Production of rubber products

During the raw material preparation process, the ingredients must be accurately weighed according to the formula. In order for the raw rubber and the compounding agent to mix evenly with each other, certain materials need to be processed:

Raw rubber should be softened in a 60-70 ℃ drying room before being cut and broken into small pieces;

Block like additives such as paraffin, stearic acid, rosin, etc. need to be crushed;

If the powdered compound contains mechanical impurities or coarse particles, it needs to be screened and removed;

Liquid additives (pine tar, coumarone) require heating, melting, evaporating water, and filtering impurities;

The compounding agent needs to be dried, otherwise it is prone to clumping and cannot be evenly dispersed during mixing, resulting in bubbles during vulcanization and affecting product quality;

3. Refining

Raw rubber is elastic and lacks the necessary properties (plasticity) for processing, making it difficult to process. In order to improve its plasticity, it is necessary to refine the raw rubber; In this way, the blending agent is easily evenly dispersed in the raw rubber during mixing; At the same time, during the rolling and forming process, it also helps to improve the permeability of the rubber material (penetrating into the fiber fabric) and the forming fluidity. The process of degrading the long-chain molecules of raw rubber to form plasticity is called plasticization. There are two methods for refining raw rubber: mechanical refining and thermal refining. Mechanical plasticizing is the process of reducing the degradation of long-chain rubber molecules and transforming them from a highly elastic state to a plastic state through the mechanical extrusion and friction of the plasticizing machine at relatively low temperatures. Thermoplastic refining is the process of introducing hot compressed air into raw rubber, which, under the action of heat and oxygen, degrades and shortens long-chain molecules, thereby obtaining plasticity.

4. Mixing

In order to adapt to various usage conditions, achieve different performance, and improve the performance of rubber products and reduce costs, it is necessary to add different additives to the raw rubber. Mixing is a process of mixing the plasticized raw rubber with the compounding agent and placing it in a rubber mixer. Through mechanical mixing, the compounding agent is completely and uniformly dispersed in the raw rubber. Mixing is an important process in the production of rubber products. If the mixing is not uniform, the role of rubber and additives cannot be fully utilized, which affects the performance of the product. The rubber material obtained after mixing, known as mixed rubber, is a semi-finished material used to manufacture various rubber products, commonly known as rubber material. It is usually sold as a commodity, and buyers can directly process and vulcanize the rubber material to produce the required rubber products. According to the different formulas, the mixed rubber has a series of different grades and varieties with different properties, providing choices.