The structure of the ordinary air expansion shaftis a long strip through the shaft, no section, so there is no slip function, and there is no corresponding slip action for the tension change due to the material change when cutting multiple strips, and the tension changes or the material thickness When it is not uniform, it is easy to produce uneven winding, broken strips, loose winding, and unwinding, resulting in material loss. The winding speed is low and the work efficiency is poor.

    Differential shaft, also known as friction shaft. It is applied to the winding shaft of the slitting machine, and also used for the unwinding shaft in special occasions. The purpose is to use the principle of the slippage of each slip ring on the differential shaft, so that multiple rolls on the shaft can always maintain constant tension for winding and unwinding. The use of differential shafts improves the speed, winding accuracy, automation, preparation time, and humanization of the slitting machine. In particular, a variety of cast polyester thin materials with poor stretch resistance and large thickness errors use differential shafts to reduce the difficulty of winding.

The differential shaft has been widely used in slitting and rewinding of plastic film, metal foil, paper rolls, and PVC film rolls. At present, it is continuously extending to other fields, other industries, and the slitting and rewinding of other special materials.