Pub Date : 2022-02-01DOI: 10.34314/jalca.v117i2.4731
Cigdem Ozkan, H. Ozgunay
The tanning characteristics of starch samples modified by different methods were investigated in our previous studies. In this study, utilization of modified starch in leather making as a retanning agent and its effect on dyeing process have been investigated. For this purpose, the molecular size of native corn starch was reduced by H2O2 oxidation and then carboxymethylated. A series of analyses (water solubility, degree of substitution, Fourier Transform Infrared Spectroscopy, Proton and Carbon Nuclear Magnetic Resonance Spectroscopy) were carried out for characterization. Then, carboxymethyl starches were used in retanning processes to be 3, 5 and 10% based on leather weight and the shrinkage temperatures and filling coefficients of the leathers were determined. Acid and metal complex dyestuffs were used in dyeing processes and the effect of carboxymethyl starch on dyeing was also investigated by examining dye consumption, dry and wet rubbing fastness and color of the leathers. From the results it was concluded that carboxymethyl starch showed a noticeable solo performance in terms of filling property and shrinking temperature without any considerable adverse effect on dyeing.
{"title":"Retanning Performance of Carboxymethyl Starch and Its Effects on Dyeing","authors":"Cigdem Ozkan, H. Ozgunay","doi":"10.34314/jalca.v117i2.4731","DOIUrl":"https://doi.org/10.34314/jalca.v117i2.4731","url":null,"abstract":"The tanning characteristics of starch samples modified by different methods were investigated in our previous studies. In this study, utilization of modified starch in leather making as a retanning agent and its effect on dyeing process have been investigated. For this purpose, the molecular size of native corn starch was reduced by H2O2 oxidation and then carboxymethylated. A series of analyses (water solubility, degree of substitution, Fourier Transform Infrared Spectroscopy, Proton and Carbon Nuclear Magnetic Resonance Spectroscopy) were carried out for characterization. Then, carboxymethyl starches were used in retanning processes to be 3, 5 and 10% based on leather weight and the shrinkage temperatures and filling coefficients of the leathers were determined. Acid and metal complex dyestuffs were used in dyeing processes and the effect of carboxymethyl starch on dyeing was also investigated by examining dye consumption, dry and wet rubbing fastness and color of the leathers. From the results it was concluded that carboxymethyl starch showed a noticeable solo performance in terms of filling property and shrinking temperature without any considerable adverse effect on dyeing.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88105047","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 : 2022-01-03DOI: 10.34314/jalca.v117i1.4696
Murshid Jaman Chowdury, M. A. Razzaq, Md. Imran Biswas, Ariful Hai Quadery, Md. Tushar Uddin
Researchers around the world are in continuous endeavor to develop environment friendly tanning agent due to adverse effect of conventionally used chromium during leather tanning. Recent trend of tanning is thus heading to chrome-free and greener chemical processing options. Vegetable tanning is an exoteric leather processing technique because of their lower pollution load on the environment. Considering the inadequacy and high costing for the commercialized tannins, development of alternative tannins from locally available plants and their characterizations are important. In this research, the stem barks of Trema Orientalis (L.) were extracted at different temperatures employing water solvent with or without additives (sodium hydroxide or sodium sulphite) to attain phenolic-rich extractives. To ascertain appropriateness as a vegetable tanning agent, the obtained extracts were thereafter characterized in respect to yield, total phenolic content, tannin content and molecular structure. The extraction yield for all extracts improves and the quality remains nearly unchanged with temperature rising. The elevated concentration of chemical additives enhances the extraction yield but lessens the quality of extracts. In terms of extraction yield and the quality of extracts the best condition for extraction was discerned at 80°C with water solvent. This water extract has a decent extent of phenolic and tannin content of 266.13 mg Gallic acid equivalent/ gm of dry extract and 30.12 % respectively. The final extract exhibits excellent leather retanning tendency comparable to the commercial quebracho tannins.
由于皮革鞣制过程中常用铬的不良影响，世界各国一直在努力开发环保型鞣制剂。因此，鞣制的最新趋势是朝着无铬和更环保的化学加工选择。植物鞣因其对环境的污染较小而成为一种开放的皮革加工技术。考虑到商业化单宁的不足和高成本，从当地可获得的植物中开发替代单宁及其特性是重要的。在不同温度下，采用添加或不添加添加剂(氢氧化钠或亚硫酸钠)的水溶剂对东方Trema Orientalis (L.)茎皮进行提取，得到富含酚类物质的提取物。为了确定作为植物鞣剂的适宜性，获得的提取物随后在产率、总酚含量、单宁含量和分子结构方面进行了表征。随着温度的升高，各提取物的提取率提高，质量基本保持不变。化学添加剂浓度的提高提高了提取物的提取率，但降低了提取物的质量。从提取率和提取率两方面确定了最佳提取条件:80℃，水溶剂。该水提取物的酚类和单宁含量分别为干提取物的266.13 mg没食子酸当量/ gm和30.12%。最终提取物表现出优异的皮革再鞣制倾向，可与商业鞣质相媲美。
{"title":"Extract of Trema Orientalis (L.) Stem Bark: A Potential Source of Environmentally Friendly Tanning Agent for Leather Industry","authors":"Murshid Jaman Chowdury, M. A. Razzaq, Md. Imran Biswas, Ariful Hai Quadery, Md. Tushar Uddin","doi":"10.34314/jalca.v117i1.4696","DOIUrl":"https://doi.org/10.34314/jalca.v117i1.4696","url":null,"abstract":"Researchers around the world are in continuous endeavor to develop environment friendly tanning agent due to adverse effect of conventionally used chromium during leather tanning. Recent trend of tanning is thus heading to chrome-free and greener chemical processing options. Vegetable tanning is an exoteric leather processing technique because of their lower pollution load on the environment. Considering the inadequacy and high costing for the commercialized tannins, development of alternative tannins from locally available plants and their characterizations are important. In this research, the stem barks of Trema Orientalis (L.) were extracted at different temperatures employing water solvent with or without additives (sodium hydroxide or sodium sulphite) to attain phenolic-rich extractives. To ascertain appropriateness as a vegetable tanning agent, the obtained extracts were thereafter characterized in respect to yield, total phenolic content, tannin content and molecular structure. The extraction yield for all extracts improves and the quality remains nearly unchanged with temperature rising. The elevated concentration of chemical additives enhances the extraction yield but lessens the quality of extracts. In terms of extraction yield and the quality of extracts the best condition for extraction was discerned at 80°C with water solvent. This water extract has a decent extent of phenolic and tannin content of 266.13 mg Gallic acid equivalent/ gm of dry extract and 30.12 % respectively. The final extract exhibits excellent leather retanning tendency comparable to the commercial quebracho tannins.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76631359","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 : 2022-01-03DOI: 10.34314/jalca.v117i1.4694
Ricardo A. Tournier, Fernando Lado
An appropriate tear strength is one of the main properties that concern customers and it is also a significant source of claims. The authors make a review of the production process, focusing on each step that can either damage the natural strength of collagen fibers or improve them, and therefore, the leather. The aim of this work, divided in Part 1 and 2, is to transfer field tannery experiences collected over 40 years of activity in different tanneries, to colleagues that are looking for world class leather production. Part 1 has been published in JALCA, 116 (12), 2021.
{"title":"Improving Tearing Resistance of Leather - Part 2 Prevention and Treatment of Low Tearing Strength in the Tannery","authors":"Ricardo A. Tournier, Fernando Lado","doi":"10.34314/jalca.v117i1.4694","DOIUrl":"https://doi.org/10.34314/jalca.v117i1.4694","url":null,"abstract":"An appropriate tear strength is one of the main properties that concern customers and it is also a significant source of claims. The authors make a review of the production process, focusing on each step that can either damage the natural strength of collagen fibers or improve them, and therefore, the leather. The aim of this work, divided in Part 1 and 2, is to transfer field tannery experiences collected over 40 years of activity in different tanneries, to colleagues that are looking for world class leather production. Part 1 has been published in JALCA, 116 (12), 2021.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83899648","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 : 2022-01-03DOI: 10.34314/jalca.v117i1.4695
J. Morera, E. Bartolí, R. Fernández, L. Cabeza
Salting is the most common method to preserve hides and skins. However, this preservation system requires the generation of large amounts of contaminated salt, approximately three million tons per year. In recent years several researchers have suggested different methods for the short-term preservation of hides using plant-based formulations, which either minimize or even completely eliminate the use of salt in the process. In this work, the possibility of using wheat bran for this purpose was studied. Two methods of application (dry and aqueous solution) have been developed. They enable the preservation of hides for one month, reducing by half the salt used in the preservation stage without undermining the quality of the final leather. These two methods contribute to the improvement of the overall sustainability of the tanning process. With dry application, the use of salt is avoided and preservation occurs because the hide is dried. The application in aqueous solution (10% wheat bran) requires its previous hydrolysis and a minimum amount of salt (10ºBé). The preservation occurs because the acidity of the hide is increased.
{"title":"A Cleaner Process for Short-Term Preservation of Hides using Wheat Bran","authors":"J. Morera, E. Bartolí, R. Fernández, L. Cabeza","doi":"10.34314/jalca.v117i1.4695","DOIUrl":"https://doi.org/10.34314/jalca.v117i1.4695","url":null,"abstract":"Salting is the most common method to preserve hides and skins. However, this preservation system requires the generation of large amounts of contaminated salt, approximately three million tons per year. In recent years several researchers have suggested different methods for the short-term preservation of hides using plant-based formulations, which either minimize or even completely eliminate the use of salt in the process. In this work, the possibility of using wheat bran for this purpose was studied. Two methods of application (dry and aqueous solution) have been developed. They enable the preservation of hides for one month, reducing by half the salt used in the preservation stage without undermining the quality of the final leather. These two methods contribute to the improvement of the overall sustainability of the tanning process. \u0000With dry application, the use of salt is avoided and preservation occurs because the hide is dried. The application in aqueous solution (10% wheat bran) requires its previous hydrolysis and a minimum amount of salt (10ºBé). The preservation occurs because the acidity of the hide is increased.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81137647","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 : 2022-01-03DOI: 10.34314/jalca.v117i1.4690
M. Sathish, R. Aravindhan, J. Rao
Chromium tanning finds a prominant place in leather manufacturing for permanent stabilization of hide/skin matrix. Though, it has multiple advantages in terms of high thermal stability, easy process and low cost etc., the current practice is not environmentally sustainable. Poor chromium exhaustion and TDS load generation are the major environmental threats of conventional chromium tanning systems. On the other hand, salt-free chromium tanning is identified as one of the efficient alternative approaches for hide/skin matrix stabilization. However, it has not been commercially practiced due to the several practical difficulties. In this work attempts have been made to develop a practically viable high-performance salt-free chromium tanning system using deliming liquor as tanning float and changing the order of addition of masking salt. The developed methodologies completely avoid the use of salt/basification process and it is suitable for all kinds of raw materials and tannery houses. Besides, the process enjoys 71-77% reduction in TDS load and the uptake of chromium is around 90%. The physical strength characteristics are on par with conventional process and the leathers exhibit good grain tightness and roundness. The developed methodologies are simple and do not require any specialty chemicals.
{"title":"Salt-free Chromium Tanning: Practical Approaches","authors":"M. Sathish, R. Aravindhan, J. Rao","doi":"10.34314/jalca.v117i1.4690","DOIUrl":"https://doi.org/10.34314/jalca.v117i1.4690","url":null,"abstract":"Chromium tanning finds a prominant place in leather manufacturing for permanent stabilization of hide/skin matrix. Though, it has multiple advantages in terms of high thermal stability, easy process and low cost etc., the current practice is not environmentally sustainable. Poor chromium exhaustion and TDS load generation are the major environmental threats of conventional chromium tanning systems. On the other hand, salt-free chromium tanning is identified as one of the efficient alternative approaches for hide/skin matrix stabilization. However, it has not been commercially practiced due to the several practical difficulties. In this work attempts have been made to develop a practically viable high-performance salt-free chromium tanning system using deliming liquor as tanning float and changing the order of addition of masking salt. The developed methodologies completely avoid the use of salt/basification process and it is suitable for all kinds of raw materials and tannery houses. Besides, the process enjoys 71-77% reduction in TDS load and the uptake of chromium is around 90%. The physical strength characteristics are on par with conventional process and the leathers exhibit good grain tightness and roundness. The developed methodologies are simple and do not require any specialty chemicals. ","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81916012","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 : 2021-12-01DOI: 10.34314/jalca.v116i12.4689
F. E. Ahmed, Rotick K. Gideon
Cutting is the process in which goods or garment material are cut and converted into pattern shapes of the goods or garment components. There are two methods of Leather cutting, which are hand cutting and machine cutting. Hand cutting is done with the use of hand knife, cutting board and cutting patterns. Machine cutting can be done using semi-automatic cutting machines or fully-automatic cutting machines. Currently, in Ethiopia, different local and foreign investors are participating in leather products manufacturing. Most of the leather product manufacturing industry and some Small and Medium enterprise’s (SME’s) in the country are using leather cutting machines in order to cut leather goods or garment parts. Most of the industry and SMEs are using imported cutting board made of plastics and rubbers. However, these cutting boards are expensive. This research aimed at developing a cutting board made from HDPE (High-Density Polyethylene) plastic waste as main material, calcium carbonate as a filler and glass fiber as a reinforcing material. Primary and secondary data gathering techniques were applied simultaneously. Primary data were collected through interview and field observation. Secondary data was gathered by reviewing different literature. The cutting board developed through collecting HDPE plastic waste, washing, shredding and melting the shredded plastic with filler and reinforcing material. The melted plastic poured in to cutting board mold and cooled. The developed cutting board was compared with HDPE cutting board available in the local market. The developed board showed relative compression and hardness properties with the HDPE cutting board available in the market. In the cost analysis, the developed cutting board is cheaper than the cutting board which available in the market. However, the cutting board in the market has better surface texture and quality than the developed cutting board. Melting HDPE plastic waste using metal or clay cooking pots and charcoal fire is a tedious task and smoke from the fire will cause human health problem and will affect environment. Consequently, manual plastic melting method is not feasible for mass production, because it is difficult to control the amount of heat (charcoal fire) during melting process. Based on this the authors recommend using machine based plastic melting and molding during HDPE and related plastic recycling.
{"title":"Development of Leather Cutting Board from Plastic Waste","authors":"F. E. Ahmed, Rotick K. Gideon","doi":"10.34314/jalca.v116i12.4689","DOIUrl":"https://doi.org/10.34314/jalca.v116i12.4689","url":null,"abstract":"Cutting is the process in which goods or garment material are cut and converted into pattern shapes of the goods or garment components. There are two methods of Leather cutting, which are hand cutting and machine cutting. Hand cutting is done with the use of hand knife, cutting board and cutting patterns. Machine cutting can be done using semi-automatic cutting machines or fully-automatic cutting machines. Currently, in Ethiopia, different local and foreign investors are participating in leather products manufacturing. Most of the leather product manufacturing industry and some Small and Medium enterprise’s (SME’s) in the country are using leather cutting machines in order to cut leather goods or garment parts. Most of the industry and SMEs are using imported cutting board made of plastics and rubbers. However, these cutting boards are expensive. \u0000 \u0000This research aimed at developing a cutting board made from HDPE (High-Density Polyethylene) plastic waste as main material, calcium carbonate as a filler and glass fiber as a reinforcing material. Primary and secondary data gathering techniques were applied simultaneously. Primary data were collected through interview and field observation. Secondary data was gathered by reviewing different literature. The cutting board developed through collecting HDPE plastic waste, washing, shredding and melting the shredded plastic with filler and reinforcing material. The melted plastic poured in to cutting board mold and cooled. The developed cutting board was compared with HDPE cutting board available in the local market. The developed board showed relative compression and hardness properties with the HDPE cutting board available in the market. In the cost analysis, the developed cutting board is cheaper than the cutting board which available in the market. However, the cutting board in the market has better surface texture and quality than the developed cutting board. Melting HDPE plastic waste using metal or clay cooking pots and charcoal fire is a tedious task and smoke from the fire will cause human health problem and will affect environment. Consequently, manual plastic melting method is not feasible for mass production, because it is difficult to control the amount of heat (charcoal fire) during melting process. Based on this the authors recommend using machine based plastic melting and molding during HDPE and related plastic recycling.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72552598","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}
The release of chromium from leather inevitably results in potential risks and this study is conducted to investigate the long-term releasing behavior. The leaching tests proceed using water at solid to liquid ratio of 1:20 and rotational speed 60 r/min for 240 hours to simulate the release of chrome leather under natural conditions. The experimental data successfully fit with the Pseudo-second-order equation, Elovich equation, and Weber-Morris model, indicating the long-term leaching behavior of chromium in heterogeneous leather is controlled by liquid-solid film, while the interparticle and intraparticle diffusion also play important roles. The leachable chromium accounts for 2.8-4.5% total chromium in leather and increases with temperature. The Three-compartment model depicts the releasing process as rapid, slow, and very slow stages, and temperature mainly affected the very slow stage. The amount of released chromium in rapid and slow stages slightly increases with temperature, which could be used to assess the hazard of chrome leather.
{"title":"Long-Term Releasing Kinetics of Chromium from Leather","authors":"Wenjun Long, Liangqiong Peng, Xiaofeng Jiang, Faming He, Wenhua Zhang","doi":"10.34314/jalca.v116i12.4688","DOIUrl":"https://doi.org/10.34314/jalca.v116i12.4688","url":null,"abstract":"The release of chromium from leather inevitably results in potential risks and this study is conducted to investigate the long-term releasing behavior. The leaching tests proceed using water at solid to liquid ratio of 1:20 and rotational speed 60 r/min for 240 hours to simulate the release of chrome leather under natural conditions. The experimental data successfully fit with the Pseudo-second-order equation, Elovich equation, and Weber-Morris model, indicating the long-term leaching behavior of chromium in heterogeneous leather is controlled by liquid-solid film, while the interparticle and intraparticle diffusion also play important roles. The leachable chromium accounts for 2.8-4.5% total chromium in leather and increases with temperature. The Three-compartment model depicts the releasing process as rapid, slow, and very slow stages, and temperature mainly affected the very slow stage. The amount of released chromium in rapid and slow stages slightly increases with temperature, which could be used to assess the hazard of chrome leather.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86473091","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 : 2021-12-01DOI: 10.34314/jalca.v116i12.4687
V. Sivakumar
Process Safety and Occupational health (PSOH) aspects in process industries are essential and need more consideration along with development in manufacturing and processing. In this regard, PSOH aspects are essential for the leather industry in order to prevent health hazards associated with it and improve upon adequate measures. Better safeguards and practices are necessary in PSOH for the benefit of not only for people working in the industry but for the environment at large. The situation is significant wherever hazardous chemicals or chemicals which could lead to compromise on safety in the workplace are involved. The degree of toxicity or hazard and exposure limit associated for some of them, inside factory premises are of major concern. In addition to the chemicals, other aspects such as dusts, noise levels, lighting, ergonomics, ventilation, personal safety and hygiene are worth considering. As mentioned above, the present paper analyzes various aspects of PSOH in leather process industries as a holistic approach.
{"title":"Analysis of Process Safety and Occupational Health in Leather Process Industry: A Holistic Approach","authors":"V. Sivakumar","doi":"10.34314/jalca.v116i12.4687","DOIUrl":"https://doi.org/10.34314/jalca.v116i12.4687","url":null,"abstract":"Process Safety and Occupational health (PSOH) aspects in process industries are essential and need more consideration along with development in manufacturing and processing. In this regard, PSOH aspects are essential for the leather industry in order to prevent health hazards associated with it and improve upon adequate measures. Better safeguards and practices are necessary in PSOH for the benefit of not only for people working in the industry but for the environment at large. The situation is significant wherever hazardous chemicals or chemicals which could lead to compromise on safety in the workplace are involved. The degree of toxicity or hazard and exposure limit associated for some of them, inside factory premises are of major concern. In addition to the chemicals, other aspects such as dusts, noise levels, lighting, ergonomics, ventilation, personal safety and hygiene are worth considering. As mentioned above, the present paper analyzes various aspects of PSOH in leather process industries as a holistic approach.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86349082","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 : 2021-12-01DOI: 10.34314/jalca.v116i12.4686
Ricardo A. Tournier, Fernando Lado
An appropriate tear strength is one of the main properties that concern customers and it is also a significant source of claims. The authors make a review of the production process, focusing on each step that can either damage the natural strength of collagen fibers or improve them and therefore, the leather. Although the authors’ experience is in bovine hides, the general concepts presented in this paper may be applied to other types of hides and skins. The aim of this work is to transfer field tannery experiences collected over 40 years of activity in different tanneries, to colleagues that are looking for world class leather production.
{"title":"Improving Tearing Resistance of Leather - Part 1 Prevention and Treatment of Low Tearing Strength in the Tannery","authors":"Ricardo A. Tournier, Fernando Lado","doi":"10.34314/jalca.v116i12.4686","DOIUrl":"https://doi.org/10.34314/jalca.v116i12.4686","url":null,"abstract":"An appropriate tear strength is one of the main properties that concern customers and it is also a significant source of claims. The authors make a review of the production process, focusing on each step that can either damage the natural strength of collagen fibers or improve them and therefore, the leather. Although the authors’ experience is in bovine hides, the general concepts presented in this paper may be applied to other types of hides and skins. \u0000The aim of this work is to transfer field tannery experiences collected over 40 years of activity in different tanneries, to colleagues that are looking for world class leather production.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76247992","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 : 2021-11-01DOI: 10.34314/jalca.v116i11.4659
Megha K. Mehta, Yang Liu, Rafea Naffa, M. Waterland, Geoff Holmes
Chemical and physical changes take place when hides and skins are processed to leather that affect the quality and strength of the material. Understanding the structure at each leather-making stage is the basis of this study but also intend to improve the process through a biochemical approach, employing a proteolytic enzyme for processing leather more cleanly with reduced environmental impact. Raman and ATR-FTIR spectroscopy in conjunction with chemometrics was used to investigate each leather-making stage from fresh green cattle hide to dry crust leather. The changes in proteins, lipids, nucleic acids and other biomolecules with leather processing was measured and reported using three novel Raman ratiometric markers, 920/1476, 1345/1259 and 1605/1476 cm-1, to discriminate the structural changes in collagen of hide using standard chemical and enzymatic method. Amide I band was deconvoluted to investigate thecollagen secondary structures using curve fitting by Gaussians function. The results of Principal Component Analysis are well-corroborated with the ratiometric markers of structural changes.
{"title":"Changes to the Collagen Structure using Vibrational Spectroscopy and Chemometrics: A Comparison between Chemical and Sulfide-Free Leather Process","authors":"Megha K. Mehta, Yang Liu, Rafea Naffa, M. Waterland, Geoff Holmes","doi":"10.34314/jalca.v116i11.4659","DOIUrl":"https://doi.org/10.34314/jalca.v116i11.4659","url":null,"abstract":"Chemical and physical changes take place when hides and skins are processed to leather that affect the quality and strength of the material. Understanding the structure at each leather-making stage is the basis of this study but also intend to improve the process through a biochemical approach, employing a proteolytic enzyme for processing leather more cleanly with reduced environmental impact. Raman and ATR-FTIR spectroscopy in conjunction with chemometrics was used to investigate each leather-making stage from fresh green cattle hide to dry crust leather. The changes in proteins, lipids, nucleic acids and other biomolecules with leather processing was measured and reported using three novel Raman ratiometric markers, 920/1476, 1345/1259 and 1605/1476 cm-1, to discriminate the structural changes in collagen of hide using standard chemical and enzymatic method. Amide I band was deconvoluted to investigate thecollagen secondary structures using curve fitting by Gaussians function. The results of Principal Component Analysis are well-corroborated with the ratiometric markers of structural changes.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77267774","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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