The importance of vulcanization pressure for rubber marine fenders

The vulcanization pressure refers to the pressure per unit area of ​​the rubber product during the vulcanization process. Except for thin-walled products such as tape, other rubber products require a certain amount of pressure during vulcanization. The pressure effect of vulcanization mainly has the following points:
1. Prevent the formation of bubbles during the vulcanization process of the rubber marine fender and improve the compactness of the rubber.
　　 During vulcanization, the rubber contains water and other volatile substances, as well as hydrogen sulfide gas that may be formed during the vulcanization reaction, which volatilize and escape at high temperatures, causing the rubber to generate bubbles. If a vulcanization pressure greater than the internal pressure of the rubber compound may be applied during vulcanization, the generation of bubbles can be prevented and the compactness of the rubber compound can be improved.
2. Make the rubber ship fender easy to flow and fill the mold cavity
　　 In order to make rubber products with clear and full patterns, the rubber must be able to flow and fill the cavity. Especially when the compound is in the uncrosslinked state during the vulcanization induction period, the effect of vulcanization pressure is more obvious. Experiments show that for molded rubber products, if the vulcanization temperature is 100-140℃, the vulcanization pressure should be within the range of 2-4.9MPA.
3. Improve the adhesion between the rubber fender and the cloth layer
　　 During vulcanization, as the vulcanization pressure increases, the depth of rubber penetration into the cloth layer increases, which can improve the adhesion between the rubber and the cloth layer and the flexural resistance of the rubber marine fender.
4. It helps to improve the physical and mechanical properties of vulcanized rubber
　　Experiments have shown that with 5MPA pressure vulcanization, its wear resistance is 10%-20% higher than the general 2MPA vulcanized rubber marine fender. This is because increasing the vulcanization pressure can increase the compactness of the vulcanizate. However, too high vulcanization pressure will also be detrimental to the performance of rubber, because high pressure, like high temperature, will accelerate the pyrolysis of rubber molecules. In addition, the structure of textile materials under high pressure will also be damaged, resulting in a decrease in flex resistance.