Dépouillements

Chemistry of syntans and their influence on leather quality / Jochen Ammenn in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 11 (11/2015)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CX, N° 11 (11/2015) . - p. 349-354 Titre : Chemistry of syntans and their influence on leather quality Type de document : texte imprimé Auteurs : Jochen Ammenn, Auteur ; C. Huebsch, Auteur ; E. Schilling, Auteur ; B. Dannheim, Auteur Année de publication : 2015 Article en page(s) : p. 349-354 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Syntans Tannage Tags : 'Tanins  synthétiques'  Formaldehyde  'Dihydroxy  diphényl  sulfone' Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The first syntan, Neradol D, was a condensate of phenolsulfonic acid and formaldehyde. While this chemistry allowed more efficient use of vegetable tannins, it was not advantageous to be applied on leather alone and has to be considered an auxiliary. Incorporating urea into the phenolsulfonic acid - formaldehyde condensation established a second generation of syntans with significantly improved lightfastness. Replacement syntans were developed to substitute vegetable tannins, giving rise to leathers of good softness and fullness. The formaldehyde condensation of dihydroxy diphenyl sulfone (sulfone) can be considered a further development of the replacement syntans with lower residual monomers. In order to compare these four generations of syntans, poly-condensates of a comparable molecular size had to be synthesized. These tested in hydrothermic denaturation of skin powder and applied in sole tanning and re tanning. The resulting leathers were compared in various aspects of performance including shrinkage temperature, softness, fullness, light fastness, and rest monomers. Note de contenu : - First and second generation syntans - Second generation syntans and replacement syntans - Replacement syntans and sulfone based syntans En ligne : https://drive.google.com/file/d/10X0FNheVCGQV9ejOTM0y9JZJc7GEv9qO/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24863 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
17581	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Fatliquor effects on collagen fibril orientation and D-spacing in leather during tensile strain / Katie H. Sizeland in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 11 (11/2015)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CX, N° 11 (11/2015) . - p. 355-362 Titre : Fatliquor effects on collagen fibril orientation and D-spacing in leather during tensile strain Type de document : texte imprimé Auteurs : Katie H. Sizeland, Auteur ; Geoff Holmes, Auteur ; Richard L. Edmonds, Auteur ; Nigel Kirby, Auteur ; A. Hawley, Auteur ; S. T. Mudie, Auteur ; Richard G. Haverkamp, Auteur Année de publication : 2015 Article en page(s) : p. 355-362 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Collagène Cuirs et peaux -- Propriétés mécaniques Déformations (mécanique) Distribution et orientation des fibres Essais dynamiques Produits de nourriture du cuir Test de déchirement Traction (mécanique) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Strength is a very important property of leather and is known to depend on the arrangement of the collagen fibrils within the material. The addition of fatliquor (penetrating oils) is an essential part of the manufacture of leather and enhances the strength and feel of leather. However, the mechanism by which fatliquor leads to increased strength is not understood. Here we use synchrotron based small angle X-ray scattering (SAXS) to monitor the collagen fibril rearrangement and internal strain of leather during tension. Differences in internal structural changes under strain with varying levels of fatliquor are investigated. It is found that when a strain of up to 40-70% was applied to leather, the orientation index (OI) of the collagen fibrils changed up to 21.8% and the d-spacing changed by up to 1.8% with no consistent differences at different levels of fatliquor. The extensibility of leather increases by 11.3% with as little as 2% fatliquor addition and the elastic modulus decreases with fatliquor addition but not in proportion to the amount of fatliquor. This change in extensibility is not reflected in differences in OI or d-spacing changes during strain. As reported previously, the fatliquor modifies the d-spacing of collagen. While fatliquor is traditionally considered to lubricate the fibers in leather, here the evidence suggests that this does not occur at the level of collagen fibrils. This provides an insight in the action of fatliquor in leather manufacture. Note de contenu : - Fatliquor addition - Scattering patterns - Tear test - Orientation index - Stress-strain - OI of cross sections En ligne : https://drive.google.com/file/d/1bwnG63Bg0OkZzrAzbZtmL75YrZ0abVXL/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24864 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
17581	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Chrome-reduced combination tanning for cleaner dyed sheep fur processing / Wei Ding in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 11 (11/2015)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CX, N° 11 (11/2015) . - p. 363-371 Titre : Chrome-reduced combination tanning for cleaner dyed sheep fur processing Type de document : texte imprimé Auteurs : Wei Ding, Auteur ; Yihan Chen, Auteur ; Ya-Nan Wang, Auteur ; Bi Shi, Auteur Année de publication : 2015 Article en page(s) : p. 363-371 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux de moutons Déchets -- Réduction Eaux usées -- Analyse Fourrures Tannage au chrome Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Chrome tanning is essential for conventional processing of dyed sheep fur as it can provide fur with high hydrothermal stability suitable for dyeing of wool at a temperature around 70°C. However, a long float length and a big offer of chrome tanning agent (16 g/L) are required for the tanning process, which lead to poor uptake of chrome and excessive discharge of chrome in wastewater. In this study, reduction of chrome offer in dyed sheep fur production was investigated to develop a cleaner tanning technology. It was found that the even distribution of chrome and satisfactory dispersion of fur collagen matrix were achieved even though chrome tanning agent offer was reduced to 2 g/L and 4 g/L. But the shrinkage temperature of the furs was only 79°C and 85°C, respectively, which resulted in a sharp area shrink of fur in following high temperature dyeing. In the combination tannage using 10 g/L amphoteric organic tanning agent (TWT) and 2 g/L or 4 g/L chrome tanning agent, the shrinkage temperature of fur was higher than 90°C accompanied by a higher utilization of chrome. These combination tanned furs were capable of enduring dyeing process at 68°C for 8 h, and presented a high uptake of post tanning chemicals because they had an isoelectric point close to that of chrome tanned fur. More importantly, the physical properties of the combination tanned dyed furs were comparable to the dyed fur made by conventional chrome tanning using 16 g/L chrome tanning agent. Note de contenu : - EXPERIMENTAL : Materials - Conventional chrome tanning of sheep fur - Chrome-reduced combination tanning of sheep fur - Post tanning processes of sheep fur - Determination of chrome content in sheep fur and dyeing wastewater - Scanning electron microscope (SEM) analysis of sheep fur - Estimation of area yield of sheep fur - Uptake of fatliquor and dyestuff in post tanning processes - Determination of isoelectric point of sheep fur - Determination of physical properties of fur - RESULTS AND DISCUSSION : Effect of reduction of chrome offer on tanning performance - Effect of reduction of chrome offer on dyeing performance - Chrome-reduced combination tanning using TWT - Dyeing performance of chrome-reduced combination tanned fur En ligne : https://drive.google.com/file/d/19OtOSxVNM2feFFTWNzaprneqTyX2j1al/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24865 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
17581	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Effect of finishing auxiliaries on permeability of leathers / Murali Sathish in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 11 (11/2015)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CX, N° 11 (11/2015) . - p. 372-378 Titre : Effect of finishing auxiliaries on permeability of leathers Type de document : texte imprimé Auteurs : Murali Sathish, Auteur ; Z. Mohammad Jamal Azhar, Auteur ; N. Nishad Fathima, Auteur ; Jonnalagadda Raghava Rao, Auteur Année de publication : 2015 Article en page(s) : p. 372-378 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux -- Finition Perméabilité Polyacryliques Polyuréthanes Porosimétrie d'écoulement capillaire Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The unique fibrous arrangement and architectural marvel of collagen in skin matrix are the basis for various physical properties of leather. Air permeability is one of the unique features of skin, which makes the leather matrix superior to synthetic materials. In leather manufacturing finishing process determines the air permeability of the final leather. Therefore, knowledge of the impact of different finishing auxiliaries on the permeability of leather may helpful in selecting an appropriate finishing system for a particular type of leather. In this work, an attempt has been made to analyze the effect of various auxiliaries used in protein, acrylic and polyurethane (PU) based finish coatings on the air permeability of leather. Capillary flow porometer was used to monitor the air permeability (Flow rate cc/sec) at different pressures (psi). The results show that the effect of wax/filler/slip and dye solution on air permeability reduction is low when compared to pigment and binder. In protein and PU finishes, the binder alone and season (combination of all finishing auxiliaries like pigment, binder, and other auxiliaries) has a strong influence on permeability reduction whereas in case of an acrylic based finish, the pigment and binder plays an important role in permeability reduction. Leather coated solely with protein binder shows minimal permeability reduction than compared to leather coated with acrylic or polyurethane binders, whereas in season, acrylic based finishing has a lower permeability profile than that of protein and PU. In that case the permeability profile of protein and PU season coated leathers is almost similar. Note de contenu : - MATERIALS AND METHODS : Permeability measurements - Measurement of film thickness - RESULTS AND DISCUSSION : Selection of uniformly permeable samples - Protein finishing - Resin finishing - PU finishing - Protein vs resin vs PU finishing En ligne : https://drive.google.com/file/d/11zE9nCljBG7eV_x7o-7Esb1m1IbAUW8Z/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24869 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
17581	-	Périodique	Bibliothèque principale	Documentaires	Disponible