In this classification, rubber coatings are divided into two groups based on the final hardness. Rubbers that fall within the Shore A hardness range are called soft rubber, while those with a Shore D hardness are known as hard rubber.

There is also a group of rubbers with hardnesses between these two ranges, which are called semi-hard rubber.

Although the final hardness of the rubber alone is not the main criterion for selecting a coating, it can create limitations in some cases. For example, in shipping containers that are subject to constant mechanical stress, the use of hard rubber is not recommended because it is less flexible. In these situations, soft rubber is a better option.

Rubber lining is divided into two categories based on the method of implementation: workshop and on-site (customer site).

🔹 2.1 Hot rubber lining
In this method, raw rubber is installed on the desired surface and then subjected to a vulcanization process to achieve the desired mechanical and chemical resistance. This process can be carried out in an autoclave or by curing with steam, hot water or hot air. Some rubbers are designed to be vulcanized at ambient temperature without the need for special curing.

🔹 2.2 Cold rubber lining
In this method, the rubber coating is already vulcanized in the factory. Therefore, after installation, it does not require a curing operation and can be used immediately.

Pre-vulcanized rubbers can be applied in both workshop and customer site environments. However, raw rubbers, depending on the type of polymer and hardness, may only be vulcanized in an autoclave.