Optimization of the physical and mechanical properties of kraft paper from cocoa by-products

The production of paper from alternative materials offers a promising pathway to reduce reliance on traditional forest resources and promote circular economy principles. This study investigated the physical (brightness and thickness) and mechanical (tensile strength) properties of Kraft paper produced from cocoa byproducts, evaluating the impact of bleaching agent concentration and cocoa variety used. A completely randomized experimental design was employed, with analysis of variance to assess the effects of bleaching agent concentration, cocoa variety, and their interaction. The properties of the paper were analyzed using CIELab chromatic coordinates, whiteness indices, and mechanical tensile tests. Treatments included varying concentrations of hydrogen peroxide as a bleaching agent and three cocoa varieties: CCN-51, Nacional, and a regional variety. The results showed that brightness was significantly influenced by the bleaching agent concentration (p=0.0013) and by the interaction between bleaching agent concentration and cocoa variety (p=0.0002). Thickness across all treatments met commercial standards, with the CCN-51 variety demonstrating the best performance at intermediate bleaching concentrations. In terms of tensile strength, the CCN-51 variety exhibited the highest performance due to its higher lignin and cellulose content, although no treatment achieved the minimum values required by international standards. In conclusion, Kraft paper derived from cocoa byproducts holds significant potential as a sustainable alternative. However, further optimization is necessary to enhance its mechanical strength and brightness to meet industry standards.