iron cover and pad_washing machine front cover

Strictly control the pH value of large roll galvanized wire bath, research shows that the size of the bath pH value directly affects the quality of steel wire coating, improper control of pH value will cause loose coating. When the pH value is greater than 3, the steel wire coating has burr caused by fine dendrites, and the surface is not smooth. The current density is strictly controlled. From the microscopic morphology, the higher the current density, the larger the zinc layer grain deposition, the less dense the corresponding zinc layer.