Reasons for black spots on the surface of the steel strip


Reasons for Black Spots on Steel Strapping Seals

1. Surface roughness of steel strip ( https://www.dlstrap.com/product/strapping-seals/ ): If the surface roughness is obvious, the gap between the steel coil layer and the layer interface will increase, which is conducive to the evaporation of the emulsion.

2. Cold coil type of annealed base material: The evaporation of the emulsion during the annealing heating process will seriously affect the quality of the cold coil. If the steel strip is wavy, it will also have a certain impact on the volatilization of the interlayer emulsion.

3. Residual chloride ions on the surface of the steel strip: If the rinsing is not clean, the chloride ions will remain on the surface of the steel strip, causing electrochemical corrosion and producing black Fe 304.

4. Emulsification volatility: high-quality emulsification thermal evaporation can reduce the shortcomings of cold-rolled coil black spots.

5. custom PET Plastic Strapping at wholesale ( https://www.dlstrap.com/product/plastic-strapping/pet-plastic-strapping.html ) price coil coiling tension: reduce coiling tension, increase coil gap, make coil gap flow, and fully volatilize and emulsify.