How to Extend the Service Life of Forming Fabric and Precautions

The forming fabric is an important piece of equipment on the paper machine. It is a component for forming and dehydrating the paper on the paper machine. It will dehydrate the pulp suspension from the headbox and run it to the subsequent sections.

Forming fabric is mainly woven from polyester monofilaments. So it has excellent strength, dimensional stability and chemical corrosion resistance. 

To significantly improve the service life of the forming fabric, manufacturers will add nylon monofilament braiding with better wear resistance at intervals in the weft. Its composite weaving structure cleverly combines the overall stability of polyester and the excellent wear resistance of nylon, which greatly enhances the durability of the forming fabric against fiber friction and mechanical wear, effectively extending the replacement cycle and reducing operating costs.

How to Effectively Extend the Service Life of Forming Fabric

Extending the service life of the forming fabric is of great significance in reducing the cost of paper production. Here are some effective experiences summarized in actual operations for reference:

Ensure Proper Alignment and Mechanical Condition

Ensure all components of the paper machine forming section are precisely aligned in a straight line and in good mechanical condition.

• All filter elements must be securely fastened and at the same height
• Check the tension rolls and automatic tension adjustment device to ensure they do not bounce up.

Poor cleaning and routine maintenance of the forming fabric are a major reason for the shortened lifespan of netting.

• The goal is to ensure that no fiber clumps form and fall into the inner side of the forming fabric.
• Keep the doctor blades in good condition.
• Prevent slurry from accumulating on the guide rolls and breast rolls.
• The doctor blade angle should be set to approximately 25°–30° to ensure effective moisture removal. This also helps to avoid scraping noises or vibrations caused by improper angles, thereby reducing wear on the forming fabric.
• Regularly inspect the breast roll doctor blade to prevent forming fabric marks and excessive water accumulation on the breast roll surface.

Maintain Proper Fabric Tension, Tracking and Drive

Check the forming fabric’s trajectory, calibration, tension, load, and slippage.

• Ensure uniform lateral tension of the paper machine.
• Do not run the forming fabric in a too relaxed state.
• Check whether the tension and load are reasonable.
• Ensure sufficient traction to prevent the forming fabric from slipping at the breast roll.

Keep the Forming Section Clean and Maintain Doctor Blades

• Prevent fiber and stock buildup. Remove any formed lumps before they fall onto the inner side of the forming fabric.
• Prevent the slurry from accumulating on the surface of the guide roller and the breast roll.
• Keep the doctor blade in good working order.
• Maintaining the doctor blade angle at approximately 25°–30° is important for effective water removal while preventing scraping noise and blade vibration, helping reduce unnecessary wear on the forming fabric.
• Adjust the doctor blade load appropriately to avoid overloading.
• Pay attention to the doctor blades’ oscillation, their abnormal oscillation may be a warning sign of equipment problems.
• Regularly inspect the breast roll doctor blade to prevent forming fabric marks and excessive water accumulation on the breast roll surface.

Optimize Spray Water and Reduce Abrasive Contamination

• Maintain the spray water temperature and pH value consistent with the slurry.
• Ensure that the water spray pipes on both sides of the forming fabric are unobstructed.
• Prevent metal fragments or other impurities from entering the spray pipes in the spray system, thereby damaging the formed fabric.
• Check the spray water pressure to avoid excessive pressure.
• Minimize the impact of abrasive fillers on the forming fabric.

Reduce Friction and Optimize Vacuum Dewatering

• The vacuum suction box panel uses a low coefficient of friction to reduce friction and wear during the operation of the forming fabric.
• Regularly check the surface of the vacuum suction box to ensure it is flat, and promptly remove any scratches or burrs.
• Avoid excessive vacuum to prevent the forming fabric from rubbing excessively, getting stuck, or getting blocked on the surface of the vacuum suction box.

In addition, regular inspection of all components in the forming section is also essential. Timely maintenance helps prevent forming fabric damage caused by component wear and extends fabric service life.