Approach towards zero discharge tanning : exploration of NaOH based opening up method / Palanisamy Thanikaivelan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVI, N° 6 (06/2001)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCVI, N° 6 (06/2001) . - p. 222-233 Titre : Approach towards zero discharge tanning : exploration of NaOH based opening up method Type de document : texte imprimé Auteurs : Palanisamy Thanikaivelan, Auteur ; T. Ramasami, Auteur ; Balachandran Unni Nair, Auteur ; Jonnalagadda Raghava Rao, Auteur Année de publication : 2001 Article en page(s) : p. 222-233 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Beam house processes are known to contribute 60-70% of the total pollution load in leather processing. The chemicals, namely sodium sulphide and lime, were not quantified and employed without proper rationale. Lime has a potential to drive swelling in a gradual manner due to its low solubility but lacks in environmental concern. Huge amounts of lime sludge and total solids formation are the main drawbacks of lime. In an earlier attempt, lime has been totally avoided for dehairing purpose. However, lime has been indispensable for the purpose of opening up of fibre bundles. Sodium hydroxide for this purpose was thought to be an improper choice due to its high alkaline nature. In this investigation an optimum concentration (1.0% offer at 350% float) of sodium hydroxide has been established for optimal opening up of fibre bundles. This has been substantiated through scanning electron microscopic, spent alkali liquor and pelt analysis, softness measurements and stratigraphic chrome distribution analysis. Performance of the leathers is shown to be on par with conventionally treated leathers through physical and hand evaluation. Especially softness of the leathers is numerically proven to be comparable with that of control. The process also enjoys elimination of deliming process coupled with a 45% reduction in total solids load on environment. En ligne : https://drive.google.com/file/d/1FMDazk_Ue4XcI_64aCdPZPIZDhE5qDlW/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4374 [article]

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Approaches toward elucidating the mechanism of tanning using an organo-zirconium complex / Kalarical Janardhanan Sreeram in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCV, N° 10 (12/2000)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCV, N° 10 (12/2000) . - p. 359-367 Titre : Approaches toward elucidating the mechanism of tanning using an organo-zirconium complex Type de document : texte imprimé Auteurs : Kalarical Janardhanan Sreeram, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Balachandran Unni Nair, Auteur ; T. Ramasami, Auteur Année de publication : 2000 Article en page(s) : p. 359-367 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The use of chromium(III) salts in tanning is under review by the global leather industry. The currently employed tanning methods lead to considerable waste of the chromium(III) salts used. An alternative mineral tanning salt based on zirconium named as Organozir has been developed. Mechanistic insight into tanning with Organozir has been gained through indirect studies. A case for invoking multi-point fixation of Organozir and the possible implications of both electrovalent and hydrogen bonding forces has been made. En ligne : https://drive.google.com/file/d/1iHDzZB20icFmxxpN4Oc56WxXNw8FGTXa/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4403 [article]

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Beamhouse and tanning operations : process chemistry revisited / T. Ramasami in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 83, N° 1 (01-02/1999)

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 83, N° 1 (01-02/1999) . - p. 39-45 Titre : Beamhouse and tanning operations : process chemistry revisited Type de document : texte imprimé Auteurs : T. Ramasami, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Chandra Babu Narasimhan Kannan, Auteur ; K. Parthasarathi, Auteur ; P. G. Rao, Auteur ; P. Saravanan, Auteur ; R. Gayathri, Auteur ; Kalarical Janardhanan Sreeram, Auteur Année de publication : 1999 Article en page(s) : p. 39-45 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Leather processing technologies are under critical review in recent times. Traditional methods in leather processing have involved the use of large amounts of water and chemical inputs. The general practice in tanneries has involved the use of nearly 35-40 litres of water per kilogram of leather processed. Processes have not been audited for utilisation of chemical inputs. In some cases, the utilisation levels of chemicals employed fall in the ranges of 40-75 % . Such non-optimum use of chemical and water input has led to problems in both cost effectiveness due to material loss and pollution from unused chemicals. It has become essential that the beamhouse and tanning processes are audited for their environmental loads. Whereas there is sufficient awareness in leather processing industries regarding the costs of compliance with national environmental regulatory norms, the potential benefits of cleaner production technologies with respect to cost saving are not fully understood. Further, with increasing inventory costs, audit of beamhouse and tanning processes is becoming crucial. Process time in leather making operations is influenced by several physico-chemical parameters. One of the major factors influencing process time of beamhouse and tanning operations in leather processing is the duration needed for diffusion of materials. A re-visit to the chemistry of beamhouse and tanning operations at this critical juncture is worthwhile. An attempt has been made in this work to critically review the process chemistry and discuss possible improvement options. Some case studies are presented in this work where reduction of BOD and COD levels by 30-40 %, Total Dissolved Solids by 25-35 %, sulphide by 50-60 % and chromium by 98-99 % has been achieved under real field conditions through improved beamhouse and tanning operations. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=7856 [article]

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Depilation of skins by pure enzymes / S. Priya in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 92, N° 5 (09-10/2008)

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 92, N° 5 (09-10/2008) . - p. 214-221 Titre : Depilation of skins by pure enzymes Type de document : texte imprimé Auteurs : S. Priya, Auteur ; A. Rajaram, Auteur ; R. Rajaram, Auteur ; T. Ramasami, Auteur Année de publication : 2008 Article en page(s) : p. 214-221 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux Epilage enzymatique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Five pure enzymes (pepsin, trypsin, chymotrypsin, elastase and papain) were used indepilation of goatskins in order to find alternatives to current methods (involving lime and sulphide). The morphologies of depilated skins and hair roots were investigated by both optical microscopy and scanning electron microscopy. There were differences in morphology depending on the possible region of attack of these enzymes at the hair root. Trypsin and elastase were very effective in unhairing with the latter having a generally extensive effect whilepapain was less so. Pepsin and chymotrypsin were ineffective. The capacity of the enzymes for depilation has also been analyzed in terms of the availability of suitable sites for each of them for cleavage of the various proteins at the hair root and their propensity to cleave has been analyzed through the proteomics tools of the Swiss-Prot program. The results have indicated that theoretical predictions can be correlated to the experimental observations on the depilation of the skin. Note de contenu : - MATERIALS AND METHODS : 1) Treatment of skins with proteolytic enzymes - 2) Histology - 3) Scanning Electron Microscopy of depilated skins and hair roots - 4) Analysis of number of cleavage sites in the proteins based on specificity of enzyme action - RESULTS : 1) Histological assessment of the depilation process - 2) SEM investigations of the structure of the enzyme treated skin - 3) SEM investigations of the structure of the hair root from enzyme treated skin - 4) Analysis of the number of cleavage sites in proteins and propensity for cleavage - Fig. 1 : Histology of skins. Optical micrographs of sections of skin depilated b different enzymes and after scudding - fixed with formalin. Sections were stained with haematoxylin and eosin. - Fig. 2 : Scanning Electron Micrographs (SEM) of skin surfaces depilated by enzymes - Fig. 3 : SEMs of hair roots skin subjected to different enzyme treatments shown at both low and high magnification - Table 1 : Cleavage sites available for proteolytic enzymes on proteins of the epidermis, hair and dermis - Table 2 : Efficacy of enzymes trypsin and chymotrypsin in cleaving the proteins present in the epidermis, hair and dermis Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35254 [article]

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Direct chrome liquor recycling under indian conditions : Part 1. Role of chromium species on the quality of the leather / Kalarical Janardhanan Sreeram in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. C, N° 6 (06/2005)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. C, N° 6 (06/2005) . - p. 233-242 Titre : Direct chrome liquor recycling under indian conditions : Part 1. Role of chromium species on the quality of the leather Type de document : texte imprimé Auteurs : Kalarical Janardhanan Sreeram, Auteur ; T. Ramasami, Auteur ; Balachandran Unni Nair, Auteur ; Chandra Babu Narasimhan Kannan, Auteur ; Jonnalagadda Raghava Rao, Auteur ; R. Ramesh, Auteur Année de publication : 2005 Article en page(s) : p. 233-242 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The direct recycling of chrome liquor in pickle or tanning bath is gaining importance in the management of chromium and total dissolved solids in tanneries. Earlier studies indicate that the pre-acidification of the chrome liquor avoids surface fixation of chromium, thereby resulting in quality leathers. This assumes significance as it alters the charge and species-wise composition of the chrome liquor. In this study, the influence of pre-acidification pH on the nature of chromium (III) species and the resulting affect on the quality of leathers has been investigated The results obtained in this study indicate that a pre-acidification of spent chrome liquor to a pH of 1.0 results in the formation of larger percentage of lower charged species, thereby avoiding the surface fixation of chromium. The organoleptic properties, chromium distribution, and SEM analysis of the leathers processed using direct recycling methodology after pre-acidification of the spent chrome liquor to pH 1.0 indicates that the quality of leathers is not impaired. There is no significant influence of the pre-acidification pH on the pollution load. En ligne : https://drive.google.com/file/d/1J-Rnt9HMf407aWjtQ-HKnQqeRA73qMDH/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4063 [article]

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High exhaust chrome-aluminium combination tanning : Part 1. Optimization of tanning / Kalarical Janardhanan Sreeram in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CI, N° 3 (03/2006)  

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Hydration in matrix stabilization of collagen fibres : relevance to mechanistic insight into tanning / Balaraman Madhan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 7 (07/2003)  

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Isolation and characterization of a low affinity chromium(III) complex in chrome tanning solutions / Jonnalagadda Raghava Rao in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 81, N° 6 (11-12/1997)  

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A new insight into the shrinkage phenomenon of hides and skins / N. N. Fathima in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVI, N° 11 (11/2001)  

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Physico-chemical and structural studies on leathers tanned using high exhaust basic chromium sulphate salt / Jonnalagadda Raghava Rao in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIII, N° 5 (07/1998)

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Role of phenolics in the stabilization of collagen / Balaraman Madhan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 4 (04/2004)  

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A semi-empirical quantum mechanical modeling study on the interaction of collagen-like peptides with polyphenolic molecules : An attempt to gain insights into vegetable tanning / Balaraman Madhan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 7 (07/2003)  

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Stepping into third millennium : Third generation leather processing : A three step tanning technique / Palanisamy Thanikaivelan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 5 (05/2003)  

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Studies on the stabilization of collagen using dialdehyde starch : Part I. Effect of autoclaving on dialdehyde starch / Swarna Vinodh Kanth in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CI, N° 12 (12/2006)  

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Two stage tanning - A new approach for chrome management / Chellappa Muralidharan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVI, N° 2 (02/2001)  

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Underlying principles in chrome tanning : Part 2. Underpinning mechanism in pickle-less tanning / Palanisamy Thanikaivelan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 2 (02/2004)  

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