Effect of PCC crystallization and morphology on flocculation with microfibrillated cellulose, on sheet densification and liquid absorption behavior

Abstract

Composite sheets consisting of elongated and aggregated cationically charged precipitated calcium carbonate (PCC) and native microfibrillated cellulose (MFC) were prepared with a wet laying method. The furnishes were prepared with and without an anionic flocculating agent (polyacrylamide) in order to adjust the structure of the sheet. The samples were compressed (densified) in order to determine the particle and microfibrillated cellulose-PCC structure coalescence and densification, as well as its subsequent influence on liquid absorption behavior. The densification affected both the vertical and lateral distribution of PCC, but the flocculating agent enhanced the compression stability and stabilized the sheets against PCC material flow. The differences between the sheets made with and without the flocculation aid affected the absorption of an anionic dye-based fluid ink, which was evident as a higher print density and less print bleeding. The absorption behavior was dependent on the sheet structure, especially on the PCC distribution within the sheets. Finally, the role of MFC on floc structure and floc formation is discussed. Graphic abstract

Green and efficient utilization of cellulose by in situ regenerating rod‐like cellulose crystals in dry blending rubber compounds

“…While it has several disadvantages: one is that it is only suitable for rubber latex system, which means that its subsequent process is more complicated than the conventional dry blending process; the other is that waste liquid will inevitably emerge in large numbers when removing the alkali and urea from the coagulum. Furthermore, the shapes and sizes of regenerated cellulose are almost uncontrollable due to the rapid precipitation of cellulose chain when adding co‐flocculating agent 22 . Therefore, it is still a hard nut to crack to evenly disperse regenerated cellulose in rubber matrix.…”

“…Furthermore, the shapes and sizes of regenerated cellulose are almost uncontrollable due to the rapid precipitation of cellulose chain when adding co-flocculating agent. 22 Therefore, it is still a hard nut to crack to evenly disperse regenerated cellulose in rubber matrix.…”