Pub Date : 2022-04-05DOI: 10.34314/jalca.v117i4.4896
Tao Zhang, Chunhua Wang, Jun Sang, Long Zhang, Yuanhang Xiao, Wei Lin
Herein, we have developed a kind of novel ester-bonded gemini quaternary ammonium salts microbicides named QAS(n+m) for leather application, in which n and m denotes the number of −CH2 between the ester groups on the spacer, and the length of alkyl chain connected to ester groups on the hydrophobic tail chain, respectively. Results indicate that the hydrophobic tail lengths and the spacer lengths in the QAS(n+m) structures affect their antimicrobial activities very differently. QAS(4+10) was used to investigate the antimicrobial mechanism, cytotoxicity, and antimold performance for wet blue leather as it exhibits the strongest antimicrobial effect. It shows QAS(4+10) is capable of inactivating microorganisms mainly by disrupting the integrity of their cell membranes. Compared to commercial leather microbicide product 2-thiocyanomethylthiobenzothiazole (TCMTB), QAS(4+10) exhibits comparable mold resistance and lower toxicity. The present work gives positive insight into the development of novel candidate microbicides for the preservation of wet blue leather.
{"title":"Novel Ester-bonded Gemini Quaternary Ammonium Salt with Good Antimicrobial Activity and Anti-mold Performance for Wet Blue Leather","authors":"Tao Zhang, Chunhua Wang, Jun Sang, Long Zhang, Yuanhang Xiao, Wei Lin","doi":"10.34314/jalca.v117i4.4896","DOIUrl":"https://doi.org/10.34314/jalca.v117i4.4896","url":null,"abstract":"Herein, we have developed a kind of novel ester-bonded gemini quaternary ammonium salts microbicides named QAS(n+m) for leather application, in which n and m denotes the number of −CH2 between the ester groups on the spacer, and the length of alkyl chain connected to ester groups on the hydrophobic tail chain, respectively. Results indicate that the hydrophobic tail lengths and the spacer lengths in the QAS(n+m) structures affect their antimicrobial activities very differently. QAS(4+10) was used to investigate the antimicrobial mechanism, cytotoxicity, and antimold performance for wet blue leather as it exhibits the strongest antimicrobial effect. It shows QAS(4+10) is capable of inactivating microorganisms mainly by disrupting the integrity of their cell membranes. Compared to commercial leather microbicide product 2-thiocyanomethylthiobenzothiazole (TCMTB), QAS(4+10) exhibits comparable mold resistance and lower toxicity. The present work gives positive insight into the development of novel candidate microbicides for the preservation of wet blue leather.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"26 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84824971","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 : 2022-04-01DOI: 10.34314/jalca.v117i3.4891
Hao Wang, Chao Lei, Yunhang Zeng, Hongguang Guo, Bi Shi
Ammonia nitrogen (NH 3 -N) pollutant has received much attention in the leather industry. An efficient strategy for removal of NH 3 -N from tannery wastewater was proposed by using a magnesium ammonium phosphate (MAP) precipitation method to remove NH 3 -N from deliming effluent with the highest NH 3 -N concentration among all leather-making effluents. Results showed that approximately 80% of NH 3 -N was removed from deliming effluent when reacting at P/Mg/N mole ratio of 1.2:1.2:1.0 and pH 9.5 for 20 min. The NH 3 -N and total nitrogen concentrations of tannery wastewater (a composite wastewater of all leather-making effluents) sharply decreased by treating deliming effluent with MAP precipitation, which greatly improved the biological treatment efficiency of tannery wastewater. The residual concentration of NH 3 -N in the treated tannery wastewater was less than 2 mg/L. The total phosphorus concentration of tannery wastewater increased by less than 0.4 mg/L, indicating that secondary pollution of phosphorus did not occur after MAP precipitation treatment.
{"title":"Efficient Removal of Ammonia-Nitrogen from Deliming Effluent by using Magnesium Ammonium Phosphate Precipitation Method","authors":"Hao Wang, Chao Lei, Yunhang Zeng, Hongguang Guo, Bi Shi","doi":"10.34314/jalca.v117i3.4891","DOIUrl":"https://doi.org/10.34314/jalca.v117i3.4891","url":null,"abstract":"Ammonia nitrogen (NH 3 -N) pollutant has received much attention in the leather industry. An efficient strategy for removal of NH 3 -N from tannery wastewater was proposed by using a magnesium ammonium phosphate (MAP) precipitation method to remove NH 3 -N from deliming effluent with the highest NH 3 -N concentration among all leather-making effluents. Results showed that approximately 80% of NH 3 -N was removed from deliming effluent when reacting at P/Mg/N mole ratio of 1.2:1.2:1.0 and pH 9.5 for 20 min. The NH 3 -N and total nitrogen concentrations of tannery wastewater (a composite wastewater of all leather-making effluents) sharply decreased by treating deliming effluent with MAP precipitation, which greatly improved the biological treatment efficiency of tannery wastewater. The residual concentration of NH 3 -N in the treated tannery wastewater was less than 2 mg/L. The total phosphorus concentration of tannery wastewater increased by less than 0.4 mg/L, indicating that secondary pollution of phosphorus did not occur after MAP precipitation treatment.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"50 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91280496","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 : 2022-04-01DOI: 10.34314/jalca.v117i3.4888
Majher I. Sarker, Cheng‐Kung Liu
In this study, a formulation and technique are developed to be used for cattle carcass decontamination prior to removal of hide in a commercially preferred time-frame to ensure meat safety and byproduct quality. This formulation offers deep cleaning on carcass surface by removing debris including manure/mud balls which are firmly attached to the hair of animal hide harboring pathogens like Salmonella and Escherichia coli. Survival of such pathogens can facilitate cross-contamination of the underlying meat and meat-processing equipment in the packing plant posing a challenge to the meat industry as well as public-health. Also, the attached adobe type mud/manure balls have potential to create holes on the hide during leather processing which degrades byproduct’s quality. Formulation was sprayed on cattle’s hide and the attached debris were brushed off from the surface. The formulation was found very efficient in cleaning the hide surface both at 5 and 8 min treatments. The highest of aerobic, Escherichia coli and Salmonella populations were reduced by 8.71, 3.63 and 3.19 Log CFU/50 in 2 , respectively when compared to water-wash. The efficacy of formulation can be optimized by adjusting its concentration and treatment time. Post-leather analysis showed no detrimental impact on byproduct caused by the formulation.
{"title":"Novel Approach of Removing Externally Attached Debris from Animal Carcass to Ensure Meat Safety and Byproduct Quality","authors":"Majher I. Sarker, Cheng‐Kung Liu","doi":"10.34314/jalca.v117i3.4888","DOIUrl":"https://doi.org/10.34314/jalca.v117i3.4888","url":null,"abstract":"In this study, a formulation and technique are developed to be used for cattle carcass decontamination prior to removal of hide in a commercially preferred time-frame to ensure meat safety and byproduct quality. This formulation offers deep cleaning on carcass surface by removing debris including manure/mud balls which are firmly attached to the hair of animal hide harboring pathogens like Salmonella and Escherichia coli. Survival of such pathogens can facilitate cross-contamination of the underlying meat and meat-processing equipment in the packing plant posing a challenge to the meat industry as well as public-health. Also, the attached adobe type mud/manure balls have potential to create holes on the hide during leather processing which degrades byproduct’s quality. Formulation was sprayed on cattle’s hide and the attached debris were brushed off from the surface. The formulation was found very efficient in cleaning the hide surface both at 5 and 8 min treatments. The highest of aerobic, Escherichia coli and Salmonella populations were reduced by 8.71, 3.63 and 3.19 Log CFU/50 in 2 , respectively when compared to water-wash. The efficacy of formulation can be optimized by adjusting its concentration and treatment time. Post-leather analysis showed no detrimental impact on byproduct caused by the formulation.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"2 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90289891","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}
In this study, alkaline metalloprotease gene 1067 was cloned from Planococcus halotolerans SCU63T and heterologously expressed in Bacillus subtilis SCK6. Using Luria Bertani (LB) broth medium as the initial medium, the optimal medium was obtained through a series of fermentation and culture optimization (g/L): yeast extract (10), soybean powder (15), urea (20), potassium chloride (6.7), calcium chloride (13.3), NaCl (10). On the basis of the optimal medium, the highest enzymatic activity of 1259.21 U/mL could be obtained by culturing at 30°C for 40 h. with pH 8, inoculation amount of 4% and filling amount of 50 mL. EDTA inhibits protease activity and PMSF promotes it, indicating that it was a metalloprotease rather than a serine protease. The optimum reaction temperature of the protease is 70°C, and the optimum pH is 9. The metal ions Zn 2+, Co2+ and surfactant β-ME, Tween 80 can improve the activity of the protease. The results of unhairing, SEM and staining show that this metalloprotease can completely dehair goatskin. Compared with the conventional chemical method, the goatskin after enzymatic unhairing has softer texture and smoother surface, and there is no obvious damage to the goatskin.
{"title":"Heterologous Expression of Alkaline Metalloproteinases in Bacillus Subtilis SCK6 for Eco-Friendly Enzymatic Unhairing of Goatskins","authors":"Shihao Zhang, Ruoshi Zhang, Xiaoguang Li, Zhe Xu, Yongqiang Tian","doi":"10.34314/jalca.v117i3.4892","DOIUrl":"https://doi.org/10.34314/jalca.v117i3.4892","url":null,"abstract":"In this study, alkaline metalloprotease gene 1067 was cloned from Planococcus halotolerans SCU63T and heterologously expressed in Bacillus subtilis SCK6. Using Luria Bertani (LB) broth medium as the initial medium, the optimal medium was obtained through a series of fermentation and culture optimization (g/L): yeast extract (10), soybean powder (15), urea (20), potassium chloride (6.7), calcium chloride (13.3), NaCl (10). On the basis of the optimal medium, the highest enzymatic activity of 1259.21 U/mL could be obtained by culturing at 30°C for 40 h. with pH 8, inoculation amount of 4% and filling amount of 50 mL. EDTA inhibits protease activity and PMSF promotes it, indicating that it was a metalloprotease rather than a serine protease. The optimum reaction temperature of the protease is 70°C, and the optimum pH is 9. The metal ions Zn 2+, Co2+ and surfactant β-ME, Tween 80 can improve the activity of the protease. The results of unhairing, SEM and staining show that this metalloprotease can completely dehair goatskin. Compared with the conventional chemical method, the goatskin after enzymatic unhairing has softer texture and smoother surface, and there is no obvious damage to the goatskin.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"68 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89501327","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 : 2022-04-01DOI: 10.34314/jalca.v117i3.4887
Yue Yu, Hui Wang, Ya-nan Wang, Jianfei Zhou, Bi Shi
Chrome-free leather manufacture is one of the major focuses of leather industry. In this work, a chrome-free tanning system based on highly-oxidized starch–zirconium complexes (HOS–Zr) was constructed. Particle size and charge properties analyses revealed that the small size (2.5 nm) and the low cationic species content (45.1%) of HOS–Zr at low pH facilitated its uniform penetration in leather at the initial stage of tanning, and the large size (89–169 nm) and the high cationic species content (77.5%) of HOS–Zr after basification contributed to its stable crosslinking between collagen fibers. A 3% HOS–Zr offer (based on the weight of ZrO2) imparted wet white with sufficient tanning effect. The physical properties of HOS–Zr crust leather were remarkably better than those of lactic acid–zirconium crust leather and were comparable to those of chrome crust leather. Wastewater in HOS–Zr tanning system showed a reduction in TOC load by 40.0% and higher biodegradability compared with chrome tanning system. As a result, this work provided a practical and sustainable approach to eliminate chrome in leather manufacture.
{"title":"Construction of a Chrome-free Tanning System Based on Highly-oxidized Starch–Zirconium Complexes","authors":"Yue Yu, Hui Wang, Ya-nan Wang, Jianfei Zhou, Bi Shi","doi":"10.34314/jalca.v117i3.4887","DOIUrl":"https://doi.org/10.34314/jalca.v117i3.4887","url":null,"abstract":"Chrome-free leather manufacture is one of the major focuses of leather industry. In this work, a chrome-free tanning system based on highly-oxidized starch–zirconium complexes (HOS–Zr) was constructed. Particle size and charge properties analyses revealed that the small size (2.5 nm) and the low cationic species content (45.1%) of HOS–Zr at low pH facilitated its uniform penetration in leather at the initial stage of tanning, and the large size (89–169 nm) and the high cationic species content (77.5%) of HOS–Zr after basification contributed to its stable crosslinking between collagen fibers. A 3% HOS–Zr offer (based on the weight of ZrO2) imparted wet white with sufficient tanning effect. The physical properties of HOS–Zr crust leather were remarkably better than those of lactic acid–zirconium crust leather and were comparable to those of chrome crust leather. Wastewater in HOS–Zr tanning system showed a reduction in TOC load by 40.0% and higher biodegradability compared with chrome tanning system. As a result, this work provided a practical and sustainable approach to eliminate chrome in leather manufacture.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"161 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75406533","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 : 2022-02-01DOI: 10.34314/jalca.v117i2.4730
R. Vreeland, J. Long
Salt curing of hides releases a significant amount of excess water that must be disposed. In larger abattoirs this can result in production of tens of thousands of gallons of saturated salt brine that is also contaminated with biological material from the hides. These brines are often stored in enclosed impoundments that ultimately fill and need replacement, or the facility must build multiple impoundments. The proprietary, biologically based, sustainable Halophilic Evaporative Applications Technology (H.E.A.T.) process has been developed as a method to accelerate the evaporation of salt saturated brines. The process has been tested for 18 months in a full-scale lagoon located at an operating American beef plant. The process successfully evaporated an additional 31.99 inches of brine (866,900 gal) acre-1 of concentrated hide brine in one year, nearly drying out the South lagoon. Ambient evaporation of the same brine in an identical control lagoon at the site was only 19.19 inches (520,000 gallons) acre-1 representing a 1.66x increase in brine evaporation from the H.E.A.T. microbes. During 2020, the plant produced 3,376,000 gallons of brine, meaning H.E.A.T. evaporated 100.4 % of plant production in one lagoon in its first year. This was accomplished without additional infrastructure, equipment or external heating. During this test, Biochemical Oxygen Demand in the lagoons decreased over 98% with concomitant odor reduction. Beginning in October 2020, the lagoon began receiving all brine produced daily by the plant. This continued over the winter period, during which time the process evaporated over 34% of the inflow. Continued fertilization and microbial augmentation are essential for the continued healthy development of the system. Overall, the process and its essential microbial populations were stimulated by continuing inflow of fresh hide brines. The microbial process increases brine evaporation of concentrated salt brines, reduces odors and represents a new environmentally friendly mechanism for solving an industrial problem that has long plagued hide producers.
{"title":"H.E.A.T. A New Sustainable Green Solution for Treating and Evaporating Hide Brine Wastewater","authors":"R. Vreeland, J. Long","doi":"10.34314/jalca.v117i2.4730","DOIUrl":"https://doi.org/10.34314/jalca.v117i2.4730","url":null,"abstract":"Salt curing of hides releases a significant amount of excess water that must be disposed. In larger abattoirs this can result in production of tens of thousands of gallons of saturated salt brine that is also contaminated with biological material from the hides. These brines are often stored in enclosed impoundments that ultimately fill and need replacement, or the facility must build multiple impoundments. The proprietary, biologically based, sustainable Halophilic Evaporative Applications Technology (H.E.A.T.) process has been developed as a method to accelerate the evaporation of salt saturated brines. The process has been tested for 18 months in a full-scale lagoon located at an operating American beef plant. The process successfully evaporated an additional 31.99 inches of brine (866,900 gal) acre-1 of concentrated hide brine in one year, nearly drying out the South lagoon. Ambient evaporation of the same brine in an identical control lagoon at the site was only 19.19 inches (520,000 gallons) acre-1 representing a 1.66x increase in brine evaporation from the H.E.A.T. microbes. During 2020, the plant produced 3,376,000 gallons of brine, meaning H.E.A.T. evaporated 100.4 % of plant production in one lagoon in its first year. This was accomplished without additional infrastructure, equipment or external heating. During this test, Biochemical Oxygen Demand in the lagoons decreased over 98% with concomitant odor reduction. Beginning in October 2020, the lagoon began receiving all brine produced daily by the plant. This continued over the winter period, during which time the process evaporated over 34% of the inflow. Continued fertilization and microbial augmentation are essential for the continued healthy development of the system. Overall, the process and its essential microbial populations were stimulated by continuing inflow of fresh hide brines. The microbial process increases brine evaporation of concentrated salt brines, reduces odors and represents a new environmentally friendly mechanism for solving an industrial problem that has long plagued hide producers.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"11 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88747329","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 : 2022-02-01DOI: 10.34314/jalca.v117i2.4727
M. A. Razzaq, M. Chowdhury, Md. Tushar Uddin
Curing of hides and skins using sodium salt is a well-established and economical preservation technique worldwide. But it contributes to generating a large amount of total dissolved solids (TDS) and increasing the salinity of water during leather processing which is a threat to the environment. The current research is an attempt to preserve goat skin using mahogany (Swietenia mahogany) seed’s extract. In real practice different percentages of mahogany seed extract were applied on raw goat skin and 3% (by weight of skin) of it showed best result. To evaluate the preservation efficiency, related parameters of preservation viz. odor, hair slip, shrinkage temperature, moisture content, bacterial count etc. were monitored regularly for 30 days. The obtained results were compared with conventional salt curing process. The experimental trial showed efficiency in lessening TDS value and chloride content. The preserved goat skins of both trials were treated following conventional leather processing techniques and physical properties were studied. The discussed preservation method exhibited comparable result in every index.
{"title":"Salt Free Preservation of Raw Goat Skin Using Swietenia Mahogany (Seed) Extract","authors":"M. A. Razzaq, M. Chowdhury, Md. Tushar Uddin","doi":"10.34314/jalca.v117i2.4727","DOIUrl":"https://doi.org/10.34314/jalca.v117i2.4727","url":null,"abstract":"Curing of hides and skins using sodium salt is a well-established and economical preservation technique worldwide. But it contributes to generating a large amount of total dissolved solids (TDS) and increasing the salinity of water during leather processing which is a threat to the environment. The current research is an attempt to preserve goat skin using mahogany (Swietenia mahogany) seed’s extract. In real practice different percentages of mahogany seed extract were applied on raw goat skin and 3% (by weight of skin) of it showed best result. To evaluate the preservation efficiency, related parameters of preservation viz. odor, hair slip, shrinkage temperature, moisture content, bacterial count etc. were monitored regularly for 30 days. The obtained results were compared with conventional salt curing process. The experimental trial showed efficiency in lessening TDS value and chloride content. The preserved goat skins of both trials were treated following conventional leather processing techniques and physical properties were studied. The discussed preservation method exhibited comparable result in every index.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"134 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77359955","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 : 2022-02-01DOI: 10.34314/jalca.v117i2.4728
S. Vasanth, T. Muthuramalingam, Sanjeev Gupta
Due to the widespread application and popularity of lasers in recent times, the usage of laser cutting for leather applications has increased as well. Laser technology is needed to provide more consistent and effective results while cutting leathers that include complicated geometries particularly in several sectors where leathers are often utilized such as footwear, apparel and fashion accessories. In this investigation, the diode laser was preferred for leather cutting due to its regulated power density, compact size and portability whereas the CO2 lasers are uncontrollable. The benefit of employing a diode laser is that it can overcome some of the disadvantages associated with CO2 lasers such as power consumption, carbonization layer and geometric inaccuracy. There is no technique available to measure the carbonization at the leather cut contour edges. Hence an attempt has been made to investigate the carbonization percentage with the help of a machine vision system to improve the machining process. The technique of measuring carbonization can be used effectively in the leather industry for the accurate measurement of carbonization. The lower duty cycle with moderate pulse width modulation (PWM) and amplitude could produce lower carbonization layer. PWM frequency has a high influential role on determining carbonization in leather cutting.
{"title":"Carbonization Region Measurement in Vegetable Tanned Goat Leather using Machine Vision System for Evaluating Performance Measures of Leather Cut Contour Edges","authors":"S. Vasanth, T. Muthuramalingam, Sanjeev Gupta","doi":"10.34314/jalca.v117i2.4728","DOIUrl":"https://doi.org/10.34314/jalca.v117i2.4728","url":null,"abstract":"Due to the widespread application and popularity of lasers in recent times, the usage of laser cutting for leather applications has increased as well. Laser technology is needed to provide more consistent and effective results while cutting leathers that include complicated geometries particularly in several sectors where leathers are often utilized such as footwear, apparel and fashion accessories. In this investigation, the diode laser was preferred for leather cutting due to its regulated power density, compact size and portability whereas the CO2 lasers are uncontrollable. The benefit of employing a diode laser is that it can overcome some of the disadvantages associated with CO2 lasers such as power consumption, carbonization layer and geometric inaccuracy. There is no technique available to measure the carbonization at the leather cut contour edges. Hence an attempt has been made to investigate the carbonization percentage with the help of a machine vision system to improve the machining process. The technique of measuring carbonization can be used effectively in the leather industry for the accurate measurement of carbonization. The lower duty cycle with moderate pulse width modulation (PWM) and amplitude could produce lower carbonization layer. PWM frequency has a high influential role on determining carbonization in leather cutting.","PeriodicalId":17201,"journal":{"name":"Journal of The American Leather Chemists Association","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75998592","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 : 2022-02-01DOI: 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":"69 1","pages":""},"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。
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