Usage of hydrogen peroxide in leather manufacturing processes and its effects on leather characteristics

In this study, hydrogen peroxide usage instead of sodium sulphide (Na2S) under alkaline condition in leather manufacturing was investigated, whether hydrogen peroxide could be an alternative to high pollutant conventional unhairing-liming process or not. Besides, the effect of hydrogen peroxide on leather properties and the pollution load of liming wastewater were studied. The results indicated that the unhairing and fiber opening performance of hydrogen peroxide were satisfactory and the physical characteristics of the leathers as well as the air permeability values were comparable to those obtained by conventional unhairing-liming process. In addition, the chemical oxygen demand (COD) and the sulfide values of the waste water were also lower than the conventional one

Dyeing properties of simple acid and metal-complex dyestuffs on the leathers tanned with various tanning materials

Tanning materials used for production of leathers may vary according to the properties required and the field of use. Since different tanning materials react with different reactive groups of the collagen, this results changes in the reactive groups available for the chemicals that will be used in further processes. Simple acid dyes are the most common used dyestuffs in the leather industry, generally without considering the type of tanning. Starting from this point, it has been investigated the consumption and fastness properties of the simple acid dyes on the leathers tanned with various tanning materials. Chromium and aluminium from mineral tanning materials; tara, gambier and valonea from vegetable ones were selected for the trials. Simple acid dyes gave good consumption and fastness values for dyeing of mineral tanned leathers however the values for vegetable tanned leathers were relatively bad. 1:1 metal complex dyes were tried as an alternative, and the results of the trials were rather good for both the mineral and vegetable tanned leathers

Manufacture of leather skirt from garment leathers tanned with various tanning materials and evaluation of visual properties

In this study, effect of material on usage and visual properties on an apparel product produced from leathers tanned with different types of tanning materials, was evaluated. For this purpose, skirts were manufactured from chromium, semi-vegetable and vegetable tanned leathers obtained from two tanneries. Skirt patterns were prepared by using Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) systems. Leather skirts were evaluated by specialists by using subjective rating scale and the obtained data were analyzed by fuzzy logic method. As conclusion of this study; when visual effects of these skirts were evaluated, it was observed that skirts produced from chromium tanned leathers had better results than the skirts produced from the leathers tanned with other types of tanning materials

Reducing the amount of tanning materials passing into wastewater in post-tanning processes

This research was carried out in order to detect and reduce the amount of the tanning material passing from leather into the float during post-tanning processes. In the research, the possibility of reducing the amount of unbound or weakly bound tanning materials, passing from leather into wastewater during post tanning processes, by forming a complex with a second tanning material used in a new float was examined. The feature of mineral tanning materials that enables them to form a complex with vegetable tanning materials was used for this purpose. It was proved that the amount of the mineral tanning material passing into wastewater during post tanning processes was reduced to some extent with vegetable tannin application after mineral main tannage, while the amount of vegetable tanning material passing into wastewater could be reduced in significant amounts of approximately 85% with mineral tanning material application after vegetable tannage

Comparative determination of physical and fastness properties of garment leathers tanned with various tanning materials for leather skirt production

In the present study, physical and fastness properties of the leathers, which are obtained from two different tanneries, similarly processed in each tannery however, differentiated from each other by tanning with chromium, vegetable and chromium-vegetable combinations and planned to be used in skirt manufacture were determined with various quality control and analysis methods and evaluated by considering their field of use. Additionally it was statistically investigated whether there is a significant difference between the physical characteristics of leather depending on the type of tanning material used. Consequently, it was deduced that the type of tanning material used in leather production has statistically significant effect on the physical characteristics of the leathers which are produced from the same origin

Spectral study on plant extracts releasing from medical fur items

The objective is to obtain leathers and furs for medical or everyday use, with high performance characteristics, through the use of new plant extracts that have not been used in leather industry so far, as an alternative to the use of chemicals with pollutant potential. Developing a complex analytical system for the characterization of natural extracts as additives and their role of fur and leather processing, is important both scientifically and technologically. The complex system consists of two spectral methods coupled and interdependent spectroscopy in the ultraviolet and visible (UV-VIS) and infrared spectroscopy with attenuated total reflection (FT/IR-ATR). For the spectral study of releasing kinetics of volatile substances, from the hair of natural furs processed for medical use, a series of oil extracts from the following plants have been selected: thyme, lavender and sage. For this purpose, desorption rates of active principles in fur supports treated by spray coating or by immersion have been analyzed and a series of fur items have been created, which can be treated with plant extracts to achieve prophylactic effects (bactericidal, anti-inflammatory, revulsive, relaxing etc)