A qualified silicone rubber product undergoes significant influence on its quality at every stage, from material research and development to mold design and processing. Among these stages, the vulcanization process is a crucial step in transforming raw materials into finished products for silicone rubber. Before the vulcanization process, we need to set an extremely important process parameter, which is the vulcanization time. If the time is set too short, it will affect the physical properties of the product or lead to incomplete vulcanization. If the time is set too long, it will also affect production efficiency. So, how can we scientifically set a reasonable vulcanization time? Yongyong Silicone Rubber Products Co., Ltd., a manufacturer with 23 years of dedicated production of silicone rubber products, will today lead everyone to discuss this issue together.
We know that the time for rubber vulcanization is the most crucial factor determining whether the product reaches the proper vulcanization state. In simple terms, it is whether the product is fully cured. The vulcanization time is usually tested using a vulcanization instrument and is determined by T90. However, rubber products come in different sizes (thickness of the rubber), and rubber is a poor thermal conductor, so it takes a long time to transfer temperature. If vulcanization time is set uniformly based on T90, it is not reasonable. Therefore, the vulcanization time for rubber products during compression molding is generally divided into two parts for selection: 1. For products with a rubber thickness greater than 6mm, the vulcanization time is set to be consistent with the actual measured T90 on the vulcanization instrument. 2. For products with a rubber thickness greater than 6mm, the vulcanization time is selected based on industry experience plus the T90 of the vulcanization instrument. Generally, for products with a rubber thickness exceeding 6mm, for every 1mm increase in rubber thickness, the positive vulcanization time increases by 1 to 1.5 minutes. The reference vulcanization time = T90 + (rubber thickness - 6) * 1 to 1.5 minutes. None of these take into account the time during the operation process. Some small factories simply reduce the vulcanization time for molding to improve production efficiency, and the products do not show any problems in appearance, but in fact, the products do not reach the actual physical properties of the material. For example, the aging resistance of the product may therefore decrease. Therefore, here we also remind everyone to choose a regular manufacturer when selecting one, as the quality is guaranteed.
Yongyong Silicone Rubber has been dedicated to silicone rubber products for 23 years. It offers consulting services ranging from material research and mold development to manufacturing of silicone rubber products. The consultation hotline is 0769-85536776.
