Crumbing

The crumbing refers to the breaking or fragmentation of the sheet into smaller pieces or crumbs. This can occur due to various reasons such as excessive tension, improper handling, or mechanical issues in the paper machine. Crumbing can result in inferior paper quality and may cause production issues if not addressed promptly.

Troubleshooting Guide:

1. This is the occurrence of small amounts of fiber, chemical, filler, etc. that are bleeding or picking out of the sheet and may collect on machine elements.

2. Check to ensure that the pH of the white water, stock chests, and wet end are within target range.

3. Chemical imbalances at wet end can cause crumbing.
— Check chemical addition rates and monitor zeta potential.

4. Too much or too little refining can contribute to crumbing.
— Optimize fibrillation refining while minimizing production of fines.

5. Check broke for chemicals, pH and types of fiber.
— Too much hardwood or sulfite pulps can contribute to crumbing.

6. High defoamer usage can impair internal bond and lead to crumbing.

7. Crumbing at the peeler roll may be due to:
— crushing in the press nip.
— too little refining.
— chemical imbalance.