Do You Know How to Use The Paper Making Felt ?

The Usage and Application of Paper Making Felt

The Change of Press Felt

• Keep the press felt clean to prevent oil stains from sticking to it.
• There should be sufficient clearance between the roller shaft and the shaft sleeve, or between rollers, to facilitate the installation of the paper making felt, avoiding the need to force the felt through the gap.
• Before the paper making felt is flattened on each roller, do not lower the upper press roller, couch roller, or lift the support roller, etc. Before the paper machine is running normally during the test run, do not apply pressure on the press roller.
• The removed bearings, oil rings, screws, and other components should be placed in a designated location, and they should be promptly installed after the paper making felt is replaced. Before starting the machine, check for any foreign objects above and below the paper making felt, as well as the pressing and auxiliary devices.
• When the paper making felt runs slowly and becomes well-operated, it can be evenly moistened with water until it reaches water absorption saturation. Then, adjust the tensioning roller to tension the felt to its optimal length, width, and dewatering state.
• When the downtime is relatively long, the paper making felt should be loosened to prevent excessive tension concentration.

When Replacing the Paper Making Felt, It Should also be Noted That

• The BOM press felt has good stiffness.
• BOM press felt have strong specificity, and even the press felt of the same specification can vary greatly in performance. Therefore, care should be taken not to use the wrong press felt.
• The front and back of the BOM press felt have significant differences. The standard side is the paper-backed side (front side), and it should not be reversed.
• The running direction of the felt on the paper machine should be in accordance with the direction indicated by the arrow on the felt surface.

The Benefits of Cleaning Paper Machine Felt

• Prevent blockage
• Prevent compaction
• Remove a certain amount of moisture from the wet felt to enhance the dewatering of the paper sheet in the press zone.

There are two methods for cleaning wet felt: mechanical and chemical.

Mechanical cleaning: During paper machine operation, paper making felts accumulate impurities such as fibers, fine impurities, and adhesives, which clog the felt pores and affect dewatering performance. Mechanical cleaning primarily relies on high-pressure spray devices, using water pressure and impact force to wash away the debris from the felt surface. The ideal cleaning system is composed of five independent parts:

• low-pressure flushing spray pipe
• detergent spray pipe
• lubricant spray pipe
• high-pressure spray pipe
• wet felt vacuum suction box

Chemical cleaning: Currently, the most commonly used chemical cleaning method for paper machine felt is shutdown cleaning. For the needle-punched felt with a bottom net composed of 100% nylon fibers, a 5~10% alkaline detergent (such as caustic soda) can be used, with the washing temperature not exceeding 50°C; the residence time is 20 minutes. After each wash, the wet felt should be thoroughly rinsed. Additionally, special attention should be paid to avoiding contact between this washing solution and wool-containing felts.
In addition, there are also some chemical cleaning agents for press felt.