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Auteur Robert J. Harvey |
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Assessment of vegetable tannin extracts by colorimetry / Timothy D. Stilwell in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVI, N° 6 (06/2001)
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Titre : Assessment of vegetable tannin extracts by colorimetry Type de document : texte imprimé Auteurs : Timothy D. Stilwell, Auteur ; Bruce W. Buehrig, Auteur ; Robert J. Harvey, Auteur ; L. Shepley Hermann, Auteur ; Jean J. Tancous, Auteur Année de publication : 2001 Article en page(s) : p. 192-204 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Spray-dried, untreated wattle and treated quebracho extracts were tested for color by four laboratories equipped with Lovibond Tintometers. A comparison of color readings was conducted at the U.S.H.S.L.A. Laboratory where more reasonably priced meters, a Jenway Colorimeter and a Milton-Roy Spectrophotometer, were used. Time for testing was shortened considerably because preliminary tannin analyses were not done and the meters were simpler to operate. Samples of extracts were weighed, dissolved in distilled water, heated to 82oC, cooled and read immediately. A ratio, constructed by dividing yellow readings by red readings, was found to be a valuable method for understanding factors that influence color such as pH and addition of reagents. En ligne : https://drive.google.com/file/d/149LW5NP9yrPYRBQMilRHVQ4FIsZpsm8H/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4371
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCVI, N° 6 (06/2001) . - p. 192-204[article]Réservation
Réserver ce documentEvaluation of modifications to the alca standard method for tannin analysis in tannery liquors / Robert J. Harvey in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 4 (04/2003)
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Titre : Evaluation of modifications to the alca standard method for tannin analysis in tannery liquors Type de document : texte imprimé Auteurs : Robert J. Harvey, Auteur ; Bruce W. Buehrig, Auteur ; Timothy D. Stilwell, Auteur ; L. Shepley Hermann, Auteur Année de publication : 2003 Article en page(s) : p. 147-152 Note générale : Biliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The American Leather Chemists Association (ALCA) Standard Method for tannin analysis was developed to provide tanners with a way to monitor the relative strength of tan liquors in their process. Although it took full advantage of existing technology in the early 1900's, that method is very restrictive, laborious and time consuming. Advances in filtering technology allow modern researchers to process materials much more efficiently than in the past. Several filtration methodologies were incorporated into existing ALCA methods, and modifications were evaluated for time efficiency, effectiveness, and comparability to the Standard Methods. Direct determination of solids on undiluted tan liquor was evaluated against the Standard Method procedures. En ligne : https://drive.google.com/file/d/1cvdwHw345S9jYb8pXl0tTH9-JDzA_-Vb/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4117
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCVIII, N° 4 (04/2003) . - p. 147-152[article]Réservation
Réserver ce documentPurification of collagenous tissue of the epidermal area during beamhouse processing / Jean J. Tancous in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIV, N° 1 (01/1999)
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Titre : Purification of collagenous tissue of the epidermal area during beamhouse processing Type de document : texte imprimé Auteurs : Jean J. Tancous, Auteur ; Robert J. Harvey, Auteur ; Bruce W. Buehrig, Auteur Année de publication : 1999 Article en page(s) : p. 20-32 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Purification of collagenous tissue of the epidermal area during beamhouse processing has been studied by using a fractionation technique. The epidermal area to the base of the hair pockets was isolated and separated into a residue fraction, a coagulable protein fraction , and a gelatin fraction. The gelatin fraction represented collagenous tissue. Collagenous tissue of the epidermal area of bated stock supplied by thirteen different tanneries varied from 78.6 to 91.3%. Collagenous tissue of the epidermal area of unbated, delimed stock, processed at a tannery, was 83.7%, it was purified by bating, in the laboratory, to 88.4% with a 1-hour bate and to 91.3% with a 3-hour bate. Collagenous tissue of the epidermal area of unbated, delimed stock, processed at another tannery, was 87.9%, it was purified by bating at this tannery to 90.5%. A wash after bate did not improve purification but pickling (or acidification) gave futher purification over bating. Note de contenu : - TANNERY SAMPLES
- U.S.H.S.L.A LABORATORY PROCEDURES: Preparation of two, two-inch squares samples - Preparation of epidermal-area samples - Fractionation of samples - Residue fraction - Gelatin fraction - Coagulable protein fraction - Method of processing laboratory control samples - Laboratory bating studies
- RESULTS AND DISCUSSION: Comparison of two-inch squares samples with epidermal area samples - Comparison of laboratory processing and tannery processing - Laboratory bating of tannery-processed, steerhide samples - Vegetable-tanned leather processing - Chrome-tanned leather processing - Improvement of purification of epidermal area by bating over deliming - Effect of washing after bating on purification - Effect of pickling after bating on purification - Effect of lowering pH after bating on purification - Appearance of residue - Coagulable protein fractionEn ligne : https://drive.google.com/file/d/1YCs6WUep2BxEhb4KzAau9IEq2U0o6vK0/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4492
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCIV, N° 1 (01/1999) . - p. 20-32[article]Réservation
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