Pub Date : 2023-09-01DOI: 10.34314/jalca.v118i9.8192
Ji-bo Zhou, Nan Sun, Xue-pin Liao, Bi Shi
The use of nanoparticle-based functional leather products has stimulated sustainable growth of the conventional leather industry. However, functional nanoparticles (FNPs) face challenges to be well penetrated and dispersed in leather because of their aggregation and mismatch charges with leather. In this study, the acrylic resin (AR) retanning agent, which was originally utilized in leather processing, was applied for the modification of FNPs. It has been demonstrated that AR can improve the electrostatic and steric repulsion among nanoparticles, inhibiting their aggregation and ensuring their penetration and dispersion in leather. Because of the limitation of leather porosity, the maximum loading amount for FNPs was about 40wt% (based on leather weight). The leather got higher results in fullness, thickening ratio, and tensile strength when the loading amount of FNPs was 11.25%. Moreover, the proposed approach in this study can be used well for other types of FNPs loaded in leather, suggesting its broad applicability.
{"title":"Investigation of High Penetration and Dispersion of Functional Nanoparticles in Leather","authors":"Ji-bo Zhou, Nan Sun, Xue-pin Liao, Bi Shi","doi":"10.34314/jalca.v118i9.8192","DOIUrl":"https://doi.org/10.34314/jalca.v118i9.8192","url":null,"abstract":"The use of nanoparticle-based functional leather products has stimulated sustainable growth of the conventional leather industry. However, functional nanoparticles (FNPs) face challenges to be well penetrated and dispersed in leather because of their aggregation and mismatch charges with leather. In this study, the acrylic resin (AR) retanning agent, which was originally utilized in leather processing, was applied for the modification of FNPs. It has been demonstrated that AR can improve the electrostatic and steric repulsion among nanoparticles, inhibiting their aggregation and ensuring their penetration and dispersion in leather. Because of the limitation of leather porosity, the maximum loading amount for FNPs was about 40wt% (based on leather weight). The leather got higher results in fullness, thickening ratio, and tensile strength when the loading amount of FNPs was 11.25%. Moreover, the proposed approach in this study can be used well for other types of FNPs loaded in leather, suggesting its broad applicability.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"109 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139346896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.34314/jalca.v118i8.8089
Chaoya Ren, Jie Liu, Fang Wang, Yong Lei, Madalina Georgiana Albu Kaya, Keyong Tang
The pyrolysis behaviors of leathers tanned with hydrolyzable tannins (Tara and Chestnut extracts), and condensed tannins (Quebracho and Mimosa extract) were studied by Thermogravimetric (TG) analysis in the present work. The TG/derivative thermogravimetry (DTG) results showed that the thermal stability of Tara- and Chestnut-tanned samples is poorer than that of Quebracho- and Mimosa-tanned ones. In order to study pyrolysis kinetics, TG experiments at different heating rates were carried out. Two methods of Flynn-Wall-Ozawa (FWO) and Friedman (FR) were employed to calculate the pyrolysis activation energy (Eα) of the samples. It was found that the average Eα of the vegetable-tanned samples is located at the range of 191.7-206.1 kJ/mol. The thermodynamic parameters (pre-exponential factor, Gibbs free energy, enthalpy, and entropy) of the samples were subsequently calculated based on the average Eα by the FR method. The Gibbs free energies of the Chestnut-, Tara-, Quebracho-, and Mimosa-tanned leathers were 176.9 kJ/mol, 179.8 kJ/mol, 179.3 kJ/mol, and 178.2 kJ/mol, respectively. The difference between the average enthalpies and the Eα is less than 5 kJ/mol, which indicated that the pyrolysis process is conductive to the product formation. The mean entropy (ΔS) of the four vegetable-tanned samples is all positive, which suggested that the pyrolysis of the samples could easily take place. This work might provide theoretical guidance for the optimization of vegetable-tanned leather waste pyrolysis.
{"title":"Study on the Pyrolysis Kinetic Behaviors of Different Vegetable-Tanned Sheepskin Leathers","authors":"Chaoya Ren, Jie Liu, Fang Wang, Yong Lei, Madalina Georgiana Albu Kaya, Keyong Tang","doi":"10.34314/jalca.v118i8.8089","DOIUrl":"https://doi.org/10.34314/jalca.v118i8.8089","url":null,"abstract":"The pyrolysis behaviors of leathers tanned with hydrolyzable tannins (Tara and Chestnut extracts), and condensed tannins (Quebracho and Mimosa extract) were studied by Thermogravimetric (TG) analysis in the present work. The TG/derivative thermogravimetry (DTG) results showed that the thermal stability of Tara- and Chestnut-tanned samples is poorer than that of Quebracho- and Mimosa-tanned ones. In order to study pyrolysis kinetics, TG experiments at different heating rates were carried out. Two methods of Flynn-Wall-Ozawa (FWO) and Friedman (FR) were employed to calculate the pyrolysis activation energy (Eα) of the samples. It was found that the average Eα of the vegetable-tanned samples is located at the range of 191.7-206.1 kJ/mol. The thermodynamic parameters (pre-exponential factor, Gibbs free energy, enthalpy, and entropy) of the samples were subsequently calculated based on the average Eα by the FR method. The Gibbs free energies of the Chestnut-, Tara-, Quebracho-, and Mimosa-tanned leathers were 176.9 kJ/mol, 179.8 kJ/mol, 179.3 kJ/mol, and 178.2 kJ/mol, respectively. The difference between the average enthalpies and the Eα is less than 5 kJ/mol, which indicated that the pyrolysis process is conductive to the product formation. The mean entropy (ΔS) of the four vegetable-tanned samples is all positive, which suggested that the pyrolysis of the samples could easily take place. This work might provide theoretical guidance for the optimization of vegetable-tanned leather waste pyrolysis.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"103 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139352952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.34314/jalca.v118i8.8091
B. Sahu, Janani V, Renganath Rao R, Akash Bhalla, M. A. Javid
Protein based finishing on leather surface is generally done using casein-based formulation which forms a transparent and breathable film. Other naturally available options such as protein extracted from flax seeds exhibit versatile application in various fields. Thus in this work, the flax seed protein which is found to be 84%, along with bees wax emulsion is explored for the first time as an Eco benign binder and as an alternative for casein based finish. The binders play very important role in leather finishing as it helps in binding the various constituents of finishing such as pigments, wax, and additives to the leather matrix. The prepared Eco benign binder formed a continuous film on the surface of the leather and improved the of physical properties and crack resistance of the leather. The FTIR and particle size analysis were carried out for the characterization of the Eco benign binder. The experimental leathers were tested for tensile strength, elongation at break, lastometer test, colour fastness and cold crack tests. The results of the said tests were satisfied and on par with control leathers.
{"title":"Impact of Flax Seed Protein and Beeswax Emulsion Blend on Leather Finishing– A Novel Eco-Benign Formulation","authors":"B. Sahu, Janani V, Renganath Rao R, Akash Bhalla, M. A. Javid","doi":"10.34314/jalca.v118i8.8091","DOIUrl":"https://doi.org/10.34314/jalca.v118i8.8091","url":null,"abstract":"Protein based finishing on leather surface is generally done using casein-based formulation which forms a transparent and breathable film. Other naturally available options such as protein extracted from flax seeds exhibit versatile application in various fields. Thus in this work, the flax seed protein which is found to be 84%, along with bees wax emulsion is explored for the first time as an Eco benign binder and as an alternative for casein based finish. The binders play very important role in leather finishing as it helps in binding the various constituents of finishing such as pigments, wax, and additives to the leather matrix. The prepared Eco benign binder formed a continuous film on the surface of the leather and improved the of physical properties and crack resistance of the leather. The FTIR and particle size analysis were carried out for the characterization of the Eco benign binder. The experimental leathers were tested for tensile strength, elongation at break, lastometer test, colour fastness and cold crack tests. The results of the said tests were satisfied and on par with control leathers.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"353 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139352567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.34314/jalca.v118i7.7855
Min Gu, Xiaoxia Zhang, Yuanzhi Zhang, Songcheng Xu, Guoying Li
The effect of salt on the collagen of hide/skin is of great significance in leather-making. However, the interaction between neutral salts and collagen has not been clear, since the microscopic interaction is hard to be observed directly from the macro level of hide/skin collagen. In this study, the collagen solutions in the typical neutral salts (NaCl, CaCl2, and Na2SO4) systems were used to explore the interaction mechanism between neutral salts and collagen via combining experiments with molecular dynamics (MD) simulation. The results of fluorescence measurements of pyrene, dynamic light scattering, atomic force microscopy, and isoelectric point suggested that the variation of the interaction between different neutral salts and collagen was accompanied with the changes in physicochemical properties of collagen. MD simulation further revealed more detailed information on the interaction mechanism between neutral salts and collagen at the molecular level. The computational results of non-bond energy of the collagen-salt model boxes indicated that the electrostatic interactions of different salts with collagen molecules had the order of CaCl2> Na2SO4> NaCl. The analyses of the visualized conformation and the radial distribution functions showed that CaCl2 with Ca2+ as contributing ion tended to form intramolecular salt bridges with collagen, while Na2SO4 with SO42-as contributing ion more likely formed salt bridges between collagen molecules in the shape of agglomerates. In contrast, NaCl with Cl-as contributing ion was scattered around the collagen models, and its effect on collagen was much smaller. The study elaborated the interaction mechanism of typical neutral salts and collagen to be helpful for further understanding and improving the use of neutral salts in many steps involved in leather production.
{"title":"Study on Interaction Mechanism between Neutral Salts and Collagen by Combining Experiments with Molecular Dynamics Simulation","authors":"Min Gu, Xiaoxia Zhang, Yuanzhi Zhang, Songcheng Xu, Guoying Li","doi":"10.34314/jalca.v118i7.7855","DOIUrl":"https://doi.org/10.34314/jalca.v118i7.7855","url":null,"abstract":"The effect of salt on the collagen of hide/skin is of great significance in leather-making. However, the interaction between neutral salts and collagen has not been clear, since the microscopic interaction is hard to be observed directly from the macro level of hide/skin collagen. In this study, the collagen solutions in the typical neutral salts (NaCl, CaCl2, and Na2SO4) systems were used to explore the interaction mechanism between neutral salts and collagen via combining experiments with molecular dynamics (MD) simulation. The results of fluorescence measurements of pyrene, dynamic light scattering, atomic force microscopy, and isoelectric point suggested that the variation of the interaction between different neutral salts and collagen was accompanied with the changes in physicochemical properties of collagen. MD simulation further revealed more detailed information on the interaction mechanism between neutral salts and collagen at the molecular level. The computational results of non-bond energy of the collagen-salt model boxes indicated that the electrostatic interactions of different salts with collagen molecules had the order of CaCl2> Na2SO4> NaCl. The analyses of the visualized conformation and the radial distribution functions showed that CaCl2 with Ca2+ as contributing ion tended to form intramolecular salt bridges with collagen, while Na2SO4 with SO42-as contributing ion more likely formed salt bridges between collagen molecules in the shape of agglomerates. In contrast, NaCl with Cl-as contributing ion was scattered around the collagen models, and its effect on collagen was much smaller. The study elaborated the interaction mechanism of typical neutral salts and collagen to be helpful for further understanding and improving the use of neutral salts in many steps involved in leather production.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"18 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139363773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.34314/jalca.v118i7.7860
Cigdem Ozkan
By-products of pomegranate juice enterprises are evaluated as a “green” raw material for many industries. In this study, pomegranate peels which are well known with high polyphenolic content were evaluated as a potential source of tanning agent for leather industry. For this purpose, firstly pomegranate peels were extracted in Koch extractor at 70°C for 8 hours. In order to determine the tanning ability, 30% of ground pomegranate peel powder (containing 7.2% of active tannin matter) was used in the tanning process and pomegranate peel tanned leather was evaluated in terms of increases in thickness and shrinkage temperature, color change and mechanical properties. The application of pomegranate peel tannin in the tanning process provided that an acceptable shrinkage temperature (68.5°C) and mechanical properties for vegetable tanned leathers. The results revealed that the tannin obtained from pomegranate peel has a remarkable tanning effect and can be used in the tanning process. Thus, it is concluded that pomegranate peels can be evaluated as a new source of tannin for leather industry.
{"title":"Tanning with Pomegranate Peel Tannin","authors":"Cigdem Ozkan","doi":"10.34314/jalca.v118i7.7860","DOIUrl":"https://doi.org/10.34314/jalca.v118i7.7860","url":null,"abstract":"By-products of pomegranate juice enterprises are evaluated as a “green” raw material for many industries. In this study, pomegranate peels which are well known with high polyphenolic content were evaluated as a potential source of tanning agent for leather industry. For this purpose, firstly pomegranate peels were extracted in Koch extractor at 70°C for 8 hours. In order to determine the tanning ability, 30% of ground pomegranate peel powder (containing 7.2% of active tannin matter) was used in the tanning process and pomegranate peel tanned leather was evaluated in terms of increases in thickness and shrinkage temperature, color change and mechanical properties. The application of pomegranate peel tannin in the tanning process provided that an acceptable shrinkage temperature (68.5°C) and mechanical properties for vegetable tanned leathers. The results revealed that the tannin obtained from pomegranate peel has a remarkable tanning effect and can be used in the tanning process. Thus, it is concluded that pomegranate peels can be evaluated as a new source of tannin for leather industry.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"2016 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139363988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.34314/jalca.v118i7.7856
S. Vasagam, M. Sornam
Sorting and aligning of crust leather for grading on position wise defect distribution is one of the methods adopted in the tanning industry. This method is generally carried out manually by a veteran on official sampling position and their input is critical because it is directly linked to sales of the crust leather. The opinion of the experts is believed to be stable and consumes a good amount of time too. Hence, in the current research a robust defect detection method and ranking of crust leather images based on image processing techniques is proposed to give a stable solution in a short span of time. A custom-made dataset of crust leather images consisting of 5640 images were used in this study. The pixel intensity has been extracted on demarcated position of various regions including neck, belly left, belly right, center and butt instead of official sampling position through horizontal and vertical mapping of coordinates with a new method Grading Score on Image Position wise (GSIP) on the actual images. The image processing techniques using Canny Edge Detection and filters such as Laplacian, Median, Prewitt, Roberts, Sobel and Scharr were implemented to get the pixel intensity grouped and classified based on parameters within acceptable range using a Naïve Bayes Classifier. The classifier confirms that the accuracy of Set I - Actual Images and Set II - Defects with implementation of canny edge detection over other image processing techniques at 99.50%. Therefore, the current research confirms that the proposed GSIP method would give an additional tool to inspectors while ranking the crust leather based on region wise surface level defect detection of crust leather images based on image processing techniques.
鞣革行业采用的方法之一是对结皮进行分拣和对齐，以便根据缺陷分布情况进行分级。这种方法一般由官方取样位置上的资深专家手工操作，他们的意见至关重要，因为这直接关系到结皮的销售。专家的意见被认为是稳定的，而且会耗费大量时间。因此，在当前的研究中，提出了一种基于图像处理技术的稳健缺陷检测方法和结皮图像排序，以便在短时间内给出稳定的解决方案。本研究使用了一个定制的皮壳皮革图像数据集，该数据集由 5640 张图像组成。通过在实际图像上使用一种新方法--图像位置分级法（GSIP）--对坐标进行水平和垂直映射，提取了包括颈部、腹部左侧、腹部右侧、中心和臀部等不同区域的划界位置的像素强度，而不是官方采样位置。使用 Canny 边缘检测和滤波器（如拉普拉斯滤波器、中值滤波器、普雷维特滤波器、罗伯茨滤波器、索贝尔滤波器和沙尔滤波器）等图像处理技术，对像素强度进行分组，并使用奈伊夫贝叶斯分类器根据可接受范围内的参数进行分类。分类器证实，与其他图像处理技术相比，采用 canny 边缘检测技术的集合 I - 实际图像和集合 II - 缺陷的准确率为 99.50%。因此，目前的研究证实，基于图像处理技术对结皮图像进行区域表面缺陷检测时，拟议的 GSIP 方法将为检测人员提供额外的工具，对结皮进行分级。
{"title":"Region Wise Surface Level Defect Detection and Ranking of Crust Leather Images Based on Image Processing Techniques","authors":"S. Vasagam, M. Sornam","doi":"10.34314/jalca.v118i7.7856","DOIUrl":"https://doi.org/10.34314/jalca.v118i7.7856","url":null,"abstract":"Sorting and aligning of crust leather for grading on position wise defect distribution is one of the methods adopted in the tanning industry. This method is generally carried out manually by a veteran on official sampling position and their input is critical because it is directly linked to sales of the crust leather. The opinion of the experts is believed to be stable and consumes a good amount of time too. Hence, in the current research a robust defect detection method and ranking of crust leather images based on image processing techniques is proposed to give a stable solution in a short span of time. A custom-made dataset of crust leather images consisting of 5640 images were used in this study. The pixel intensity has been extracted on demarcated position of various regions including neck, belly left, belly right, center and butt instead of official sampling position through horizontal and vertical mapping of coordinates with a new method Grading Score on Image Position wise (GSIP) on the actual images. The image processing techniques using Canny Edge Detection and filters such as Laplacian, Median, Prewitt, Roberts, Sobel and Scharr were implemented to get the pixel intensity grouped and classified based on parameters within acceptable range using a Naïve Bayes Classifier. The classifier confirms that the accuracy of Set I - Actual Images and Set II - Defects with implementation of canny edge detection over other image processing techniques at 99.50%. Therefore, the current research confirms that the proposed GSIP method would give an additional tool to inspectors while ranking the crust leather based on region wise surface level defect detection of crust leather images based on image processing techniques.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"43 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139364170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.34314/jalca.v118i7.7857
P. Caglayan
Isolation and identification of protease and lipase producing moderately halophilic bacteria from soak liquor samples and studying their adverse effects to the sheepskin using scanning electron microscopy may provide critical data on decomposition of raw hide/skin materials during soaking process. Moreover, enzyme-production properties of the moderately halophilic isolates (such as catalase, oxidase, lipase, protease, urease, caseinase, amylase, cellulase, pullulanase, xylanase) were determined. The effects of different NaCl concentrations, pH and temperature values on the growth of moderately halophilic bacterial isolates were tested. In the present study, four moderately halophilic bacterial isolates were isolated and selected for further experiments. The isolated species designated as SLMHB5, SLMHB10, SLMHB12, SLMHB13 were similar to Vibrio alginolyticus, Terribacillus halophilus, Vibrio alginolyticus, and Vibrio parahaemolyticus species, respectively. Scanning electron micrographs of sheepskin samples demonstrated that enzymatic activities of moderately halophilic bacteria isolated from soak liquor samples which decomposed the skin structure. After 35-days storage period, the sheepskin sample showed bad odor, sticky appearance and hair slip. Hence, it is recommended to control these microorganisms during the soaking process with an effective antimicrobial agent.
{"title":"Isolation and Identification of Moderately Halophilic Bacteria from Soak Liquor Samples Collected of Leather Tanneries","authors":"P. Caglayan","doi":"10.34314/jalca.v118i7.7857","DOIUrl":"https://doi.org/10.34314/jalca.v118i7.7857","url":null,"abstract":"Isolation and identification of protease and lipase producing moderately halophilic bacteria from soak liquor samples and studying their adverse effects to the sheepskin using scanning electron microscopy may provide critical data on decomposition of raw hide/skin materials during soaking process. Moreover, enzyme-production properties of the moderately halophilic isolates (such as catalase, oxidase, lipase, protease, urease, caseinase, amylase, cellulase, pullulanase, xylanase) were determined. The effects of different NaCl concentrations, pH and temperature values on the growth of moderately halophilic bacterial isolates were tested. In the present study, four moderately halophilic bacterial isolates were isolated and selected for further experiments. The isolated species designated as SLMHB5, SLMHB10, SLMHB12, SLMHB13 were similar to Vibrio alginolyticus, Terribacillus halophilus, Vibrio alginolyticus, and Vibrio parahaemolyticus species, respectively. Scanning electron micrographs of sheepskin samples demonstrated that enzymatic activities of moderately halophilic bacteria isolated from soak liquor samples which decomposed the skin structure. After 35-days storage period, the sheepskin sample showed bad odor, sticky appearance and hair slip. Hence, it is recommended to control these microorganisms during the soaking process with an effective antimicrobial agent.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"385 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139363983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.34314/jalca.v118i6.7657
M. Sathish, P. Thanikaivelan, Nayan Sarkar, R. Aravindhan, J. R. Rao
The development of commercially successful salt-free chrome tanning technology is the need of global leather sector to reduce the total dissolved solids in wastewater. Though some attempts have been made to develop salt-free chrome tanning technology, drawbacks such as slow diffusion of chromium, unevenness in softness and other organoleptic properties are the major concern. The generation of localized acid swelling might be a reason for the above drawbacks and no scientific literature available for the same. Hence, it is important to analyze the effect of acid swelling and its impact on the diffusion of chromium, ageing characteristics of wet-blue leather and physical properties of crust leather. The results show that the acid swelling delays the diffusion of chromium in tanning process and also enhances the growth marks on wet-blue leather. The ageing study reveals that the wet-blue obtained from acid swollen system dehydrates faster than the conventional salt based chromium tanning system. In addition, the wet-blue leather from acid swollen system is prone to fungal attack. The industrial glove leather obtained from acid swollen system has reduced strength characteristics viz., 15% reduction in tensile strength, 17% reduction in tear strength and 20% reduction in grain crack/bursting strength. Further, the degree of heterogeneity in softness is high for crust leather obtained from acid swollen system and also more looseness with internal emptiness. Color value measurements reveal that the crust leather obtained from the conventional tanning system is lighter in shade than the acid-swollen system. The results will be useful to design commercially viable salt-free or low-salt tanning systems as well as to tackle the inadvertent industrial scenario where the tanners are looking for solutions for accidental acid swelling and subsequent salvage of the leathers for possible recovery and applications.
{"title":"Effect of Acid Swelling and Its Impact on the Properties of Cow Industrial Glove Leathers","authors":"M. Sathish, P. Thanikaivelan, Nayan Sarkar, R. Aravindhan, J. R. Rao","doi":"10.34314/jalca.v118i6.7657","DOIUrl":"https://doi.org/10.34314/jalca.v118i6.7657","url":null,"abstract":"The development of commercially successful salt-free chrome tanning technology is the need of global leather sector to reduce the total dissolved solids in wastewater. Though some attempts have been made to develop salt-free chrome tanning technology, drawbacks such as slow diffusion of chromium, unevenness in softness and other organoleptic properties are the major concern. The generation of localized acid swelling might be a reason for the above drawbacks and no scientific literature available for the same. Hence, it is important to analyze the effect of acid swelling and its impact on the diffusion of chromium, ageing characteristics of wet-blue leather and physical properties of crust leather. The results show that the acid swelling delays the diffusion of chromium in tanning process and also enhances the growth marks on wet-blue leather. The ageing study reveals that the wet-blue obtained from acid swollen system dehydrates faster than the conventional salt based chromium tanning system. In addition, the wet-blue leather from acid swollen system is prone to fungal attack. The industrial glove leather obtained from acid swollen system has reduced strength characteristics viz., 15% reduction in tensile strength, 17% reduction in tear strength and 20% reduction in grain crack/bursting strength. Further, the degree of heterogeneity in softness is high for crust leather obtained from acid swollen system and also more looseness with internal emptiness. Color value measurements reveal that the crust leather obtained from the conventional tanning system is lighter in shade than the acid-swollen system. The results will be useful to design commercially viable salt-free or low-salt tanning systems as well as to tackle the inadvertent industrial scenario where the tanners are looking for solutions for accidental acid swelling and subsequent salvage of the leathers for possible recovery and applications.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"35 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139371796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.34314/jalca.v118i6.7659
Tingyuan Chen, Yunhang Zeng, Bi Shi
Enzymatic bating is important for producing clean, soft, and high-yield leather. However, it is prone to cause damage to hide collagen fibers and result in loose grain or damaged grain surface due to the longer enzymatic hydrolysis time of the grain layer than the middle layer caused by the slow mass transfer and the rapid hydrolysis reaction of the bating agent in hide. Considering trypsin is the most common bating agent, soybean flour (SF) that contains environmental friendly Kunitz trypsin inhibitor (KTI) was used after delimed hides were treated with trypsin for a certain time to opportunely inhibit its activity in the grain and avoid bating defects. The fluorescence micrographs of hides bated with fluorescently labelled trypsin and KTI showed that KTI could cover only the surface layers when it was added after bating for a certain time, whereas trypsin could penetrate the hide completely. When sufficient SF was added to the bating float at 2 h, the damage to hide collagen caused by trypsin was effectively reduced. In particular, the grain surface remained intact after bating for 8 h. The decrease in the strength of leather caused by bating was also reduced. In addition, the usage of SF scarcely affected the fiber dispersion of the middle layer, thereby ensuring the softness of leather. In summary, opportunely inhibiting the activity of trypsin in the grain could prevent hide damage and improve the quality of leather.
{"title":"Preventing Enzymatic Damage to Hides by Timely Inhibition of Trypsin Activity with Soybean Flour during Bating Process","authors":"Tingyuan Chen, Yunhang Zeng, Bi Shi","doi":"10.34314/jalca.v118i6.7659","DOIUrl":"https://doi.org/10.34314/jalca.v118i6.7659","url":null,"abstract":"Enzymatic bating is important for producing clean, soft, and high-yield leather. However, it is prone to cause damage to hide collagen fibers and result in loose grain or damaged grain surface due to the longer enzymatic hydrolysis time of the grain layer than the middle layer caused by the slow mass transfer and the rapid hydrolysis reaction of the bating agent in hide. Considering trypsin is the most common bating agent, soybean flour (SF) that contains environmental friendly Kunitz trypsin inhibitor (KTI) was used after delimed hides were treated with trypsin for a certain time to opportunely inhibit its activity in the grain and avoid bating defects. The fluorescence micrographs of hides bated with fluorescently labelled trypsin and KTI showed that KTI could cover only the surface layers when it was added after bating for a certain time, whereas trypsin could penetrate the hide completely. When sufficient SF was added to the bating float at 2 h, the damage to hide collagen caused by trypsin was effectively reduced. In particular, the grain surface remained intact after bating for 8 h. The decrease in the strength of leather caused by bating was also reduced. In addition, the usage of SF scarcely affected the fiber dispersion of the middle layer, thereby ensuring the softness of leather. In summary, opportunely inhibiting the activity of trypsin in the grain could prevent hide damage and improve the quality of leather.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"35 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139371762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.34314/jalca.v118i6.7660
B. Sahu, Diya Deepak Sharma, Yogesh Sekar, Akash Bhalla, J. Alla
The oxidation of fish oil is a type of chain reaction. The use of oxidizing agents enhances the rate of oxidation of the same. This study predominantly focuses on the role of potassium persulfate as an accelerating agent in fish oil oxidation, its kinetics, and application in rapid fish oil tanning. The use of potassium persulfate (1%) completes the fish oil oxidation within 4 days, confirmed by its kinetic studies. Chamois leathers made using potassium persulfate (1%) exhibited excellent water absorption capacity (454%). The physical parameters such as tensile strength, shrinkage temperature, surface morphology, and organoleptic properties of the experimental leather exhibit better results than control leathers.
{"title":"The Kinetic Study on Potassium Persulfate Accelerated Fish Oil Oxidation-An Agreeing Conclusion on Chamois Tanning","authors":"B. Sahu, Diya Deepak Sharma, Yogesh Sekar, Akash Bhalla, J. Alla","doi":"10.34314/jalca.v118i6.7660","DOIUrl":"https://doi.org/10.34314/jalca.v118i6.7660","url":null,"abstract":"The oxidation of fish oil is a type of chain reaction. The use of oxidizing agents enhances the rate of oxidation of the same. This study predominantly focuses on the role of potassium persulfate as an accelerating agent in fish oil oxidation, its kinetics, and application in rapid fish oil tanning. The use of potassium persulfate (1%) completes the fish oil oxidation within 4 days, confirmed by its kinetic studies. Chamois leathers made using potassium persulfate (1%) exhibited excellent water absorption capacity (454%). The physical parameters such as tensile strength, shrinkage temperature, surface morphology, and organoleptic properties of the experimental leather exhibit better results than control leathers.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"14 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139371136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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