A statistically designed evaluation of nanocellulose, refining and cationic starch on the properties of linerboard from recycled old corrugated containers (OCC)

Abstract

Methods to improve the physical properties of recycled paper can greatly enhance its potential applications, especially for packaging. This study aimed to understand the effect of refining, cationic starch addition, and cellulosic nanofibers (CNF) generated from old corrugated containers (OCC) addition with recycled OCC on tensile index (TI) and ring crush index (RCI). Linerboard from OCC made on an industrial paper machine was compared with the lab prepared handsheets, and the results indicated that the lab procedure including the refining step produced board reflective of the industrially made linerboard. CNF addition was observed to decrease the drainage rate of the unrefined OCC pulp stock but not significantly when the OCC pulp stock was refined to a freeness of 300 mL CSF. The results of a statistically designed experiment showed that cationic starch, refining, and the interaction between cationic starch and CNF were significant parameters that improve TI. Through experiments that measured the retention of the pulp stock, it was determined that CNF retention was only 44.8% without cationic starch and increased to 90.0% with cationic starch present, thus explaining their interaction. This study indicates that CNF from OCC can be combined with cationic starch at appropriate levels to improve properties of the resulting board without critically decreasing the drainage rate.