I still remember that the phenomenon of silica gel products turning yellow has become a mark in the minds of many people. When the silica gel smart phone cover came out, silica gel cover rushed into the market in a large area. Soon after the transparent white and other protective covers were used, it turned yellow and discolored. As a result, people remember that the problem of silica gel products turning yellow is essential, So what is the main reason for the yellowing of silica gel products? Have you really understood?

Generally speaking, there is no whitening phenomenon in the vulcanization process of silica gel products manufacturers. However, in the process of raw material manufacturers, the yellowing of materials is related to the iron ion content of silica, the pH value of silica gel, the production process of silica gel and the catalyst used in the production of raw rubber. Of course, the iron content of silica varies from batch to batch, If not measured, then whether the product will turn yellow also has a certain factor!

In terms of catalyst, the raw rubber generally uses tetramethylammonium hydroxide as catalyst. If it is not handled properly in the medium breaking stage, the raw rubber will turn yellow. Take the raw rubber out of the box and compare it. In addition, high vinyl raw rubber (vinyl content of more than 1%) is particularly prone to yellowing. If you use more high vinyl raw rubber than others in your formula, there may be a situation that the mixed rubber is not as transparent as others.

On the other hand, it is the correct use of products in different environments, such as long-term exposure, ozone environment, high temperature storage and so on. Finally, the environmental problems of raw material manufacturers. When kneading machine is used, it is necessary to pay attention to whether the impeller has cracks and water leakage and whether the cold water is too cold, which leads to condensation water on the inner wall of the cylinder. These easily lead to yellowing of the rubber mixture, especially in summer. Pay attention to the temperature difference. There are also packing, check whether there is leakage in packing.