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JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) . Vol. XCIX, N° 5Mention de date : 05/2004Paru le : 15/05/2004 |
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Ajouter le résultat dans votre panierEquilibrium and kinetics of vegetable tanning process / Xuepin Liao in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 5 (05/2004)
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Titre : Equilibrium and kinetics of vegetable tanning process Type de document : texte imprimé Auteurs : Xuepin Liao, Auteur ; Xiao Du, Auteur ; Wei Tang, Auteur ; Bi Shi, Auteur Année de publication : 2004 Article en page(s) : p. 191-196 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cinétique chimique
Tannage végétalIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Vegetable tanning is an adsorption process of tannins onto hide collagen. Its equilibrium and kinetics were investigated in detail by using hide powder, cattle hide and sheepskin. The experiments indicated that the Freundlich model could be used to describe the adsorption equilibrium of tannins onto hide powder, and a pseudo-second-order rate model could be used to describe adsorption kinetics with an error of less than 6%. The adsorption capacities calculated by the adsorption rate model were close to that of actual measurements. The adsorption heat, within 8-50 kJ/mol, confirmed that the adsorption mechanism of tannins onto hide powder is hydrogen bond adsorption. Further studies indicated that the Freundlich model and pseudo-second-order rate model can also be used to describe the practical vegetable tanning process. The equilibrium adsorption capacities of tannins onto cattle hide and sheepskin calculated by the pseudo-second-order rate model were consistent with the actual measurements with an errors of less than 5%. It can be concluded that pseudo-second-order rate model can be used to predict the adsorption capacity of tannins in the vegetable tanning process. En ligne : https://drive.google.com/file/d/1LAODRGZCYrB6sJmDYIfgDMdbdQXXEAiM/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4192
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCIX, N° 5 (05/2004) . - p. 191-196[article]Réservation
Réserver ce documentBioaccumulation route for secured recovery and recoup of chromium from tannery wastewaters / Rathinam Aravindhan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 5 (05/2004)
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Titre : Bioaccumulation route for secured recovery and recoup of chromium from tannery wastewaters Type de document : texte imprimé Auteurs : Rathinam Aravindhan, Auteur ; Balachandran Unni Nair, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Balaraman Madhan, Auteur Année de publication : 2004 Article en page(s) : p. 197-204 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Increasing concern regarding the toxicity and environmental impact of the chromium metal ion discharge from the tannery has led to investigations into alternative effluent treatment technologies. The use of biological materials for heavy metal ion removal and recovery technologies has gained widespread acceptability during recent years because of its high performance at low cost compared to other treatment methodologies. In this work a species of brown seaweed is shown to accumulate chromium from tannery wastewaters. Bioaccumulation provides a cheaper means for the removal of heavy metals; however, the reuse of recovered metal is a challenging problem. The chromium-loaded seaweed was advantageously used as a reductant for the manufacture of basic chromium sulfate. The developed product has been employed for tanning of goatskins. Studies reveal that the quality of the wet blue leathers is on a par with the leathers tanned with commercial BCS. Shrinkage temperature of the leathers is comparable and is above 110 °C at an offer of 1.25% Cr2O3. Chromium exhaustion is about 74%. Performance of the crust leathers is comparable to that of conventional tanned leathers. This methodology provides a holistic approach for the recovery and reuse of chromium from tannery wastewaters. En ligne : https://drive.google.com/file/d/1NV60UnTMQv2VtNRP6uAxvoHuLfCyALv4/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4193
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCIX, N° 5 (05/2004) . - p. 197-204[article]Réservation
Réserver ce documentEffects of drying methods on chrome-tanned leather / Cheng-Kung Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 5 (05/2004)
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Titre : Effects of drying methods on chrome-tanned leather Type de document : texte imprimé Auteurs : Cheng-Kung Liu, Auteur ; Joseph Lee, Auteur ; Nicholas P. Latona, Auteur Année de publication : 2004 Article en page(s) : p. 205-210 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The drying operation is a critical leather-making step to attain the required physical properties for leather products. There are various drying methods currently being used today in leather manufacturing. To make qualityleather, it is imperative to understand the effects of different drying methods on the physical characteristics of leather. Results from our comparison study showed that the method applied in a drying operation significantly affects the physical properties of leather, particularly area retention and compliance. Observations indicated that toggle drying produces higher area yield, but may result in stiffer leather. One of the important findings from this study is that there is a direct link between grain break and stiffness of leather. Data indicated that stiffer leather often results in poor break. Our research again showed that residual water content is a key factor for softness. Vacuum drying without toggling yields better toughness and softness, but does not significantly improve area yield. We also presented a dimensionless quantity "toughness index" that showed a strong correlation with the resultant area retention and stiffness of leather. Toughness index is independent of the geometry of the leather samples. Therefore, even without knowing the thickness or shape of the samples, one can still make an effective comparison of properties. En ligne : https://drive.google.com/file/d/1EEJP60KggcBGB4Srvs8_i1uxHMx7C8pZ/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4194
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCIX, N° 5 (05/2004) . - p. 205-210[article]Réservation
Réserver ce documentDiffusion and thermodynamic behavior of insect repellant and suntan lotion in automotive leather coatings / Loyd J. Burcham in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 5 (05/2004)
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Titre : Diffusion and thermodynamic behavior of insect repellant and suntan lotion in automotive leather coatings Type de document : texte imprimé Auteurs : Loyd J. Burcham, Auteur ; Hans Krose, Auteur Année de publication : 2004 Article en page(s) : p. 211-219 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The diffusion and thermodynamics of insect repellant and suntan lotion absorption into a series of polyurethane and polyacrylic resins used in leather finishing are examined. Physical testing of these resins applied as crosslinked and uncrosslinked thin-films on leather show that DEET exposure causes drastic reduction in Veslic dry rub fastness (greatly improved with a "desorption period" prior to testing). Reductions in rub fastness of samples exposed to suntan lotion were somewhat less severe than with DEET and were greatly improved by crosslinking, but severe yellowing observed during aging indicates continued degradation by non-volatile penetrants. Effective diffusion coefficients (De) and saturation weight uptake levels at equilibrium (Msat) were calculated from free-film gravimetric sorption experiments. These results indicate very high saturation levels (1000-4000 wt % for DEET absorption, ~200 wt % for suntan absorption) and even total dissolution of uncrosslinked polycaprolactone/polyester-based urethanes in DEET. Interestingly, Deep Woods OFF® (25 % DEET in an ethanol/hydrocarbon-based propellant) had identical saturation values as DEET, but with significantly higher diffusion rates - indicating diffusion promotion by highly volatile propellant solvents that do not remain absorbed in the polymer. More fundamentally, both the diffusion and saturation parameters were found to vary with the glass transition temperature, Tg, where higher Tg polymers exhibit lower diffusivity but higher equilibrium saturation levels. Calculations of sorption levels in thin-films on leather (using De values from free-film experiments) also reveal that surface wear properties degrade long before total saturation is achieved. En ligne : https://drive.google.com/file/d/10uImOEBv5_MMX7akJ1iR8pMxQymJPJxN/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4195
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