Why do silicone products turn yellow
The yellowing of silicone products over time, or the yellowing of silicone molds made from them, is a headache for the silicone industry. Let's briefly analyze the reasons below.
1、 Added vulcanizing agent. The performance of vulcanizing agents can be divided into ordinary type and yellow resistance. Ordinary non yellowing vulcanizing agents can be applied to some non exposed silicone products with darker colors or low color requirements, even if the silicone turns yellow, it will not have a significant impact. And anti yellowing vulcanizing agents are applied to products that require exposure, lighter and brighter colors, and higher color requirements. By adding anti yellowing vulcanizing agents, the color of silicone products is greatly guaranteed. However, it cannot be ruled out that the poor quality of the vulcanizing agent itself may cause the liquid silicone to appear light yellow during production and molding. In such cases, it is necessary to choose whether to replace the silicone raw material according to product requirements.
2、 In terms of craftsmanship. The different variable conditions during the molding of transparent silicone products are also the main reason for the yellowing of the color after molding. For example, if the mold temperature is too high, the vulcanization time is too long, or after secondary vulcanization, etc.
