Poor dark marks (corrugations) of silicone products are a kind of poor appearance of silicone products, which are manifested in the appearance of two colors or messy ripples on the surface of the silicone products after molding, and the distribution of ripples is disorderly.
The solution is as follows:
1. The mixing of silica gel products is not uniform when preparing materials, that is to say, the mixing time is too short after adding the color masterbatch, resulting in the color masterbatch being not completely dispersed uniformly, resulting in poor dark marks (corrugations) of the silica gel product during molding. This problem can be solved by refining raw materials.
2. The vulcanization temperature is too high. Any kind of silicone color masterbatch has its temperature resistance. When the vulcanization temperature exceeds the temperature resistance upper limit of the color masterbatch, it will cause the color masterbatch to change color at high temperature. The temperature resistance values of the various color masterbatches are different, so it may cause a certain color masterbatch to change color, and a certain color masterbatch does not change color, and naturally there will be poor dark marks (corrugations) of silicone products. It can be solved by adjusting the mold temperature. How much the temperature is reduced, the answer is to continue to reduce it until there is no dark mark (corrugation).
3. When the mold temperature is continuously lowered, the dark mark (corrugation) of the silicone product is solved, but the silicone product is not completely cured (unfamiliar). So basically, the temperature resistance of silicone color masterbatch itself is too poor, and it usually appears on some brighter color masterbatches such as red, green, yellow, etc. The temperature resistance of this kind of color masterbatch will be relatively poor, such as used to match with other color masterbatches. Toning, it is easy to have the dark marks (corrugations) of silicone products. At this time, you need to consider looking for color masterbatches with similar colors to re-color to solve such defects.
4. Maybe in the usual production, there will be such a situation, a certain color paste has been used before, and there will be no dark marks (corrugations) of silicone products, but it is used when a certain color is toned However, dark marks (corrugations) appeared. This may be due to the incompatibility of this color paste with a certain color paste, resulting in poor dark marks (corrugations) after molding of the silicone product. If there is no solution, it is relatively simple, just replace the color paste.
5. Unreasonable discharge of rubber during molding of silicone products. This is the most likely factor to cause dark marks (corrugations) in silicone products. As the silicone material is cut too thick and narrow, the heating of the rubber is uneven, resulting in silicone products. Defective dark marks (wavy). The improvement method is also the opposite. It can be effectively solved by changing the cutting specification of the rubber material to thinner and wider so that it can completely cover the key type.
6. The storage time of silica gel products is too long after preparation, resulting in poor fluidity of the rubber material, and then causing poor dark marks (corrugations) of the silica gel products. In addition, if too much vulcanizing agent is added during material preparation, it will also cause such defects.