Views: 13 Author: Easttai Publish Time: 2020-11-14 Origin: Site
How to deal with paper machine paste net
Paper machine gluing means that there are pieces of holes on the mesh surface that are blocked and cannot filter water. Paste has a great influence on paper formation and dehydration as well as normal papermaking. When appearing along the mud net, after the paper goes online, the paper around the mud net is filtered, the thickness of the pulp layer becomes thin, the paper on the sticky net flows to the surrounding, the sticking surface becomes a thin pulp area or no pulp area, and finally becomes As a transparent hole or hole in the paper. Germany insists that the common type of confusion has star-shaped white dots, and each white dot is blocked by 1-4. There are also strips with a length of about 20-30 mm and a width of about a few holes. At the end of the net joint, the star-shaped white dots are pasted into a horizontal rod with a certain width and greater density.
The main reasons for paper machine pasting are the following types:
⑴ A mixture of fine fiber and non-fibrous characteristics.
If calcium carbonate is used as the filler, the mixture of the yellow sticky substance of calcium carbonate and the fine fibers can cause the phenomenon of sticky network.
The temperature in summer is very high. If you use free rosin pulp, the pulp will solidify and stickiness will easily occur.
(2) Resin block. If wood pulp with higher resin content is used, the resin block will stick to the net.
⑶, asphalt blocks, white wax spots, plastic spots, oil stains, rubber blocks, paint spots, etc., mainly appear in paper machines that use waste paper pulp containing these impurities as raw materials.
Nutnet not only affects paper quality, but also affects production. In many cases, it is necessary to stop work, or even stop the machine several times. In the most serious case, the concrete material is not cleaned at all and the steel must be replaced.
How to deal with the paper machine paste net:
⑴, the treatment of the paste net caused by non-resin obstacles
a. When the sizing net is built, the vacuum degree of the vacuum suction tank should not be too high, preferably lower than usual. If the total vacuum degree is reduced, the moisture of the wet paper sheet will excessively affect the normal imitation. You can also reduce the vacuum degree of the first and second vacuum boxes only.
b. Appropriate tensioning of the forming net is often effective in eliminating the paste caused by the pits on the net, the paste at the fold and the elimination of paste at the joints;
c. Strengthen the washing of the net during the return journey of the forming net, especially the swinging high-pressure washing water system should be normal, and the pressure should reach 20-25kg/cm2;
d. When the glue net is found, please immediately remove the foam in the front box of the net. Because the foam contains a lot of alcohol. Because of the fool's extract, the foam is often connected to the net together with the paper, and then becomes a paste net.
In addition, measures such as appropriately reducing the freeness of the rosin compound when the temperature is high in summer, reasonably controlling the dissolution and adding process of calcium carbonate, and preventing the appearance of yellow sticky substances will help solve the problem of paste network.
(2) The following measures can be adopted for the paste net caused by resin barrier:
a. Reasonably control the resin content of pulp, which is the most basic measure;
b. Reasonably control the pH value and use alum to control resin barriers;
c. Strengthen the cleaning work, regularly clean the pipes, beaters, storage tanks and various paste tanks to prevent excessive accumulation of resin. When falling into the paper, it will cause a paste network on the paper machine
d. Use resin dispersant and fixing agent to disperse and remove resin.
How to deal with the paper machine paste net? When using waste paper as a raw material, it is necessary to strengthen the treatment of waste paper to prevent the mixing of impurities such as asphalt and plastic. When the net is stuck, it is generally blown with steam, and organic solvents (such as gasoline or kerosene) can be used to clean asphalt, rubber blocks, oil stains, and paint. Under normal circumstances, do not use acid to treat the forming mesh, because the mesh wire becomes matte after acid erosion, it is easy to hang on the fiber, and the phenomenon of meshing is more heavy. The easy-adhesive mesh at the joint of the general forming mesh is also treated with chemicals during welding, which is related to the unsmooth mesh wire. Sometimes the paste network caused by the bonding of fine fibers, resin and CaSO4 precipitates can not be washed away with acid, alkali, benzene, etc., but the copper ammonia solution is used to dissolve the small fibers, and good results can be achieved. Note that a lot of clean water should be used after treatment to avoid corrosion of the forming screen. Use less than 10% alkaline combustion solution or 5-10% hydrochloric acid solution (note that the concentration does not exceed 10%) or other cleaning agents to clean the plastic net. When washing carefully, you must turn off all the wetting water, washing water, washing at crawl speed, and thoroughly washing with water after washing.