The process flow of the corrugated cardboard production line: Use a single-sided corrugated machine to produce single-sided corrugated cardboard with firm corrugations and intact inner paper. After being transported over the conveyor bridge and transported to a gluing machine to coat the composite surface paper, it enters the double facer machine for drying, and then cut longitudinally and crosswise into corrugated cardboard of appropriate sizes according to production requirements.
Obviously, the causes of base paper waste and low cardboard yield are mainly concentrated in key processes such as single facer machines, conveyor bridges, gluing machines, drying, and vertical and horizontal cutting of cardboard. Let’s talk about common problems in actual operations and their corresponding solutions below.
Single facer corrugated machine of corrugator line
Problem 1) After the single-sided machine is turned on and the original paper is input, the corrugated paper and the inner paper are not adhered neatly.
The first is the deflection of the output paper, which can be corrected instantly by increasing the machine speed. Secondly, the edges of the lining and corrugated paper rolls on the same side are not in the same straight line. It can be solved by the “three points and one line method”. That is, set a point on the preheater cylinder surface of the corrugating machine or lining and corrugated paper. After loading the paper 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 left and right by visual inspection until the corrugated paper、The inner paper edge and the set point form a line.
Problem 2）The original paper cracks after passing through the preheater, causing paper breakage.
First reduce the preheating area according to the paper quality. When a joint occurs, manually pull the base paper or use additional force to reduce the mechanical tension according to the rotation direction of the base paper to avoid the problem of paper breakage.
Problem 3) When the corrugated paper and lining paper were inspected by the manufacturer, there was a palm-sized gap in the roll. After being fed into the corrugating machine, the single-sided corrugated board was short of material.
Before starting the machine, prepare lining paper and corrugated paper that are slightly larger than your palm (the color and weight are the same as the base paper on the corrugating machine). If there is a gap in the lining paper, take the lining paper. If there is a gap in the corrugated paper, take the corrugated paper. Dip a little glue from the glue tray and put it on the base paper. Before entering the corrugating machine, just clamp the gap on both sides and glue it on. Actions must be quick, accurate, timely and safe.
Problem 4) After meeting the production quantity, there will be remaining paper ends, with more corrugated paper and less inner paper.
Under normal circumstances, it is not necessary to cut the base paper until the less base paper is used up before stopping the machine. When shutting down, use a knife to cut the base paper neatly. The excess single-sided corrugated cardboard will be bonded to the newly produced single-sided corrugated cardboard on the conveyor bridge for use when producing cardboard of the same width and material next time.
In addition, if the machine is shut down for any reason and there are remaining paper ends, it can be manually rewinded onto a base paper roll of the same specification and quality.
Problem 5) Try to avoid turning on the machine frequently, which can effectively eliminate the non-adhesive parts of the inner paper and corrugated paper.
Conveyor bridge of corrugator line
Problem 1) There is too much accumulation of single-sided cardboard on the conveying bridge, the dryer speed is too fast or the dryer is suddenly accelerated and then torn off, and then the bonding is not strong.
Operators of the conveyor bridge should pay attention：Increase the speed of the dryer at a constant speed and do not start too fast. When bonding broken ends, the upper overlap surface should be along the running direction of the cardboard, and the machine must not be stopped during the joint. At the same time, pay attention to the single facer machine. The stacking amount of single-sided corrugated cardboard should not exceed one-third of the conveyor bridge length.
Problem 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.
Problem 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 machine of corrugator line
Problem 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.
Problem 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.
Dryer of corrugator line
Problem 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.
Problem 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.
Problem 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.
Slitter scorer and NC cutter of corrugator line
Problem 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.
Problem 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.
Problem 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 of corrugator line 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.
