What chemical process is used to make rubber?

How Is Rubber Processed?

Regardless of whether the rubber is natural or synthetic, the processing options are generally the same. Additional processing compounds the rubber so it can be used for a variety of industrial purposes. These are the four main steps.

1. Compounding (Formulating)

Adding chemicals to a rubber base creates rubber compounds. Chemicals can stabilize the polymers or reinforce the strength of the rubbers. Sometimes, compounding can also stretch the rubber, which reduces the final cost.

2. Mixing

Similar to compounding, this step includes additives that are mixed in with the rubber. To improve ingredient dispersion and avoid raising the temperature too high, professional mixers complete this in two steps. First they create a masterbatch that includes additives, such as carbon black. After cooling the rubber, they then add the chemicals necessary for vulcanization.

3. Shaping

Some of the common shaping techniques include coating, extrusion, casting, calendering, and molding. Depending on the final product, manufacturers could rely on several shaping techniques.

4. Vulcanization

Vulcanization is a chemical process in which the rubber, natural or synthetic, is heated with sulfur, accelerator, and activator. This process forms cross-links between long rubber molecules, which improves elasticity, resilience, tensile strength, viscosity, hardness, and weather resistance. This is the final step of the process. In the past, this took up to five hours. Due to modern-day advancements, vulcanization can be completed in 15 to 20 minutes.

Processing rubber

Both natural and synthetic rubber are processed to turn it into a usable product. The processes vary according to the intended use of the final product. Chemicals are added to the rubber to make it stable. Without this, the rubber would get brittle if it got cold or become sticky during high temperatures.

To make rubber strong and durable, it goes through a heat-treatment phase known as vulcanisation. The heat creates extra bonds or cross-links between the rubber molecules to make it stronger. In this process, rubber chemicals also play a key role by making it more durable and less energy-intensive. After vulcanisation, any imperfections are removed from the rubber and it is then shaped or moulded into the final product.