Natural Rubber
Have you ever seen a milky liquid flowing from a plant?
Some of you might have seen a spurge or a dandelion with its flying seeds in spring… When a part of their stem is broken, a white fluid called latex come out. Besides these, many other plants secrete this fluid to heal their tissues.
The tree in the image is the rubber tree (Hevea brasiliensis). Although its homeland is the Amazon rainforest in South America, today it is mostly grown in Southeast Asian countries such as Indonesia, Malaysia and Thailand. The rubber tree produces plenty amounts of latex. This latex contains intensive amounts of a substance called rubber.
Rubber is used in the production of various goods, especially car tyres! How interesting, isn’t it? The fluid coming from the trunk of a tree is actually the raw material for car tyres. And this is not the only item. It is also used in erasers, surgical gloves, elastic bands, shoes, balloons and so on... Besides, rubber gains adhesive properties when heated and mixed with certain chemicals, that’s why adhesives are also produced from rubber.
What is the journey of natural rubber from the tree to the production of goods?
The first step in the production of natural rubber is to collect latex from the trees. Latex is collected in the morning. The trunk of the trees is cut with special knives so as to slice grooves. The fluid running down from the grooves is gathered in containers. Latex solidifies when left in the open air. To avoid this solidification, ammonia is added to the collected fluid.
Then, chemicals such as formic acid, acetic acid are added to this fluid. The rubber substance is left to become lumpy. The rubber come out of the fluid is passed through large rollers. After passing through the rollers, the rubber is removed from excess water, gets thinned and becomes ready to dry.
The layers of rubber are hung on a rope like clothes, and are let dry. This process is done in farmer gardens, forests or factories. The layers dry in the open air in a few days. This process takes less time in factories. The rubber is dried in special places called smokehouses. As it dries, it changes in colour and gradually turns brown. Depending on its purpose of use, the rubber is transported to the factory where the relevant product is produced.
Rubber becomes sticky at high heat and brittles at low heat. That’s why, it is passed through special processes in factories. One of these processes is the method accidentally discovered by Charles Goodyear in 1839. In this method, rubber is cooked with sulphur. So, it becomes durable against bad conditions and has a flexible structure. If you think about car tyres, you can imagine this better....
Rubber was even used in BC. It was used in such different fields in such great amounts that resources became insufficient over the years. That’s why, artificial (synthetic) rubber started to be made. Synthetics became more durable and useful than natural ones in time. The rubber used today is 70% synthetic.
Since it is a recyclable material, natural rubber is eco-friendly compared to synthetic rubber or plastic. But it has still negative impacts on the environment.
There are rubber tree forests created only for natural rubber production. Since there is only one type of tree planted in these forests, biodiversity in that area declines. This factor poses a threat to tropical forests and the living beings there. Chemicals used to increase the yield pollute soil and water. Also, these trees need more water than the other plants in the area.
All raw materials we use have positive and negative sides. Considering all of these, we can say that the best way to protect nature is to consume less.
