Effect of production conditions on the characteristics and the drainage of cellulose nano-fibrils

Abstract

Many studies have shown that cellulose nanofibrils (CNFs) are powerful in improving paper strength. However, CNFs are usually manufactured as a slurry and their drainage is critical to their internal addition in the papermaking process. Therefore, the production conditions of CNF for internal addition must be established in order for its use to spread in the paper industry. In this study, various CNFs were made in a laboratory according to the functions of pulp type, freeness, and the pass number of grinding. The viscosity, average particle size, zeta-potential, and the fiber width of the CNFs were measured. After the physical properties of the CNFs were measured, the drainage rates of the CNF slurries were determined through the use of a pressure dehydration tester. An increased pass number of grinding simultaneously increased the viscosity of the CNFs and decreased their particle size and fiber widths. However, the relationship between the pass number and the zeta-potential of the CNFs was not observed. As the pass number of grinding increased, the drainage rates of the CNFs decreased linearly. Specifically, the decrease in the drainage of the CNFs made from SwBKP was lower than those made from HwBKP. Therefore, the pulp type and the pass number of the CNFs should be controlled for the purpose of their internal addition in the papermaking process.