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Two stage chrome tanning system (basification in a separate float) influence of organic SO2 reduced chrome tan / Victor John Sundar in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 88, N° 1 (01-02/2004)
[article]
Titre : Two stage chrome tanning system (basification in a separate float) influence of organic SO2 reduced chrome tan Type de document : texte imprimé Auteurs : Victor John Sundar, Auteur ; Chellappa Muralidharan, Auteur Année de publication : 2004 Article en page(s) : p. 23-26 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Basification (chimie)
Caractérisation
Chrome trivalent -- Oxydation
Cuir -- teneur en chrome
Cuirs et peaux -- Analyse
Dioxyde de soufreLe dioxyde de soufre, également appelé anhydride sulfureux (nom qui n’est plus employé en chimie), est un composé chimique de formule SO2. Il s'agit d'un gaz incolore, dense et toxique, dont l'inhalation est fortement irritante. Il est libéré dans l'atmosphère terrestre par les volcans et par de nombreux procédés industriels, ainsi que par la combustion de certains charbons, pétroles et gaz naturels non désulfurés. L'oxydation du dioxyde de soufre, le plus souvent en présence de catalyseurs tels que le dioxyde d'azote NO2, conduit au trioxyde de soufre SO3 et à l'acide sulfurique H2SO4, d'où la formation de pluies acides16. Elle a pour conséquence une inflammation de l'appareil respiratoire.
Le dioxyde de soufre est utilisé comme désinfectant, antiseptique, antibactérien, gaz réfrigérant, agent de blanchiment, gaz catalyseur pour les noyaux de fonderie dans le procédé Ashland et comme conservateur de produits alimentaires, notamment pour les fruits secs, dans la production de boissons alcoolisées et dans l'élaboration du vin. (Wikipedia)
Eaux usées -- Analyse
Stabilité thermique
Tannage au chrome
Wet-blue (tannage)Peau tannée au chrome (le chrome donne une couleur bleue)Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The two stage chrome tanning process has been investigated for its properties of high chrome exhaustion and the possibility of recycling the spent liquor. Chrome salts prepared by sugar and SO2 reduction have been used in the system. The investigations indicated that irrespective of the nature of tanning salt used the system provides waste minimisation and pollution reduction. Speciation studies support the earlier finding that higher oligomeric species of chromium provide greater hydrothermal stability regardless of the tanning methodology or tanning salt used. Note de contenu : - EXPERIMENTAL METHODS : Current process methodology - Tanning trials by the two-stage tanning system (basification in a separate float)
- RESULTS AND DISCUSSION : Thermal stability - Estimation of chromium - Estimation of sulphate and chloride in spent solutions
- SPECIES SEPARATION STUDIES IN BCS AND IN SPENT TANNING SOLUTIONS
- RESULTS AND DISCUSSION : Chromium in spent tan liquors - Thermal stability - Characterisation of first stage liquor - Assessment of wet blue leathers
- Appendix - Chrome analysis oxidation methods
- Table 1 : Chromium present in spent tan liquor bath
- Table 2 : Peak temperature of thermograms and chromium content of wet blue
- Table 3 : Distribution of species in original BCS and in first-stage spent liquor
- Table 4 : Characteristics of first stage spent liquors
- Table 5 : Chromium content of wet blueEn ligne : https://drive.google.com/file/d/1uXg_mFr6WAghsEZfDattria3rOeoVm0e/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39652
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 88, N° 1 (01-02/2004) . - p. 23-26[article]Two-stage temperature change chrome tanning : A more sustainable tanning process / Hui Zeng in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIV, N° 5 (05/2019)
[article]
Titre : Two-stage temperature change chrome tanning : A more sustainable tanning process Type de document : texte imprimé Auteurs : Hui Zeng, Auteur ; Weixing Xu, Auteur ; Bi Shi, Auteur Année de publication : 2019 Article en page(s) : p. 153-162 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Absorption
Caractérisation
Croûte (cuir)On entend par "cuir en croûte" des cuirs ayant subi les opérations jusqu'au tannage, à l'exclusion de toute opération de corroyage ou de finissage, mais qui, par opposition aux wet-blue ont été séchés.
Cuirs et peaux -- Propriétés mécaniques
Cuirs et peaux de bovins
Surfaces -- Analyse
Tannage au chrome
Température
Wet-blue (tannage)Peau tannée au chrome (le chrome donne une couleur bleue)Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Under the guidance of molecular simulation of Cr(III) species in water solution, a novel chrome tanning process, the two-stage temperature change chrome tanning, was developed. In stage I, the pickled cattle hide was first tanned by a small amount of chrome tanning agent under room temperature to obtain basic hydrothermal stability. Then, in stage II, the pre-tanned wet-blue was tanned again under a high temperature (≥ 60°C) to enhance the reactivity of Cr(III) with collagen fibers. The shrinkage temperature of crusts, the absorptivity of chrome tanning agent and fatliquoring agent, the mechanical property and surface morphology of crusts were characterized to evaluate the tanning effect. The results showed that when the dosage of chrome tanning agent in two stages was 2 wt% (tanned under room temperature) and 1 wt% (tanned under 60°C), respectively, the best performances of crust were achieved. In these conditions, the shrinkage temperature of crust was 104.6°C. The comprehensive absorptivity of chrome tanning agent reached up to 96.3%. The absorptivity of fatliquoring agent in wet-blue was 90.2%. The mechanical property and grain fineness of the crust were comparable to those of conventional chrome tanned crust with 6 wt% chrome tanning agent. As a result, an efficient and more sustainable chrome tanning process with less offer of chrome tanning agent was achieved. Note de contenu : - EXPERIMENTAL : Materials and equipment - preparation of chrome tanned samples (wet-blue/crusts) - The main Cr(III) species under different temperature - Measurements and instruments
- RESULTS AND DISCUSSION : The states of Cr2(SO4)3 in water solution at penetration stage and combination stage of chrome tanning - Effect of tanning conditions on properties of wet-blue/crusts - Effect of tanning conditions on Ts of crusts - Effect of tanning conditions on comprehensive absorptivity of chrome tanning agent
- Effect of tanning conditions on Cr2O3 content of wet-blue - Effect of tanning conditions on mechanical property of crusts - Effect of tanning conditions on grain morphology of crusts - Effect of tanning conditions on the chrome distribution in experimental wet-blue - Further optimization of the temperature change chrome tanning technology - Effect of chrome tanning agent dosage in stage II on tanning effect of experimental wet-blue/crusts - Effect of the chrome tanning agent dosage in stage II on the properties of experimental crustsEn ligne : https://drive.google.com/file/d/1wQIwx4fNXcMH-sJ-KpQZiW-bbAkzYMCd/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32475
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Code-barres Cote Support Localisation Section Disponibilité 20910 - Périodique Bibliothèque principale Documentaires Disponible Understanding dispersion of copper phthalocyanine alpha blue pigment in polyethylene masterbatch with the use of wax / Mert Yücetürk in COLORATION TECHNOLOGY, Vol. 136, N° 6 (12/2020)
[article]
Titre : Understanding dispersion of copper phthalocyanine alpha blue pigment in polyethylene masterbatch with the use of wax Type de document : texte imprimé Auteurs : Mert Yücetürk, Auteur ; Mehmet Özgür Seydibeyoglu, Auteur Année de publication : 2020 Article en page(s) : p. 526-534 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Bleu (couleur)
Caractérisation
Cires
Dispersions et suspensions
Essais dynamiques
Films plastiques
Granulométrie
Mélanges-maîtres (chimie)
Phtalocyanine de cuivre
Pigments inorganiques
Polyéthylène
Traction (mécanique)Index. décimale : 667.3 Teinture et impression des tissus Résumé : Coloured plastics and polymers are widely used in packaging and consumer goods. Despite their critical roles, there is limited literature on detailed analysis of effective pigment dispersion in polymer matrices for masterbatch applications. In this study, detailed research was conducted on pigment dispersion using different wax materials and their performances in polyethylene masterbatches were compared. During the study, it was first found that the presence of salt crystals plays a critical role in dispersion in one of the tested pigments. Using a laser particle size device, it was shown that homogeneous particle size distribution is another critical parameter for proper pigment distribution. Although filter testing is a common method in industrial applications, there is very limited information in the academic literature. The filter test method was used to examine the effects of different polyethylene waxes on pigment dispersion. The best filter pressure values were obtained in masterbatches made with micronised wax. It was also observed that the improved dispersion increased the mechanical properties of the masterbatch. The masterbatch colours were measured with a sphere spectrophotometer and it was observed that uniform pigment distribution increased the colour strengths. Similar results were also seen in polyethylene films produced by the blown film process. Note de contenu : - EXPERIMENTAL : Materials - Scanning electron microscopy - Pigment particle size analysis - Masterbatch production - Measurement of the quality of dispersion - Preparation of plates - Colour measurement - Tensile test - Preparation of plastic films
- RESULTS AND DISCUSSION : Pigment analysis - Masterbatch analysisDOI : https://doi.org/10.1111/cote.12506 En ligne : https://onlinelibrary.wiley.com/doi/epdf/10.1111/cote.12506 Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34706
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Code-barres Cote Support Localisation Section Disponibilité 22386 - Périodique Bibliothèque principale Documentaires Disponible Unhairing of bovine skin with fungal enzymes by immersion and spread throughout the epidermis / Maria Laura Garro in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 103, N° 1 (01-02/2019)
[article]
Titre : Unhairing of bovine skin with fungal enzymes by immersion and spread throughout the epidermis Type de document : texte imprimé Auteurs : Maria Laura Garro, Auteur ; Betina Galarza, Auteur ; Carlos Greco, Auteur ; Roque Hours, Auteur Année de publication : 2019 Article en page(s) : p. 28-34 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse quantitative (chimie)
Caractérisation
Cuirs et peaux de bovins
Diffusion (physique)
Enzymes fongiques
Epiderme
Epilage enzymatique
Immersion
Microscopie électronique à balayage
Travail de rivière (cuir)Index. décimale : 668.5 Parfums et cosmétiques Résumé : The use of enzymes during unhairing in the leather industry to partially reduce sulfide can decrease H2S emission to almost 50%. However the proteolysis needs to be controlled to prevent collagen damage. In bovine epidermis, the stratum corneum plays a crucial role as a hydrophobic barrier. In order to facilitate the diffusion of enzymes, it is necessary to generate channels through this barrier to allow enzymes pass without damaging the collagen. In an ideal enzymatic unhairing the proteolytic activity should be restricted to the basal lamina and pilosebaceous unit. During this experiment, fungal enzyme extracts (CE) were applied on bovine skin in the soaking and unhairing steps as part of the tanning process. The skin contacted with the solutions in two different ways : in direct contact with the epidermis (Mode I) and immersed in the solution (Mode II). Various keratinolytic fungi, previously isolated and selected from different soil samples were used : Neurospora crassa, Verticillium albo-atrum, Trichophyton ajelloi, Chrysosporium sp, Aspergillus sydowii, Paecilomyces lilacinus and Acremonium murorum. The fungal isolates were cultivated under solid state conditions using hair waste obtained from the hair-saving unhairing process as substrate. Enzyme extracts were characterized according to their keratinolytic and proteolytic activity and protein content. Once the immersion with fungal enzymes was finished, the treatment with N. crassa, T. ajelloi, Chrysosporium sp, A. sydowii and P. lilacinus, showed unhaired skin and epidermis removed. After the contact between the epidermis and fungal enzymatic extract of T. ajelloi empty hair follicles were observed. The morphological changes were studied with SEM (Scanning Electron Microscopy). Note de contenu : - INTRODUCTION : Epidermis - Basal lamina - Dermis - Objectives
- MATERIALS AND METHODS : Fungal strains isolates : culture and characterization - Assessment of protein content and proteolytic activity - Assay of proteolytic and keratinolytic activities - Mode I. Permeability assay of bovine skin epidermis with fungal enzyme extracts - Epidermis - Basal lamina - Dermis - Objectives
- MATERIALS AND METHODS : Fungal strains isolates : culture and characterization - Assessment of protein content and proteolytic activity - Assay of proteolytic and keratinolytic activities - Mode I. Permeability assay of bovine skin epidermis with fungal enzyme extracts - Control wells - Mode II. Assay with bovine skin immersed in the solutions - Control tubes - Scanning electronic microscopy (SEM) protocol
- RESULTS AND DISCUSSION : Assay of proteolytic and keratinolytic activities - SEM observationEn ligne : https://drive.google.com/file/d/1ym8R2Zy2q7HOf8f4HNvldFgm04pmesC6/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31790
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 103, N° 1 (01-02/2019) . - p. 28-34[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 20620 - Périodique Bibliothèque principale Documentaires Disponible Unique rare earth pigments for more thermally comfortable leathers in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 7 (07/2014)
[article]
Titre : Unique rare earth pigments for more thermally comfortable leathers Type de document : texte imprimé Année de publication : 2014 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Adhésion
CalcinationLa calcination est une technique de préparation d'échantillon utilisée en chimie analytique qui permet de prendre en compte ce phénomène. Elle consiste à chauffer l'échantillon à haute température (typiquement 500 à 1 000 °C) sous air ou sous atmosphère neutre pour provoquer des réactions physiques et chimiques et mettre ainsi l'échantillon dans un état de référence.
En effet, un certain nombre de propriétés des matériaux dépendent de la température et de l'historique de l'échantillon comme de l'humidité. La calcination permet de l'abstraire de ces effets et donc d'avoir des mesures reproductibles, de pouvoir comparer différents échantillons. En revanche, il faut être conscient que l'échantillon analysé n'est pas l'échantillon prélevé. La méthode est similaire à l'analyse des extraits secs mais utilise une température plus élevée.
Caractérisation
Cuirs et peaux -- Propriétés organoleptiques
GadoliniumLe gadolinium est un élément chimique, de symbole Gd et de numéro atomique 64.
Le gadolinium est un métal faisant partie des terres rares. Il est gris argent, malléable et ductile à la température ambiante.
Il cristallise sous forme hexagonale à température ambiante, mais possède une autre forme allotropique connue sous le nom de forme bêta, de structure cubique centrée au-dessus de 1508 K.
Le gadolinium est assez stable dans l'air sec. En revanche, il s'oxyde rapidement dans l'air humide. Le gadolinium réagit lentement avec l'eau et est soluble dans les acides dilués.
L'oxyde de gadolinium a été isolé en 1880 par Jean Charles Galissard de Marignac et Paul-Émile Lecoq de Boisbaudran prépara le métal pur en 1886. Son nom provient du minerai duquel il a été d'abord obtenu, la gadolinite, découvert par Johan Gadolin en 1794.
Il est ferromagnétique et son point de Curie est 293 K soit environ 20 °C. Il a la plus grande capacité d'absorption des neutrons thermiques parmi tous les éléments naturels (49 kbarns).
Le gadolinium présente une certaine toxicité. En effet, il entre en compétition avec le calcium dans les processus calcium-dépendants du corps humain (respiration, battements du cœur, contraction des muscles, coagulation...) et peut mener à de graves dommages selon sa concentration. C'est pourquoi les composés du gadolinium qui sont utilisés en médecine comme agent de contraste pour l'imagerie par résonance magnétique (IRM) sont obligatoirement complexés. Ainsi, leur toxicité est annulée.
Il est aujourd'hui principalement extrait de la monazite ((Ce, La, Th, Nd, Y)PO4) et de la bastnäsite ((Ce, La,Y)CO3F).
Imagerie (technique)
Molybdène
Morphologie (matériaux)
Oxyde de cérium
Photostabilité
Pigments -- Propriétés optiques
Pigments -- Synthèse
Pigments inorganiques
Rayonnement infrarouge
Taille des particules
Terres raresIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : This paper reports the investigations carried out on the synthesis, characterization and optical properties of a new class of rare earth based near infrared reflective yellow pigments as an alternative to toxic inorganic pigments. The rare earth yellow pigments can be prepared by employing calcination method. The present work reveals that the doping of molybdenum for ceria in gadolinium cerium lattice changes the color hue from cream white to dark yellow. The calcination temperature employed for preparation of these pigments was about 1000°C. This temperature was found to be much lower than that required to achieve the intense yellow hue through conventional solid state calcinations reaction (above 1500°C). X-ray diffraction data confirm the crystalline character of the pigments. The pigment thus developed serves as a potential candidate for NIR reflective pigments for leather applications on account of its NIR reflectance value of 96% in the wavelength region 1100 nm. Thermal images of the finished leather exposed to NIR light clearly indicate the lower heat retention character. The pigment properties were in good agreement with industrial requirements. They also serve as environmentally safer pigments. Note de contenu : - MATERIALS AND METHODS : Materials - Synthesis of yellow pigment - Size evaluation - Phase purity - Surface morphological analysis - Optical characteristics - Preparation of finishing formulation - Characterization of finished leathers
- RESULTS AND DISCUSSION : Powder X-ray diffraction analysis - Particle size and morphological analysis - Near infrared reflectance of leather - CIE la color coordinates - Effect of light fastness on finished leathers - Organoleptic properties assessed by tactile evaluation - Adhesion test - Thermal imaging of leatherEn ligne : https://drive.google.com/file/d/10_yV-ltFY9v0lyCw6gnCIQ7cK9O7c5UL/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21707
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Code-barres Cote Support Localisation Section Disponibilité 16423 - Périodique Bibliothèque principale Documentaires Disponible Urethane methacrylate reactive diluents for UV-curable polyester powder coatings / Theodore J. Hammer in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 18, N° 2 (03/2021)
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PermalinkUseful process data from the injection molding machine / Felix A. Heinzler in KUNSTSTOFFE INTERNATIONAL, Vol. 104, N° 2 (02/2014)
PermalinkUsing ashes from incineration of chromium sulphate tanned leather scrap - Part 1 : Characterization of ashes and chromium extraction in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 84, N° 6 (11-12/2000)
PermalinkUsing ashes from incineration of chromium sulphate tanned leather scrap. Part 2 : Tanning liquors, additives in footwear adhesives and fillers in mortars / M. J. Ferreira in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 85, N° 6 (11-12/2001)
PermalinkUsing biodegradable organic salt for cotton garment dyeing to reduce effluent pollution / Ali Raza in COLORATION TECHNOLOGY, Vol. 138, N° 4 (08/2022)
PermalinkUsing electrically conductive polyaniline/polyvinyl alcohol hydrogel electrodes to perform electrodeposition of polysaccharides / Qinghua Wang in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 20, N° 6 (11/2023)
PermalinkUtilisation des extraits tinctoriaux en tannerie / J.-J. Rodier in REVUE TECHNIQUE DES INDUSTRIES DU CUIR, Vol. LXIII (Année 1971)
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PermalinkUV-curable alkyd coating with self-healing ability / Saman Nornadila Mohd in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 16, N° 2 (03/2019)
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