Production of test lines paper with occ modified fibers and sodium caseinate crosslinker.

Currently, there is significant competition in recycling waste paper and using it for producing various types of paper used in the packaging sector. The paper derived from recycled pulps lacks good strength due to the gradual shortening of fibers and the reduction in bonding characteristics. Considering this challenge, in this study, after converting old corrugated containers (OCC) into pulp and then refining them, they were oxidized in an alkaline environment using hydrogen peroxide at varying percentages of 0, 0.5, 1, 2, 3, and 4 to create diversity and increase reactive groups. Sodium caseinate was then added to the pulp suspension at levels of 0.5, 1, 2, 3, 4, 5, 6, 7, 8, and 9 percent as a cross-linking agent. Finally, standard handmade papers were produced from them. The status of the formed functional groups was measured by FTIR spectrum, and the mechanical strength and water absorption of the produced papers were measured according to the standards of the Technical Association of the Pulp and Paper Industry (TAPPI). FTIR results showed that the oxidized pulp samples had high absorption at the wavenumber 1650, which corresponds to the carboxyl group. Additionally, the calculation of the carboxyl groups using the methylene blue absorption method indicated that the highest amount of carboxyl groups was in the 1 percent hydrogen peroxide treatment. The addition of sodium caseinate to the pulp suspension significantly increased the mechanical strength of the resulting papers. [ABSTRACT FROM AUTHOR]