the wintering period, the leaves of the rubber trees die and fall off, changing the landscape of the plantation before new leaves are formed again.
Natural rubber comes from the rubber tree
Natural rubber is the result of the coagulation of the latex from the rubber tree. Deriving from laticiferous vessels present in the bark of the tree, natural rubber is a product containing no solvents or chemical additives. It is also a renewable raw material: the latex is carefully harvested to avoid depleting or damaging the tree.
Where does rubber grow?
Rubber is native to South America. Its cultivation has spread to Southeast Asia and, to a lesser extent, West and Central Africa.
The rubber tree’s qualities
Rubber trees are a significant carbon sink. A rubber plantation resembles a forest – rubber is a reforestation species.
The timber is useful, being used to make pulp and furniture, for marquetry or as firewood.
Since the mid-twentieth century, all plantations have consisted of grafted clones and selected plant material.
Rootstocks are raised in nurseries for six months before receiving a graft. These small rubber trees are then transplanted into the field, with a density of about 500 to 550 trees per hectare. After six years, they reach physiological maturity and the vegetative stage that allows tapping (incision of the bark) to begin. The rubber tree has a life cycle of about 30 years.
The harvesting begins with a fine incision – to avoid damaging the tree – in the bark, allowing the latex to flow into cups placed below the tappin notch.
The most common tapping frequency is every four days.
The rubber can be harvested in the liquid state (latex) or after coagulation in the field (cup lump). It is then taken to the factory.
Simple and durable processing
At the factory, the cup lumps are cured in the bunkers for several days before being processed. This raw material is then blended, washed several times, granulated, dried and pressed into standard 35 kg bales. Strict compliance with quality standards throughout the production chain ensures achievement of the required specifications. The finished product is then labelled ‘Technical Specified Rubber’ (TSR). The rubber is shipped to customers (often tyre producers) by container.
Green energy supply
There are numerous solutions for powering the rubber factories with green and sustainable energy: the rubber dryers can be fueled with rubber wood from old depleted trees. The electricity can be supplied by solar, wind or hydro power installations.
Natural rubber is prized for its physical properties:
- its low thermal conductivity
- its very high elasticity
- its impact resistance
- its vibration and noise damping qualities.
Rubber: a raw material used in many domestic and medical items
|Origin||Annual global consumption||Products|
|Synthetic rubber||Derived from natural gas and petroleum by-products||58% of annual global consumption||Tyres, manufactured articles, elastic thread, carpets, surgical protection products, condoms, etc.|
|Natural rubber||Extracted from rubber bark||42% of annual global consumption||Tyres, manufactured articles, elastic thread, carpets, surgical protection products, condoms, glue etc.|