Journal of Korea TAPPI ISSN:0253-3200(Print) 펄프종이기술

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.