Addition of Reed-Derived Cellulose Nanofibers to Change Handsheet Properties

This study investigated the effects imparted to paper handsheets by the addition of reed cellulose nanofibrils (RCNF) and ultrasonic treatment of the handsheets. RCNF addition, especially when combined with ultrasonic treatment, increased the density and tensile strength of the handsheets. The tensile strength increased from 38.9 to 62.6 N.m/g, when 5 wt% RCNF were added and ultrasonic treatment was performed for 20 min. Basically, the increase in tensile strength was due to an increase in the inter-fiber bonding strength, which conformed to the Page equation. The addition of RCNF decreased the number of voids at the handsheet surface and increased the inter-fiber bonding, as confirmed by scanning electron microscopy images. The number of such voids was further reduced and inter-fiber bonding was increased by the ultrasonic treatment.