The prevention and treatment of the quality problems of writing paper production

1. Beating

The slurry for producing writing paper can be beaten with various types of beaters, but at present it tends to be beaten with a disc refiner. Be aware of slurry temperature changes during beating. If the slurry temperature is too high, it will affect the sizing effect, leading to a decrease in sizing, which is very important for writing paper. Therefore, attention should be paid to the production process by changing the pulping process to reduce the temperature of the slurry, such as beater teeth wear, so that cut off capacity, etc., you must replace the new grinding plate, generally when the grinding plate tooth pattern wear up. #, about It can be replaced. Every time you replace a new disc, you must add fresh water to start the disc mill to grind, and the contact surface between the discs must reach +#. The quality of the refining can be ensured by the top. Due to the changes in raw materials and cooking conditions, the quality of the slurry also changes. Therefore, the beating operators must adjust the beating conditions in time according to the incoming slurry. Otherwise it will cause the pulp quality to fluctuate, affect the quality of the paper, and seriously cause the paper to be discarded.

2. Headbox

The headbox is a key equipment for the paper machine. It determines the formation of the web and the uniformity and stability of the paper web distribution, and has a great influence on the physical strength properties of the paper. Problems can be solved by observing the flow of pulp in production. For example, when it is found that there is a fixed wide or narrow longitudinal flow in the pulp stream ejected from the lip, the reason is usually caused by deformation of the lip or hanging of the upper lip. In addition, the rise of the fixing elements and the forming wire in the forming zone also causes a longitudinal flow phenomenon in the pulp flow. Therefore, the analysis process must be carefully observed.

Excessive adjustment of the screw during production will cause permanent deformation of the upper lip plate resulting in non-uniform quantitative distribution. Therefore, check the flatness of the upper lip regularly, and if necessary, readjust the lip so that the opening is uniform. Pulp fabrics should be reconstructed with multi-tube fabrics, and conical fabric masters should be used wherever possible. In order to prevent the instability of the pulp flow generated by the multi-ply cloth itself. Homogenizing rollers are the main components for leveling the pulp stream and preventing fiber flocculation, but the separation rollers and vortexes that tend to damage the distribution of the pulp flow are easily generated in the homogenizer roller, and tend to result in the formation of a slurry and a slurry. After discovering this phenomenon in production, it is necessary to properly adjust the rotation number and direction of rotation of the homogenizer roller. For those systems that do not work well, the direction of rotation of the homogenizer roller is preferably the opposite of the flow of the slurry at the bottom of the headbox, otherwise a significant portion of the flow will pass along the bottom, causing serious non-uniformity. Keeping the headbox clean is an important task in the operation of the headbox. It is a very common phenomenon that bubbles that are mixed with air accumulate on the flow path or the upper lip of the headbox. When the speed of the pulp flow is greater than 0.9 m/s, the problem of the water headbox can be basically solved. The stagnation zone formed in the air-cushion or open headbox creates slurry that can cause cleaning problems and can be removed by adjusting the speed and direction of the homogenizer roll. When installing the lip, carefully inspect the joints and ensure that they are straight to prevent accumulation or slurrying in uneven areas. In addition, the slurry and the drugs in it gradually accumulate on the surface of the headbox, so the headbox must be brushed regularly.

3. Department of network

The processing and manufacturing of all the rollers of the net department must be strictly in accordance with regulations, especially the rigidity and surface of the rollers should be fully noted, otherwise the papermaking nets will wrinkle and bulge in the production. The rollers of the net part, especially the breast roll, are easy to adhere to the fine fibers, so care must be taken to prevent the sticking material from causing deformation of the net, such as furrows or squeaks. At the same time, the squeegee of the breast roller should be checked regularly to prevent local squeezing into the pulp. Material and so on.

Reprinted from: China Used Equipment Network