Novel Bio-inorganic Composite as a Sustainable Strength Additive and Potential Alternative to Inorganic Fillers for Papermaking

This study explores the development and characterization of a novel bio-inorganic composite filler containing precipitated calcium carbonate (PCC) and regenerated cellulose (RC) derived from pineapple crown waste for papermaking. Hand sheets containing modified precipitated calcium carbonate (MdPCC) exhibited significant improvements in tensile strength (up to 68.21% increase at 15% of 20% MdPCC loading), burst index (up to 10.51 kg/cm2), burst factor (up to 95.50), and double fold (263–3383 at 25% of 20% MdPCC loading) compared to control paper. This exceptional improvement in double fold is attributed to MdPCC’s ability to facilitate stress transfer between paper fibers, leading to a more even distribution of stress and enhanced fold resistance. RC containing different dosages of PCC were characterized by different analytical techniques in order to evaluate the effective retention of the PCC into RC and paper matrix subsequently. PCC alone causes a decrease in the strength of the paper; hence, the proposed filler may overcome this drawback. This study provides the alternative pathway to replace the high dosage of inorganic filler along with no compromise in the strength properties of the paper.