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Why do silicone products appear dark marks after successful production? ​

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The dark marks (corrugations) of silicone products are a kind of poor appearance of silicone products, which is manifested in the appearance of two colors or messy corrugations on the surface of silicone products after molding, and the distribution of corrugations is disordered.

The solution is as follows:

    1. The mixing of the silicone products is uneven during the preparation, that is to say, the mixing time after adding the color masterbatch is too short, resulting in the color masterbatch not being completely dispersed evenly, resulting in poor dark marks (ripples) of the silicone products during the molding of the silicone products. This problem can be solved by refining raw materials.

  2. The vulcanization temperature is too high. Any kind of silica gel masterbatch has its temperature resistance. When the vulcanization temperature exceeds the upper limit of the temperature resistance of the color masterbatch, it will cause the color masterbatch to change color at high temperature. The temperature resistance values of various color masterbatches are different, so it may cause a color masterbatch to change color, and a color masterbatch to not change color. It can be solved by adjusting the mold temperature. How much the temperature is lowered, the answer is to continue to reduce it until there is no dark mark (ripple) defect.

  3. When the mold temperature is continuously lowered, the dark marks (corrugations) of the silicone products are solved, but the vulcanization of the silicone products is incomplete (undercooked). Then it is basically because the temperature resistance of the silicone color masterbatch itself is too poor. It usually appears on some color masterbatches with brighter colors such as red, green, and yellow. The temperature resistance of such color masterbatches will be relatively poor. For example, it is used to match with other color masterbatches. Toning, it is easy to have bad dark marks (ripples) in silicone products. At this time, it is necessary 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 never been badly dark marks (ripples) on silicone products when it was used before, but it is used when a certain color is toned. However, there is a dark mark (ripple) defect. This is probably because this color paste is not compatible with a certain color paste, resulting in poor dark marks (ripples) after the silicone products are formed. The solution is relatively simple, just replace the color paste.

  5. The unreasonable discharge of rubber material during molding of silicone products is the most likely factor to cause bad dark marks (corrugations) in silicone products. Because the silicone raw material is cut too thick and too narrow, the rubber material is heated unevenly, resulting in silicone products. Defective dark marks (waves). The improvement method is also the opposite. It can be effectively solved by changing the cutting specification of the rubber material to be thinner and wider so that it can completely cover the key type.

  6. The long storage time of the rubber compound for silicone products will lead to poor fluidity of the compound, which in turn results in poor dark marks (ripples) in the silicone products. In addition, if too much vulcanizing agent is added during material preparation, it will also cause such defects.

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