Some rubber products manufacturers will produce the phenomenon of de-rolling when producing nitrile rubber products >80 degrees or more, which will seriously affect the normal production of nitrile rubber products. Relatively speaking, the nitrile rubber products with lower hardness appear to be unrolled during the production process. The probability of the problem is less, then is the hardness of the nitrile rubber higher, and the worse the roll of the rubber compound? How to improve the roll-to-roll properties of high-hardness nitrile rubber products?
The wrapping roller is a common working method for plasticizing, mixing and hot-smelting on the rubber mixing machine. The wrapping roller is to ensure that the rubber is tightly wrapped in the front roller during the rubber mixing process to form a smooth and gap-free coating roller rubber. The necessary processing performance, the rubber package roll property is related to the rubber type, the type and amount of the compounding agent, and the process operation. Therefore, the hardness is not the only factor affecting the rollability of the nitrile rubber, and the rollability of the nitrile rubber It cannot be determined simply by the hardness. In theory, the nitrile rubber with a Shore hardness of 35-90 can be smoothly wrapped, but the process operation is different for the nitrile rubber-coated rolls of different hardness.
For high-hardness nitrile rubber products, in order to ensure smooth rubber coating, rubber products manufacturers should choose nitrile rubber or reclaimed rubber with relatively low Mooney viscosity; use hard reinforcing performance and hardening effect. Carbon black, or a combination of hardening resin to reduce the amount of carbon black, increase the rubber content of nitrile rubber products; add appropriate amount of silica, generally less than 30 parts; can use a certain amount of dioctyl or coumarone resin As a plasticizer; it can reduce the amount of lubricity softener and filler while reducing the plasticity of nitrile rubber, and reduce the probability of occurrence of de-rolling; use benzoic acid.
In actual production, the fluidity of nitrile rubber increases with the production of temperature, the intermolecular force is weakened, and the strength is reduced, which leads to the problem of stripping of the rubber. Therefore, the rubber product manufacturer needs to adjust the roll temperature of the mill. Roller distance, rotation speed and mixer temperature of the mixer reduce the roll distance of the mill.
High hardness is not the only factor that causes the denitrification of the nitrile rubber. When the rubber product manufacturer adjusts the formula of the nitrile rubber product to improve the roll property of the rubber compound, it is necessary to pay attention to various materials while considering the rubber roll. The effect of compounding agent on the oil resistance, wear resistance and other properties of nitrile rubber products, reasonable control of the amount of various compounding agents in the nitrile rubber formula, and finding a balance between the roll properties and other properties. The quality of the nitrile rubber product simultaneously improves the nitrile rubber-coated roll process.