Views: 0 Author: Site Editor Publish Time: 2022-08-29 Origin: Site
There will be short heads in the drying section of the paper machine. Even if the wet paper sheets entering the drying section have a dryness of more than 32%, they have a certain strength. Let's take a look at the main reasons for the breakage of the drying section of the paper machine with the editor of Tianyang Paper Machine:
The phenomenon of paper machine breakage includes the following aspects:
1) The strength of the paper itself is not enough or there are weak points
If the paper industry has too much moisture and the dry cloth knots are irregular, the knot marks will be pressed on the paper, which will lead to weak points and break the paper industry. Folding in the press section, severe end breakage in the later stage of drying when the tension is large or transverse cracks on the wet section paper, etc. will also cause end breakage in the drying section of the paper machine. When the basis weight of the sheet fluctuates, the drying speed will be inconsistent. When the basis weight of the paper sheet is small, it is easy to dry out and cause the paper sheet to shrink too much, and the end of the paper is broken.
2) The tension of the paper sheet is too large, causing the end to break
There are two reasons for excessive sheet tension:
First, the transmission ratio between each group of drying cylinders is too large, which often causes end breakage when the paper sheets are violent in the late drying stage or there are problems with the transmission parts, causing the tension to fluctuate. Need to pay attention to adjust the tension between the drying cylinders at any time.
Second, the dryer temperature is too high. In the early stage of drying, serious sticking to the cylinder causes end breakage; during the drying process, the paper sheet is over-dried, resulting in severe shrinkage of the paper sheet and end breakage. When the end breaking time is long, the drying cylinder temperature rises due to no heat transfer to the paper sheet for a long time, and the end breaking will occur when the paper is re-transferred.
3) The debris between the drying cylinders causes the paper page to break
①The damaged paper that has not been cleaned will pass through the dry cloth and drying cylinder with the paper sheet. At this time, the paper sheet is prone to breakage and lead to end breakage.
②The scraper is not strict and the paper foam is leaking, and the paper foam is easy to stick to the edge of the paper and damage the edge of the paper, which will cause end breakage in the later stage of drying.
③Some viscous substances brought into the paper material will also stick to the surface of the cylinder and cause breakage.
4) Broken ends caused by dry cloth
①When the dry cloth is pleated, the paper sheet corresponding to the pleats is not well dried due to poor contact with the drying cylinder, which makes the drying section of the paper machine break between the drying cylinder and the calender.
② Rough cadre joints are easy to crush the paper and cause broken ends.
③If there is oil and resin on the dry cloth, it will stick to the paper, and even the edge of the canvas will open the edge of the paper, resulting in broken ends, etc.