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Transparent silicone products will not turn yellow after a few years, but sometimes in production, some transparent silicone products that have just come out of the oven look yellow and seem to have changed color. Why do transparent silicone products turn yellow?
1. Vulcanizing agent
1). The performance of vulcanizing agent is divided into ordinary type and anti-yellowing property. Its application range has the following two aspects:
2). Ordinary non-yellow vulcanizing agent, used in some non-exposed silicone products that can be used for darker colors or low color requirements.
3). Anti-yellowing vulcanizing agent is used for products that need to be exposed, lighter and brighter in color, and have higher color requirements.
2. Process
When transparent silicone products are molded, 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). The vulcanization time is too long,
3). After secondary vulcanization
3. The quality of the raw material itself is too poor
Sometimes we add anti-yellowing vulcanizing agent to the rubber compound, but the transparent silicone product still looks yellow after molding, it may be that the anti-yellowing ability of the raw material is too poor. Direct replacement.
Summarize:
Although silicone products have excellent weather resistance and aging resistance. But sometimes the silicone products that have just come out of the oven are yellow. In order to avoid this situation, the curing agent should be selected according to the requirements, the temperature of the mold and the curing time of the product should be strictly controlled in terms of technology, and the yellowing resistance of the raw materials should be paid attention to.
1. Vulcanizing agent
1). The performance of vulcanizing agent is divided into ordinary type and anti-yellowing property. Its application range has the following two aspects:
2). Ordinary non-yellow vulcanizing agent, used in some non-exposed silicone products that can be used for darker colors or low color requirements.
3). Anti-yellowing vulcanizing agent is used for products that need to be exposed, lighter and brighter in color, and have higher color requirements.
2. Process
When transparent silicone products are molded, 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). The vulcanization time is too long,
3). After secondary vulcanization
3. The quality of the raw material itself is too poor
Sometimes we add anti-yellowing vulcanizing agent to the rubber compound, but the transparent silicone product still looks yellow after molding, it may be that the anti-yellowing ability of the raw material is too poor. Direct replacement.
Summarize:
Although silicone products have excellent weather resistance and aging resistance. But sometimes the silicone products that have just come out of the oven are yellow. In order to avoid this situation, the curing agent should be selected according to the requirements, the temperature of the mold and the curing time of the product should be strictly controlled in terms of technology, and the yellowing resistance of the raw materials should be paid attention to.
