Why do rubber materials need to be molded? What are the purposes of plasticizing?

Rubber has good elasticity, but this property brings difficulties to product production. If the elasticity of raw rubber is not reduced first, most of the mechanical energy will be consumed in elastic deformation during the processing. And it is not possible to obtain the required shape for rubber processing technology, which has certain requirements for the plasticity of raw rubber. For example, mixing generally requires a Mooney viscosity of around 60, and wiping requires a Mooney viscosity of around 40 for the rubber material, otherwise it cannot be operated smoothly. Some raw rubber is very hard and has high viscosity, lacking basic and contractual process performance - good plasticity. In order to meet various process requirements, it is necessary to carry out plasticization to cut the molecular chain of the raw rubber under mechanical, thermal, chemical and other actions, reducing the molecular weight. Temporarily causing rubber to lose its elasticity and become a soft and malleable rubber compound. It can be said that raw rubber molding is the foundation of other technological processes.

The purpose of raw rubber plasticization is to: firstly, to obtain a certain plasticity of raw rubber, making it suitable for the requirements of mixing, rolling, extrusion, molding, vulcanization, as well as the manufacturing of rubber slurry, sponge rubber and other processing processes; The second is to make the plasticity of the raw rubber uniform, in order to produce a uniform quality rubber material.