1. Purpose & Functional Orientation
This device is installed at the in‑feed section of roll‑fed paper cutters, sheeters and printing machines. It eliminates residual curl stress of paper rolls caused by long‑term winding around the paper core. Before entering subsequent processes, the web is restored to flat condition, so as to guarantee the accuracy and stability of paper feeding, positioning, cutting and printing.
Application: All electrically controlled. Suitable for paper rolls, film rolls and sheet‑type web materials prone to curling.
2. Working Principle
After long‑term winding on the paper core, the paper web retains internal bending stress. When unwound, it naturally bends toward the inner side of the roll (curl direction).
The web passes over one or more decurl shafts. Adjust the relative position of decurl shafts to change the decurl angle (the wrap angle of web against decurl shafts).
The web undergoes repeated slight bending in the direction opposite to its original curl, which gradually releases internal stress.
After multiple reverse bending cycles, residual stress of the web is removed, delivering flat paper output.
3.Three Types of Decurl Configurations
3.1 Triangular Decurl
Matching tension control is required. The paper‑web threading path at the decurl section forms a triangle. The whole unit can rotate 360°, enabling full adjustment of the web wrap‑angle range and decurl depth.
CHM Paper Sheeter Machine|Paper Roll to Sheet Sheeter Machine-Decurler Display
3.2 Straight‑Line Decurl
Matching tension control is also required. It features a compact structure with a wide adjustable wrap‑angle range.
3.3 Rubber‑roller Decurl
It comes with built‑in tension adjustment. Supported by large‑arc rubber rollers, the unit can rotate by a certain angle to adjust the wrap‑angle range; the pressing force is also adjustable.
4. Technical Features & Performance Effects
Prevent paper defects: Avoid edge‑warping, bulging and corner‑curling of paper after cutting or printing.
Improve processing accuracy: With flat paper web, the precision of paper feeding, positioning, cutting and printing processes is significantly enhanced.
Reduce errors: Effectively minimize quality defects such as skew cutting, uneven paper lengths and printing dimension deviations.
Wide adaptability: Adjustable decurl angle to fit paper materials of different grammages and varying curl levels.
5. Installation and Commissioning
Mount the decurl device between the in‑feed section and processing station, ensuring consistent web running direction.
Route the web sequentially over guide rollers and decurl shafts, and verify correct wrap‑angle position.
tart operation at low speed, observe web condition and gradually adjust the decurl angle.
Check the flatness of outgoing paper, perform repeated fine‑tuning until edge‑warping and corner‑curling are eliminated.
Record the optimal angle parameters as standard settings for mass production.
6. Maintenance
Regularly clean the surface of decurl shafts to prevent accumulation of paper dust and oil contaminants, which would impair bending uniformity.
Inspect the angle‑adjustment mechanism for looseness; retighten components when necessary.
Check whether guide rollers rotate freely and ensure adequate bearing lubrication.
After long‑term shutdown, perform dry‑run test prior to formal production to confirm normal rotation of all rollers.
In summary, the decurl unit effectively relieves the bending deformation of paper rolls and eliminates web‑curl defects. With strong versatility, this component has been widely applied in various printing machine,paper sheeter machine,paper mills,printing houses. Should you wish to know more product features and technical details, please feel free to contact us.
CHM,the Chinese professional manufacturer of paper sheeter machien and A4 paper cutting machine.With over 2o years of experience in this industry,we will provide you the suitable and useful suggestions.
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