The experiment shows that the stiffness of the white board can be improved by mixing slurry and adding interlayer spray starch.
White paper board (coated and not coated) the most important performance is whiteness, smoothness, gloss, printing suitability and box performance.And the stiffness of strength index, loose thickness is directly affect the smoothness of white paper board, glossiness, printing suitability and box performance of a major index.Whiteness can be solved by selecting surface paste to improve the whiteness of the base paper, choosing high whiteness pigment and changing the coating formula.Printing suitability, ink absorption can be achieved through the type of pigment and coating adhesive adjustment.
The main factors affecting the stiffness and loose thickness of the board: the stiffness of the board measured by the white paper refers to the bending moment when bending 38 mm wide board to 15 ° Angle under certain conditions, expressed by g ^ 2 c m(g ^ 2 cm) or m N ^ 2 m(mm ^ 2 m).
Stiffness is determined by the tensile strength of the outer layer and the compressive strength of the bottom layer when the material is subjected to bending.The main factors affecting stiffness are the loose thickness of the original paper and the binding force between the fibers.Under the same quantitative condition, stiffness is proportional to the quadratic square of thickness.Stiffness is greatly affected by the type of fibers and the bonding strength between fibers.Broadleaved wood short fiber, machine wood pulp made of paper than needle wood long fiber made of paper stiffness.
As is known to all, the existence of lignin has a bad influence on the nature of pulp, lignin content is too high pulp beating slow, poor adhesion between fibers, the paper made of low tightness, poor strength;But on the other hand, the presence of lignin can reduce the fiber swelling capacity, increase the stiffness of the paper.
The traditional view that lignin reduces the strength of paper is questioned. It is proposed that the main cause of paper decomposition is the acidity of paper rather than lignin.
The use of good chemical auxiliaries, strengthen the bonding strength between the fibers, improve the stiffness of the paper stiffening agent on the paper stiffness has a positive effect.In particular, the use of interlayer spray starch can not only increase the interlayer bonding strength, but also improve the stiffness of cardboard.The starch spray can increase the binding force of the paper layer by 2 %, but it can't be achieved by adding starch spray to the pulp.
In the white paper board production technology, choosing appropriate material and the brand of commodity pulp, formulate appropriate beating pulp ratio and process conditions, with good chemical agents enhance the bonding force between the fiber and adjust the machine operation, decrease the press line pressure, calender line, appropriate to reduce the paper moisture, can improve the stiffness, thickness of white board.Also increase the surface of the non-crystal degree and cover ability.To improve product quality, reduce production cost, the effect is obvious.