Nitrile Rubber Encyclopedia

Several causes and solutions of a large number of bubbles after nitrile rubber vulcanization 3

Create Date:2020-05-22 09:06:57Click volume:249
Several causes and solutions of a large number of bubbles after nitrile rubber vulcanization 3

When nitrile rubber is vulcanized, unqualified plastic compound and improper setting of vulcanization parameters may cause a large number of bubbles in the vulcanized rubber; when nitrile rubber is used to produce molded rubber products, the mold structure design is unreasonable and the vent hole If the quantity is too small, it will lead to problems such as gas in the rubber during the vulcanization process, and bubbles will appear in the vulcanized rubber (the bubbles that appear in this reason will be concentrated in one or some locations, the number is too small), then rubber products manufacturers should how to respond?

6. The plasticizing time of nitrile rubber is too long

The purpose of plastic smelting is to reduce the elasticity and viscosity of rubber, and to improve the plasticity, fluidity, solubility, and adhesiveness of the compound. When nitrile rubber is smelted, it is necessary to strictly control the parameters of the smelting process. If the smelting time is too long, it will cause the problem of over-smelting of the rubber, and the 2LLYY522 indicators such as strength, elasticity and wear resistance of the smelting rubber will decrease, increasing the power Consume. In addition, during the plasticizing process of nitrile rubber, the acetone extracts in the rubber compound, especially the aerobic compounds, will increase with the continuous increase of the rubber compound plasticizing time, resulting in a large number of bubbles in the rubber vulcanization process.

Therefore, when plasticizing nitrile rubber, it is necessary to reasonably control the plasticizing time to avoid over-refining of the rubber and avoid bubbles in the vulcanized rubber.

7. Improper setting of vulcanization parameters

Nitrile rubber products are not fully vulcanized or vulcanized during vulcanization, and the vulcanized rubber looks like there are many bubbles. Rubber product manufacturers should set the vulcanization process parameters reasonably, increase the vulcanization pressure and vulcanization temperature appropriately, and extend the vulcanization time in a timely manner to ensure that the nitrile rubber compound is fully vulcanized, to avoid under-vulcanization of rubber, and to avoid a large number of "bubble" in the vulcanized rubber.

8. The mold structure is unreasonable or the vent hole is improperly set

When using nitrile rubber to produce molded rubber products, unreasonable mold design and improper vent setting are also one of the main reasons that cause bubbles in the rubber compound. Rubber vulcanization needs to be carried out under high temperature conditions. When the temperature of the vulcanization mold rises, nitrile rubber compounds and compounding agents will generate volatile matter. Only when these volatile gases are discharged from the mold, bubbles will not appear in the product.

When designing moulded nitrile rubber product molds, rubber products with complex structures need to design parting lines, running grooves, exhaust holes, etc. reasonably, and use vacuum pumps to draw vacuum if necessary to avoid stagnation of rubber products.

At present, there are three main production methods of nitrile rubber products. The use of nitrile butadiene rubber, nitrile butadiene rubber / nitrile reclaimed rubber alone or nitrile reclaimed rubber alone can be used to ensure the performance of nitrile rubber products. , And can effectively reduce costs. When using nitrile reclaimed rubber or nitrile rubber / recycled rubber together to produce rubber products, rubber product manufacturers also need to pay attention to the above problems; strictly control the quality of raw materials, properly adjust the formula, and set the process parameters reasonably to avoid a large number of bubbles in nitrile vulcanized rubber .