The effect of natural dyes on the strength of the leather

A scientific study was conducted to identify changes associated with certain physical and mechanical properties of the leather stained with natural extracts. The purpose of the work is to obtain the most environmentally friendly leather, using natural dyes in the finishing works of the leather industry, coloring the leather and improving the physical and mechanical properties of raw materials. In the leather industry, plants are commonly utilized as sources of tannins. This study explores the application of plant-based materials during the finishing process and examines their impact on the physical and mechanical properties of leather, particularly during the coloring process. The tearing load of the leather was measured and analyzed. For this study, chrome-tanned cattle leather produced by "TuranSkin" was used. During the leather finishing process, natural dye extracts were employed as alternatives to chemical pigments. The natural dye extracts included walnut shells, onion peels, and oak bark. Three control samples were prepared for comparison: one using a standard chemical pigment, one using water instead of a chemical pigment, and an unfinished leather sample. The analysis revealed that natural extract-based dyes not only provide coloring properties but also enhance the physical and mechanical characteristics of leather. Based on these findings, the use of natural dyes is recommended for leather finishing processes in the leather industry.