The Forming Fabric How to Affect The Finished Paper Quality

The forming fabric is the core component of the paper machine clothing, directly involved in pulp dewatering, wet paper web formation and transportation, and its performance has a decisive impact on the quality of the finished paper.

1. Dehydration Performance and Fiber Distribution Uniformity

1) The mesh number, weaving method, and air permeability of the forming fabric determine the dehydration rate and uniformity. Dehydration too quickly can lead to uneven fiber coagulation, resulting in "pulp flow" or "semi transparent" areas; If dehydration is too slow, it will affect the speed and dryness of the paper machine.

2) High fiber support (such as three-layer mesh structure) can make the fibers more evenly arranged, reduce Z-direction arrangement, thereby improving paper tightness, tensile strength, and tear resistance.

2. Surface Quality and Mesh Marks of Finished Paper

1) If there are mesh marks on the surface of the forming fabric (caused by fabric nodes or uneven structures), they will leave imprints on the paper surface, affecting printing suitability and appearance.

2) Mesh free design can produce paper with a smoother and more delicate surface, especially suitable for cultural paper and tissue paper.

3. Retention Rate and Filler Retention

1) The forming fabric needs to have good retention of fine fibers and fillers. If left with poor properties, it will lead to loss of fillers, increase in white water concentration, and result in uneven ash content and decreased strength of the paper.

2) Stuffing (mesh blockage) will further reduce retention and dehydration efficiency, resulting in uneven paper thickness, thin areas or holes.

4. Operational Stability and Paper Uniformity

1) If the formed net deviates, arches, or wears, it can cause lateral quantitative fluctuations in the paper web, resulting in "loose edges," "cracked edges," or even paper breakage.

2) Mesh with poor dimensional stability is prone to elongation or contraction during high-speed operation, which can damage the uniformity of the paper.

5. Two Sided Difference Control

1) The use of top and bottom mesh collaborative dewatering (such as a mesh structure) can reduce the double-sided nature of the paper, making the front and back sides closer together.

2) Although some forming fabric can accelerate dehydration, they may experience increased wear due to shortened water lines, indirectly affecting the quality of the resulting paper.

6. Material and Lifespan Affect Long-term Stability

1) Polyester forming fabric (replacing early copper mesh) can maintain long-term stable dehydration and molding performance due to its corrosion resistance, wear resistance, and long service life.

2) If there is wear, shrinkage or blockage in the later stage of use of the formed net, it will lead to a decrease in dehydration ability, an increase in white water reflux, and ultimately cause paper breakage or paper disease.

In summary, the forming fabric directly affects the uniformity, strength, surface quality, and production efficiency of the paper through multiple dimensions such as dehydration control, fiber support, surface replication, and operational stability. Choosing a forming fabric that is suitable for the type of paper, vehicle speed, and process conditions, and maintaining its good operating condition, is the key to ensuring high-quality paper production.