The problem of cardboard degumming occurs in every factory, but each control is different. Sometimes the paste is not done well, resulting in insufficient paste viscosity and degumming. There is also equipment reasons, such as excessive vibration of the equipment, non-parallel pressure rollers and other causes of cardboard degumming. Another part is degumming of cardboard caused by operator error. This article will share how to solve the problem of segmental degumming and facial paper degumming in five-layer cardboard.
1. How to solve the problem of segmental degumming in the five-layer cardboard? Please check the ballast roller!
In the production of five-layer paperboard, it was found that some parts of the middle layer of the whole paperboard were well bonded, and some parts were not bonded, and there was a phenomenon of degumming. What caused this?
First of all, the five-layer cardboard is partly bonded well and partly bonded badly, which can eliminate the problem of glue. If there is a problem with the glue, there will be problems in the adhesion of the entire cardboard. It is only a partial poor adhesion, that is, the cardboard is not completely in contact during the bonding process, and the upper layer of tile paper and the middle paper are separated during the bonding process. So when the glue dries, it won’t stick.
So, what makes the corrugated paper first keep contact with the middle paper during the bonding process of the cardboard? It is a canvas belt. The canvas belt is pressed by the front ballast roller. Only when the canvas belt is pressed and coherently, the cardboard can be bonded well, otherwise there will be segmental degumming. The ballast roller jumps or shakes at the paper feed port of the hot plate, which will cause this situation, which will cause the cardboard to be glued twice during the bonding process.
To solve this problem, first check whether the bearings at both ends of the ballast roller are damaged, and see if the ballast roller is stuck when it moves up and down. If this problem is solved, there will be no middle-layer degumming of the five-layer cardboard.
2. How to solve the degumming of corrugated cardboard?
When the single-faced corrugated cardboard and surface paper are conveyed from the multi-preheater, they will be sent to the preheating roller and the glue roller, and then the two layers of single-faced corrugated cardboard and one layer of paper are sent to the bonding and drying together. Dry machine. There are many reasons for the degumming of the cardboard surface paper. Among them, the surface paper degumming caused by improper temperature control and tension control of the double-sided machine is the most obvious.
(1) Control the pressure of the pressure plate on the cardboard
There are many types of pressure plates, such as airbag pressure plates, gravity reels, and so on. When the cardboard enters the hot plate of the double-sided machine, the pressure of the pressure plate on the cardboard is insufficient, which causes the surface paper to not quickly and effectively bond with the tile paper, thereby forming degumming. Of course, the pressure should not be too heavy, otherwise it will cause the cardboard to collapse.
(2) Control the gelatinization temperature
The temperature is mainly reflected in the control of the gelatinization temperature. When the hot plate cannot provide the proper temperature for the paste, the paste will have two results: one is that the paste is gelatinized in advance, causing false stickiness; the other is that the paste is not gelatinized. , Resulting in weak bonding.
Solution: In production, check whether the gelatinization temperature of the paste and the temperature transferred by the hot plate have reached the temperature required by the paper, so as to avoid poor cardboard adhesion. In winter, the gelatinization temperature can be lowered to 56℃-59℃, and in summer, the gelatinization temperature can be adjusted to 59℃-62℃.
(3) Control the size and uniformity of tension
Tension is one of the important reasons for the forming of corrugated cardboard. The size and uniformity of the tension will affect the forming, gluing and bonding strength of the cardboard.
During production, start-up, sudden shutdown, replacement of the original paper roll, or significant change in the diameter of the paper roll during unwinding of the paper web will cause significant changes in tension. Improper control of the paper web tension will cause waste products, such as excessive tension, causing shattered tiles, collapsed tiles, bursts, paper web folds, ruffles, cardboard bending, etc. If the tension is too small, it will cause blistering, paper web skew, Cardboard warping, etc.
The change of tension can be solved by installing a constant tension control system. The principle is to detect the change of the output paper web tension in real time, and adjust the braking force of the base paper brake in real time according to the change, forming a closed-loop control loop of “detection-feedback-brake”, so that the paper web is always maintained at the set tension level Run on. If a very small tension level is required, only a constant tension control system is not enough, and a mid-to-high-end brake is needed to cooperate. When changing the paper roll, the automatic paper splicing machine and the constant tension control system can realize the basic constant tension.
In addition, don’t accumulate too much single-tile paper on the flyover. If the tension is too large, the single-tile paper will be worn down and the cardboard will not be thick enough. In addition, the sky bridge sucks too much air, which can easily cause the corrugation to collapse. Pay attention to the rotation of each axis, and check the parallelism of each axis frequently and pay attention at all times.