An eco-benign tanning system using aluminium, tannic acid, and silica combination / N. N. Fathima in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 2 (02/2004)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCIX, N° 2 (02/2004) . - p. 73-81 Titre : An eco-benign tanning system using aluminium, tannic acid, and silica combination Type de document : texte imprimé Auteurs : N. N. Fathima, Auteur ; Balachandran Unni Nair, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Subramani Saravanabhavan, Auteur Année de publication : 2004 Article en page(s) : p. 73-81 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : One of the best ways to combat chrome pollution is to avoid chromium itself in tanning. With this view, a chrome-free combination tanning system has been established using aluminium, tannic acid, a precursor to vegetable tannins and silica. Since tannic acid has low molecular weight compared to vegetable tannins, it can be successfully used to make a variety of leathers and the problems associated with vegetable tannins like hard biodegradability of tannins, fullness and darkness of leathers can be avoided. The presence of aluminium not only improves the hydrothermal stability of leather but also gives a pleasant pastel color to the leather due to the formation of aluminium-tannic acid complex, which produces colour in the matrix thus leading to the concept of natural dyeing. The fastness properties of the color obtained have been studied and have been found to be significantly good. The presence of silica in the combination system gives rise to softness and fluffiness. The amount of tannic acid, aluminium sulfate and sodium metasilicate has been chosen as 10, 5, and 5% (on pelt weight), respectively. In order to avoid pollution due to pickling operation, pickle-less tanning has been carried out. Both upper and garment leathers have been made and the characteristics of the same have been studied. The shrinkage temperature of the leathers obtained from this combination tanning system is about 95°C. The physical strength characteristics and the organoleptic properties of the leathers obtained are on par with or better than the conventional chrome tanned leathers. The effluent arising from this tanning system has been analyzed for its environmental impact. The exhaustion of aluminium is about 98%. Also, there is significant reduction in the COD and TDS. Thus, an eco-benign chrome-free combination tanning system has been established. En ligne : https://drive.google.com/file/d/1r-90QymqgKFRS1dTnYGfvzvHwoxG55AG/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4182 [article]

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An enzymatic beamhouse process coupled with semi-metal tanning and eco-benign post tanning leads to cleaner leather production / Subramani Saravanabhavan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. C, N° 5 (05/2005)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. C, N° 5 (05/2005) . - p. 174-186 Titre : An enzymatic beamhouse process coupled with semi-metal tanning and eco-benign post tanning leads to cleaner leather production Type de document : texte imprimé Auteurs : Subramani Saravanabhavan, Auteur ; Balachandran Unni Nair, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Palanisamy Thanikaivelan, Auteur Année de publication : 2005 Article en page(s) : p. 174-186 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Leather industry in the world is presently undergoing radical transformation due to environmental pollution and discharge statutes. Hence, the industry is stressed to search for cleaner leather processing. Present leatherprocessing methodologies are known to contribute higher pollution loads. This method of tanning process comprises 'do-undo' logic. In addition, the conventional methods followed in leather processing subject the collagen matrix to wide variation in pH (2.8 - 13.0). This is evidenced from the emission of huge amount of pollution loads such as bio-chemical oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), total solids (TS), sulfates, chlorides and chromium. In the study illustrated here, the hair and flesh removal as well as fiber opening have been achieved using bio-products at pH 8.0, pickle free semi-metal tanning employing aluminium, vegetable tannins and silica followed by post-tanning using environmental benign chemicals. Hence, eco-benign chemicals have been used throughout the leather processing. It has been observed that the extent of hair removal and opening up of fiber bundles are comparable to that of conventionally processed leathers. This has been demonstrated through scanning electron microscopy (SEM) and softness measurements. The shrinkage temperature of the experimental leathers obtained from this combination tanning system is about 100°C. Performance of the leathers is shown to be on par with conventionally chrome-tanned leathers through physical strength and hand evaluation. The developed process also exhibits significant reduction in BOD, COD, TDS and TS loads by 46, 33, 91, and 92%, respectively. Further, the developed process appears to be economically viable. En ligne : https://drive.google.com/file/d/1C3W77yjX6Y9IzNX6AsVESIapVLntwBAh/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4065 [article]

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A bio-driven lime and pickle free tanning paves way for freener garment leather production / Rathinam Aravindhan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 2 (02/2004)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCIX, N° 2 (02/2004) . - p. 53-66 Titre : A bio-driven lime and pickle free tanning paves way for freener garment leather production Type de document : texte imprimé Auteurs : Rathinam Aravindhan, Auteur ; Balachandran Unni Nair, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Subramani Saravanabhavan, Auteur Année de publication : 2004 Article en page(s) : p. 53-66 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Conventional methods employed in leather processing subject the skin or hide to a wide variety of chemicals. This contributes to an increase in COD, TDS, chlorides, sulfates and other mineral salts in tannery effluent. A process sequence has now been explored viz., enzymatic dehairing, enzymatic fiber opening, and pickle-free chrome tanning for tanning red hair sheepskins, which limits the use of unsafe chemicals. A process for dehairing at pH 8.0 has been achieved by employing a commercial enzyme. A novel opening up system has been established again using enzymes. A pickle-basification free chrome tanning has been adopted to tan the enzyme treated matrices. Using the above said strategy, garment leathers have been made from wet-salted sheepskins. This leads to substantial decrease in chemical consumption from 442 to 38 kg for tanning one metric ton raw skins. Performances of leathers are on a par with conventionally opened up leathers, which is substantiated through physical and hand evaluation. This has also been verified through scanning electron microscopic analysis and softness measurements. The process also enjoys reduction in COD and TS loads on the environment by 84%. This process has also been proved to be economically viable, when compared with conventional process. Thus, the bio-driven pickle-free chrome tanning process leads to the manufacture of garment leathers with a cleaner environment. En ligne : https://drive.google.com/file/d/1R3Gr4jJtrt9ZhcdUgqu8bhjYEHRRMtAE/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4175 [article]

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Biochemical method for extraction and reuse of protein and chromium from chrome leather shavings : a waste to wealth approach / Anupama Pati in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVIII, N° 10 (10/2013)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVIII, N° 10 (10/2013) . - p. 365-372 Titre : Biochemical method for extraction and reuse of protein and chromium from chrome leather shavings : a waste to wealth approach Type de document : texte imprimé Auteurs : Anupama Pati, Auteur ; Rubina Chaudhary, Auteur ; Subramani Saravanabhavan, Auteur Année de publication : 2013 Article en page(s) : p. 365-372 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Amylase L'amylase (EC 3.2.1.1) est une enzyme digestive classée comme saccharidase (enzyme qui brise les polysaccharides). C'est surtout un constituant du suc pancréatique et de la salive, requis pour le catabolisme des glucides à longue chaîne (comme l'amidon) en unités plus petites. L'amylase est également synthétisée dans de nombreuses espèces de fruits pendant leur maturation, ce qui les rend plus sucrés, et aussi durant la germination des grains de céréales. Elle joue un rôle essentiel dans l'amylolyse (ou hydrolyse) de l'amidon de malt d'orge, processus nécessaire à la fabrication de la bière, ainsi que dans l'hydrolyse du glycogène, permettant sa transformation en glucose. Il y a deux iso-enzymes de l'amylase : l'amylase pancréatique et l'amylase salivaire. Elles se comportent différemment au focusing isoélectrique, et peuvent être séparées en testant par les anticorps monoclonaux spécifiques. La ptyaline ou amylase salivaire est une substance qui existe dans la salive. L'alpha-amylase brise les liens α(1-4)glycosidiques à l'intérieur des chaînes de l'amylose et de l'amylopectine pour ultimement donner des molécules de maltose (disaccharides de α-glucose). Elle ne peut attaquer que les amidons hydratés et cuits. Possède un site de liaison à l'émail donc participe à l'élaboration de la pellicule acquise exogène. Se lie avec affinité au Streptococcus viridans (en) ce qui conduit à sa clairance ou à son adhésion selon que l'amylase est en solution ou adsorbée à la surface dentaire. L'amylase liée à une bactérie conserve environ 50 % de son activité enzymatique. La bactérie liée à l'amylase peut donc fermenter le glu que celle-ci produit en acide organique. Bases (chimie) Biochimie Chrome Cuirs et peaux -- Déchets -- Recyclage Enzymes Une enzyme est une protéine dotée de propriétés catalytiques. Pratiquement toutes les biomolécules capables de catalyser des réactions chimiques dans les cellules sont des enzymes ; certaines biomolécules catalytiques sont cependant constituées d'ARN et sont donc distinctes des enzymes : ce sont les ribozymes. Une enzyme agit en abaissant l'énergie d'activation d'une réaction chimique, ce qui accroît la vitesse de réaction. L'enzyme n'est pas modifiée au cours de la réaction. Les molécules initiales sont les substrats de l'enzyme, et les molécules formées à partir de ces substrats sont les produits de la réaction. Presque tous les processus métaboliques de la cellule ont besoin d'enzymes pour se dérouler à une vitesse suffisante pour maintenir la vie. Les enzymes catalysent plus de 5 000 réactions chimiques différentes2. L'ensemble des enzymes d'une cellule détermine les voies métaboliques qui peuvent avoir lieu dans cette cellule. L'étude des enzymes est appelée enzymologie. Les enzymes permettent à des réactions de se produire des millions de fois plus vite qu'en leur absence. Un exemple extrême est l'orotidine-5'-phosphate décarboxylase, qui catalyse en quelques millisecondes une réaction qui prendrait, en son absence, plusieurs millions d'années3,4. Comme tous les catalyseurs, les enzymes ne sont pas modifiées au cours des réactions qu'elles catalysent, et ne modifient pas l'équilibre chimique entre substrats et produits. Les enzymes diffèrent en revanche de la plupart des autres types de catalyseurs par leur très grande spécificité. Cette spécificité découle de leur structure tridimensionnelle. De plus, l'activité d'une enzyme est modulée par diverses autres molécules : un inhibiteur enzymatique est une molécule qui ralentit l'activité d'une enzyme, tandis qu'un activateur de cette enzyme l'accélère ; de nombreux médicaments et poisons sont des inhibiteurs enzymatiques. Par ailleurs, l'activité d'une enzyme décroît rapidement en dehors de sa température et de son pH optimums. Extraction (chimie) Hydrolyse enzymatique Peptidases pH Protéines Température Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Chrome shavings are one of the major solid wastes generated during the leather making process. The presence of chromium in waste creates difficulty in disposing to landfill and incineration. Growing environmental concern about the toxicity and environmental impact of the chromium solid waste generated from the tannery has become key issue. In this work, a study has been made to extract protein from chrome shavings through a biochemical method. In this biochemical method the combination of chemical and enzyme processes have been employed to achieve the optimum extraction of protein. Optimization studies on enzyme and alkali concentration, time, pH and temperature on protein extraction were performed. Further, protein extraction by protease mixed with ?-amylase has also been investigated. It was found that there was significant change in the protein extraction by protease in the presence of ?-amylase. The protein extraction efficiency by conventional and biochemical method is found to be 60 and 80%, respectively. This study provides a biochemical method of hydrolysis for chrome shavings to protein and chromium. Note de contenu : - EXPERIMENTAL : Materials - Characterization of chrome shavings - Optimization of protease and ?-amylase - Optimization of nature of alkalis for extraction of protein - Amalgamation of protease and ?-amylase - Pilot study - Recovery and reuse studies - RESULTS AND DISCUSSION : Optimization of protease, ?-amylase dosage and temperature on protein extraction - Optimization of weight of chrome shavings on protein extraction - Optimization of pH - Optimization of nature of alkali and its dosage - Effect of amalgamation of protease and ?-amylase on protein extraction - Reuse of protein and chromium in leather - Control leathers vs experimental leathers (E1 and E2) : an appraisal bulk properties of the leathers En ligne : https://drive.google.com/file/d/1jpyjFKHh00GgKitphEi2gQp_A5_yJsnv/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=19446 [article]

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Development of formaldehyde-free leathers in perspective of retanning : Part 1. Benchmarking for the evolution of a single syntan system / Palanisamy Thanikaivelan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CII, N° 10 (10/2007)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CII, N° 10 (10/2007) . - p. 306-314 Titre : Development of formaldehyde-free leathers in perspective of retanning : Part 1. Benchmarking for the evolution of a single syntan system Type de document : texte imprimé Auteurs : Palanisamy Thanikaivelan, Auteur ; C. Ram Mohan, Auteur ; Subramani Saravanabhavan, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Balachandran Unni Nair, Auteur Année de publication : 2007 Article en page(s) : p. 306-314 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The awareness of health risks due to the use of leather products is escalating day by day. The demand for eco-labelled leather and leather products is increasing in the developed countries. Eco-labeling concepts force the tanners to look into various options for developing eco-benign products. Formaldehyde is classified as a probable human carcinogen. In this study, an attempt has been made to produce leather without formaldehyde by employing formaldehyde-free syntans. A relative measure of performance of formaldehyde-free and formaldehyde based syntans has been done to test their ability to produce leathers with desired properties by employing these syntans individually. Three formaldehyde-free syntans (resin, acrylic and protein) and two formaldehyde based syntans have been chosen for optimization trials. Trials have been carried out to find out the optimal amount of individual syntans required for providing sufficient properties to the leather. Based on organoleptic and strength properties as well as other property evaluation, it has been found that 12 and 8% formaldehyde based syntans A and B and 8, 10 and 12% formaldehyde-free resin, acrylic and protein syntans are capable of providing sufficient properties to the leather. There seems to be a considerable relation between the nature of the syntans and properties imparted to the leather. Aromatic syntans tend to decrease the strength and softness properties of leathers with increasing offer. Relation between the fullness of leathers and offer of syntans has been substantiated through scanning electron microscopy. The leathers treated with formaldehyde-free syntans do not contain free formaldehyde when analyzed using standard procedure and hence do not possess any health risks. En ligne : https://drive.google.com/file/d/15iClkdMNH44GxjWG196MOaLkn6-kQ0cG/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3324 [article]

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Enzymatic removal of melamin in enzyme based dehairing and fiber opening / Punitha Velmurugan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 7 (07/2008)  

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Integration of chrome tanning and wet finishing process for making garment leathers / Palanisamy Thanikaivelan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. C, N° 6 (06/2005)  

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A modified leather processing method for water and pollution reduction in tannery / Subramani Saravanabhavan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 1 (01/2008)  

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Natural dyeing of leathers using natural materials / Jonnalagadda Raghava Rao in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 3 (02/2008)  

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A new leather-making process for meeting eco-label standards : Processing of goatkins / Subramani Saravanabhavan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CI, N° 5 (05/2006)  

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Performance and eco-impact of reverse processed hair sheep gloving leather / Subramani Saravanabhavan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 9 (09/2008)  

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Single step hair removal and fiber opening process : Simultaneous and successive addition of protease and a-amyiase / Palanisamy Thanikaivelan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CI, N° 11 (11/2006)  

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Studies on the development of pickle-sess vegetable tanning / Subramani Saravanabhavan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 7 (07/2004)  

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