In the process of papermaking, we need paper making machines, drum pulper, paper digester, pulp washer and so on. What’s the working principle of these paper making machines?
Dehydration mechanism and characteristics of the table
Water mechanism: water attached to copper screen is first scrapped out by front horn. When the copper screen slides over the horizontal plane in the front of the table, this will form a wedge space with the inclined plane at the rear. Due to the relative motion that two planes are gradually separating and the adhesion effect of water, the wedge space will generate negative pressure to further accelerate the dehydration process. The separated water is attached on the bottom surface of the copper screen and is pushed down to the neat table that it is scrapped out here.
Dehydration characteristics of the table
Because the effect of dehydration table is tempered, the screen of middle or high speed paper making machine often uses the table for dehydration to reduce the loss of fiber fillings and rubber and improve the paper formation. At the same speed, the dehydration effect of single table is not better than that of common table roll. But the number of the table in the same length range of screen and table is more than that of table roll. Therefore, the total amount of dehydration water of the table is larger than that of table roll.
Working process of drum pulper
Controlled by the weighing device, waste paper is transmitted by the conveyor belt into high concentration repulping area. Water and chemicals should be also weighed by the weighing device. In the high concentration area waste paper will be soaked by water and chemicals soak to reach14%-18% concentration. During the rotation process, the waste paper will reciprocally drop and fall onto the hard inner surface of rotating drum from a high height, which can effectively make the waste paper dispersed into the fibers without broken impurities. The repulpped pulp can move forward through the opening of the U shaped baffle in the rotating process. At about 40℃, it will enter the screening area in 20mins to 30mins. Here it will be diluted to 3%-4% concentration by the water spraying pipes of the rotating drum, and flow into pulp tank through the sieve holes, while the impurities will be discharged from the opening at the end of the drum.
The drum pulper system has the following advantages:
- Excellent function of the impurity removal;
- Low power consumption;
- Good deinking effect ;
- Due to screen is very tempered, the chance of the impurity getting mixed with good pulp through the sieve holes is very low;
- The impurity is almost not contained of fiber and water.
Fiber classification processing
Using a screen or the fiber grading classifier, the fiber can be divided into long fiber pulp and short fine fiber pulp. The screen is called fiber grading screen, such as Ultra-VC fiber grading screen from TBC Company. The fiber classification has the following advantages:
A. To reduce power consumption, because fine fiber can be without pulp beating process.
B. To fully perform the function of long and short fiber respectively.
Heat treatment method and relevant equipment of hot melt adhesive
Heat treatment method and relevant equipment of hot melt adhesive: heat dispersion.
This method is a kind of the heat mechanical processing method that makes high strength processing on the fiber in the pulp by the means of pressing and rubbing under the conditions of higher concentration (25%-35%) and heating (About 100℃) n order to achieve for melting dispersion of inks and stickies. By the heat dispersion, the ink particles are quite small (<2μm) and evenly distributed in the pulp. Through this kind of heat dispersion, small and fine ink particles will get melted by the dryer cylinder and cannot be found by visual inspection. So they will not cause the adhesion problem of them onto screen, roller, blanket and tank. Therefore, after the heat dispersion treatment, the total dust caused by the ink can be removed 97% and non-ferrous dust can be removed by over 90%. The equipment of heat dispersion processing mainly consists of the following:
- concentration equipment: gap former thickener, inclined screw, screw press dehydration equipment.
- heat disperser: single-roller type or double-roller type of roller (shaft) heat disperser; conical type or disc type of disc grinding heat disperser.
Anyang Machinery Co., Ltd. (AM) was founded in 1968. It is a big state-owned enterprise licensed to manufacture pulp and paper-making machinery, cement equipment and chemical equipment under the state-owned assets supervision and administration commission of the state council.
Anyang Machinery Co., Ltd. has won a high reputation at home and abroad by contributing to the market with high-quality and good service. Our products have been exported to Indonesia, Vietnam, Pakistan, Malaysia and other countries with stable and reliable performance of equipment in the papermaking industry.