Paper Machine Drying Section Paper Break
Wet paper into the dryer section, the dryness has reached more than 32%, with a certain intensity. But in the dry part there will be paper broken phenomenon. So what’s the reason that cause paper break in drying section?
The reason that cause paper break in drying section
1. The paper itself is not enough strength or weak point
Such as paper, water is too large, dry felt knot is not structured, easy to squeeze the knot on the paper, resulting in weak spots so that the sheet breaks;
Paper sheets in the press section occur criminals, severe, that is, when the tension in the late dry break, or in the wet section of paper there are horizontal cracks, as well as holes, etc., can also cause the drying section of the paper sheet breakage;
Paper quantitative fluctuations occur, the drying speed will be inconsistent, the paper quantitative small office, dry quickly, so easy to dry and make the paper shrink too much, there are broken ends in the dry. When this happens, it should be addressed for specific reasons.
2. Excessive tension caused paper sheets broken head
There are two reasons for the excessive sheet tension:
First, the ratio between the various groups of dryer cylinder is too large, often in the late dry sheet more intense, resulting in broken, or transmission parts have problems, such as belt slippage, gear irregularities, the tension fluctuations, but also Will result in broken head. Therefore, pay attention to adjust the tension between the dryer cylinder, always pay attention to the transmission of work-like decorations is very important.
Second, the dryer temperature is too high, in the early dry will occur above the serious damage caused by the broken cylinder, and in the drying process, it will cause over-drying of the paper, the paper shrinks violently broken. Sometimes even break a long time, because a long time does not heat the paper to make the cylinder temperature increases, and then pass the paper operation, such a break will happen. Therefore, the drying part “look at steam” should pay attention to the steam pressure and drying cylinder temperature changes.
3. Caused by the debris between the dryer
When did not deal with clean broke paper, as the break paper through between the felt and dryer, easy to break the paper pad and broken; unsmooth scraper and leakage of paper foam, easy to dip in the paper edge , first of all, the edge of the paper is damaged, leading to breakage in the later stage of drying; some of the sticky substances introduced into the paper by the damaging paper also stick to the surface of the cylinder to cause breakage. Therefore, should pay attention to clean the damaged paper with compressed air, and often pay attention to remove the blade at the scraper, and the working conditions scraper.
4. Dry felt cause paper break
Dry felt pleated, will make the folds corresponding to the paper, cause poor drying due to poor contact with dryer, making paper broken between dryer and calender; dry felt joints rough, easy to compress the paper, resulting in paper break; sticky oil and resin on the dry felt, etc., will stick to the paper; even canvas side open line, rejection to rejection, will also open the mouth of paper, resulting in the whole broken. Therefore, in normal work, we should always observe the working conditions of the dry felt and find out the problems are solved promptly.
