Old Corrugated Containerboard (OCC) Bleaching for Tissue Application: Metal Ion Removal Pretreatments and Hydrogen Peroxide-Based Delignification

Abstract This study investigates the oxidative bleaching of Old corrugated containerboard (OCC) using alkaline hydrogen peroxide to improve pulp brightness and evaluate its suitability for hygiene tissue applications. As conventional recycled fiber supplies decline, OCC represents a promising alternative recovered fiber source. Metal-ion control pretreatments, including ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) chelation, acid washing, and flotation deinking, were evaluated to remove Fe, Cu, and Mn, which catalyze peroxide decomposition through Fenton-type reactions. Two OCC sources from the southern United States and Colombia were compared to assess the effect of furnish origin on bleachability. The U.S. OCC exhibited higher lignin content (Kappa 89 vs. 61.8), longer fibers (1.7 vs. 0.9 mm), and lower ash content (2.1% vs. 10.1%) than the Colombian OCC. Metal-ion removal improved peroxide stability, resulting in brightness gains of up to 17 ISO points and Kappa reductions of up to 36 points. Bleached OCC was evaluated alone and in blends containing 5–20% commercial bleached recycled fiber pulp (RFP). Although OCC reduced blend brightness, it improved softness, bulk, and compressibility without significant losses in tensile strength, demonstrating its potential as an alternative recycled fiber for tissue manufacturing.