What are the winding methods of the film rewinder?

1. Surface winding (contact winding or friction winding):
Working principle: The surface friction between the surface winding roller and the wound material is used to drive the film roll and complete the winding. As the diameter of the film roll continues to increase, the film roll gradually moves outward along the guide rail.
Structural form:
Single-roller surface winding: The winding shaft and the paper core are against the winding roller. The winding roller rotates under the drive of the motor. The friction between it and the paper core drives the paper core and the mandrel to rotate together to achieve the winding of the film. Most of the mandrels use air-expanding mandrels, which are easy to operate and reliable to clamp.
Double-roller surface winding: Compared with single roller, double-roller surface winding has two winding rollers, which can provide more stable friction and better winding effect, and is suitable for some film materials with higher winding quality requirements.
2. Center winding:
Working principle: The film is wound on the center shaft through a center shaft or air-expanding shaft as the core component of the winding. The center shaft is usually driven directly by a motor or rotated by a transmission device, so that the film is tightly wound on the center shaft. This winding method can ensure that the internal structure of the film roll is tight, and is suitable for some film materials that require high internal strength of the film roll.
Features: The winding speed is fast and can meet the requirements of high-speed rewinding. However, it is necessary to pay attention to controlling the tension during the winding process to avoid excessive stretching or relaxation of the film.
3. Surface and center combined winding:
Working principle: Combining the advantages of surface winding and center winding, the surface winding method is used in the early stage of winding, so that the film can be quickly wound on the winding roller; when the diameter of the film roll reaches a certain degree, it is switched to the center winding method to ensure the tight internal structure of the film roll and the winding quality.
Features: This winding method can be flexibly adjusted according to the characteristics of the film and the winding requirements, and is suitable for many different types of film materials.
4. Interval winding:
Working principle: During the winding process, the winding roller does not rotate continuously, but intermittently. When the winding roller stops rotating, the film will remain still under a certain tension, and then the winding roller rotates again to wind the film on it. This winding method can effectively control the tightness and neatness of the film roll, and is suitable for some film materials with high winding accuracy requirements.
Features: The winding process is relatively complicated, and a precise control system is required to control the rotation and stop time of the winding roller, but high-quality film rolls can be obtained.
5. Double-axis cross winding (active winding):
Working principle: Two winding shafts are used to alternately wind. When the film roll on one winding shaft reaches a certain diameter or completes the winding task, the other winding shaft starts working, and the film roll that has been wound is unloaded and replaced with a new winding shaft. This winding method can achieve continuous production and improve production efficiency.
Features: It is necessary to be equipped with a complex mechanical structure and control system to ensure the smooth alternation of the two winding shafts. But it can reduce the downtime of the equipment and is suitable for large-scale production occasions.