Views: 0 Author: Site Editor Publish Time: 2023-12-28 Origin: Site
Paper breaks are the most undesirable occurrence in normal production of paper machines. It seriously disrupts the production order, brings passiveness to the air supply, paper breakage, transmission and other systems, and requires a lot of manpower, time and other costs. Especially try to avoid paper breaks in the dryer section.
Problems with the wet paper itself:
(1) slime: If there is slime mixed in the paper pulp, because the moisture of the slime is difficult to escape, when the paper web passes through the Couch roll area or the press roller area, the low amplitude of the slime and surrounding thus causing Paper page breakage
(2) Resin: When forming the mesh part, the slurry where the resin is stuck is placed around, causing paper holes and possible paper breaks;
(3) Hard pulp lumps: If the slurry is not properly processed and the slurry contains hard pulp lumps, it will affect the fiber interweaving of the paper sheet, causing perforation and paper breakage when passing through the press roller;
(4) Rotten edges: cracks on the edge of the paper, which can easily cause breakage during pressing;
(5) The pH value is too high: When the pH value of the slurry is greater than the required value, the slurry will become sticky, which will affect the dehydration of the wet end and the paper sheet will easily stick to the roller and break;
(6) Paper defects caused by abnormal paper making conditions in the wire section: imbalance of pulp-to-web speed ratio, incorrect selection of web quality, poor web dehydration rate, resulting in poor formation and possible paper breaks.
Press felt Disadvantages:
The fur layer in some places is not strong and easy to peel off; the surface fluff has been shaped to varying degrees, making the fluff in some places appear longer or shorter. In addition, the blanket may be damaged or broken if it is not adjusted in time during the production process.
The press felt or roller surface is not clean:
(1) The holes in the vacuum roller shell are blocked;
(2) There are uneven thick paper foam and pulp blocks stuck to the surface of the paper roller;
(3) The scraper on the upper top press roller or stone roller is not tight;
(4) The press felt is not clean or partially blocked.
Unreasonable operating conditions:
(1) The edge sealing width of the vacuum chamber in the vacuum roller is smaller than the width of the paper web, which causes excessive moisture at the edge of the paper web and may crush the paper edge;
(2) The pressure control of the pressing line is not tight;
(3) Speed difference control is unreasonable;
(4) The edge sealing of the vacuum chamber of the vacuum suction roller is too high.