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:

Alignment and Cleanliness Are Where Wear Starts

Most forming section problems show up as forming fabric wear before they show up as breakage, and almost all of them trace back to alignment and cleanliness. 

On the paper machine we run, the single biggest lifespan killer isn’t the forming fabric itself, but what gets between the fabric and the rolls. If the forming section isn’t dead straight, the wire tracks to one side and you feel it as uneven edge wear within a shift. 

To avoid these problems, we always set the filter elements at the same height and torque them down, because a loose one vibrates and beats the fabric in the same spot every revolution.

Common Forming Fabric Tension Errors and How to Avoid Them

Don’t let the forming fabric run slack, or it will wander around the rolls and slip at the breast roll. 

But don’t crank it up to compensate, either. Over-tension moves the damage elsewhere: it overstresses the forming fabric and the rolls, and loads the surrounding components harder than they’re built for. 

The number on the gauge matters less than how evenly it’s spread across the width. A 5% side-to-side imbalance is enough to walk the seam out of position or make the forming fabric track crooked. Hold it stable and even — enough traction to grip, not enough to strain. 

And trust the reading only after you’ve checked the hardware: watch the tracking and the load at the same time, and confirm the tension roll isn’t bouncing. A bouncing roll lies to the sensor, so find out why it’s bouncing before you touch any settings.

Cleanliness Is Non-Negotiable

Slurry and fibre that build up on the guide and breast rolls will eventually fall onto the inside of the forming fabric, where they grind against the vacuum box. 

The breast roll doctor blade is often overlooked: Once the doctor blade becomes dull, periodic marks will appear on the forming fabric, and water will accumulate on the roll surface, forcing you to increase the vacuum to ensure the paper passes through smoothly.

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.

The Hidden Causes of Forming Fabric Wear

Spray water damage to the forming fabric is often more severe than people expect. 

The temperature and pH of the spray water should be kept similar to those of the slurry to prevent the polyester material from experiencing thermal or chemical shock.  

Meanwhile, keep the pressure moderate; if it’s too high, it will force the filler and fine fibers into the forming fabric openings. 

The real enemy is contamination: one metal sliver in the spray header scores the forming fabric for its whole life. 

Same story on the vacuum box, a flat, burr-free panel with a low-friction cover keeps the fabric from galling, but over-vacuum will suction the wire onto the box and drag it until it jams.

None of this is complicated, but it’s all sequential.

Wear on the chest roll doctor blade can cause an increase in vacuum pressure, resulting in accelerated wear on the anilox blanket and causing other problems that may arise as a result.

Inspect the section end to end on a fixed schedule, you can catch the chain before it starts and longer the use life of your forming fabric.

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.