The complex ions in basic chromium sulphate solutions : a short note / Stanley G. Shuttleworth in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 68 (Année 1984)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 68 (Année 1984) . - p. 180 Titre : The complex ions in basic chromium sulphate solutions : a short note Type de document : texte imprimé Auteurs : Stanley G. Shuttleworth, Auteur Année de publication : 1984 Article en page(s) : p. 180 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Composés complexes Conductimétrie Ions complexes Liqueurs de tannage Solutions (chimie) Sulfate de chrome Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Conductimetric titrations of freshly boiled, concentrated, one-third basic chromium sulphate tanning liquors (S02 reduced dichromate), showed that the average or predominant complex was probably a dimer, in which two chromium atoms are linked in ring formation with two OH groups, and two sulphate groups are bidendately bound to this complex. It was suggested that both of these sulphates formed part of the ring structure, but Slabbert considers this to be unlikely due to the fact that bond angles would be strained. En ligne : https://drive.google.com/file/d/1Dsil0lFMc5wMY9eD1qWAr5OA1S85hU_l/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34154 [article]

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The effect of polymeric phosphate chain length on shrinkage temperature and vegetable tanning penetration / Elton L. Hurlow in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXXXI (Année 1986)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXXXI (Année 1986) . - p. 197 - 207 Titre : The effect of polymeric phosphate chain length on shrinkage temperature and vegetable tanning penetration Type de document : texte imprimé Auteurs : Elton L. Hurlow, Auteur ; David A. Boast, Auteur ; Stanley G. Shuttleworth, Auteur Année de publication : 1986 Article en page(s) : p. 197 - 207 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The use of linear polyphosphates as pretannages for promoting quick vegetal tanning penetration rates has proceeded without much consideration of the theoretical aspects of polyphosphate chain length mediation of penetration. Polyphosphates are available in a range of chain lengths and empirical evidence suggests those of between 5 and 15 phosphate units as most beneficial. Polyphosphates are known to increase shrinkage temperature and this is shown to occur with increasing chain length. Consideration of spatial dimensions together with experimental evidence allows a theory to be proposed accounting for polyphosphates in sufficient intermolecular crosslinking occurs to prevent acidic swelling of the fibres and a low degree of permeability results. With very large polyphosphates there is sufficient multipoint intermolecular binding to suppress swelling but the physical size of the bound polyphosphates block the access channels available for vegetable tanning penetration and hence result in slow rates of penetration. Medium chain length polyphosphates exhibit sufficient intermolecular crosslinking potential to inhibit swelling but are small enough to allow the quick passage of vegetable tanning into the interior of the hide. En ligne : https://drive.google.com/file/d/1EMmoHcRj2-S4c-sQuBagQTZORnXXoFcM/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9173 [article]

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The relationship between conductivity and dissolved solids in tannery wastewater / R. A Rowswell in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. N° 71 (Année 1987)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. N° 71 (Année 1987) . - p. 111-114 Titre : The relationship between conductivity and dissolved solids in tannery wastewater Type de document : texte imprimé Auteurs : R. A Rowswell, Auteur ; Stanley G. Shuttleworth, Auteur ; Desmond R. Cooper, Auteur Année de publication : 1987 Article en page(s) : p. 111-114 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : A study has been made of the relationship between conductivity and total dissolved solids, since the former is often used to monitor tannery wastewater because of its convenience. The results presented show that caution must be exercised in converting the one to the other by a standard factor because of the different types of salts present and their proportions. En ligne : https://drive.google.com/file/d/1iStznZUxFJydsamdi7JcZ2Z763w2B-Tq/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9163 [article]

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The use of ambient temperatures in the liritan sole leather system / David A. Boast in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXXXII (Année 1987)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXXXII (Année 1987) . - p. 242-252 Titre : The use of ambient temperatures in the liritan sole leather system Type de document : texte imprimé Auteurs : David A. Boast, Auteur ; Stanley G. Shuttleworth, Auteur ; Desmond R. Cooper, Auteur Année de publication : 1987 Article en page(s) : p. 242-252 Note générale : Bibliogr. Langues : Américain (ame) Résumé : Pilot plant studies have been carried out on the use of the LIRITAN "Flip Flop" sole leather system with mimosa extract at ambient temperatures. The temperature of the small experimental tanks (circular pits) made from plastic was controlled solely by climatic conditions over the 26 week period of assessment, with the ambient temperature varying mainly in the region of 16° to 27°C in the summer months of this experiment. The variation of temperature in the circulation tanks was much less than this as these were insulated. In the case of commercial production in large pits there would be more of a heat-sink and the temperature variations would be less severe. This work was done to try to produce acceptable leather in tanneries which lack adequate heating facilities for a warm circulator system, thus extending the area of use of the LIRITAN system and cutting costs. One of the advantages of a warm circulator system is that the sludge formation is reduced. In this trial the accumulation of sludge at the lower temperatures has been overcome by the use of a dispersing sytan (PELLUTAX 64 – HENKEL). Using the established warm (35°C) circulator LIRITAN system, 8 days was found to be sufficient for a satisfactory degree of tannage, using a tan liquor of 118° Barkometer (15.5° Baumé). In this trial the tannage time has been extended to two weeks with the tan strength maintained at 118° Barkometer, in order to obtain the same degree of tannage as the 8 day warm circulator system. As a mean of comparison, each piece of leather was halved after the initial 2 weeks ambient temperature tannage. One half was processed directly after the ambient tannage and the other half was given an additional tannage by hot pitting at 40°C and 140° Barkometer (18° Baumé) for 4 days. The results indicate that satisfactory sole leather can be produced in a two week ambient tannage, but that the addition of a 4 day hot pit system improved the degree of tannage, increased the density and reduced the water absorption. Whether the additional advantages conferred by the hot pitting is worth the extra effort, time, cost and installation of a limited heating system would have to be determined by each individual tanner. En ligne : https://drive.google.com/file/d/1Wx9Uq4kw6kkINlYyqFGB_GLOw0-2PQbH/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9036 [article]

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Vegetable tan wastage in typical sole leather processes / Stanley G. Shuttleworth in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXXIII (Année 1978)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXXIII (Année 1978) . - p. 508-514 Titre : Vegetable tan wastage in typical sole leather processes Type de document : texte imprimé Auteurs : Stanley G. Shuttleworth, Auteur ; Neville P. Slabbert, Auteur ; David A. Boast, Auteur ; Thomas Eberle, Auteur Année de publication : 1978 Article en page(s) : p. 508-514 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux Gaspillage -- Lutte contre Prétannage Semelles Tanins végétaux Tannage végétal Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : In view of the high oxygen demand and resistance to biodegradation of vegetable tannins, tightening effluent standards require processes which minimize vegetable tan wastage in sole leather production. A study is made of typical modem processes, including bleach and wash liquors, in order to ascertain optimum methods of minimizing vegetable tannins in the effluent. It is concluded that the Liritan process can give 95 percent tan utilization if the color vat operates alternately as a tempering vat to eliminate bleach and wash liquors. Next in order of economy is a weak liquor suspender system followed by a powder drum tannage. Unacceptably high tan wastage appears to occur in an all-drum tannage with syntan pretannage or an all-pit counter current process. Note de contenu : - Water gain in vegetable tanning - Comparison of various processes : Countercurrent all-pit processes - The all-drum process - Weak suspender plus drum processes - The liritan process - Finishing processes - General notes on the economics of pretanning systems - General conclusions En ligne : https://drive.google.com/file/d/1OvEhTMdCvY_0HYNsY3bRzgkTUxlxE47n/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41164 [article]

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