How do color marks form during the production of silicone products?

How do color marks form during the production of silicone products?
High molding temperature
Reason: If the temperature is too high during the molding process of silicone, the golden masterbatch will decompose or discolor, resulting in color marks. Especially for some temperature-sensitive golden pigments, color changes may occur at high temperatures.
Solution: Accurately control the molding temperature and determine the optimal molding temperature range through experiments. High-precision temperature control equipment can be used to monitor and adjust the temperature in real time; at the same time, optimize the molding process to shorten the residence time of silicone at high temperatures.
Improper injection or extrusion speed
Reason: If the injection or extrusion speed is too fast, the silicone will flow unevenly in the mold or flow channel, causing turbulence, uneven distribution of golden pigments, and color marks; if the speed is too slow, the silicone may stay in the mold for too long and discolor.
Solution: Adjust the appropriate injection or extrusion speed according to the shape, size and mold structure of the product. Determine the optimal speed parameters through trial molds to ensure that the silicone flows smoothly and evenly in the mold.
Mold problem
Reason: The mold surface is not smooth, there is oil or mold release agent residue, which will affect the surface quality of the silicone and cause color marks. In addition, poor mold exhaust will also cause bubbles to form during the molding process, which will affect the uniformity of color.
Solution: Clean and maintain the mold regularly, use appropriate detergent to remove oil and mold release agent residue on the mold surface; optimize the mold exhaust system, add exhaust grooves or use breathable steel materials to ensure that the gas can be discharged smoothly during the molding process.