Natural rubber is the one that is extracted from the latex produced by certain plants, commonly known as rubber trees. Its processing has been carried out for centuries, and it is an ecological process, so much so that even today rubber is considered a 100% ecological material, being the only natural rubber on the market.
What is rubber?
Rubber derives from the processing of latex, which is obtained by sectioning the bark of a typical Amazon tree, the Hevea brasiliensis. It is an elastomer, that is, a polymeric material of natural or synthetic origin that is characterized by its great elasticity. This last quality consists of the ability to significantly deform when an external force is applied and return to its original shape.
Currently, much of the use of natural rubber has been replaced by synthetic rubbers, produced through industrial processes that allow products to be manufactured with the same performance, but at a much lower cost.
History of natural rubber
Production was, for years, the only prerogative of the Amazon basin, source of so much wealth, and this was one of the reasons why many Europeans speculated with Brazilian plantations.
Natural rubber was already known in Europe in the mid-19th century, but it only came from plantations in South America. Plantations were not started until the 20th century also in Southeast Asia, where the humid climate was favourable.
The invention of vulcanization, which is usually attributed to the American Charles Goodyear and dates to 1844, helped spread its use. In fact, latex is unusable without this process because:
- It is sticky when exposed to the sun and breaks down at high temperatures.
- It is very brittle at low temperatures.
- Turns brown and coagulates when stored in air.
Thus, until a few decades ago, it was the only rubbery and elastic material on the market.
Liquid rubber processing
After harvesting, the liquid rubber is filtered, diluted with water and mixed with a series of substances to improve mechanical and abrasion resistance, in particular carbon black (which is why the colour of rubber products is usually black) . If black colour is to be avoided, white additives such as precipitated silica, clay or precipitated gypsum are used.
These chemical treatments modify its structure, making it resistant and elastic, since it is initially a material that is very sensitive both to changes in temperature and to light:
- Softens with heat.
- Hardens in the cold.
- Colour changes when exposed to direct light.
To stabilize natural rubber and make it more resistant, a process called sulphur vulcanization is carried out, a process introduced in 1840 and that we use in the manufacture of our rubber ferrules.
The processing costs of natural rubber are high, which is why, over the years, the consumer products industry has increasingly chosen to use synthetic rubber as an environmentally friendly substitute for natural rubber.
However, we must not forget that synthetic rubbers are made from petroleum and are not environmentally friendly. In contrast, rubber is a completely biodegradable natural material at the end of its life cycle.
Natural latex is itself biodegradable and safe for the environment, but the substances it is treated with, such as ammonia, tetramethyl disulphide and zinc oxide, as a preservative against bacterial spoilage, make it difficult to recycle.
In fact, wastewater treatment plant operators report that latex is one of many harmful materials that are not affected by the biological treatment system.
Therefore, the resulting products are difficult to recycle. Now, no technique has been found to reuse it while preserving all its qualities. However, it can be used to make fewer elastic products with lower purity requirements. For example, flexible end caps made from recycled bitumen are more flexible at low temperatures and more resistant at high temperatures than normal bitumen.
In addition, it can also be used as fuel in cement factories and in some thermal power plants, and the “powder” made from recycled rubber granules. Among which the tires used, are applied to improve the appearance, flexibility, and stability of artificial grass sports fields.
At FORTAPS we use vulcanized rubber that gives our ferrules that characteristic black color. In addition, we make the customized pieces, in the same way that we do with the plastic caps. Consult our catalogue, and you will be able to choose the most suitable ferrules for your product. And do not hesitate to contact us for any query or clarification.