1: Reasons for impurities and black spots on the surface of the silicone tube:
1: The raw material is defective. 20% of the reasons for black spots in the production process of silicone tubes/strips come from the black spot impurities in the raw materials.
2: Secondary rubber mixing results in too many black spots. Generally, the vulcanizing agent will fail after long-term storage of the compounded rubber. At this time, it is necessary to re-mix and add the vulcanizing agent, and black spot impurities may also appear in the second rubber compound.
3: Caused by molding operation. During the production process, if the exhaust stroke of the machine is too large, black spots may be sucked in during exhaust.

Two: the treatment method of impurities and black spots on the surface of the silicone tube:
1: Before mixing the rubber compound, it is necessary to carefully check whether the product has black spot impurities.
2: During the secondary rubber mixing process, there may be contamination of the rubber from the hands, the vulcanizing agent and the air, resulting in black spot impurities in the molded and vulcanized products.
3: During the molding operation, the surrounding environment of the machine and the indoor environment need to be strictly controlled, and do not pay attention to the excessive debris on the mold. There are many debris on the new online mold, so the general silicone products Processing manufacturers will first sandblast the mold or spray Teflon to keep the mold clean during mold washing, which can solve the key black spot defects; during the process of weighing materials, it is necessary to pay attention to clean hands, and clean the work surface and surrounding everything that may cause damage. All items with black spots and impurities should be cleaned up. Human phenomenon is an important factor for the appearance of bad appearance. Therefore, you should organize and rectify yourself to develop good operating habits to prevent bad appearance of black spots!

At the same time, it is also reminded to pay attention to the following points: deal with the dirt and impurities of the product while mixing the rubber, the hands of the operator when mixing the rubber, the tools that come into contact with the rubber material, the production machine should be kept clean, the extrusion lines should be kept clean and so on. matter