Content: Tannins are high molecular weight polyphenols, naturally synthesized by plants to defend themselves against biotic and abiotic stress factors. Their role as antioxidant, antibiotic and antibacterial agent has been known for many years among agriculture, food, pharma and cosmetics industry. If tannins would perform an antibacterial activity in a vegetable tanned leather, the leather itself could be certified as an antibacterial material. This effect could be very interesting for all the applications in which the leather, being in contact with sweat and bacteria, becomes a solution to reduce more or less severe hyperhidrosis and bromhidrosis. The goal of the study was the assessment of the antibacterial activity of vegetable tanned leathers with natural tannins to produce articles in direct contact with human skin and, therefore, their effect on sweat, bacterial growth and metabolite production. Firstly, the antibacterial activity has been evaluated and compared between leathers tanned with Chestnut, Quebracho and Tara extracts, chrome tanned leathers and synthetic materials. The trial was performed in vitro by inoculating gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacterial strains. A later step defined the most suitable blend of tannins to obtain, after tanning and/or retanning, an antibacterial natural leather. Furthermore, the vegetable tanned leathers, made with this tannins blend, have been the target of an in vivo trial during which 15 panelists have worn two differently made shoes. The lining and insole inside the right shoe have been made with vegetable tanned leathers with tannins, while the ones inside the left shoe contained only synthetic material. The shoes have been worn for 28 consecutive days, followed by a molecular and bioinformatic analysis of microbiota samples taken from the inner surface of the shoes by using a sterile swab. Lastly, a biochemical analysis of volatile short chain fatty acids has been carried out to investigate the byproducts of the bacteria responsible for the unpleasant odor of shoes. Take-Away: 1. Vegetable tanned leather is a wonderful antibacterial material thanks to the presence of natural tannins, such as chestnut, quebracho and tara. This property is appreciated in the production of insole leather, lining, leather goods and automotive interiors. 2. The problem of bromhidrosis (bad feet odor) can be avoided by using vegetable tanned leather. 3. In particular, vegetable leathers tanned with tannins used to make inside part of the shoes permit to avoid the formation of cheesy and acidic odours thanks to their antibacterial properties and their capacity to absorb sweat.

Content: ZnO nanoparticles were developed by 1:2 ratios of Zinc sulphate heptahydrate and Sodium hydroxide by using precipitation method. The structure, morphology of ZnO nanoparticles were investigated by using XRay Diffraction, Scanning Electron Microscopy and Transmission electron Microscopy. X-Ray Diffraction confirms the formation and average crystallite size of ZnO nanoparticles. Scanning Electron Microscopy studies shows the ZnO nanoparticles were in spherical in structure. These ZnO nanoparticles were used in different ratios along with conventional finishing formulations and coated on the leather surface. The performance properties such as water fastness, rub fastness and flexing resistance were evaluated. Application of ZnO nanoparticles in leather finishing showed significant improvement in overall performance properties than conventional finishing formulations. XRD confirms the formation of ZnO nanoparticles (wurtzite structure) at 36.67° (101) plane and the particles size was in the range of 43 nm. SEM image shows that the particles are in the spherical structure wheras EDAX investigate the stoichiometry and chemical purity of the samples to confirm the presence of zinc and oxygen. Optimum quantity up to 2-5 g/L of the season of ZnO nanoparticle is desirable for upgrading the value of leathers by improving color fastness to water, rub fastness and flexing resistance (wet & dry) properties significantly in cationic (wet), NC lacquer emulsions and PU top coat dispersions in finishing formulations. Take-Away: Optimum quantity up to 2-5 g/L of the season of ZnO nanoparticle is desirable for upgrading the value of leathers by improving color fastness to water, rub fastness and flexing resistance (wet & dry) properties significantly in cationic (wet), NC lacquer emulsions and PU top coat dispersions in finishing formulations.

Content: Leather manufacturing involves discharge of large quantities of solid and liquid wastes. While efficient recycling methods and in-plant controls have considerably reduced the discharge of obnoxious liquid streams, satisfactory methods to the solid waste management still elude the leather manufacturers. Landfilling is an easy option for the disposal of solid wastes like chrome shavings and trimmings, but is subjected to stringent environmental regulations because of the presence of chromium in these materials. Considerable efforts have been made to recycle the chrome containing wastes by methods such as incineration, pyrolysis and alkaline or enzyme hydrolysis. These recycling processes, however, are seldom complete without further environmental problems. Unfortunately, in such recycling processes the inherent fibrous structure of these materials gets completely destroyed. Applications based on the fibrous nature of the shavings and trimmings are presently limited but various possibilities are being explored continuously. An efficient way of utilization of these fibrous waste materials may be to combine them in a suitable form with synthetic polymers to give composite materials. Short fiber reinforcement of polymers is an important area in polymer composites where both synthetic and natural fibers are effectively used. Footwear has become a basic necessity like food, shelter and clothes. Soles are bottom components of footwear and some important polymeric materials used in footwear fabrication are last, soles and Insoles. This research aims at reducing the solid waste (Chrome shavings) generated by leather industry and reusing them as low cost shoe components such as soles and insole material. In this research, the footwear components were prepared using chrome shaving (tannery solid waste), EPDM (ethylene propylene monomer rubber) and isoprene rubber with different inorganic oxide/hydroxide nano particle based fillers. In this study, soles are prepared by using strap cutting machine, two roll mill and compression moulding machine. The soling materials made characterised using FT-IR and SEM and tested for mechanical properties. Due to good mutual compatibility between Isoprene, EPDM and leather fibre with inorganic nano clay based fillers, the composites are well in terms of all the physic-mechanical behaviours like hardness, density, abrasion resistance and grain crack suitable for shoe sole application. Take-Away: 1. Ethylene propylene monomer rubber and leather fibre with inorganic nano clay based fillers, the composites are well in terms of all the physic-mechanical behaviours like hardness, density, abrasion resistance and grain crack suitable for shoe sole application. 2. An efficient way of utilization of these fibrous waste materials may be to combine them in a suitable form with synthetic polymers to give composite materials. Short fiber reinforcement of polymers is an important area in polymer composites where both synthetic and natural fibers are effectively used.

Content: Consumers perceive leather as a durable and natural product. To support this positive image, car manufacturers have set demanding performance profiles addressing wear, emissions and sustainable manufacture. Poor performance of auto leather becomes visible as the polymeric finishing coat wears off or cracks over time. Therefore ageing property is seen as a representative key performance parameter and is determined by checking how flexible and strong a polymer coating remains after leather has been exposed to light, heat and humidity for a given time. Ageing of leather is complex to determine and depends on various parameters and requires a full system approach . In a first step different type of crusts (wet-blue, wet-white) were prepared and finished with a standard polyurethane coating. It turned out that the selection of the right fat liquors and tanning agents as well as the presence of vegetable tannins play an important role. On top of this the effective use of proper protective chemicals like anti-oxidants is needed. In a second approach the polymer coating itself was studied and optimized with regard to aged flexing and abrasion. Parameters like polymer type, crosslinking, application technology, coating thickness and impact of additives were investigated and tested when applied on the best crust leathers selected from part 1 of this work. Results show that not only is the right selection of polymers critical but also so is the way the coat is being applied . Furthermore coating thickness greatly defines wear (abrasion), lightfastness and ageing properties. Additives like dulling agents, levelers, feel agents, waxes ,fillers although needed can weaken the integrity of the polymer matrix and consequently reduce physical and chemical fastness properties. This may also apply to a certain extent to protective additives such as anti-oxidants and UV stabilizers, but when used properly their advantages outweigh the potential disadvantages. As to application, special emphasis is given to transfer coating technology which can provide advantages in application and quality consistency but also with regards to fastness properties such as wear and ageing. Take-Away: - crust leather has a critical impact on performance of finishing coat of automotive leathers and requires careful selction of products and use of protective chemical - polymer selection and use of protective chemical play an important role for achieving good aged flexing performance - type of application of finishing coat on auto leather further determines the performance of coating

Content: Fine hair is the biggest seasonal challenge for bovine leather production in the United States. The origin, timing and severity of the fine hair problem can be unpredictable and vary from year to year. Seasonal changes on the hair growth cycle are prompted by the lower temperature from fall to winter; the cow hair increases in amount, length and thickness. This problem is very old and has increased in intensity due to changes in the leather manufacturing process, cattle breeding conditions and breed diversity. The amount of fat and thickness of the hide also play important roles. The extent of the problem has not been documented and is not fully understood by the scientific community. The presence of fine hair (residual hair) on the wet blue and final leather are a cause of downgrading the leather. If the wet blue has fine hair, it cannot be removed in further processing in crust or finishing. Some leather types can tolerate more fine hair than others. In this paper we will conduct a scientific evaluation of the fine hair on American bovine hides, wet blue and finished leathers through cross sections and stains, optical and electron microscope observations. We will include measurements of hair thickness and hair depth inside the hide. The work will compare sulfide and oxidative unhairing of winter hides, characterize and show the details of the fine hair through cross sections, and offer indicative measures to minimize the problem. Information from the largest wet blue manufacturer in the US with four tanneries will provide insight on the fine hair seasonality, types of breeds and cattle displacement temperature ranges and will discuss adaptive changes needed in the “Winter” time to control the fine hair. Take-Away: 1) scientific review and evaluation of the problem of fine hair though cross sections and stains, optical and electron microscopy observations 2) evaluate the fine hair on sulfide and oxidative unhairing; providing indicative measures to minimize the problem 3) characterize the seasonality of the fine hair problem regarding the types of breeds, displacement temperature ranges and adaptative changes to control the fine hair

Content: Car industry is highly demanding for low emission parameters and despite remarkable results have been achieved since the last decade, the requests are day by day more sophisticated. The focus on emission is a severe task and requires the investigation on emissions on full-range and involves the expertise of multi and inter disciplinal competences. The leather industry is a clear key ring for car interior suppliers and it is also focusing on more sustainable processes and reducing the emission of pollutants to the environment, prompting the commitment of leather suppliers, tanneries, and chemical auxiliaries producers. From our perspective, in fact, one of the major problems that car interior producers are currently facing is the production of low-emitting leather, which requires special chemical auxiliaries to be achieved. In this context, our research has focused on the study of VOC volatile substances from car interiors, in particular on finishing systems, aiming at their reduction without losing the original performances of the finished leather article. Our investigation focused on full grain finished leathers, evaluating the contribution to the VOC emission from crust leather to the finished articles. A preliminary study showed that silicon compounds family brought an important contribution to the emission from a qualitative and quantitative perspective: these substances play a crucial role in terms of the final article performances (such as resistance), and quality. So, our investigation focused on innovative silicon-free auxiliary combination to give low VOC emission contribution from the leather compared with the same performances of the original silicon containing finishing. In order to evaluate the impact of the emissions, a series of analyses of the volatiles were performed: static headspace VDA 277 (and/or PV3341) analysis and active air sampling analysis GS 97014-3 type were performed, indicating that silicon contribution was very high in the emission. In addition, the quality of the leather was also assessed and characterised through standard automotive tests such as stick-slip, abrasion trials with Taber tester and Martindale machine, ball plate method, fogging test; rub fastness provided with Veslic tester (wet, dry, alcohol, gasoline), dry-rubbing trial with Gakushin tester. The set of result showed that standard leather containg silicon compounds on the finishing produced high VOC emission and high performance articles, thus contributing to VOC emission. Conversely, the novel finishing auxiliaries had low VOC emission, no silicons, yet high performance leather and therefore should be chosen from a more environmental point of view. Take-Away: Low VOC emission from novel leather finishing albeit high resistance leather.

Content: Providing peculiar enhanced features to leather items is a factor of primary importance for the marketing of high-end articles; although the tanning production is oriented to satisfy a wide market range, it is mainly in the 'high end' and 'premium luxury' categories that the quality properties of the material are more expressed, indeed, and where the main current challenges have been focalized, in terms of technological innovation, sustainability and product quality. The light-coloured leathers belongs to the category of materials designed especially for the luxury market. For this type of articles, the uniformity of the colour and the agreeableness of the overall surface appearance are crucial requirements for the most of international fashion and luxury brands. One of the most common and undesirable defects of this type of article is the alteration of the color, with particular reference to the effects of yellowing of the surface of the material. There are several causes able to contribute to this type of defects, due to the complexity of the matrix and to the variability of traditional or innovative production processes used: from the fragility, photosensitivity and thermo-sensitivity of the finishing polymers, to the chemical instability of some finishing pigments, further than the presence of photosensitive additives, the migration of skin components or assembly components of the articles (fats, fillers, plasticizers, glues, etc.), up to the indirect contribution of environmental and thermo-climatic factors able to affect negatively the performance of the material. SSIP, which has always been involved in research and consulting activities for the leather industry with regards to defect monitoring, through this work, would offer an overview of all the main tools for advanced diagnostics (with particular reference to Scanning Electronic Microscopy and to chromatographic and spectroscopic methods) aimed to the identification of the causes of yellowing, beside to explore innovative solutions for the development of strategies for the resolution and / or minimization of the problem of yellowing. The technical solutions will include innovative tanning processes, innovative finishing methods, and leather surface treatments carried out in order to provide a sensible attenuation of surface absorption of IR (infrared) and UV (ultraviolet)-visible radiation. Take-Away: Advanced Diagnostics and innovative solutions for leather yellowing

Content: Surfactants are used as auxiliaries in every wet processing process of leather production and discharged into wastewater, which would cause potential ecological risks. In this paper, fresh luminescent bacillus liquids were employed to evaluate the ecological toxicity of six surfactants, including anionic, cationic and non-ionic surfactants, and mixture of two typical ionic and nonionic surfactants after a 15-min exposure period. Non-ionic surfactants AEO and Tween80 showed slight light inhibition ie.10-35% to luminescent bacteria. The toxicity of anionic surfactants with polar sulfonic group was: penetrant T(EC50=406.81mg/L) ＞SDBS(EC50=573.37mg/L). The toxicity of cationic surfactants was: DTAB（EC50=10.68mg/L）＞SKC （EC50=73.96mg/L）. The addition of nonionic surfactants reduced the toxicity of ionic surfactants. 1-1 mixture of SKC and AEO: EC50=80.17mg/L, 1-1 mixture of SDBS and AEO: EC50=624.34mg/L. These results provided ecological parameters for the selection of surfactants in the process of ecological leather production. Take-Away: 1. The toxicity measurement by luminescent bacteria, which is simple and convenient, was used to evaluate the toxicity of surfactants, and the reproducibility was improved in our study. 2. The toxicities of six different surfactants was evaluated by EC50 which provided ecological parameters for the selection of surfactants in the process of ecological leather production.

Content: Chamois leathers are basically oil tanned leathers, usually requires 10 to 15 days to process from raw skins. In chamois making, air oxidation plays a major role, free radicals initiate the oxidation process in oil, which oxidizes the double bond of the fatty acid and then the oxidized oil interacts with collagen to stabilize the skin by coating the fibers (Fig 1). In the present study an attempt has been made to reduce the time for chamois leather processing. A common oxidizing agent (Benzoyl peroxide (BPO) was utilized to enhance the oxidation of oil and reduce the time duration. It has been observed that the oxidation of oil in the presence of benzoyl peroxide has significantly reduced the duration of process from 15 to 4 days. Strength properties such as tensile, percentage elongation and organoleptic properties were found to be on par with control leather. The water absorption values of the experimental leathers improved by 1-26 %, compared with control leather. Microscopic analysis (SEM) was employed to study the fiber alignment of the chamois leathers. Take-Away: 1. Time reduction in chamois leather processing 2. Inexpensive and common oxidising agents were employed 3.Improved water absorption of chamois leather

Content: Unhairing process is usually considered as the most polluted process in leather production. The conventional method of unhairing which using lime and sodium sulfide produces a large amount of sludge and waste water. In order to reduce pollution, we developed a novel unhairing enzyme and named as WB600-KerT, which possesses low collagen-degrading ability and high keratin-degrading ability in previous study. The objective of this study is to study the properties and effect of WB600-Kert to replace traditional chemicals in unhairing process. It found that the protease of WB600-Kert exhibited optimum keratin activity at 40°C. Compared with commercial unhairing enzyme and conventionally sodium sulfide methods, WB600 exhibited better unhairing effect and higher efficiency. The results indicated that goat skin unhaired with WB600 achieve enough softness, shrinkage temperature and tear strength as well as conventionally sodium sulfide methods Furthermore, if adding a small amount of sodium sulfide, the unhairing process could be accelerated while the unhairing effect was further improved. Generally speaking, this enzyme showed good application potential in unhairing process and was effective for reducing pollution which may promote the development of leather industry. Take-Away: 1. The protease of WB600-KerT was firstly applied to hair removal. 2. The addition of little sodium sulfide in WB600-KerT could enhance unhairing efficiency.