Impact of kaolin on physicomechanical properties of density-graded cement bonded paperboards

Abstract

Paperboards of thickness 0.6 cm with densities of 0.8, 0.9, and 1.0 g/cm3 were produced from waste papers mixed with cement and kaolin. Printing and corrugated waste papers were employed in the proportions of 50.0/25.0/25.0, 50.0/37.5/12.5, and 50.0/12.5/37.5 (paper/cement/kaolin), respectively. The dimensional and strength properties of the boards were investigated. The values obtained range from 0.40 to 0.94 g/cm3, 51.19 to 68.10%, 0.14 to 3.10%, 0.01 to 1.69 Nmm-2, and 119.98 to 567.32 Nmm-2 for observing the density, water absorption, thickness swelling, modulus of rupture, and modulus of elasticity, respectively. The board of proportion 25/25 of kaolin/cement was densest with high strength. As the nominal density and kaolin content were increased from 12.5 to 37.5%, an increase was observed in density and strength properties. Similarly, as the proportion of kaolin and cement content were increased, the rate of moisture uptake to cavity decreased. This study shows that boards from printing papers were more dimensionally stable than corrugated papers. It revealed that printing papers could be better raw material for manufacture paperboard than corrugated papers. Information provided in this study could be used as a guideline for the manufacture of paperboard reinforced with kaolin as an additional constituent for quality improvement.