Huai 'an Bst Trade Co., LTD , https://www.bstoral.com
The corrugated paperboard production process begins with the single-faced corrugating machine, which creates a strong single-sided corrugated board by combining the fluted paper with a flat liner. After this initial step, the material is conveyed through a bridge to the gluing machine, where a rubber-coated composite paper is applied. The board then moves into the dryer, where it is dried and pressed according to the required specifications. Finally, the board undergoes slitting and cross-cutting to form the final box board.
It’s clear that waste in raw materials and low yield often stem from several critical stages in the process, including the single-faced machine, conveyor bridge, gluing, drying, and cutting operations. Below are some common issues encountered during these steps and practical solutions to address them.
1. **Single-Faced Corrugating Machine**
- **Misalignment of Paper**: If the original paper is not properly attached to the corrugated medium, check for skewing. Adjust the speed or use the "three points and one line" method—aligning a fixed point on the preheater cylinder with the paper edge and adjusting accordingly.
- **Paper Cracking in Preheater**: Reduce the warm-up area or manually assist in feeding the paper to avoid excessive tension.
- **Torn Paper in Reel**: If the paper tears at the reel, prepare a slightly larger piece of corrugated paper and apply a small amount of glue before inserting it into the machine. Ensure quick and accurate handling.
- **Excess Paper Ends**: Avoid cutting off excess paper unless necessary. When shutting down, cut neatly to ensure proper adhesion during the next run.
- **Frequent Start-Ups**: Minimize start-ups to prevent sticking and improve efficiency.
2. **Conveyor Bridge**
- **Overloading the Bridge**: Ensure the stacking capacity doesn’t exceed one-third of the bridge length. Maintain consistent dryer speed to prevent poor adhesion.
- **Width Mismatch**: Adjust the paper grippers to match the width of the corrugated paper. Trim any excess if needed.
- **Misaligned Boards**: Before starting the dryer, shift each layer of cardboard 2–3 cm to align with the slitter.
3. **Glue Compound**
- **Brittle Base Paper**: Reduce tension or manually rotate the web until it runs smoothly.
- **Misaligned Edges**: Align edges carefully before sending to the dryer. If misfeeds occur, increase the dryer speed, but be aware that some waste may result.
- **Uneven Running Distance**: Adjust the position of the paper guide to ensure even feeding and proper alignment.
4. **Dryer**
- **Long Drying Time**: Avoid long stops unless necessary. If stopping for more than a few minutes, cut the glued layers and bake the open sections.
- **Belt Misalignment**: Adjust the belt using the rectification handwheel. Inspect and manually bond any unqualified boards.
- **High Temperature**: Increase dryer speed and reduce steam, while informing the gluing machine to apply more adhesive.
5. **Pressure Line, Vertical & Horizontal Cutting**
- **Broken Paper or Pressure Line Errors**: Adjust the pressure roller depth based on humidity and ensure the concave wheel is properly aligned.
- **Delayed Trimming**: Keep the slitter adjusted and notify the conveyor operator to move the gripper if necessary.
- **Blunt Knife**: Replace or sharpen the transverse knife promptly to prevent tearing.
To minimize waste and improve yield, it's essential to manage the paper web effectively, keep trimming within 0.5–2 cm, and handle defects quickly. Always prioritize quality over repair when necessary, and eliminate artificial waste through careful planning and real-time adjustments. By addressing these issues proactively, operators can significantly enhance efficiency and reduce material loss throughout the corrugated board production line.