Huai 'an Bst Trade Co., LTD , https://www.bstoral.com
The corrugated paperboard production line begins with a single-faced corrugating machine, which creates strong single-sided corrugated paperboard by bonding corrugated medium with flat liner paper. After passing through a bridge, the material is coated with adhesive and sent to the dryer for heat-setting and pressing according to production specifications. The board then undergoes slitting and cross-cutting to form box boards.
It’s clear that raw paper waste and low yield often occur in key stages such as the single-faced corrugating machine, conveyor bridge, gluing process, drying, and cutting operations. Below are some insights and practical solutions based on real-world experience.
1. **Single-Faced Corrugating Machine**
- If the original paper isn’t properly attached to the corrugated medium, it may result in misalignment or poor adhesion. Adjusting the speed and using the “three points and one line†method can help align the paper correctly.
- Paper cracking during preheating can be avoided by reducing the warm-up area or manually guiding the web to reduce tension.
- When tearing occurs at the reel, use a slightly larger piece of corrugated paper to patch the gap before feeding it into the machine.
- Excess paper heads should be cut neatly when shutting down to prevent damage. If not used immediately, they can be rewound for future use.
- Frequent starts and stops should be avoided to prevent sticking and tearing.
2. **Conveyor Bridge**
- Too many single-sided boards on the bridge can cause adhesion issues if the dryer speed is too fast. Operators should maintain consistent speed and ensure the stacking doesn’t exceed one-third of the bridge length.
- Adjust the paper grippers to match the width of the corrugated paper to avoid scraping.
- Before drying, adjust the position of each layer to ensure alignment.
3. **Glue Compounding**
- If the base paper becomes brittle after preheating, reduce tension or assist in rotating the web to prevent tearing.
- Misaligned edges during drying can lead to waste. Ensure all layers are aligned before entering the dryer.
- If the paper edge isn’t perpendicular to the gripper, adjust the position of the folder to improve alignment.
4. **Dryer**
- Prolonged dryer operation can cause plastic separation, especially in three-ply boards. Avoid stopping unless necessary, and cut off excess layers if downtime exceeds a few minutes.
- Dryer belt deviation can cause glue loss and poor adhesion. Adjust the belt and inspect glued boards for quality.
- High drying temperatures can lead to debonding. Increase dryer speed, reduce steam, and adjust glue application accordingly.
5. **Pressure Line, Vertical and Horizontal Cutting**
- Pressure roller depth should be adjusted based on paper humidity to avoid breaking the surface or inner layers. Check for wheel misalignment.
- Delayed trimming can cause material shortages. Adjust the slitter device and coordinate with the conveyor system if needed.
- Dull knives can tear the board during cutting. Regularly sharpen or replace blades and avoid over-tightening to prevent injury.
In addition to addressing these issues, it's important to optimize paper usage, keep trimming within 0.5–2 cm, and handle defective boards promptly. Avoid reusing damaged or unglued sections. By improving efficiency and minimizing human error, you can significantly reduce paper waste and increase cardboard yield.