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Mapping tear, strength and collagen fibril orientation in bovine, ovine and cervine hides and skins / S. J. Kelly in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 1 (01/2018)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIII, N° 1 (01/2018) . - p. 1-11 Titre : Mapping tear, strength and collagen fibril orientation in bovine, ovine and cervine hides and skins Type de document : texte imprimé Auteurs : S. J. Kelly, Auteur ; Richard L. Edmonds, Auteur ; Sue M. Cooper, Auteur ; Katie H. Sizeland, Auteur ; Hannah C. Wells, Auteur ; T. Ryan, Auteur ; Nigel Kirby, Auteur ; A. Hawley, Auteur ; S. T. Mudie, Auteur ; Richard G. Haverkamp, Auteur Année de publication : 2018 Article en page(s) : p. 1-11 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux -- Analyse Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux de bovins Cuirs et peaux de cervidés Cuirs et peaux de moutons Diffusion aux petits angles Distribution et orientation des fibres Fibrilles de collagène La fibrille de collagène est une structure constituée d'un assemblage de fibres de tropocollagène (assemblage de 3 protéines de collagène alpha (alpha 1 - alpha 1 - alpha 2) en une hélice droite. Résistance à la déchirure Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Leather is a natural and variable material. The variation in strength has previously been shown to be due in part to the collagen fibril orientation. However, the extent of variation in strength and orientation over a skin/hide is not well established. Synchrotron small angle X-ray scattering is used to measure collagen fibril orientation (O) and orientation index (OI). Tear strength is measured in two orthogonal directions across ovine and cervine skins and bovine hides. Average normalized strengths varied between species with cervine leathers having the greatest overall strength followed by bovine then ovine leathers. Ovine had the greatest variability in strength across the skin. There were no obvious regions of generally stronger or weaker skin within individual skins or hides. The predominant collagen fibril direction was perpendicular to the backbone of all species, with the greatest perpendicular alignment in ovine followed by cervine. Collagen fibril orientation in leathers made from of ovine, bovine and cervine skins have been analyzed quantitatively and in detail. Findings suggest an unpredictable variability in collagen arrangements within each species but a notable difference in strength between species. Note de contenu : - METHODS : Leathers - Test samples - Tear strength - Small angle X-ray scattering (SAXS) - Orientation and orientation index - Samples - RESULTS : Tear strength - SAXS measurements - Variation of O in the OSP grid square sample - Orientation index - Orientation - Correlation between O and tear strength - Difference between belly and back En ligne : https://drive.google.com/file/d/18J4tLzzVaEGSbu3Mx6EnI4zz0Ct7Kl_y/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=29744 [article]

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Preservation of bovine hide using less salt with low concentration of antiseptic, Part I : effectiveness of developed formulations / Majher I. Sarker in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 1 (01/2018)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIII, N° 1 (01/2018) . - p. 12-18 Titre : Preservation of bovine hide using less salt with low concentration of antiseptic, Part I : effectiveness of developed formulations Type de document : texte imprimé Auteurs : Majher I. Sarker, Auteur ; Wilbert Long, Auteur ; Cheng-Kung Liu, Auteur Année de publication : 2018 Article en page(s) : p. 12-18 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Bactéries -- Comptage Chlorure de sodium -- Suppression ou remplacement Cuirs et peaux -- Analyse Cuirs et peaux -- Conservation Cuirs et peaux de bovins Cytométrie de flux Formulation (Génie chimique) Hydratation Microscopie Peaux brutes -- Détérioration Tests d'efficacité Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Bovine raw hides are commercially cured either with high salt concentration of about half the weight of actual hide or 95% saturated brine solution. This conventional technique is very popular due to the availability of common salt (sodium chloride) and its cost-effective procedure but it generates a huge pollution problem increasing salinity. As a result, an alternative method of using less or no salt for hide preservation needs to be developed. For the preservation of hide it is essential to arrest microbial attack on hide as the main constituent of raw hide is protein which is very susceptible for bacterial degradation. Such bacterial degradation leads to the putrefaction of raw hide before converting them into leather. Agricultural Research Services scientists at Wyndmoor, Pennsylvania, have developed antiseptic based formulations for hide curing where only 45% saturated brine solution is used. The newly developed formulations have been found more effective in limiting microbial growth for a longer time on cured skin than the regular brine process and thus preserve hides for more than 30 days. In-process analysis of cured hides during storage period reveals the compatibility of the alternative curing process in comparison to the traditional method. Therefore, this new development will not only preserve hide through better protection from microorganisms but also offers improved conservation of the environment. Note de contenu : - EXPERIMENTAL : Materials - Protocol for the alternative hide preservation - Efficiency analysis of the developed formulations in limiting microbial growth - Determination of water activity and moisture content - Determination of bacterial count - Texture analysis of the cured hides - Scanning electron microscope studies (SEM) - Rehydration of cured hides - Hide degradation analysis - RESULTS AND DISCUSSION : Efficacy tests for the developed formulations - Bacterial count in cured hides - Texture analysis - Microscopie analysis of cured hides - Rehydration studies - Physical changes of the cured hides En ligne : https://drive.google.com/file/d/1j7WnpJKjBtDWbWzwGFVUqSFb3S3d1HVN/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=29747 [article]

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A cleaner deliming process using sodium gluconate for reduction in nitrogen pollution in leather manufacture / Yunhang Zeng in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 1 (01/2018)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIII, N° 1 (01/2018) . - p. 19-25 Titre : A cleaner deliming process using sodium gluconate for reduction in nitrogen pollution in leather manufacture Type de document : texte imprimé Auteurs : Yunhang Zeng, Auteur ; Ya-Nan Wang, Auteur ; Ying Song, Auteur ; Jianfei Zhou, Auteur ; Bi Shi, Auteur Année de publication : 2018 Article en page(s) : p. 19-25 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux Cuirs et peaux -- Analyse Décapage Gluconate de sodium Le gluconate de sodium est un composé organique de formule brute Na1C6H11O7. C'est un sel sodique de l'acide gluconique. Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Ammonium salts used in deliming process are the main source of high ammonia nitrogen (NH3-N) concentration in tannery wastewater. To reduce nitrogen pollution in leather manufacture without sacrificing quality of resultant leathers, a cleaner deliming agent prepared by mixing sodium gluconate (60 wt.%), citric acid (15 wt.%) and ammonium sulfate (25 wt.%) together was employed for deliming limed cattle hide pelt. The results indicated that this cleaner deliming agent penetrated the whole pelt very quickly and successfully formed a buffer system of pH 8-9 with the alkali from liming, which prevented acid swelling and damage to the fiber network of pelt. The delimed pelt had a cleaner grain surface with a higher extent of calcium removal than the conventional ammonium delimed pelt. The concentrations of NH3-N and total nitrogen (TN) in the cleaner deliming effluent were dramatically reduced by 86% and 79%, respectively. Moreover, the cleaner deliming scarcely affected subsequent bating process with trypsin. Note de contenu : - EXPERIMENTAL : Materials - Experimental and control deliming and bating processes - Analyses of penetration of deliming agents - Determination of deliming float pH - Determination of concentration of hydroxyproline (Hyp) in deliming effluent - SEM and EDS analyses of delimed pelt - Determination of concentrations of NH3-N, TN, TOC, COD and BOD5 in deliming effluent - Determination of concentrations of protein and Hyp in bating effluent - Observation of mass transfer of trypsin in bated pelt - RESULTS AND DISCUSSION : Penetration and pH buffering capacity of deliming agent - Extent of calcium removal from pelt - Effect of deliming on bating - Environmental benefits En ligne : https://drive.google.com/file/d/15pYiNAZ3f0fxj-aCNZveRUGAmKAQ-gNM/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=29748 [article]

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Improvement in tanning properties of natural leather through surface modification assisted by CO2 low-temperature plasma / Fangming Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 1 (01/2018)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIII, N° 1 (01/2018) . - p. 26-33 Titre : Improvement in tanning properties of natural leather through surface modification assisted by CO2 low-temperature plasma Type de document : texte imprimé Auteurs : Fangming Liu, Auteur ; Yuanping Jiang, Auteur ; Wenlan Xu, Auteur ; Zhengjun Li, Auteur ; Li Lixin, Auteur Année de publication : 2018 Article en page(s) : p. 26-33 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Chrome trivalent -- Absorption Cuirs et peaux Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux -- Propriétés organoleptiques Stabilité hydrothermale Tannage au chrome Technique des plasmas Traîtements de surface Wet-blue (tannage) Peau tannée au chrome (le chrome donne une couleur bleue) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Low temperature plasma (LTP) technology is a green, solvent-free, clean, efficient environment-friendly surface treatment technology. The pioneering works were carried out by applying LTP to surface modification of natural leather in order to improve the chrome tanning exhaustion rate. The effects of different treatment time on tanning exhaustion rate, micro-structure, chemical compositions, mechanical and organoleptic properties of leather were studied. The optimal CO2 plasma treatment time is about 10 min, at which the chrome tanning exhaustion rate increases from 78.49% to 91.82% compared with untreated leather. The SEM results show that some micro-pores, fissures, deep ravines and filamentous fibers can be observed due to the surface etching effect. From the XPS analysis, compared with the untreated leather, the O1s concentration and the O1s/C1s ratio of the 10min LTP modified leather both increase from 18.75% to 28.85% and from 0.258 to 0.479, respectively. The results show that appropriate LTP process can effectively improve the chrome tanning exhaustion rate, which reduces the emission of heavy metal chromium in waste liquor and also has a good synergistic effect on improving the comprehensive performance of leather such as hydrothermal stability, physical-mechanical and organoleptic properties. The LTP modification technology may be a new potential method for cleaner high-exhaustion chrome tanning technology. Note de contenu : - EXPERIMENTAL : Materials - LTP treatment - Chrome tanning - Characterization and performance test - Mechanical properties test - Organoleptic properties test - RESULTS AND DISCUSSION : The effect of LTP treatment on chrome tanning absorption rate and the hydrothermal stability of wet blue - Surface morphology observation of leather - XPS analysis - The mechanism of applying LTP technology to tanning process - Mechanical property - Organoleptic property En ligne : https://drive.google.com/file/d/1EM7noWdiA1YqRbHNmjib-7EZiGTBA5kg/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=29749 [article]

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