Lime-free unhairing : Part 5. Some peculiarities of dyeing lime-free leather / A. Zaliauskiene in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 90, N° 2 (03-04/2006)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 90, N° 2 (03-04/2006) . - p. 73-79 Titre : Lime-free unhairing : Part 5. Some peculiarities of dyeing lime-free leather Type de document : texte imprimé Auteurs : A. Zaliauskiene, Auteur ; Kestutis Beleska, Auteur ; Virgilijus Valeika, Auteur ; J. Balciuniene, Auteur ; V. Valeikene, Auteur ; V. Tricys, Auteur Année de publication : 2006 Article en page(s) : p. 73-79 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Coefficient de diffusion Un coefficient de diffusion est une grandeur caractéristique du phénomène de diffusion de la matière. Le coefficient de diffusion mesure le rapport entre le flux molaire dû à la diffusion moléculaire, et le gradient de concentration de l'espèce chimique considérée (ou, plus généralement, de la variable d'effort entraînant cette diffusion), comme formulé par la loi de Fick. Colorants Cuirs et peaux -- Teinture Hydrophobie Pénétration (physique) Rouge (couleur) Thermodynamique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The interaction of leather, prepared by the lime-free method, and a series of 1:2 metal complex dyes has been investigated by determining the distribution of the dyes at equilibrium. Kinetic and thermodynamic aspects such as the rate of dyeing, heat of dyeing, entropy, affinity of dyes on the lime-free and conventional leather have been studied. The diffusion coefficient was calculated by means of the Weisz pore and Krenk models. It has been established that the sorption isotherms for these dyes on both types of leather fibres show a Langmuir type of behaviour. The dyeing system hydrophobic C.I. Acid Red 247/lime-free leather has a positive heat of dyeing: dyeing is an endothermic process in this case. The change of entropy of interaction of hydrophobic C.I. Acid Red 247 and leather fibres is 24 cal/mol•K. An increased degree of freedom should be associated with water molecules such as those hydrating the dye and the fibre, and possibly, due to randomness in the fibre itself. This decreased degree of the order of water molecules results in a positive change of entropy, which then is the thermodynamic cause of the hydrophobic bonding. The influence of factors such as, initial amount of dye, pH of leather and temperature on the dyeing process was established. The results have shown that lime-free leather absorbs lesser amounts of dye during dyeing but that, the dye penetrates more deeply compared with conventional leather. The amount of dye, pH and temperature has no influence on such a tendency. On the other hand, the investigation has shown that the factors mentioned have a more marked influence on the progress of dyeing of lime-free leather compared with dyeing conventional leather. This means that inconsiderable deviation from determined parameters of dyeing can markedly deteriorate the quality of the dyed leather. The data obtained have confirmed that the change in the method of liming considerably influences subsequent processes in leather processing. Note de contenu : - EXPERIMENTAL PROCEDURE : Leather samples for dyeing - The preparation of leather fibres for dyeing - Dyes and dyeing - Determination of hydrophobicity of dyes - Determination of depth of dye penetration into leather - Investigation of dyeing kinetics - Thermodynamic investigation of dyeing - RESULTS AND DISCUSSION : Kinetic and thermodynamic investigation - Investigation of dyeing parameters on the progress of dyeing - Table 1 : Indexes of pelt and leather obtained by use of lime-free and conventional unhairing - Table 2 : The dependence of diffusion coeffficient on unhairing method - Table 3 : The thermodynamic characteristic of dyeing process En ligne : https://drive.google.com/file/d/16mWq3L-c0sNpayWDNSSXPgzVTvU4htbU/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39160 [article]

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

New possibilities for mechanical softening of leather / V. Tricys in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 90, N° 3 (05-06/2006)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 90, N° 3 (05-06/2006) . - p. 112-116 Titre : New possibilities for mechanical softening of leather Type de document : texte imprimé Auteurs : V. Tricys, Auteur ; K. Kazanavicius, Auteur Année de publication : 2006 Article en page(s) : p. 112-116 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Assouplissement (mécanique) Cisaillement (mécanique) Cuirs et peaux -- Propriétés mécaniques Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : We present our results for work on leather softening by shearing and the effect of shearing parameters on leather's relative elasticity. Leather softening processes have been executed and elasticity parameters have been determined using specially constructed instruments. It has been stated that, when employing this particular leather softening technique, leather's deformation characteristics are of no worse quality than when employing a conventional (vibration) technique. These reasons suggest that the shearing technique of leather softening may be applicable in the leather industry. An increase of shearing speed and number of cycles had no substantial effect on the leather’s elasticity. We applied graphical methods to the experiments on the effect of shearing parameters on one of leather quality indicators - its elasticity. The calculations of the corresponding relationships are presented in the paper. En ligne : https://drive.google.com/file/d/11lB6M0Ar7OyV8fVyr8YH4Zt0TyQDLqzv/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39143 [article]

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Stimulation of the chrome tannage process by vacuum / V. Tricys in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 87, N° 2 (03-04/2003)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 87, N° 2 (03-04/2003) . - p. 78-81 Titre : Stimulation of the chrome tannage process by vacuum Type de document : texte imprimé Auteurs : V. Tricys, Auteur ; Kestutis Beleska, Auteur ; Virgilijus Valeika, Auteur Année de publication : 2003 Article en page(s) : p. 78-81 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux Tannage au chrome Tannage sous vide Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : This paper presents the results of an investigation into the promotion of leather manufacturing by vacuum. The chromium tannage process was chosen as a model and influence of the factors such as thickness of pelt, temperature, concentration of Cr2O3 in the chroming solution and additionally, the use of pressure on the rate of solution penetration and qualitative indexes of leather was investigated. It was established that the use of 0.01 MPa vacuum reduces the duration of chroming to 3-20 minutes depending on the pelt thickness. An increase of temperature does not noticeably shorten the time of chroming but it has a positive influence on the shrinkage temperature of the leather. An increase in concentration of the chromium compounds in the chroming solution does not result in a large increase of amount of Cr2O3 in the leather. Comparing the acceleration of the process by either pressure or vacuum proved the use of vacuum to be more effective than the use of pressure. Note de contenu : - Influence of pressure difference on duration of chromium tannage - Influence of pelt thickness on duration of the chromium tannage - Influence of temperature on the chroming process - Table 1 : Chrome content and shrinkage temperature of samples after chroming 'with solution' A – penetration through flesh side first ; B – through grain side first En ligne : https://drive.google.com/file/d/18H12t5EvsVbsQweaCvbmIWY_JNG0dTuk/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39803 [article]

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

---

1 (1 - 3 / 3)