Characteristics Of Leather Research Articles

The Impact of Cashew Nut (Anacardium occidentale) Testa Tannin Feeding Ratio on the Chemical and Mechanical Characteristics of Leather Tanned from Cowhide, Goatskin and Sheepskin

In recent years, there has been a growing interest in exploring natural alternatives to synthetic tannins, driven by concerns over sustainability and environmental impact. Natural tannins offer several advantages, including biodegradability, renewability, and lower environmental impact compared to synthetic chemicals. Among the natural tannins under investigation, cashew nut testa tannin has emerged as a promising candidate due to its abundance, renewability, and potential benefits in leather tanning applications. This research investigated the impact of varying feeding ratios of cashew nut testa tannin on the chemical and mechanical characteristics of leather tanned from cowhide, goatskin, and sheepskin. The objective was to determine how different concentrations of cashew nut testa tannin influence the quality and performance of the leather. Leather samples were prepared using different feeding ratios of cashew nut testa tannin and subjected to a series of chemical and mechanical tests. The results indicated that the absorption of tannin and the resultant chemical stability varied with the type of hide or skin, with each exhibiting unique optimal ratios for tannin uptake. Higher tannin ratios generally improved the tensile and tear strength of the leather across all types, with significant enhancements noted in goatskin and sheepskin. However, an increase in tannin ratio reduced the flexibility of cowhide, while goatskin and sheepskin maintained adequate flexibility. The study demonstrates that cashew nut testa tannin is an effective and sustainable tanning agent, capable of producing quality leather. The findings suggest that the leather industry can utilize cashew nut testa tannin to enhance leather properties, with potential customization of tannin feeding ratios to meet specific performance requirements. Further research is recommended to explore long-term durability and economic viability on a commercial scale. This study contributes to the development of eco-friendly tanning practices and provides insights into optimizing the use of cashew nut testa tannin for various types of leather.

Influence of Retanning Agents on Physical Characteristics of Snow-White Glove Leather from Goat Skin

The quality of leather is subject to various elements, such as the specific raw material used, and the processing techniques implemented throughout the production process. Goatskin, renowned for its exceptional softness and durability, is frequently employed in the production of gloves owing to its desired attributes, notably its capacity to produce snow-white gloves. Retanning is an essential step in the leather manufacturing process as it significantly improves the characteristics of the leather. Through an investigation into the impacts of distinct retanning agents on goatskin leather gloves, this research endeavor seeks to offer significant knowledge regarding the most effective retanning procedures that can augment the tactile attributes of snow- white leather gloves. In this study, formaldehyde, alum, chromium, and chromium alum were employed as retanning agents. The retanned leathers were assessed by physical parameters, Principal Component Analysis (PCA), and Fourier Transform Infrared spectroscopy (FTIR), then compared to a commercially available snow-white leather glove. The physical characteristics of chrome alum retanned leather showed a high degree of softness (6.60±0.02 mm), good tear strength (1.530±117 N/cm), and tensile strength (1.500±100 N/cm 2 ). The principal component analysis (PCA) also supported that the properties of chrome alum retanned snow-white glove leather closely resemble commercial leather and the result from this study suggested that all factors notably impact the skin's physical quality, except for thickness. Additionally, the FTIR analysis reveals similar functional groups from the different retanned leathers indicated by comparable peaks and stretching patterns. Therefore, chrome-alum could be a well alternative retanning agent for the production of snow-white glove leather.

Characteristics of leather produced by using Acacia nilotica ssp tomentosa pods as tanning materials from Blue Nile State-Sudan

Chrome salt utilization in tanning industry become spread over the world owing to its preferred quality in leather industry. However, Environmental concerns of chromium have shifted the interest of current research to metal-free and friendly processing options. Vegetable tanning, have been proven to be environmentally safe and manageable, while producing good quality leather with similar characteristics as that of chromium tanned leather. So, the objective of this research work is to determine the properties of leather using vegetable tanning materials from the pods of Acacia nilotica ssp tomentosa in the form of powdered pods and extract. Results indicated a significant difference in the properties of the tanned skin. Chemical properties of the tanned leathers by extracts of Acacia nilotica ssp tomentosa pods are found to be quite normal. Tensile strength values of tanned skin with pods extracts are higher than that tanned with powdered pods. On the other hand, tanned skin with tannin extract produced greater skin elongation 44.39% compared to tanned with pods powder which was 34.94%. This work provides useful information on the potential leather production by using vegetable tannin materials for leather industries in Sudan and beyond.

Characteristics of leather produced by using Acacia nilotica ssp tomentosa pods as tanning materials from Blue Nile State-Sudan

Characteristics of leather produced by using Acacia nilotica ssp tomentosa pods as tanning materials from Blue Nile State-Sudan

Preparation of a ricinoleic acid modified amphoteric polyurethane for leather cleaner and simplifying production

Realizing green processes in wet finishing (including tanning, retanning, and fatliquoring) has become a big concern in the leather industry. Although the development of chrome-free tanning agents has made great contributions to the cleaner production of leather in recent years, the retanning and fatliquoring processes matched with this promising system still have many disadvantages, such as low compatibility, complex processes, and high pollution. Here, a novel multifunctional amphoteric polyurethane (RAWPU, an amphoteric polyurethane modified by ricinoleic acid) was synthesized and applied in the processing of chrome-free tanned leather. As a result, this product has not only the retanning characteristics of leather but also the lubrication characteristics of leather, thus integrating the traditional retanning and fatliquoring processes into one step. In addition, the hygienic performance of leather treated with RAWPU is better than that of the leather treated by commercial agents. More interestingly, compared with commercial agents which are nondegradable, RAWPU synthesized in this work easily degrades. This work is of great significance to the practical production of leather.

Overview of the Leather Industry and Pollution Impact

The growing awareness of the human and environmental vulnerability, to the pollution resulting from industrial activity, highlights the urgent need for control and mitigate the degradation of the world as we know it. The leather industry, considered as one of the industries with a significant environmental impact, applies several chemicals, some of them considered as hazardous chemicals, such as chromium, in leather production. The restricted EU environmental regulations have driven the search for a process that ensures regulatory compliance and a final product that fulfills society’s requirements. The present review describes alternative options, applied in the leather tanning process in the last five years, to overcome some of the industry barriers, without compromising the final characteristics of leather.

Recycling of used domestic waste oils: A benign emulsifier-free lubricating material for leather process

The leftover vegetable oils after frying of food at higher temperature is toxic to environment as diminutive of technologies for proper disposal and reuse of waste cooking oil. An highly water soluble and emulsifier-free phosphorylated fatliquor with the emulsion stability of more than 60 min from economically cheap deep fried oils on transesterification with highly biodegradable ecologically innocuous and water soluble Poly (ethylene glycol) with p-Toluene Sulphonic acid followed by phosphorylation produces highly water dispersible and stable material for leather applications. The synthesised phosphorylated fatliquors were ascertained for the lubrication of collagen fibres and fibre splitting of goat skin by SEM analysis. The transesterification has confirmed by FT-IR, fat composition oils, COD, BOD, total solid in spent liquor were analysed. Physical characteristics of leathers were analysed by tensile strength, tear strength, elongation and quality assessments by hand evaluation by experts. Acid, iodine, saponification values, particle size of phosphorylated fatliquors, surface wettability, thermal stability of leathers were analysed and the properties compared. The finding can assist an emulsifier-free lubricating process significantly as currently available leather chemicals.

Evaluation of Dye Fixatives – A Comparative Study

Dyeing is the important unit process in leather manufacturing, which adds value to the leather. Although formic acid is used for fixing of dyes in leather processing, difficulties do arise in fixation of certain dye stuffs. Further high quantities of formic acid used do create health issues and adds to high cost of production. Compounds such as formic acid, acetic acid, mixture of organic acids and quaternary ammonium compounds have been found to function as dye fixatives. The efficacy of these compounds to function as dye fixatives for various dye stuffs and substances either alone or along with formic acid has been studied in detail in this work. The physical and color characteristics of leather and spent liquor analysis have been carried out.

Recycling of Chrome-Tanned Leather and Its Utilization as Polymeric Materials and in Polymer-Based Composites: A Review.

Tanneries generate large amounts of solid and liquid wastes, which contain harmful chemical compounds in the environment, such as chromium, that is used in the tanning process. Until now, they have been almost completely dumped in landfills. Thus, finding eco-sustainable and innovative alternatives for the management and disposal of these wastes is becoming a huge challenge for tanneries and researchers around the world. In particular, the scientific and industrial communities have started using wastes to produce new materials exploiting the characteristics of leather, which are strongly connected with the macromolecular structure of its main component, collagen. None of the reviews on leather waste management actually present in the scientific literature report in detail the use of leather to make composite materials and the mechanical properties of the materials obtained, which are of fundamental importance for an effective industrial exploitation of leather scraps. This comprehensive review reports for the first time the state of the art of the strategies related to the recovery and valorization of both hydrolyzed collagen and leather waste for the realization of composite materials, reporting in detail the properties and the industrial applications of the materials obtained. In the conclusion section, the authors provide practical implications for industry in relation to sustainability and identify research gaps that can guide future authors and industries in their work.

Influence of Sampling Location on Physical and Mechanical Properties of Full Grain Leather

Full grain leather refers to the strongest and most durable part of the cattle hide, consisting of the grain layer and the part of the underlying corium, and has not been sanded or buffed to remove any imperfections, that means it displays the more natural characteristics of leather. Leather quality changes with sampling location, depending on variation present in the leather fibrous structure. Leather properties were also affected by tanning and finishing processes utilized during production. Full grain leather, instead finishing, sometimes go only through an ironing process for the desired sheen is obtained. Therefore, with the purpose of analysing the influence of the leather processing level, and sampling location on their quality, in this paper, the physical and mechanical properties of differently (synthetic and chromium) tanned finished and non-finished cattle full grain leathers, sampled from the bend, shoulder and belly of side leather cuts were evaluated. Their applicability for footwear uppers were assessed by measuring leather thickness, mass per unit area, apparent density, tensile strength and percentage elongation at break, all according to the standardised test methods.

Performance Evaluation of Dimethyl Silicone Oil as Archaeological Dry Leather Lubricant

This study aimed to investigate?the treatment effect?of dimethyl silicone oil on archaeological dried leather. Leather samples, without treatment and treated in a vacuum, were submitted to an accelerated aging at 100°C for 72 hours. In order to evaluate the efficacy of treatment, leather characteristics were examined before and after treatment with dimethyl silicone oil and after accelerated aging. Colorimetry, ATR-FTIR spectroscopy, shrinkage temperature measurement and differential scanning calorimetry were used to examine the leather characteristics and the effectiveness and stability of treatment. The results revealed that the dimethyl silicone oil has a suitable performance in the treatment of dry leather. The results also showed that the use of dimethyl silicone oil significantly reduces the changes in leather during accelerated aging. In other words, dimethyl silicone oil treatment improves the leather stability against deterioration.

Fatliquoring process on tuna fish skin tanning for the shoe upper leather

Fatliquoring is a part of tanning process, which is penetrating the fatliquoring agent into leather’s empty cells. The process changes the physical characteristics of leather, which make it softer, more elastic, flexible, and give smooth grain surface. This study is conducted to investigate the effects of type and dosage of fatliquors on the physical properties of tuna skin leather for the shoe upper. The types of fatliquors used are natural and synthetic, and the dosages are 3%, 6%, 9%, 12%, and 15%. Thickness increase, tear strength, tensile strength, elongation at break, and organoleptic properties of the leather are investigated. Based on this study, the types of fatliquor significantly affect the tear strength and elongation at break. The dosages of fatliquor which are nested in the type of fatliquor significantly affect tear strength, tensile strength, and elongation at break. The best treatment in this study is synthetic fatliquor with dosage of 3%. The treatment produced leather with thickness increase of 32.4%, tear strength of 95.3 N/mm, tensile strength of 27.9 N/mm2, elongation at break of 45.3%, dark brown colour, smooth feel or handle, and good flexibility.

Quality of Leather Using Vegetable Tannins Extract of Acacia Mangium Bark from Waste of Industrial Plantation

The purpose of this study was to determine the characteristics of leather using vegetable tanning ingredients from the bark of Acacia mangium Willd. Tanning agent ingredients are provided in the form of bark powder and extract. The first phase of the preparation of the bark into powder and the second stage is the extraction of tannin from A.mangium bark. Extraction using water at 1000C for 30 minutes then evaporated so that tannin extract was obtained. Then the second stage is carried out the tanning process using both materials. Data analysis uses paired two sample for means T-test. The results of statistical analysis showed significant differences in the characteristics of the leather produced. Chemical analysis of leather tanned using A.mangium bark obtained moisture content of 16.76%, ash of 3.42%, tannin bound 18.99% and degree of tanning 38.21% while chemical analysis of leather tanned using tanneries A.mangium bark extract which is moisture content 16.03%, ash 4.18%, bound tannin 32.41% and 84.82% tanning degree. The physical properties of leather using A.mangium bark powder were tensile strength 493.84 kg / cm2, elongation 34.94%, zwik strength / lastability 6.66 mm (leather cracked). Compared to the characteristics of leather using tanner A.mangium bark extract, tensile strength was 254.32 kg / cm2, elongation 44.39%, zwik / lastability strength 8.63 mm (leather not cracked).

Leather solid waste: An eco-benign raw material for leather chemical preparation – A circular economy example

One of the long lasting problems associated with leather industry is to meet environmental standards for both liquid and solid wastes. Statistics show that one tonne of wet-salted hides/skins yields around 650 kg of solid waste. Among various wastes generated, trimmings for the most part have been underutilized. Collagen presents in trimmings waste are effectively used but hair goes unutilized or at the most as feed for boilers during gelatin manufacturing. Hence, newer technology is needed for complete and effective utilization of raw trimmings. In leather manufacture, formaldehyde condensates polymers are used as re-tanning agent to enhance the compaction of leather. However, these products are hard for biodegradation and also cause the release of free formaldehyde in leather, which is a known carcinogen. Here, there is a need for development of formaldehyde free re-tanning agent for eco-benign leather processing. In this work an attempt had been made to develop formaldehyde free biodegradable eco-benign re-tanning agent from raw trimming of tannery solid waste as a circular economy model. Alkaline (7.5%w/w NaOH) – hydrogen peroxide (10%w/w) pre-treatment followed by thermal hydrolysis at 100 °C for 5 h was an optimized method for effective hydrolysis of trimmings and the process of preparation of product results in the holistic utilization of raw trimmings. The developed product was characterized using Dynamic light scattering and FTIR techniques. The product prepared was further used in leather manufacture as a re-tanning agent and was found to impart multifunctional properties to leathers such as fullness, grain tightness and shade of dye brilliance. Product improves the mechanical strength characteristics of leather and also the exhaustion of post-tanning chemicals. SEM analysis shows that the experimental leather is more compact and flat than control. This novel strategy had not only solved the issue of solid waste but also resulted in a greener leather auxiliary leading to greener environment.

PENGARUH PERBANDINGAN TERONG BELANDA (SOLANUM BETACEUM CAV.) DENGAN RUMPUT LAUT (EUCHEUMA COTTONII) TERHADAP KARAKTERISITIK LEATHER


 
 
 This study aimed to determine the effect of tamarillo and seaweed ratio on the characteristics of tamarillo leather and to know the optimum ratio of tamarillo and seaweed on the characteristics of leather. The experimental design was used completely randomized design with the ratio of tamarillo and seaweed as treatment, which consist of 6 levels such as: 100% : 0%, 95% : 5%, 90% : 10%, 85% : 15% : 80% : 20%, and 75% : 25%. The treatment was repeated as many as 3 times then obtained 18 units of the experiment, the data obtained from the result research were analyzed by variance and if the treatment had an effect on the variable then continued with Duncan test. The results showed that tamarillo and seaweed ratio had a significant effect on moisture content, total sugars, vitamin C, curde fiber content, color (score), texture and taste level (hedonic and score), and overall acceptance (hedonic) of leather. Ratio 75% : 25% is produce best characteristic with 12.61% moisture content, 23.93% total sugars, 33.70 mg/100g vitamin C, 21.81% curde fiber content, color rather orange and liked, typical aroma of tamarillo and liked, very elastic texture and very liked, typical of tamarillo taste and very liked, and overall acceptance of very liked.
 
 

A comparative study on designer and customer preference models of leather for vehicle

The purpose of this study is to examine the difference in the tactile perception between designers and customers for leathers in vehicle interiors and to derive preference models that describe the relationship between the tactile perception and physical measurements the leathers. An experiment was performed on ten natural leathers manufactured in the automotive industry. The questionnaires were designed based on six pairs of adjectives: wet-dry, slippery-sticky, smooth-rough, flat-bumpy, hard-soft, and thin-thick for sensory evaluation. In addition, eight physical measurements were selected to identify the characteristics of leathers that affect the tactile perception of designers and customers. The relationship between the experiment results and physical measurements was determined by correlation and regression analyses. The statistical results show a significant difference between designer and customer in the tactile properties of the leathers. Also, the tactile perception from both designers and customers was associated with more than one physical measurement, while the designers and customers showed different tactile association with physical measurements. This study contributes to the comprehension and recognition of the differences in preferences for leathers in vehicle interiors between designers and customers and, by designing the prediction model of preference based on the physical measurements, the uncertainty in the market for automobile manufacturers can be reduced.

Electrochemical treatment of spent tan bath solution for reuse

Abstract A spent tanning bath contains high concentration of salts, chromium and protein. The treatment system for removal of chlorides or chromium from this effluent is expensive. In this context this waste has to be reused. Our study focuses on the application of advanced oxidation processes for protein removal present in a tanning bath. To improve the quality of the chromium tanning bath, two electrochemical processes (electrooxidation and peroxi-electrocoagulation process, PEP) are investigated in a batch reactor. The effects of operational parameters such as reactor configuration, current density and electrolysis time on chemical oxygen demand (COD) and protein removal efficiency are examined. Results indicated that under the optimum operating range for process, the COD and protein removal efficiency reached 53 and 100%, respectively. The optimum values are determined for the hybrid process (PEP) under 0.13 A·cm−2 over 2 h. The treated tanning bath is used as a tanning solution in leather processing. The influence of chromium salt dose, pH solution, stirring time and contact time on the leather characteristic is evaluated. The hides tanned after the addition of 0.25% of commercial chromium salt, at pH solution, leaving them stirring for 4 h with a contact time of 2 days, and showed good hydrothermal stability and physical characteristics of leather.

Leather quality of beefalo‐Nellore cattle in different production systems

The aim was to compare the effects of two production systems on performance, carcass traits and physical-mechanical characteristics of leather from Beefalo-Nellore steers and heifers and to determine if the response to the production system was similar for both genders. A total of 40 Beefalo-Nellore cattle, 20 steers and 20 heifers, were evaluated. Animals were divided into two production systems: slaughtered at 15 (intensive system) or 26 (extensive system) months of age. In the intensive system, all animals received a ration containing 600 g/kg corn silage and 400 g/kg concentrate. In the extensive system, animals were kept on a pasture predominantly based on Brachiaria sp. and supplemented with 2 kg/day concentrate. In the intensive system, there was no difference in slaughter weight (470 kg body weight) between steers and heifers but steers in the extensive system had greater slaughter weight than heifers (463 and 428 kg body weight, respectively). Leather weight was higher for animals in the intensive than extensive system but there was no difference in leather weight once excess fat was removed. Leather quality from Beefalo-Nellore cattle slaughtered at 15 or 26 months of age is similar although carcass yield is higher for cattle slaughtered at a younger age.

Leather quality of some Sudan desert sheep and goats

Leather quality of some Sudan desert sheep and goats

Maskeleme Maddeleri Kullanılarak Kromla Tabaklanmış Giysilik Mamul Derilerin Bazı Kimyasal Özelliklerinin Belirlenmesi

This study has been conducted for the purpose of determine the some chemical characteristics of leather by making use of masking materials in tanning process. During the process of tanning, traditionally chromium salts and masking materials such as sodium formate, sodium acetate, sodium citrate, phthalic acid, sodium oxalate were used. At the end of these process, determination of volarite matter, determination of matter soluble in dichloromethane, chromium oxide in leather, determination of nitrojen content and hide substance and pH as well as chemical analyzes were applied. According to the findings, on the effect of some chemical characteristics of leather masking materials were ascertained. Findings suggested that sodium asetate and sodium oxalate gave the best results