How is rubber made?

How Rubber is Made (The Simple Version)

There are two types of rubber: natural and synthetic. Both are made differently and there are many variants. Natural rubber is made from latex, produced by trees and plants and combined with acid, water, heat, oxygen, carbon black and sulfur: made into strong, and flexible rubber. Synthetic rubber is made by a chemical process: linking polymer molecules together, using different chemicals to make different types of synthetic rubber.

What is rubber?

Rubber is an elastic substance with many purposes and different forms. The technical term for rubber is an elastomer (polymer) and there are two types; natural rubber and synthetic rubber.

Types of rubber

Natural Rubber

Natural rubber is also called latex or india rubber and is an elastic substance made from natural products like trees or plants.

Synthetic Rubber

Synthetic rubber is man-made or artificial made by a chemical reaction between various polymers. There are many different synthetic rubbers. See the most common here below:

  1. Styrene-butadiene rubbers (SBR) this type is mostly used to produce cars, trucks and bicycles tires.
  2. Nitrile butadiene rubber (NBR) this sort rubber is used in many products, for example hoses, seals, lab and cleaning gloves and footwear.
  3. Chloroprene rubber (CR), is mostly used in neoprene: a very known product for wetsuits. Read more about how neoprene is made.
  4. Silicone rubber (SI) is used in many products for cooking, baking and food storage products and there are many silicone sealants.
  5. EPDM rubber (ethylene propylene diene monomer) this kind of rubber has good insulating and waterproof properties and is mostly used for sealings. Sealings for house roofs, windows and also doors of a freezer or refrigarator.

How is a Rubber Made?

There are two kinds of rubber and they are both made or produced differently.

Natural rubber is produced

  1. Latex is a milky liquid which is extracted from a rubber tree or plant (called latex tapping).
  2. The milky liquid is filtered and reacted with acid to stimulate the coagulation process.
  3. After the coagulated latex it is ready for the rolling proces to squeeze out the water and hanged out to dry in the sun.
  4. Commonly carbon black is added to improve strength and durability. Carbon black is a black powder that is a by-product from burning heavy petroleum products.
  5. Vulcanization: hardening the rubber by treating it with sulfur at a high temperature. This proces creates extra bonds or cross-links between the molecules of the rubber, so they don’t easily fall apart.

Synthetic Rubber is produced

Synthetic rubber is produced in many different ways and it can have many properties. In this case, below is an explanation how a tire is made.

  1. First the monomers styrene and butadiene are extracted from oil or petroleum.
  2. Using the two monomers butadiene and styrene in a chemical reaction will create the polymer Styrene-butadiene. This is also a white milky liquid, like latex from rubber trees.
  3. The next fases are almost the same as with natural rubber. Carbon black powder is added to improve strength and durability.
  4. Vulcanization: hardening the rubber by treating it with sulfur at a high temperature.

What is a Rubber made of?

Natural Rubber

Natural rubber can be made out of more than 2500 plants, but the most common and best ones, you will read below.

Rubber trees

Rubber trees produce latex: a yellow or white liquid milky substance. The most used tree for natural rubber is the Hevea brasiliensis. But there are many more trees that also produce a certain latex form. See some of those trees in the list below.

  • Hevea brasiliensis als called Pará rubber tree
  • Castilla elastica
  • Gutta-percha

Rubber plants

Many flower plants also produce the same kind of latex that can be used to produce rubber. But this method is less popular and is not used that much in production. I guess the reason for that is because harvesting is pretty difficult and less efficient.

  • Landolphia
  • Dandelion
  • Euphorbia

Synthetic rubber

Synthetic rubber can be made with different materials (monomers and polymers) through a chemical reaction. Most of those monomers or polymers are extracted from:

  • Oil or petroleum
  • Coal
  • Limestone

Where is rubber made?

Most of the natural rubber is made in Thailand, Indonesia, and Malaysia.

Most of the synthetic rubber is made in the United States and China. Here is a list of the companies that produce synthetic rubber.

Why is rubber good material for wetsuits?

Rubber has a lot of good quality and is used in many products. But why do we use rubber for wetsuits? Most wetsuits are made of chloroprene rubber, also called neoprene. Neoprene is a synthetic rubber. Why is this neoprene such a good product for wetsuits?

It is a good insulator of heat

This is the main reason why rubber is used in wetsuits. Since it doesn’t conduct heat. Especially neoprene is a good insulator, because it is filled with many micro air or gas bubbles. Air is well known as a good insulator.

It is waterproof

Rubber is waterproof, it will not let water through and it will not absorb water. Also, the material will not get weak or loose any of its quality by contact with water.

It has a good elasticity and flexibility

All rubber kinds are elastic, some of them are more elastic and some are less. The amount of flexibility is mostly determined by the vulcanization process during production. Wetsuit flexibility and stretch is very important.

It is strong and durable

Another good property of rubber is that it is very strong and durable. It has high tensile strength and high resilience against tearing. Next to its strength, it has incredible durability.