Corrugated carton "Pan board" solution (2)

When the viscosity is low and the vehicle speed is slow, the rubber roller cannot be glued, which may not only cause the phenomenon of rubber loss, but also cause the corn starch glue to infiltrate into the core paper and the paper board, resulting in poor bonding and forming a “cooking board” shape. (The smaller the amount of face paper, the more severe); Longitudinal warpage: The paperboard is too moist; The paper is loose, the surface paper and the core paper are initially bonded and separated, and there is delamination; the cardboard has a low bonding strength, and the paperboard side pressure strength and the carton The compressive strength decreases accordingly.
Solution: According to the actual needs of the choice of adhesive, if necessary, by adjusting the viscosity of corn starch glue to meet the needs of corrugated board production. Corn starch viscosity adjustment should consider the performance of the base paper, the use of objects and corrugated production equipment, vehicle speed, heating capacity and other factors. The viscosity of starch glue used in general production line is 50～90s, and the viscosity of starch glue used in stand-alone production is 20～50s. The viscosity of high-strength corrugated cardboard, single-faced corrugated cardboard and fine corrugated cardboard is about 30±5. s, the viscosity of ordinary corrugated board adhesive is approximately (40 ± 10) s.
3. Excessive application of glue and its solution
Excessive sizing is also one of the main reasons for the phenomenon of “squeezing the board”. In terms of corrugated board production, there is a problem of excessive sizing of both single-sided and double-sided machines. For a single-sided machine, in the gluing mechanism, the rotational speed of the sizing roller on the mechanical Design is slightly slower than that of the corrugating roller, so as to ensure that the sizing roller transfers a proper amount of adhesive evenly over the corrugation peak. When the base paper is bonded and pressed, the adhesive penetrates into the paper fibers, and then solidifies to achieve a bonding effect. However, when the amount of sizing is excessive, the excess adhesive is pushed out to both sides of the corrugation peak, causing the sizing lines to become wider and larger. When these excess binders are dried, they shrink, and this shrinkage force pulls the paper back. When a single-sided machine uses a high-quantity liner, it has sufficient tightness to resist this pull-in force, causing the liner to shrink and warp: when using a low-quantity liner, it is not resistant to low tightness. Wave tension can easily cause shrinkage in the paper. Similarly, for the double-sided machine, when the low-precision paper is used, it will also cause shrinkage and deformation of the tissue due to the inability to resist the tensile force, and thus the phenomenon of blistering may occur even in the case of a severe phenomenon.
Solution: The only solution when using low basis weight paper is to strengthen the control and adjustment of the production process and try to overcome the quality problems caused by the low basis weight of the base paper. In the case of ensuring the adhesion of the paperboard, the amount of sizing should be adjusted as much as possible, and the speed of the machine should be increased so as to avoid affecting the expansion and contraction of the paper fibers due to excessive sizing or overheating temperatures. The size of the sizing amount is usually 1 to 2 mm for the width of the strip on the peak. The specific situation should be based on the quantification of the surface paper and the liner paper.
4. Impact of mechanical equipment and solutions
When the gap of the corrugated roll or pressure roll of the single-sided machine or the double-sided machine is uncomfortable or unbalanced, the relevant parts are loosened, and the wear of the corrugating roll dies is serious. When the top area of ​​the rake tooth increases, the glue is increased. The coating amount makes the paper or liner paper easily deformed after bonding; when the temperature of the corrugating roll, the pressure roll or the preheating roll is too high or too low, the corrugated paperboard is easily deformed after molding. .
Solution: Check and maintain the corrugating roller, pressure roller and related parts regularly. If the corrugating roller is severely worn, repair or replace the new corrugating roller in time. In the production process, attention should be paid to the adjustment of the temperature of the corrugating roller, pressure roller, or preheating roller. Attention should also be paid to the control of the tension.
The phenomenon of "cocooning board" is one of the common failures in the production of corrugated board. There are many possible causes for this phenomenon. In actual production, it is difficult for us to determine exactly what kind of factors caused it. Therefore, we can find out the reasons through a simple elimination method, and then use the corresponding solutions to eliminate and improve the production quality of corrugated board.