Striving for Sustainable Solutions: Optimizing Utility Properties of Recycled Paper with the Addition of Wet Strength Resin

Paper producers are increasingly challenged to meet customer demands for high-quality sanitary papers amidst rising price pressures and diminishing quality of recycled fibers. One promising avenue for enhancing paper quality involves augmenting wet strength. For this purpose, synthetic wet strength resins are used, among other things. This study explores the efficacy of utilizing a polyamide-epichlorohydrin resin-based agent for the internal sizing of white wastepaper. Such chemicals, when added to cellulosic fibers in proper amounts before the paper is made, can not only improve water resistance and air permeability of the finished product but also significantly affect both the dry and wet strength paper, which is a crucial aspect for sanitary papers. This study shows that the appropriate addition of resin allows the wetted recycled paper to retain even more than 30% of its dry strength, while in the dry state, the breaking strength of the paper is improved by approximately 46%. As the demand for more sustainable and resistant paper products continues to grow, the use of wet strength agents is expected to increase in the coming years, as well as the need for research in this field. This research therefore undoubtedly contributes to advancing sustainable practices within the paper industry, aligning with the principles of circular economy by optimizing the utility of recycled fibers while maintaining product quality.