What causes transparent silicone products to turn yellow
Since transparent silicone products are transparent, how can they turn yellow? Can they still be transparent after turning yellow, and what are the reasons for this? Is it oxidation? Normally, transparent silicone products do not turn yellow even after being stored for several years. However, sometimes during production, some newly produced transparent silicone products turn yellow. So why do transparent silicone products turn yellow and what are the reasons?
1、 Regarding vulcanizing agents
1. The performance of vulcanizing agents can be divided into ordinary type and anti yellowing type
2. Ordinary non yellowing vulcanizing agent, applied to some non exposed silicone products with darker colors or low color requirements.
3. Anti yellowing vulcanizing agents are applied to products that require exposure, light and bright colors, and have high color requirements.
2、 In terms of craftsmanship
The main problems that cause the color of transparent silicone products to turn yellow after molding are:
1. The mold temperature is too high
2. Excessive vulcanization time
3. After secondary sulfurization
3、 Poor quality of raw materials themselves
Sometimes we add anti yellowing vulcanizing agents to the rubber material, but the transparent silicone product still looks yellow after molding. It is possible that the anti yellowing ability of the raw material is too poor. For raw materials with poor anti yellowing ability, it is recommended to replace them directly.
Conclusion: Although silicone products have weather resistance and aging resistance. But sometimes the freshly baked silicone products still turn yellow. To avoid this situation, it is necessary to choose the vulcanizing agent according to the requirements, strictly control the temperature of the mold and the vulcanization time of the product in terms of the process, and pay attention to the anti yellowing properties of the raw materials.
Transparent silicone products have the above reasons for yellowing, and of course, if there are other unknown reasons, specific problems need to be analyzed, because the mold silicone products made from different quality silicone raw materials will be different.