The reasons that affect the adhesive strength of corrugated board are complicated. In a word, base paper, adhesive, corrugated board machinery, production planning and staff operation level all exert influence on it, and the above factors also affect each other. Which properties of base paper can cause paperboard adhesion
1, the moisture content of the paper rolls, cardboard or corrugated medium is too dry (< 6%) or too much moisture (> 12%) , will cause corrugated board adhesion. Too dry, the swelling of the adhesive and bonding of the necessary moisture is absorbed by the base paper, resulting in gum non-gelatinization phenomenon. Excessive moisture, excess moisture on the absorption of heat, resulting in insufficient heat, and poor adhesion. The solution is to strictly control the moisture of the base paper, too dry must be spray wet treatment, too much water must be appropriate to increase the moisture of the base paper, preheating area, if the effect is still poor, you must change the paper.
2. The water absorption or water permeability of base paper, base paper material, tightness and sizing degree, determines its water absorption or water permeability. Absorbent or water permeability is too poor base paper, will inhibit the penetration of adhesive adhesion; absorbent or water permeability is too strong base paper, one will cause non-gelatinization phenomenon, two will produce gel penetration phenomenon. The former solution is the use of additives in the adhesive, the use of additives to improve the surface of the hydrophobic properties of base paper, so that the adhesive can penetrate. In addition, an appropriate increase in the amount of adhesive coating is also necessary. We know that the corrugated board adhesive is first of all corrugated peak coating, and then with the surface of paper or sandwich combination, adhesive transfer between any layer is hindered, will affect the bonding effect. For example, a company's class a straw pulp corrugated paper, after re-treatment, poor water absorption, do not use water-resistant adhesive can not be good adhesion. The latter solution is to increase the viscosity of the adhesive appropriately.
3. The breaking length of base paper is the ratio of the strength of base paper to the weight of base paper. If the length of the broken paper is low, then in the tile line speed to a certain extent, it is bound to cause frequent paper break and stop. At this point, stay in the oven in the corrugated cardboard absorb too much heat, no matter how good adhesive can not get good adhesion. In this case, the solution is to reduce the speed, or improve the quality of base paper, the length of the break into the base paper inspection items.
4, The original paper side loose, if the corrugated side loose, will cause corrugated uneven, affect the bonding with the board; if the board side loose, will form a crease on the surface of the board. Poor adhesion when severe. The solution is to replace the base paper.
