Yi-Chun SUN, Shun-Xun LI, Zhi-Feng YAO, Wei LI, Bo XU, Jin ZHOU
Insole construction is considered to be related to stability in sports, and custom-made insoles with their scientifically tailored approach and effective construction are considered to be the main means of adjusting posture and reducing risk in sports. We have designed a non-100% full-fit design insole (CDI) with an arch support insole and metatarsal liner to determine whether this insole can be adapted to lower limb kinematics. Eleven healthy volunteers participated in this randomized crossover test in which a motion capture and 3D gait analysis system was used to measure the subjects’ lower limb kinematic data while exercising at different slopes and speeds wearing three different insoles: CDI, control Insole (CI) and arch support insoles (ASI). In addition, the experiments introduced the speed and slope factor, analyzed the extent to which speed slope affects joint angle using UNIANOVA, and compared the performance differences between the three insoles in different planes in pairs. The CDI inhibited ankle dorsiflexion and knee flexion in the sagittal plane; in the frontal plane, CDI reduced knee adduction and hip abduction angles. There was a statistically significant difference (p < 0.05) between the change in joint angle and the velocity slope. Slope*speed had a greater effect on the ankle and knee joints (%sig>30%). The results show that the CDI has better kinematic adjustability in the ankle and knee joints due to its superior insole design approach. Therefore, wearing the CDI may be an effective way of reducing risks in sports.
{"title":"Effect of Custom-designed Insole with Arch and Metatarsal Support on Adjustment of the Lower Limb Kinematics","authors":"Yi-Chun SUN, Shun-Xun LI, Zhi-Feng YAO, Wei LI, Bo XU, Jin ZHOU","doi":"10.24264/lfj.23.2.7","DOIUrl":"https://doi.org/10.24264/lfj.23.2.7","url":null,"abstract":"Insole construction is considered to be related to stability in sports, and custom-made insoles with their scientifically tailored approach and effective construction are considered to be the main means of adjusting posture and reducing risk in sports. We have designed a non-100% full-fit design insole (CDI) with an arch support insole and metatarsal liner to determine whether this insole can be adapted to lower limb kinematics. Eleven healthy volunteers participated in this randomized crossover test in which a motion capture and 3D gait analysis system was used to measure the subjects’ lower limb kinematic data while exercising at different slopes and speeds wearing three different insoles: CDI, control Insole (CI) and arch support insoles (ASI). In addition, the experiments introduced the speed and slope factor, analyzed the extent to which speed slope affects joint angle using UNIANOVA, and compared the performance differences between the three insoles in different planes in pairs. The CDI inhibited ankle dorsiflexion and knee flexion in the sagittal plane; in the frontal plane, CDI reduced knee adduction and hip abduction angles. There was a statistically significant difference (p < 0.05) between the change in joint angle and the velocity slope. Slope*speed had a greater effect on the ankle and knee joints (%sig>30%). The results show that the CDI has better kinematic adjustability in the ankle and knee joints due to its superior insole design approach. Therefore, wearing the CDI may be an effective way of reducing risks in sports.","PeriodicalId":38857,"journal":{"name":"Leather and Footwear Journal","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136369402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two antimicrobial gels, formulated with natural biopolymers (collagen and chitosan), limonene, and an imidazole derivative, were subjected to cytotoxicity tests. In these two compositions, the limonene content was 0.4% and 0.67%. The cytotoxicity tests were performed in vitro, using MTT methodology, and a standardized human normal cells line, HUVEC type. These cells were exposed to different levels of gel concentrations in the culture media. The final concentration of each gel type in culture media was situated between (0-0.125) μL/mL. The cell viability was determined after 24, 48 and 72h of exposure. The analyses showed that after 24h of exposure, the viability of the cells is greater than 91%, after 48h the viability is greater than 80%; after 72 h of exposure, the viability of the cells is greater than 74%. These values reveal that both selected gels exhibit no cytotoxicity for the normal cell line.
{"title":"Studies Regarding the Cytotoxicity of Antimicrobial Gels Formulated with Natural Biopolymers","authors":"Mohammed Shaymaa Omar MOHAMMED, Nicoleta RADU, Rodica Roxana CONSTANTINESCU, Petruta CORNEA, Magdalina URSU, Narcisa BĂBEANU","doi":"10.24264/lfj.23.2.5","DOIUrl":"https://doi.org/10.24264/lfj.23.2.5","url":null,"abstract":"Two antimicrobial gels, formulated with natural biopolymers (collagen and chitosan), limonene, and an imidazole derivative, were subjected to cytotoxicity tests. In these two compositions, the limonene content was 0.4% and 0.67%. The cytotoxicity tests were performed in vitro, using MTT methodology, and a standardized human normal cells line, HUVEC type. These cells were exposed to different levels of gel concentrations in the culture media. The final concentration of each gel type in culture media was situated between (0-0.125) μL/mL. The cell viability was determined after 24, 48 and 72h of exposure. The analyses showed that after 24h of exposure, the viability of the cells is greater than 91%, after 48h the viability is greater than 80%; after 72 h of exposure, the viability of the cells is greater than 74%. These values reveal that both selected gels exhibit no cytotoxicity for the normal cell line.","PeriodicalId":38857,"journal":{"name":"Leather and Footwear Journal","volume":"240 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136369405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shunxun LI, Yichun SUN, Jin ZHOU, Bo XU, Zhifeng YAO, Wei LI
Although both fabricated insoles and customized insoles were designed with varied function components, current knowledge approved that customized insoles worked much better. However, how the customized insoles achieved a better performance in term of load re-distribution was still lacking quantitative assessment. The aim was to determine whether the customized insole structure based on a novel customization procedure proposed in this study performs better than the prefabricated insoles in terms of plantar pressure re-distribution efficiency. This study included ten healthy subjects, each wearing four types of insoles accordingly (control insoles; arch support insoles; orthotic insoles; customized insoles), and plantar pressure was collected in a walking state. The custom insoles are made by determining the subject’s plantar surface and key plantar points, then following the customization procedure to finish them. The plantar area was divided into eight zones and then a pressure transfer algorithm was used to gain insight into the plantar pressure. Compared to the control group insoles, the arch support of the customized insoles reduced pressure in the hallux region and transferred pressure from the M4-5 to the MH and LH regions, while the metatarsal pad enhanced the pressure transfer in the mid-foot, and the anterior-posterior height difference of the insole plays a role in pressure transfer. Furthermore, the customized insoles performed close to the professional orthotic insoles. Design strategy with accurate insole’s component location and reasonably plantar surface matching, our customized insole demonstrated advantages such as a better loading redistribution and significant pressure relieving on the forefoot.
{"title":"Investigation of the Effectiveness of Plantar Pressure Redistribution of Customized Insole Structure Designed Based on Plantar Structure","authors":"Shunxun LI, Yichun SUN, Jin ZHOU, Bo XU, Zhifeng YAO, Wei LI","doi":"10.24264/lfj.23.2.6","DOIUrl":"https://doi.org/10.24264/lfj.23.2.6","url":null,"abstract":"Although both fabricated insoles and customized insoles were designed with varied function components, current knowledge approved that customized insoles worked much better. However, how the customized insoles achieved a better performance in term of load re-distribution was still lacking quantitative assessment. The aim was to determine whether the customized insole structure based on a novel customization procedure proposed in this study performs better than the prefabricated insoles in terms of plantar pressure re-distribution efficiency. This study included ten healthy subjects, each wearing four types of insoles accordingly (control insoles; arch support insoles; orthotic insoles; customized insoles), and plantar pressure was collected in a walking state. The custom insoles are made by determining the subject’s plantar surface and key plantar points, then following the customization procedure to finish them. The plantar area was divided into eight zones and then a pressure transfer algorithm was used to gain insight into the plantar pressure. Compared to the control group insoles, the arch support of the customized insoles reduced pressure in the hallux region and transferred pressure from the M4-5 to the MH and LH regions, while the metatarsal pad enhanced the pressure transfer in the mid-foot, and the anterior-posterior height difference of the insole plays a role in pressure transfer. Furthermore, the customized insoles performed close to the professional orthotic insoles. Design strategy with accurate insole’s component location and reasonably plantar surface matching, our customized insole demonstrated advantages such as a better loading redistribution and significant pressure relieving on the forefoot.","PeriodicalId":38857,"journal":{"name":"Leather and Footwear Journal","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136369789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gresy GRIYANITASARI, Ambar PERTIWININGRUM, Nanung Agus FITRIYANTO, Yuny ERWANTO
Chrome tanning is an essential process to convert raw animal skin into leather, in which collagen, as the main structure of leather, is stabilized against degradation through cross-linking using chromium, consisting of two steps: penetration and basicity. However, the uptake of chrome in leather still needs to be improved. The purpose of this study was to find the best heating time in the chrome tanning process by thermal analysis. Pickled sheepskin was used as raw material for the chromium tanning process. The samples were varied into four categories: heated at the penetration stage of the tanning process (Initial Heating), heated at the basification stage of the tanning process (Final Heating), and heated both at the penetration and basification stage (Continuous Heating). In this study, the thermal stability of wet blue leather was evaluated by shrinkage temperature behavior (Ts), thermogravimetry analysis (TGA/DTG), and differential scanning calorimetry (DSC). The tanning efficiency was measured by Cr2O3 content. The results demonstrated that wet blue samples heated continuously shows better thermal characteristics. In conclusion, the results can be used for finding the best possible technique for the leather tanning process using chrome salts to gain thermal stability.
{"title":"The Effect of Heating Time on the Thermal Stability of Chrome-Tanned Leather","authors":"Gresy GRIYANITASARI, Ambar PERTIWININGRUM, Nanung Agus FITRIYANTO, Yuny ERWANTO","doi":"10.24264/lfj.23.1.3","DOIUrl":"https://doi.org/10.24264/lfj.23.1.3","url":null,"abstract":"Chrome tanning is an essential process to convert raw animal skin into leather, in which collagen, as the main structure of leather, is stabilized against degradation through cross-linking using chromium, consisting of two steps: penetration and basicity. However, the uptake of chrome in leather still needs to be improved. The purpose of this study was to find the best heating time in the chrome tanning process by thermal analysis. Pickled sheepskin was used as raw material for the chromium tanning process. The samples were varied into four categories: heated at the penetration stage of the tanning process (Initial Heating), heated at the basification stage of the tanning process (Final Heating), and heated both at the penetration and basification stage (Continuous Heating). In this study, the thermal stability of wet blue leather was evaluated by shrinkage temperature behavior (Ts), thermogravimetry analysis (TGA/DTG), and differential scanning calorimetry (DSC). The tanning efficiency was measured by Cr2O3 content. The results demonstrated that wet blue samples heated continuously shows better thermal characteristics. In conclusion, the results can be used for finding the best possible technique for the leather tanning process using chrome salts to gain thermal stability.","PeriodicalId":38857,"journal":{"name":"Leather and Footwear Journal","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135950233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
According to the reports of CSA (Central Statistics Agency) 2020 Ethiopia is the 10th in the world and 1st in Africa by cattle production. Furthermore, the leather sector is the priority sector in Ethiopia. Leather industries are facing challenges in improving productivity and quality in the competitive market nowadays. The input materials for leather industries are goat and sheep skin, and cattle hide in Ethiopia. However, there are raw hide and skin defects due to preslaughter, during slaughter and post-slaughter process. This study focuses on the minimization of the major defects in preslaughter and during the slaughter of raw hide and skin process by application of Pareto analysis and fishbone diagram in Ethiopia in the case of Dire Dawa city. The Pareto analysis reveals that priority should be given to solving the problems of pre-slaughter and during-slaughter defects of raw hide and skin. Based on cause-and-effect diagram analysis, the main causes are: machine, material, environment, man, measures and management, root causes, heated metal shape for brand mark, during diseases different action is taken, hit animal using different steel, grass used for food, animals home making material, drinking water, stick, topography, hot area, old area, lack of awareness about hide and skin outputs, traditional methods of water in forage for the animals during farming, traditional methods used for medications for raw hide and defects identified. Finally, a few recommendations are made to reduce raw hide and skin defects.
{"title":"An Application of Pareto Analysis and Cause-and-Effect Diagram in Raw Hide and Skin Defects Minimization in Ethiopia: Selected Case Dire Dawa City Slaughterhouse (Ethiopia)","authors":"Berihun NEGASH","doi":"10.24264/lfj.23.1.5","DOIUrl":"https://doi.org/10.24264/lfj.23.1.5","url":null,"abstract":"According to the reports of CSA (Central Statistics Agency) 2020 Ethiopia is the 10th in the world and 1st in Africa by cattle production. Furthermore, the leather sector is the priority sector in Ethiopia. Leather industries are facing challenges in improving productivity and quality in the competitive market nowadays. The input materials for leather industries are goat and sheep skin, and cattle hide in Ethiopia. However, there are raw hide and skin defects due to preslaughter, during slaughter and post-slaughter process. This study focuses on the minimization of the major defects in preslaughter and during the slaughter of raw hide and skin process by application of Pareto analysis and fishbone diagram in Ethiopia in the case of Dire Dawa city. The Pareto analysis reveals that priority should be given to solving the problems of pre-slaughter and during-slaughter defects of raw hide and skin. Based on cause-and-effect diagram analysis, the main causes are: machine, material, environment, man, measures and management, root causes, heated metal shape for brand mark, during diseases different action is taken, hit animal using different steel, grass used for food, animals home making material, drinking water, stick, topography, hot area, old area, lack of awareness about hide and skin outputs, traditional methods of water in forage for the animals during farming, traditional methods used for medications for raw hide and defects identified. Finally, a few recommendations are made to reduce raw hide and skin defects.","PeriodicalId":38857,"journal":{"name":"Leather and Footwear Journal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135950231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The results of the research prove that adhesives based on chloroprene rubber can be obtained not only in combination with phenol-formaldehyde resins, but also with other polymers. Selected chlorobutyl rubber (CIIR) and high styrene rubber (KER) proved to be substitutes for phenolic resins, which were used to obtain adhesive compositions with good properties. Despite the existing opinion on the same polarity of the components of the adhesive composition, guaranteeing the most favorable properties, it was shown that compositions with different polarity have all the parameters of quality adhesives. Components with different polarity also show the effect of mutual reinforcement, which determines the alignment, orientation ability of macromolecular chains and occurrence of cohesion and adhesion interactions. The observed textures obtained after mechanical impact proved this claim. Adhesives with more developed textures have better adhesive properties. The selected research methods successfully predict the properties of the components and facilitate their selection and amount.
{"title":"Study of Adhesion-Cohesion Interactions between Polymers in Adhesive Compositions","authors":"Darina ZHELEVA, Rashko DIMITROV","doi":"10.24264/lfj.23.1.4","DOIUrl":"https://doi.org/10.24264/lfj.23.1.4","url":null,"abstract":"The results of the research prove that adhesives based on chloroprene rubber can be obtained not only in combination with phenol-formaldehyde resins, but also with other polymers. Selected chlorobutyl rubber (CIIR) and high styrene rubber (KER) proved to be substitutes for phenolic resins, which were used to obtain adhesive compositions with good properties. Despite the existing opinion on the same polarity of the components of the adhesive composition, guaranteeing the most favorable properties, it was shown that compositions with different polarity have all the parameters of quality adhesives. Components with different polarity also show the effect of mutual reinforcement, which determines the alignment, orientation ability of macromolecular chains and occurrence of cohesion and adhesion interactions. The observed textures obtained after mechanical impact proved this claim. Adhesives with more developed textures have better adhesive properties. The selected research methods successfully predict the properties of the components and facilitate their selection and amount.","PeriodicalId":38857,"journal":{"name":"Leather and Footwear Journal","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135950232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aims to tan the skin with reverse tanning based on the order of pH, thereby reducing the use of chemicals and water due to the pH regulation process. The reverse tanning method will result in a faster tanning process and reduce the use of many chemicals, so that the pollutant load released from the tanning process will be much reduced. Conventional leather tanning is carried out through many processes starting from the BHO (Beam House Operation) process, tanning, post-tanning, and finishing; this process is carried out through a 14-15 step process that produces a large number of pollutants. This is because in conventional leather processing a lot of pH adjustment processes are carried out that go back and forth. In this study the leather processing steps were ordered based on the pH of the tanning process, the chemicals and the pH of the process were regulated by the sequence of the process steps to avoid some repeated acidification and basification/neutralization as in conventional leather processing. The process begins with soaking, liming, fleshing, deliming, tanning, dyeing, fatliquoring, and chrome tanning. This process begins with an alkaline pH of 11 and ends with an acidic pH of 3.8. Chrome tanning is done with variations in the amount of chrome of 2%, 3%, 4%. The results showed that leather with 4% chromium produced the highest Ts of 103 °C, tensile strength of 39.86 N, tearing strength of 13.19 N/mm, seam strength of 12.8 N/mm, elongation of 46.87%, Cr content (VI) 1.68 ppm. These results have met the standard ISO/TR 20879:2007 Footwear. The reverse tanning process with a process from high to low pH without adjusting the pH back and forth by adding solutions and salts means reducing liquid waste in the leather tanning process. So, this process can reduce the amount of liquid waste or pollutants.
本研究的目的是根据pH值的顺序进行反向晒黑，从而减少因pH值调节过程而导致的化学品和水的使用。反制革方法将使制革过程更快，减少许多化学品的使用，从而大大减少制革过程中释放的污染物负荷。传统的皮革鞣制从BHO (Beam House Operation)过程、鞣制、鞣制后和整理开始，经过许多过程;这个过程是通过14-15个步骤的过程，产生大量的污染物。这是因为在传统的皮革加工中，进行了许多来回的pH调节过程。在本研究中，皮革加工步骤是根据鞣制过程的pH值来排序的，化学物质和过程的pH值是由过程步骤的顺序来调节的，以避免一些重复的酸化和碱化/中和在传统的皮革加工。这个过程开始于浸泡，石灰，肉质，划界，鞣制，染色，加脂和铬鞣制。这个过程开始于pH值为11的碱性，结束于pH值为3.8的酸性。铬鞣是在铬含量为2%、3%、4%的情况下进行的。结果表明，铬含量为4%时，皮革的最高Ts值为103℃，抗拉强度为39.86 N，撕裂强度为13.19 N/mm，接缝强度为12.8 N/mm，伸长率为46.87%，Cr含量(VI)为1.68 ppm。这些结果符合ISO/TR 20879:2007鞋类标准。不通过添加溶液和盐来来回调节pH值，从pH值高到pH值低的反制革工艺，减少了皮革制革过程中的液体浪费。因此，这个过程可以减少液体废物或污染物的数量。
{"title":"Reduction of Pollutants in the Tanning Industry Using the Reverse Tanning Method against the Physical Properties of Leather","authors":"Heru Budi SUSANTO, Swatika JUHANA","doi":"10.24264/lfj.23.1.1","DOIUrl":"https://doi.org/10.24264/lfj.23.1.1","url":null,"abstract":"This study aims to tan the skin with reverse tanning based on the order of pH, thereby reducing the use of chemicals and water due to the pH regulation process. The reverse tanning method will result in a faster tanning process and reduce the use of many chemicals, so that the pollutant load released from the tanning process will be much reduced. Conventional leather tanning is carried out through many processes starting from the BHO (Beam House Operation) process, tanning, post-tanning, and finishing; this process is carried out through a 14-15 step process that produces a large number of pollutants. This is because in conventional leather processing a lot of pH adjustment processes are carried out that go back and forth. In this study the leather processing steps were ordered based on the pH of the tanning process, the chemicals and the pH of the process were regulated by the sequence of the process steps to avoid some repeated acidification and basification/neutralization as in conventional leather processing. The process begins with soaking, liming, fleshing, deliming, tanning, dyeing, fatliquoring, and chrome tanning. This process begins with an alkaline pH of 11 and ends with an acidic pH of 3.8. Chrome tanning is done with variations in the amount of chrome of 2%, 3%, 4%. The results showed that leather with 4% chromium produced the highest Ts of 103 °C, tensile strength of 39.86 N, tearing strength of 13.19 N/mm, seam strength of 12.8 N/mm, elongation of 46.87%, Cr content (VI) 1.68 ppm. These results have met the standard ISO/TR 20879:2007 Footwear. The reverse tanning process with a process from high to low pH without adjusting the pH back and forth by adding solutions and salts means reducing liquid waste in the leather tanning process. So, this process can reduce the amount of liquid waste or pollutants.","PeriodicalId":38857,"journal":{"name":"Leather and Footwear Journal","volume":"167 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135950235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aims to improve the quality of finished leather for seat covers by knowing the effect of isocyanate as a cross-linker to reduce delamination on the finished leather. Delamination is a condition where the three layers of finish (base coat, medium coat, and top coat) do not stick together, resulting in the lifting of the top coat during the adhesion test. The raw material used in the trial is C60 quality crust dyed cowhide, 1.1 mm to 1.4 mm thick with an area of ± 3 sqft. The stages of the finishing process include semi-finished selection, stacking, spraying (base coat), rest, stacking, roller embossing, rest, milling, stacking, spraying (medium coat, top coat), rest, stacking, laboratory, and measuring. The formulation of the improved seat cover article was carried out by increasing the percentage of cross-linker in the base coat mixture. The production formulation used 2% cross-linker, trial 1 used 3% cross-linker, and trial 2 used 4% cross-linker. The best results are with the addition of 4% cross-linker to reduce delamination and have an adhesion resistance value of 24.5 N. The conclusion is that the greater the addition of cross-linker as much as 4% in the base coat of the article seat cover will reduce delamination, increase thickness from 1.1 mm to 1.2 mm, improve color fastness resistance to a value of 4, and reduce softness value from 3.92 mm to 3.42 mm.
{"title":"Effect of Isocyanate as Cross-linker to Reduce Delamination of Finished Leather for Automotive Seat Cover","authors":"Prasetyo HERMAWAN, Sekar Nirwana SARI, Wahyu Fajar WINATA, Elis NURBALIA","doi":"10.24264/lfj.23.1.2","DOIUrl":"https://doi.org/10.24264/lfj.23.1.2","url":null,"abstract":"This study aims to improve the quality of finished leather for seat covers by knowing the effect of isocyanate as a cross-linker to reduce delamination on the finished leather. Delamination is a condition where the three layers of finish (base coat, medium coat, and top coat) do not stick together, resulting in the lifting of the top coat during the adhesion test. The raw material used in the trial is C60 quality crust dyed cowhide, 1.1 mm to 1.4 mm thick with an area of ± 3 sqft. The stages of the finishing process include semi-finished selection, stacking, spraying (base coat), rest, stacking, roller embossing, rest, milling, stacking, spraying (medium coat, top coat), rest, stacking, laboratory, and measuring. The formulation of the improved seat cover article was carried out by increasing the percentage of cross-linker in the base coat mixture. The production formulation used 2% cross-linker, trial 1 used 3% cross-linker, and trial 2 used 4% cross-linker. The best results are with the addition of 4% cross-linker to reduce delamination and have an adhesion resistance value of 24.5 N. The conclusion is that the greater the addition of cross-linker as much as 4% in the base coat of the article seat cover will reduce delamination, increase thickness from 1.1 mm to 1.2 mm, improve color fastness resistance to a value of 4, and reduce softness value from 3.92 mm to 3.42 mm.","PeriodicalId":38857,"journal":{"name":"Leather and Footwear Journal","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135950234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laurenţia ALEXANDRESCU, Mihai GEORGESCU, Maria SÖNMEZ, Mihaela NIȚUICĂ, Maria-Daniela STELESCU, Dana GURĂU
This paper presents experiments on developing and characterizing biodegradable polymer composites based on polyvinyl chloride and expanded poly(ethylene vinyl acetate) (EVA) post-consumer waste. This type of waste is a thermoplastic material collected from the footwear industry, residues from the production of outer and intermediate soles and used footwear. It is used due to its shock absorption properties and low density (0.6-0.8 g/cm3). To make these products, EVA is injected into molds, a process that generates waste that cannot be reused. In this paper, a method of EVA waste recovery is presented and the possibility of developing a recycled product is investigated. Expanded EVA waste is cryogenically ground to sizes of min. 500 nm, functionalized by a mechanical process at temperature with polydimethylsiloxane (PDMS) and mixed in the composite in various proportions (10, 20, 50%). This composite will be made into a low-density product, with low cost, recovery and reuse of waste, and last but not least, biodegradable. The methodology for making the new materials involves the following steps: sorting waste, grinding, functionalization and compounding. These operations are easy to manage and do not involve new equipment. Compounding, the most important operation, will be performed on an extruder-granulator. The experimented biodegradable composites were physico-mechanically characterized. Waste transformation (ground and functionalized) into new value-added products will lead to remarkable improvements in the life cycle of raw materials and the sustainable use of this waste, contributing to sustainability, improving eco-efficiency and economic efficiency and reducing the “pressure” of waste on the environment.
{"title":"Biodegradable Polymer Composite Based on Polyvinyl Chloride and Poly (Ethylene-Vinyl Acetate) Waste","authors":"Laurenţia ALEXANDRESCU, Mihai GEORGESCU, Maria SÖNMEZ, Mihaela NIȚUICĂ, Maria-Daniela STELESCU, Dana GURĂU","doi":"10.24264/lfj.23.1.6","DOIUrl":"https://doi.org/10.24264/lfj.23.1.6","url":null,"abstract":"This paper presents experiments on developing and characterizing biodegradable polymer composites based on polyvinyl chloride and expanded poly(ethylene vinyl acetate) (EVA) post-consumer waste. This type of waste is a thermoplastic material collected from the footwear industry, residues from the production of outer and intermediate soles and used footwear. It is used due to its shock absorption properties and low density (0.6-0.8 g/cm3). To make these products, EVA is injected into molds, a process that generates waste that cannot be reused. In this paper, a method of EVA waste recovery is presented and the possibility of developing a recycled product is investigated. Expanded EVA waste is cryogenically ground to sizes of min. 500 nm, functionalized by a mechanical process at temperature with polydimethylsiloxane (PDMS) and mixed in the composite in various proportions (10, 20, 50%). This composite will be made into a low-density product, with low cost, recovery and reuse of waste, and last but not least, biodegradable. The methodology for making the new materials involves the following steps: sorting waste, grinding, functionalization and compounding. These operations are easy to manage and do not involve new equipment. Compounding, the most important operation, will be performed on an extruder-granulator. The experimented biodegradable composites were physico-mechanically characterized. Waste transformation (ground and functionalized) into new value-added products will lead to remarkable improvements in the life cycle of raw materials and the sustainable use of this waste, contributing to sustainability, improving eco-efficiency and economic efficiency and reducing the “pressure” of waste on the environment.","PeriodicalId":38857,"journal":{"name":"Leather and Footwear Journal","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135950236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Formic acid is known as a fixing agent in vegetable tanning process but this material is corrosive and irritant. Citric acid has the potential to be developed as an alternative fixing agent. This research aims to study the ability of citric acid as an alternative fixing agent in the tanning process, especially vegetable tanning of goatskin. The tanning process was carried out by the drum method. Pickled goatskins were tanned with mimosa and then fixed with citric acid. The concentration of citric acid varied from 1%; 1.5%; 2%; 2.5%; to 3%, to determine the optimum concentration. A fixing agent of 2% formic acid was used as a control. The results show that the control skin had similar characteristics to the treated skin. Physical properties of T4 have met the standard of SNI 0253-2009. It can be concluded that the optimal concentration of citric acid that can be used as an alternative fixing agent in vegetable tanning process of goatskin is 2.5%.
{"title":"Citric Acid as an Effective and Safe Fixing Agent in Vegetable Tanning Process of Goatskin","authors":"Nur Mutia Rosiati, Mustafidah Udkhiyati","doi":"10.24264/lfj.22.4.3","DOIUrl":"https://doi.org/10.24264/lfj.22.4.3","url":null,"abstract":"Formic acid is known as a fixing agent in vegetable tanning process but this material is corrosive and irritant. Citric acid has the potential to be developed as an alternative fixing agent. This research aims to study the ability of citric acid as an alternative fixing agent in the tanning process, especially vegetable tanning of goatskin. The tanning process was carried out by the drum method. Pickled goatskins were tanned with mimosa and then fixed with citric acid. The concentration of citric acid varied from 1%; 1.5%; 2%; 2.5%; to 3%, to determine the optimum concentration. A fixing agent of 2% formic acid was used as a control. The results show that the control skin had similar characteristics to the treated skin. Physical properties of T4 have met the standard of SNI 0253-2009. It can be concluded that the optimal concentration of citric acid that can be used as an alternative fixing agent in vegetable tanning process of goatskin is 2.5%.","PeriodicalId":38857,"journal":{"name":"Leather and Footwear Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45043898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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