The nitrile reclaimed rubber has excellent oil resistance and can be used as a substitute for nitrile rubber to produce various rubber-resistant seals, oil-resistant rubber strips and other molded rubber products or extruded rubber products. When nitrile rubber is used to produce molded rubber products, the process A slight mishandling will affect the yield of nitrile molded products. What problems should be paid attention to when producing nitrile reclaimed rubber? How to improve the yield of nitrile molded products?
There are many reasons for the yield of the nitrile reclaimed rubber molded products. For example, the quality of the nitrile reclaimed rubber is not good, and the uneven dispersion of the compounding agent during the mixing causes the surface of the product to be uneven, and the shrinkage of the rubber causes the size of the nitrile reclaimed rubber molded product to be in error. If the vulcanization pressure is too large, the product will form a reverse line cut when the product is discharged, and the yield of the nitrile molded product can be improved from the four aspects of the rubber material selection, the kneading process, the mold design and the vulcanization condition.
1. Raw material selection
When using molded nitrile rubber to produce molded rubber products, if it is a rubber product with strict requirements on appearance, it is necessary to use high-density and impurity-free nitrile reclaimed rubber to avoid rough and dull surface and affect the yield of nitrile products. The use of nitrile reclaimed rubber containing impurities can also lead to the softness and appearance defects of nitrile products; the production of high-oil-resistance and high-resistance molded rubber products by nitrile reclaimed rubber requires the use of high-capacity and high-strength Nitrile reclaimed rubber to improve the comprehensive index of nitrile molded rubber products.
For the compounding agent containing moisture or volatile substances, special treatment such as drying is required to avoid bubbles in the nitrile reclaimed rubber product.
2. Mixing process
As the first major process in the production process of nitrile reclaimed rubber products, the uneven dispersion of the compounding agent can easily lead to problems such as tearing, whitening, delamination and bubbles of the product. Therefore, in actual production, it is necessary to Thickness, size, viscosity and other indicators reasonably adjust the mixing process conditions to avoid problems such as lack of glue, creases or bubbles when the nitrile reclaimed rubber is vulcanized due to excessive viscosity and too small, and the glue after the mixing is completed. The material is parked for a period of time, and the parking time is controlled at 16-24 hours, avoiding bubbles and spots, and improving the yield of the nitrile reclaimed rubber product.
3. Product mould
When nitrile reclaimed rubber is used to produce molded rubber products, whether the size of the mold itself is unreasonable or the size of the finished product caused by shrinkage of the rubber is not accurate enough, the yield of recycled rubber products will decrease; therefore, the molded nitrile reclaimed rubber products are designed. When the mold is used, the shrinkage of the rubber material is taken into consideration to improve the yield of the nitrile molded product.
4. Vulcanization conditions
In the production process of nitrile reclaimed rubber products, the unreasonable setting of vulcanization conditions such as vulcanization time, vulcanization pressure and vulcanization temperature will also affect the yield of nitrile products; for example, if the vulcanization time is too short, the sulfur will be too low, and the vulcanization time will be too long, resulting in nitrile rubber. When the product is demoulded, cracks are generated, the vulcanization pressure is insufficient to generate bubbles, the vulcanization pressure is too large to cause deformation, and the vulcanization temperature is too high to be scorched. Therefore, when the nitrile reclaimed rubber is used to produce the molded rubber product, the vulcanization conditions should be properly controlled, and the vulcanization temperature should be controlled. At 140-200 ° C, the vulcanization pressure is controlled between 1.4-3.4 MPa. For thicker nitrile reclaimed rubber products, it is best to choose low-temperature long-term vulcanization.
Increasing the quality of molded-type nitrile reclaimed rubber products is of great significance for improving production efficiency and economic benefits. Do you have other methods?