Tension control is a very important mechanism of the web-fed flexographic printing machine. If the tension of the printing material changes during the paper feeding process, the material belt will jump, resulting in misregistration.  it may even cause the printing material to break or fail to operate normally. In order to make the printing process stable, the tension of the material belt must be constant and have an appropriate size, so the flexographic printing machine should be equipped with a tension control system.