Industry News

Summary of raw materials that easily contaminate molds in rubber product formulations

2019-12-31
    The use of contaminated molds in the production of rubber products, while lightly affecting the appearance of the rubber products and directly causing the finished rubber products have no use value; therefore, avoiding mold pollution is of great significance for improving the quality of rubber products and improving the yield. In actual production, there are many reasons why rubber molds are contaminated during use and storage. One of the raw materials that are easily contaminated in rubber products is one of them. So what raw materials are easy to contaminate the mold?

    1. Variety of rubber that easily pollutes the mold

    There are many types of rubber. Diene rubber contains a large number of double bonds, which is susceptible to cracking due to the action of ozone. It is easy to wet the metal surface. Among them, diene natural rubber is the most likely to contaminate molds. Butyl rubber and nitrile rubber are the second most common. The rubber HYL28Y11Y1J-SXC has little pollution and the butyl rubber has the least pollution.

    It should be noted that the new raw rubber replacement material—recycled rubber—because its composition is more complex, the contamination of rubber molds cannot be generalized. If recycled rubber is used in the production process of contaminated rubber oil and other additives, then the recycled rubber produced will easily contaminate the mold; from this perspective, rubber products manufacturers are best to choose environmentally friendly recycled rubber, currently the country is also Continuously strengthen environmental protection supervision, I believe that in the future will be able to occupy the recycled rubber market will be environmentally friendly, odorless recycled rubber.

    2.Rubber fillers that easily contaminate the mold

    Rubber fillers are the largest amount of compounding agents other than rubber in the production of rubber products. If the filler used is highly polluting, the rubber mold is naturally contaminated. Among them, clay, calcium silicate and other fillers have good dispersibility in rubber and little pollution; the light calcium pollution most commonly used in rubber products needs to be judged based on particle size. The greater the reinforcing properties of carbon black in the reinforcing filler, the less the pollution.

    3. Which plasticizers are easy to contaminate rubber molds

    Rubber plasticizers can improve rubber plasticity and fluidity by reducing the intermolecular force and glass transition temperature of rubber products during the production of rubber products. They are the most commonly used functional additives in the production of rubber products. Among them, the better the compatibility and the more volatile the plasticizer, the easier it is to contaminate the rubber mold, and the plasticizer with good thermal stability will have less pollution to the mold; due to the increase in the amount of softener, the pollution resistance of the rubber will be reduced. If necessary, processing aids such as phosphoric acid-based plasticizer-tributyl phosphate can be used to suppress softener contamination of the mold.

    4. Compounding agent that easily pollutes mold in vulcanization system

    In the production of rubber products, sulfur is the most commonly used vulcanizing agent, and it is also the main pollution element; sulfur, zinc oxide, and stearic acid are the most likely to contaminate the mold. The accelerator TMTD and accelerator D are the most polluting in the accelerator product. The accelerator TMTD can be used in combination with the accelerator DM to reduce the pollution of the accelerator. When magnesium oxide is used in the vulcanization system, the later it is added, the greater the contamination. This requires special attention.

    Therefore, rubber materials and compounding agents must be selected during the production of rubber products to avoid serious pollution of raw materials to rubber molds. When using recycled rubber to produce rubber products to reduce production costs, try to use non-polluting recycled rubber products.