The technological process of the corrugator line is to use a single-face corrugator to produce a single-faced corrugated board with firm corrugation and inner paper，After being transported through the conveyor bridge to the gluing machine coated composite surface paper, Into the dryer for drying, then crimping, longitudinal cutting, and cross-cutting are made into box boards according to production requirement.
Obviously, the main reasons for the waste of base paper and the low yield rate of paperboard are mainly in the key processes of single facer, conveying bridge, gluing and compounding, drying, and vertical and horizontal cutting of crimping paper. Let’s talk about the author’s opinion on the common problems and solutions in actual operation.
1) After the single-sided machine is turned on, the base paper is input, and the corrugated paper does not fit neatly with the inner paper.
The first is that the output paper is skewed, which can be corrected instantly when speeding up.
Secondly, the inner paper and corrugated paper rolls are not on the same straight line with the side line. It can be solved by the “three points and one line method”. That is, set a point on the cylinder surface of the corrugating machine or the preheater of the lining and corrugating paper. After the paper is loaded on the shaftless mill roll stand before starting the machine, press the button on the shaftless mill roll stand at one end of the corrugated paper or lining paper, and adjust the left and right visually until the corrugated paper , The inside line of the paper is in line with the three points of the set point.
2) The base paper is cracked by the preheater, causing paper breakage.
First, reduce the preheating area according to the paper quality. When a joint occurs, it can be avoided by manually pulling the base paper or assisting in reducing the mechanical tension in the direction of rotation of the base paper.
3) When the corrugated paper and lining paper are inspected by the manufacturer, a palm-sized opening is torn in the roll, and the single-sided corrugated board is short of material after being input into the corrugator.
Prepare lining and corrugated paper slightly larger than the palm of your hand before starting the machine (the color and weight/M2 should be the same as the base paper on the corrugated sheet). Take the lining paper with gaps in the lining paper, and take the corrugated paper with the corrugated paper gaps. Dip a little glue on the glue plate. , Clamp the notch on both sides before the raw paper enters the corrugator and stick it on. The action must be fast, accurate, timely and safe.
4) After meeting the production quantity, there will be surplus paper heads, and the corrugated paper and inner paper have more on one side and less on the other.
Under normal circumstances, it is not necessary to cut off, and then stop the machine until the less-used base paper is used up. When stopping, use a knife to neatly cut the base paper. The surplus single-sided corrugated cardboard, when the same-width and homogeneous base paper is used for the next production, will be bonded to the newly-produced single-sided corrugated cardboard on the conveying bridge.
In addition, if there are remaining paper ends when stopping for some reason, it can be manually rewinded onto a large reel of the same specification and quality.
5) Try to avoid frequent startup, which can effectively prevent the non-adhesive parts of the lining and corrugated paper.
- Conveyor bridge
1) There is too much pile of single-sided cardboard on the bridge, and the drying machine speeds too fast or suddenly accelerates and breaks and the bonding is not strong.
Operators of the conveyor bridge should pay attention to the dryer to increase the speed at a constant speed and not start too fast. For bonding and broken ends, the upper lap surface should follow the direction of cardboard running, and no stopping is allowed during joints. At the same time, note that the stacking volume of single-sided corrugated cardboard on the single-sided machine should not exceed one-third of the bridge length.
2) When the width of the single-sided corrugated cardboard is inconsistent with that of the corrugated paper, it is scraped off by the paper clamp that controls its direction.
When the corrugated paper is wide, the two paper clips of the paper clamp should be adjusted to be slightly smaller than the width of the corrugated paper; if the paper is wide, cut the part wider than the corrugated paper neatly in front of the paper clamp.
3) After the dryer is turned on, all layers of single-sided cardboard are not aligned.
Before the dryer is turned on, move the single-sided cardboard clamps of each layer by 2-3 cm according to the in and out dimensions of one side of the slitting edge knife.
- Gluing and compounding
1) According to the customer’s request, use ordinary cardboard paper as the face paper. After the preheater, the base paper becomes brittle, and then it is torn when it enters the dryer. Reduce the surface paper force, or manually turn the roll paper until it is normal.
2) After entering the dryer, the paper and the single-sided cardboard are not aligned, and the emergency production paper has different widths.
First, when the paper edges and paper heads of each layer are aligned, they can be fed into the dryer. When feeding is uneven, speed up the dryer to run straight, but the uneven part has become a waste. Whether the face paper is wider or narrower than the single-faced corrugated cardboard, it must be aligned on one side.
Furthermore, if the edge of the tissue paper roll and the paper clamp are not in the same vertical line, even if the edges of the base paper and the paper head are aligned and fed to the dryer, they will be uneven after running for a certain distance.
In order to solve this problem, we may wish to hang a thread from the side of the paperboard of the conveying bridge paper clamp in advance, and hang a thread to the top of mill roll stand of the facial paper. It is appropriate to be 0.5cm away from the roll paper, and click the button on the mill roll stand，adjust the edge of the facial paper until it is perpendicular to the thread drop.
1) Due to the long parking time of the dryer, the cardboard is opened in a large area, especially the three-layer board.
Try not to stop during production. It is necessary to stop. The operator predicts the parking time according to the situation. If it is not a short time (more than two minutes for five-layer boards and more than half a minute for three-layer boards)to stop, each layer of paper should be cut before the gluing machine, and drive the cardboard out of the drying tunnel.
2) The conveyor belt of the dryer is off-track, the edge of the cardboard is glued, and the adhesion is poor.
Adjust the rectifying hand wheel; when stacking, unqualified cardboard is detected by hand gluing.
3) The temperature of the drying tunnel of the dryer is too high, and the cardboard glue is degummed and broken, which is more common in the three-layer cardboard and the brittle inner paper.
Increase the speed of the dryer, and at the same time exhaust steam and reduce pressure appropriately, and notify the gluing machine to increase the amount of glue as needed.
- Crimping, vertical and horizontal cutting
1) The crimping wheel crushes the inner paper and the surface paper; the crimping exceeds the allowable error.
Depending on the dry humidity of the paper and cardboard, the crimping depth can be adjusted flexibly, so that the paper indentation inside is clear without breaking or cracking; except for the size error, it is the deflection of the concave wheel under the crimping wheel, just correct it.
2) The trimming is not adjusted in time, resulting in a lack of material and exposed tiles on the cardboard, and the sum of the two trimmings is less than one centimeter.
The left and right moving devices of the slitting machine should be adjusted in time, and if necessary, the conveying bridge can be notified to adjust the paper clamp to the left or right.
3) The cross-cutting knife is too blunt, and the cross-section of the imported kraft carton board is easy to tear when production.
The knife should be sharpened or replaced in time; the knife on the bottom should not be too tight to avoid injury to the knife.
In addition to eradicating the above problems, the paper web should be reasonably used according to the number and size of the cardboard produced, and the cutting edge of the cardboard should be controlled within 0.5-2cm as far as possible. The production can be cleverly matched to deal with faulty paper defects accurately and timely.
For open glue and lack of material cardboard, do not repair and use without affecting the quality, eliminate man-made waste, and you have found an effective way to reduce the loss of paper and increase the yield of the corrugator line.