Application of some Plant Extracts as Biocolorants for Leather During Finishing Process

In this research, chrome-tanned bovine crust leathers were dyed during the finishing process using plant extracts: walnut shell (Juglans regia), oak bark (Quercus cortex), and onion peel (Allium cepa). In this study, the standard recipe applied by the factory was used in the leather finishing process. For this recipe, various plant extracts were used instead of pigments, and groups that did not contain pigment and any dyestuff were formed as the control groups. After these processes, color measurement analyzes were performed on Konica Minolta CM 3600d spectrophotometer. In order to investigate the effects of walnut shell (Juglans regia), oak bark (Quercus cortex), and onion peel (Allium cepa) on the other performance properties of leather, dry and wet rub fastness test according to standard method TS EN ISO 11640 (2001) was performed. The results of the study were statistically evaluated using the NCSS method (Number Cruncher Statistical System). As a result of the study, it was noticed that, depending on the extract, different colors were obtained. It was found that the dry and wet fastness of leathers treated with plant extracts improved.