When linerboard is manufactured by blending recycled OCC pulp with recycled pulp from aseptic carton, the results reported that factors other than surface roughness are related to the coefficient of friction. Calendering exacerbated the problem of a sharp decrease in coefficient of friction according to the mixing of aseptic carton pulp. Therefore, we tried to understand the aforementioned changes in the coefficient of friction by evaluating the effect of the surface residue of fines derived from aseptic carton on the sliding angle and surface roughness of aseptic carton-based recycled paper. Handsheets were made from recycled pulp extracted from aseptic cartons and then coated with fines slurries at 3% and 5% concentrations. It was confirmed that the higher the proportion of recycled pulp fines used in handsheet coating, the lower is the coefficient of friction of the handsheets. Coating the handsheets with a large amount of recycled pulp fines reduced friction after calendering. This study suggested that influence factors such as changes in actual contact area are essential to be investigated in controlling the friction coefficient of recycled paper.

Recently, when a paper mill in Thailand produced linerboard by mixing recycled OCC pulp with recycled pulp from aseptic cartons, the coefficient of friction decreased rapidly as the mixing ratio of pulp from aseptic cartons increased. The study was carried out to investigate the main causes of reduced coefficient of friction of recycled linerboard made by blending aseptic cartons and OCC. Three types of stock from the actual site were used for analysis: aseptic carton, old corrugated containers (OCC) and 50:50 blended stock. Handsheets were made from these three stocks by using a square handsheet former and the effect of machine calendering treatment on the handsheet was analyzed to investigate the relationship between the coefficient of friction and the surface roughness of the handsheet. Regardless of the type of pulp, calendering reduced the surface roughness of paper and the coefficient of friction as well. However, when comparing papers of different types of pulp, simply having a lower surface roughness than other papers did not mean that the coefficient of friction is lower. In the case of paper made from OCC mixed with aseptic carton pulp, the surface friction was sharply lowered by calendering treatment. It was judged that calendering exacerbated the problem of a sharp decrease in coefficient of friction according to the increase of mixing ratio of aseptic carton pulp. The relationship between friction and actual contact area of handsheets was discussed.