How to choose a paper machine forming fabric?

August 18, 2020

últimas notícias da empresa sobre How to choose a paper machine forming fabric?

 

Polyester forming mesh is commonly used in the forming part of paper machine. In the past, copper meshes were mostly used, and polyester molding meshes were mostly used. The molding mesh was mainly woven from polyester monofilaments.

In order to increase the service life of the forming net, some manufacturers add nylon monofilaments with better wear resistance to the weft at intervals.

Extending the service life of the forming wire is of great significance for reducing the cost of paper production. The following are some effective experiences summarized in the actual operation of the paper machine for reference.

1. The elements of the Fourdrinier paper machine must be accurately aligned in a line and in good mechanical condition;
-All water filter elements must be fastened well and at the same height;
-Check that the tension roller and automatic tension adjustment device cannot bounce up;

2. Poor net case cleaning and daily maintenance is one of the main reasons for the shortened net life;
(a) Make sure that no fiber buildup forms a slug that falls inside the forming wire;
(b) Keep the scraper in good condition;
-Prevent slurry from accumulating on the guide roller and breast roller;
-The first outer roller is very important to prevent the net from being damaged by the pulp;
-The angle of the scraper (approximately 25~30 degrees) is very important to ensure proper wiping without scratching noise and jumping;
-The scraper load needs to be tested repeatedly, but overload must be avoided;
-For any and all scrapers, swing is a good warning;
-Check the breast roller scraper frequently to avoid mesh marks or excessive water on the breast roller;
(c) Check the holes in the drain pan, rusty bolts or sprinkler valves;
-Uneven water flow around the spray valve may cause the metal to peel off and break and flow through the spray pipe;

3. Eliminate abrasive fillers, such as calcium sulfate;

4. Check the trajectory, correction, tension, load and slip of the net;
-Ensure that the transverse tension of the paper machine is even;
-Don't run the forming net under too loose state;

5. Keep the temperature and pH of the spray water consistent with the slurry;
-Ensure that the spray clean water pipes on both sides are not blocked;

6. The upper surface of the vacuum suction box with low friction coefficient;
-Check if the upper surface of the vacuum suction box is flat;

7. Reduce the number of vacuum suction boxes and increase the opening;
-Reduce the degree of vacuum to prevent the forming net from jamming or blocking on the vacuum suction box;

8. Remove the coarse sand in the slurry (centrifugal cleaner);
-Check whether there are scratches and burrs on the surface of the forming board, vacuum suction box and cutting board;

9. Use net life extension agent (net cleaning agent);

10. There should be adequate traction to ensure that the net does not slip at the breast roller;

11. Run under the lowest suction box vacuum in the operating regulations;
-Ensure that the water flow can freely enter the water seal groove from the suction box;

12. Check the installation of the forming plate to ensure that there is enough space for even and smallest breast roll drainage;

13. Check the cleaning of the net steering roller system;
-Check the scraper, scraper load, spray water, bearing and excessive spray water pressure;

14. Check the wear streaks of the edge fixing device or the headbox cheek to determine if the installation is too low.