Film winding torque principle

As the winding diameter increases, the film slowly tightens, and the hardness of the film roll is affected by the torque force exerted by the central axis. For specific winding methods, please refer to the article "Introduction to the Winding Methods of Film Slitting Machines". When using the center curling or surface curling method, generally speaking, the winding tension value is 25% to 50% greater than the tension when the film first enters the winding process. . Then as the diameter increases, it slowly decreases to a tension value or lower than the tension when entering the winding. When the crimping tension is greater than the tension of the film entering the roll, the surface drive will generate or apply a negative torque. As the diameter of the roll increases, the surface drive will gradually provide smaller braking force until it reaches 0 torque, that is It is said that the winding tension and the film running tension are equal at this time.
If the take-up tension is initially programmed lower than the film entry tension, the surface drive will apply a positive torque to balance the higher film entry tension with the lower take-up tension. Although different film winding machines have different hardness formation, the basic principles are the same, and the TNT principle can be used to achieve stable winding. The setting and programming of TNT parameters by Lipu Machinery need to be combined with the design of the winding process, the type of material, the material type of the winding, the operating speed of the winding, and many other factors to choose the winding process that best suits you.