The effect of using bulking agents on the physical and strength properties of the medium corrugated board made by NSSC and OCC

The strength properties of medium corrugated board which is made using recycled pulp are always important. The aim of this study was to investigate the effect of bulking agent’s addition and acetylated starch on the strength properties of corrugated board from neutral sulfite semi-chemical and old corrugated container pulp. For this purpose, the pulp was treated with two materials separately including tri (propylene glycol) butyl ether and di (propylene glycol) butyl ether bulking agents in the 0.9% dry weight of the pulp level. In addition, each of these bulking agents was added with acetylated starch (at the level of 4% of dry weight of the pulp) to the pulp suspension. The strengths properties of corrugated board were measured. The results showed that the corrugated board treated by tri (propylene glycol) butyl ether and di (propylene glycol) butyl ether bulking agents had the highest bulk and thickness in comparison to other samples. Also, the strength properties of samples decreased by adding bulking agents. Acetylated starch was used to improve the strengths of samples. Addition of acetylated starch with bulking agents improved the strengths of samples. Corrugated board with tri (propylene glycol) butyl ether and acetylated starch showed highest tensile, burst, tear strengths, stiffness, CMT and RCT. Results showed that the effect of different treatments is statistically significant in all trials.