When using a nitrile rubber or a nitrile reclaimed rubber to produce a molded rubber product, the rubber compound is required to have good plasticity, fast vulcanization speed, but is not easy to be scorched, small compression set, small aging resistance, etc. Plasticity, vulcanization rate, and scorch tendency affect each other and require formulation adjustment. Therefore, the rational design of the molded nitrile rubber product formulation can provide better conditions for the molding process of the product.
1. Vulcanization system design needs to consider the vulcanization process
Different types of molded nitrile rubber products have different vulcanization methods and vulcanization conditions, and different vulcanization systems are required. When using nitrile rubber or nitrile reclaimed rubber to produce oil-resistant rubber products, rubber manufacturers need to combine the vulcanization method, vulcanization temperature and time, rubber storage time and properties of nitrile rubber products, and generally choose sulfur dosage during sulfur vulcanization. It can be controlled in 1-1.5 parts, and the amount of accelerator can be controlled in 0.5-0.5 parts, which can prepare vulcanizate with better comprehensive performance.
2. The amount of lubricant needs reasonable control
Good fluidity and plasticity can promote the uniform filling of the nitrile rubber in the mold cavity. The lubricant can significantly increase the fluidity of the rubber. However, in the actual production process, the lubricant is used too much. The surface of the precipitate will affect the mutual fusion of the rubber compound during the molding process, so that the molded rubber product cannot be vulcanized and formed normally. Therefore, the amount of the lubricant must be properly controlled. Usually, a very small amount of lubricant can significantly improve the nitrile rubber. Or process performance of nitrile reclaimed rubber.
3. Strictly control the moisture content of raw materials
When a nitrile rubber or a nitrile reclaimed rubber is used to produce a molded rubber product, if the rubber itself contains moisture or the moisture content of the compounding agent is too high, or the nitrile rubber compound and the compounding agent, the compounding agent and the compounding agent react with each other to generate moisture. One will lead to the appearance of large and small bubbles in the molded product; the second, if the moisture content is too high, the dispersion of the compounding agent will be uneven, and partial scorch and partial gel problems may occur. Therefore, when using a nitrile rubber/recycled rubber to produce a molded rubber product, the rubber product manufacturer not only needs to consider the moisture in the raw material, but also needs to consider whether the rubber compound and the rubber compound, the rubber compound and the compounding agent, and the compounding agent and the compounding agent are Producing large amounts of moisture or volatiles is especially important when designing formulations.
Molded nitrile rubber/recycled rubber products are also required to be formulated with other compounding agents. For example, if the amount of the release agent used in the nitrile molded product formulation using the release agent is too large, there may be problems such as heavy skin and cracks caused by poor fusion.
In summary, in the production process of molded nitrile rubber/recycled rubber products, the formulation design has an important influence on the quality of the products. It is necessary to strictly control the types and dosages of the compounding agents in the formula according to actual needs; When nitrile rubber produces molded rubber products to reduce costs, it is necessary to adjust the formulation in time.