In the unwinding tension zone, the operator needs to input the proper tension value, and the tension control adopts the closed-loop tension automatic control system. The system has a pair of tension sensors, fixed at the ends of a guide roller in the unwinding tension zone, for measuring the actual tension value of the printing material. The system will correct the tension deviation and maintain the input tension level. In the printing tension zone, the speed of the printing material entering and exiting the zone is controlled to ensure a stable tension value. Generally, the diameter of the discharge tension roller is increased to increase the linear velocity of the discharge tension roller surface so that a tension zone with a constant tension value can be formed between the feed tension roller and the discharge tension roller.

In order to eliminate the influence of the printing plate on the tension of the printing material, the diameter of the printing roller should also be gradually increased to keep the tension in the area stable. Therefore, users should pay attention to the maintenance of the machine, the position of the impression cylinder on the flexo unit can not be freely exchanged. The tension value of the rewinder tension zone is based on the situation of the printing material to be rewound, and the rewinding motor is independently controlled to ensure the tension value. In general, for extensible materials such as plastic films, the value of the tension or the gradation rate should be fixed at the time of rewinding; for the non-extensible and smooth surface of the substrate, the rate of change in the degree of gradation must be large. .

Source: HC Network Printing Industry Channel