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":"1 1","pages":""},"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":"6 1","pages":""},"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":"33 1","pages":""},"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":"68 1","pages":""},"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":"47 1","pages":""},"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":"2011 1","pages":""},"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":"107 1","pages":""},"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":"42 1","pages":""},"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}
Pub Date : 2021-11-01DOI: 10.34314/jalca.v116i11.4662
S. Kailasam, K. Balaji, S. Kanth
The current study focuses on the isolation of Bacillus cerus from mangrove rhizosphere and its ability to treat semi-chrome process liquor of upper leathers. This strain has been identified by its molecular characteristics (16s rRNA sequencing) and confirmation has been obtained from neighbor joining tree. Minimum inhibitory concentration of the strain has been found to be 50 ppm. The growth pattern of this organism has been investigated in the presence of chromium, which showed the bacterial strain can grow luxuriantly at 50 and 100 ppm concentration of chromium. Biosorption study has been conducted at different concentrations (50, 100, 150, 200 and 250 ppm) of chromium. The biosorption capability of Bacillus cerus has been found to be 80.78, 73.19, 65.86, 59.44 and 39.27% for 50, 100, 150, 200 and 250 ppm respectively. Chromium sorption from the semi-chrome process liquor by Bacillus cerus has also been investigated, which showed a reduction of 76.15, 68.56, 61.63, 56.29 and 36.51% against 50, 100, 150, 200 and 250 ppm of chromium. Sorption characterization has been carried out by FTIR (Fourier Transform Infra-Red spectroscopy) and SEM (Scanning Electron Microscopy) analyses and the results confirmed the presence of sorption of chromium in Bacillus cerus.
{"title":"Biosorption of Chromium from Spent Semi-Chrome Liquor: Part 1 Effective Pollution Abatement using Bacillus cerus","authors":"S. Kailasam, K. Balaji, S. Kanth","doi":"10.34314/jalca.v116i11.4662","DOIUrl":"https://doi.org/10.34314/jalca.v116i11.4662","url":null,"abstract":"The current study focuses on the isolation of Bacillus cerus from mangrove rhizosphere and its ability to treat semi-chrome process liquor of upper leathers. This strain has been identified by its molecular characteristics (16s rRNA sequencing) and confirmation has been obtained from neighbor joining tree. Minimum inhibitory concentration of the strain has been found to be 50 ppm. The growth pattern of this organism has been investigated in the presence of chromium, which showed the bacterial strain can grow luxuriantly at 50 and 100 ppm concentration of chromium. Biosorption study has been conducted at different concentrations (50, 100, 150, 200 and 250 ppm) of chromium. The biosorption capability of Bacillus cerus has been found to be 80.78, 73.19, 65.86, 59.44 and 39.27% for 50, 100, 150, 200 and 250 ppm respectively. Chromium sorption from the semi-chrome process liquor by Bacillus cerus has also been investigated, which showed a reduction of 76.15, 68.56, 61.63, 56.29 and 36.51% against 50, 100, 150, 200 and 250 ppm of chromium. Sorption characterization has been carried out by FTIR (Fourier Transform Infra-Red spectroscopy) and SEM (Scanning Electron Microscopy) analyses and the results confirmed the presence of sorption of chromium in Bacillus cerus.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"56 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86040737","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.v116i11.4663
Zhi-Kua Chen, Tao Luo, Xu Zhang, B. Peng, Chunxiao Zhang
Leather made with soybean phospholipid fatliquors is prone to problems such as yellowing, elevated hexavalent chromium content, and undesirable odor. In this study, the aforementioned typical defects of soybean phospholipid fatliquors were investigated in respect to the main components, the antioxidants and the unsaturation degree of the natural soybean phospholipid. The results showed that the oxidation of soybean phospholipid is the primary source for its yellowing, elevated hexavalent chromium content, and undesirable odor. The volatile aldehydes produced by lipid oxidative rancidity are the main components of the undesirable odor. The purification of natural soybean phospholipid through removing the non-phospholipid components cannot solve the problems caused by oxidation of phospholipid. Furthermore, as a typical natural antioxidant existing in natural soybean phospholipid, tocopherols can restrain the oxidation of phospholipid to a certain degree, however, the dissolving out and destruction of tocopherols at high temperature in the phospholipid purification process can lead to more obviously oxidation of phospholipids. Additionally, the oxidation defects of phospholipid cannot be completely resolved by adding extra tocopherols, even at high dosages. The research finds that the defects of soybean phospholipid fatliquors can be thoroughly solved by increasing the saturation degree of lipid through addition reaction, the suggested iodine value of phospholipid products is lower than 20 g I2/100 g.
用大豆磷脂脂质制成的皮革容易出现发黄、六价铬含量升高和难闻气味等问题。本研究从大豆磷脂的主要成分、抗氧化剂和天然大豆磷脂的不饱和程度等方面考察了上述大豆磷脂脂类的典型缺陷。结果表明，大豆磷脂氧化是其发黄、六价铬含量升高和产生异味的主要原因。油脂氧化酸败产生的挥发性醛是产生不良气味的主要成分。通过去除非磷脂成分提纯天然大豆磷脂，并不能解决磷脂氧化带来的问题。此外，作为天然大豆磷脂中存在的一种典型的天然抗氧化剂，生育酚可以在一定程度上抑制磷脂的氧化，但在磷脂纯化过程中，生育酚在高温下的溶出和破坏会导致磷脂的氧化更加明显。此外，磷脂的氧化缺陷不能通过添加额外的生育酚完全解决，即使在高剂量。研究发现，通过加成反应提高脂质饱和度，可以彻底解决大豆磷脂脂质液的缺陷，磷脂产品的建议碘值低于20 g /100 g。
{"title":"Typical Defects of Natural Phospholipid Fatliquors in Leather Industry and Their Solutions","authors":"Zhi-Kua Chen, Tao Luo, Xu Zhang, B. Peng, Chunxiao Zhang","doi":"10.34314/jalca.v116i11.4663","DOIUrl":"https://doi.org/10.34314/jalca.v116i11.4663","url":null,"abstract":"Leather made with soybean phospholipid fatliquors is prone to problems such as yellowing, elevated hexavalent chromium content, and undesirable odor. In this study, the aforementioned typical defects of soybean phospholipid fatliquors were investigated in respect to the main components, the antioxidants and the unsaturation degree of the natural soybean phospholipid. The results showed that the oxidation of soybean phospholipid is the primary source for its yellowing, elevated hexavalent chromium content, and undesirable odor. The volatile aldehydes produced by lipid oxidative rancidity are the main components of the undesirable odor. The purification of natural soybean phospholipid through removing the non-phospholipid components cannot solve the problems caused by oxidation of phospholipid. Furthermore, as a typical natural antioxidant existing in natural soybean phospholipid, tocopherols can restrain the oxidation of phospholipid to a certain degree, however, the dissolving out and destruction of tocopherols at high temperature in the phospholipid purification process can lead to more obviously oxidation of phospholipids. Additionally, the oxidation defects of phospholipid cannot be completely resolved by adding extra tocopherols, even at high dosages. The research finds that the defects of soybean phospholipid fatliquors can be thoroughly solved by increasing the saturation degree of lipid through addition reaction, the suggested iodine value of phospholipid products is lower than 20 g I2/100 g.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"103 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74998201","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：