Assessment of Inorganic Bonded Paperboards Produced from Kraft and Recycled Newsprint

Homogeneous cement bonded paperboards were made with recycled newsprints and Kraft paper with ordinary Portland cement and curing reagent. Boards were produced at the blending proportions of 100:0, 50:50 and 0:100 respectively and at cement/ paper ratio of 1:1, 2:1 and 3:1 respectively. Dimensional movements were evaluated to investigate the effect of the variables used in board manufacturing before and after exposure to accelerated aging tests procedure. Increase in mixing ratio and blending proportion caused decrease in Thickness Swelling (TS) and Water Absorption (WA) while TS and WA of the untreated boards were lower than the accelerated aging treated boards. The dimensional movement of Kraft paper was higher than that of recycled newsprint before and after accelerated aging treatment. The strongest and most dimensionally stable board was produced at the highest level of cement/ paper ratio. The pre-accelerated ageing test carried out showed that mechanical properties were higher 2:1 and 3:1 paper cement mixing ratios. Kraft paper produced the strongest and most dimensionally stable board than recycled newsprint. From this study Kraft paper and recycled newsprint proved to be suitable for the manufacture of cement bonded paperboard capable of meeting the needs in core and low cost housing construction.