The main problem of yellowing of silicone products

In the production of silicone products, some of the transparent silicone products that have just been baked are yellowed. Why does the transparent silicone product turn yellow?

The main problems of yellowing of silicone products are as follows:

1. Vulcanizing agent

1. The performance of vulcanizing agent is divided into common type and anti-yellow property, and its application range has the following two aspects.

2, the general type is not resistant to yellow vulcanizing agent, applied to some non-exposed silicone products that can be used for darker colors or less demanding colors.

3. Anti-yellow vulcanizing agent is applied to products that need to be exposed, lighter in color and more vivid, and have higher color requirements. The quality of vulcanizing agent is highly correlated with hydrogen-containing silicone oil.

2. Process aspects

When the transparent silicone product is molded, the color of the transparent silicone product turns yellow after molding. There are mainly problems:

(1. The mold temperature is too high;

(2. The curing time is too long;

(3. After the second addition of sulfur.

3. The quality of the raw materials themselves is too bad.

Sometimes we add anti-yellow vulcanizing agent to the rubber compound, but the transparent silica gel product still looks yellowish after molding. It may be that the yellowing resistance of the raw material is too bad.

Summary of solutions: Although silicone products have excellent weatherability and aging resistance. But sometimes there are still yellowing of the silicone products that have just been released. In order to avoid this situation, it is necessary to select the vulcanizing agent according to the requirements. In the process, the temperature of the mold and the vulcanization time of the product should be strictly controlled. The raw material should pay attention to the yellowing resistance of the raw material.