An effective and harmless recycling technology for hazardous chrome-tanned leather wastes / Minghui Li in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 108, N° 2 (03-04/2024)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 108, N° 2 (03-04/2024) . - p. 67-77 Titre : An effective and harmless recycling technology for hazardous chrome-tanned leather wastes Type de document : texte imprimé Auteurs : Minghui Li, Auteur ; Xu Zhang, Auteur ; Honghong Chen, Auteur ; Sadaqat Ali Chattha, Auteur ; Xin Yan, Auteur ; Biyu Peng, Auteur Année de publication : 2024 Article en page(s) : p. 67-77 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Agents de tannage Chimie analytique Chrome -- Recyclage 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 -- Déchets -- Recyclage Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux -- Propriétés physiques Déchromage Hydrolysat de collagène Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Utilizing leather production waste to create raw materials for leather chemicals, and reintroducing it into the leather making processing, represents an ideal approach to achieving an “internal circular economy” within the leather industry. This study focuses on the reutilization of dechromed collagen fibres, obtained from chromium shavings, to generate a retanning filling. The effects of hydrolysis conditions on the viscosity, and gel strength of the dechromed collagen hydrolysates were investigated. The application effectiveness of the collagen hydrolysates with different particle sizes in the leather retanning filling process was also compared. The findings indicate that alkali hydrolysis is more conducive to producing collagen hydrolysates with a relatively higher proportion of medium and low molecular weight components, while acid hydrolysis favours the production of collagen hydrolysates rich in high molecular weight components. Additionally, collagen hydrolysates with an average particle size of 162.8 nm exhibit the best filling efficacy, imparting favorable organoleptic and physical properties to the leather. Herein, a method for preparing protein fillers, using chrome shavings as raw materials, was established, i.e., the dechromed collagen fibres (with a chromium content of approximately 33.6 mg/kg) were mixed with 2000% of water and adjusted to pH 3.0 with a small amount of sulfuric acid, and heated at 60°C with continuous stirring for 11 hours. After hydrolysis, the pH was adjusted appropriately to reuse it in the wet blue retanning filling process. The research outcomes have significant guiding implications for promoting the "internal circular economy" and sustainable development within the leather industry. Note de contenu : - EXPERIMENTS AND METHODS : Experimental materials - Dechroming of chrome shavings - Hydrolysis of dechromed collagen fibres - Performance of collagen hydrolysate as a retanning agent - Analysis and testing - RESULTS AND DISCUSSION : Preparation and performance analysis of dechromed collagen fibres materials - Influence of hydrolysis conditions on the fundamental characteristics of collagen hydrolysates - Correlation between the particle size of collagen hydrolysates and filling efficiency - Table 1 : Properties of the collagen hydrolysates - Table 2 : Physical and mechanical properties of the crust leather En ligne : https://drive.google.com/file/d/1hD0IMUh9EOcTIH7DeQDo-eDaYvoQEeci/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40933 [article]

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Collagen hydrolysate : Soluble skin applied in post-tanning processes : Part 2 - Interaction with acyrlic retanning agents / Carlos S. Cantera in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 86, N° 5 (09-10/2002)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 86, N° 5 (09-10/2002) . - p. 195-202 Titre : Collagen hydrolysate : Soluble skin applied in post-tanning processes : Part 2 - Interaction with acyrlic retanning agents Type de document : texte imprimé Auteurs : Carlos S. Cantera, Auteur ; J. Martegani, Auteur ; G. Esterelles, Auteur ; Jorge A. Vergara, Auteur Année de publication : 2002 Article en page(s) : p. 195-202 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : acrylique, Acide L'acide acrylique ou acide acroléïque ou acide prop-2-énoïque est un composé organique de formule brute C3H4O2 et de formule semi-développée CH2=CHCOOH. C'est un acide carboxylique et un alcène vinylique, et se présente comme un liquide incolore à l'odeur âcre. L'acide acrylique et ses esters, les acrylates, sont utilisés dans la fabrication de matières plastiques, dans les peintures acryliques et dans divers autres polyacryliques qui ont de multiples usages. Agents de tannage Copolymères Cuir pleine fleur Cuirs et peaux de bovins Hydrolysat de collagène Post-tannage Tannage synthétique Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : In the upgrading of tannery solid wastes, the commercial application of the by-products obtained is the key to attractive technological alternatives. In the particular case of chrome shavings hydrolysed by an alkaline-enzyme process, the uses of collagen hydrolysate (CH) are the driving force for the start-up of a project when consideration is given to the amounts generated and to the diversity of applications, in addition to the fact that basic chrome salts -obtained from the dissolution of the chrome cake - may be used as trouble-free assistants to the fresh tanning agent. The present paper, which follows the Part I of this study ; "Collagen Hydrolysate : ‘soluble skin’ applied in post-tanning processes I. Characterisation” (JSLTC, 2000, 84,29) shows the experimental results obtained from the manufacture of various types of bovine leathers carried out at the CITEC pilot plant and in tanneries using CH in the post-tanning processes. In addition, the interactions of CH with acrylic retanning agents, studied at laboratory scale, are included. CH performs in a synergistic fashion with various retanning agents. In addition to its cosmetic-lubricating effect which enhances the leather grain properties and provides greater softness improving the resistance of the fibrous tissue, there is also a ‘restoring effect’ upon the grain surface of the semi-finished leather, masking preservation defects and damage marks on the skin. The interaction with dyes is evident from the intensified colours and improved homogeneity of the dyeing. CITEC has developed, besides CH, a copolymer CH-acrylic acid : "acrylic-protein" retanning agent MCH-106, that shows good properties in the development of full grain leather and splits. The application of the CH and the acrylic-protein MCH-106 in processing full-grain leather generates leathers of similar or higher quality to the standard one. The application of CH in leather manufacture is an attractive response to the question of how to use the by-products derived from the treatment of the chrome shavings. Note de contenu : - EXPERIMENTAL DEVELOPMENT : Experiments at CITEC - ANALYSIS OF THE RESULTS : CH application trials at the tannery - Table 1 : Reduction in formic acid consumption in the 'mixture solutions' With regard to the sum of the individual values (expressed in %) - Table 2 : Reduction in the salt KCr (SO4)2.12H2O consumption in the ‘mixture solutions’ with regard to the sum of the individual values (expressed in %) - Table 3 : Physical properties of the upper leather prepared with acrylic-protein retanning agent MCH106 and CH En ligne : https://drive.google.com/file/d/1ApP8ftPrxBi4iuQPgF3ZwC9qWN4r9ckE/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39859 [article]

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Collagen recovered, purified and enzymatically hydrolysed from tannery waste / M. E. Errasti in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 108, N° 1 (01-02/2024)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 108, N° 1 (01-02/2024) . - p. 1-8 Titre : Collagen recovered, purified and enzymatically hydrolysed from tannery waste Type de document : texte imprimé Auteurs : M. E. Errasti, Auteur ; Laura M. I. Lopez, Auteur Année de publication : 2024 Article en page(s) : p. 1-8 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Collagène Cuirs et peaux -- Déchets -- Recyclage Déchets industriels -- Recyclage Enzymes végétales Hydrolysat de collagène Hydrolyse Peptidases Produits chimiques -- Purification Récupération (Déchets, etc.) Tannage -- Déchets Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : One of the main challenges of the tannery industry is the management of the waste generated during the leather manufacturing process. This study aimed to recover the collagen from tanning industry waste to acquire knowledge about its conversion into high value-added ingredients with bio-functional properties. To this end, collagen was purified from rawhide waste from the leather industry, characterised by electrophoresis and compared with commercial collagen. Subsequently, it was subjected to an enzymatic treatment using plant proteases from Bromelia hieronymi under mild reaction conditions to produce hydrolysates, since the production of bioactive peptides by enzymatic hydrolysis is a sustainable way of taking advantage of protein by-products. The hydrolysates were characterised by matrix-assisted laser desorption/ionisation time-of-flight (MALDI TOF) mass spectrometry, showing peptides with molecular weights ranging from 1,000 to 6,000 Da. Liquid chromatography-mass spectrometry (LC-MS/MS) analysis allowed identifying 31 peptides from the a, chain of type I collagen and another 13 from the a2 chain of type I collagen. The probability that the peptides identified were bioactive was predicted with the Peptide Ranker software ('in silico analysis'). This demonstrated that 70% of them had high bioactive potential. These results showed that the collagen recovered from the waste of the tannery industry and hydrolysed by proteases from Bromelia hieronymi becomes a suitable source to obtain a product with greater added value than the original material and with multiple potential industrial applications. Note de contenu : - Chemicals - Collagen recovery - Plant enzymatic preparation - Preparation of collagen hydrolysate - Collagen hydrolysate characterisation - Table 1 : Chemical characterisation of the spiits before and alter the preliminary processing. Values are expressed as meant SD - Table 2 : HC peptides identified by LC-MS/MS and the potential to be bioactive (a Score obtained with PeptideRanker) En ligne : https://drive.google.com/file/d/1Y7TX9F5xRUSAxM8b0VRzEpEI3v406L0t/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40927 [article]

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Gel-sol transitions of chrome tanned leather waste hydrolysate / F. Langmaier in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 85, N° 3 (05-06/2001)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 85, N° 3 (05-06/2001) . - p. 100-105 Titre : Gel-sol transitions of chrome tanned leather waste hydrolysate Type de document : texte imprimé Auteurs : F. Langmaier, Auteur ; M. Stibora, Auteur ; Karel Kolomaznik, Auteur Année de publication : 2001 Article en page(s) : p. 100-105 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse thermique Colles Colloides Cuirs et peaux -- Déchets -- Recyclage Hydrolysat de collagène Sol-gel, Procédé Tannage au chrome Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The properties of gels of collagenous hydrolysates from enzyme treatment of chrome-tanned leather waste, were monitored with the use of the DSC technique. The temperatures at which gels melt, the energies of the gel—sol transitions (determined by use of the DSC technique) and the gel strength (in degrees Bloom) correspond to those of gels of the qualitative class 9—10, as specified by the National Association of Glue Manufacturers. Due to the lower mean molecular weight of the hydrolysates (when compared with commercially available glues) and the wider molecular weight distribution. hydrolysed gels from enzyme hydrolysates (hydrolysis times less than 3 h) are used at concentrations approximately three times higher than is usual with commercially available glues of the above—mentioned quality. Glues of this qualitative class are often used in industry in concentrations of 50/ and higher and thus the higher concentration of hydrolysates from chrome-tanned leather waste will not represent an obstacle when they are used in a similar way. Note de contenu : - Material used and techniques : Starting materials - Technique - Table 1 : Characteristics of original materials - Table 2 : Characteristic parameters of gels and DSC curves of their gel—sol transitions - Table 3 : Results of the analysis ol’ scatter of energies of the gel—sol transitions (cf. Table II) - Table 4 : Results of the analysis of gel strength scatter (Bloom) - Appendix : The technology of enzymatic chrome leather waste decomposition En ligne : https://drive.google.com/file/d/1__AZx2sEjxM4JTnVaRMM4RN6o_UWi8Hx/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40364 [article]

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Increased chromium tanning efficiency with collagen hydrolysates / A. Aslan in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 90, N° 5 (09-10/2006)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 90, N° 5 (09-10/2006) . - p. 201-204 Titre : Increased chromium tanning efficiency with collagen hydrolysates Type de document : texte imprimé Auteurs : A. Aslan, Auteur ; G. Gulumser, Auteur ; Bugra Ocak, Auteur Année de publication : 2006 Article en page(s) : p. 201-204 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux de moutons Extraction (chimie) Hydrolysat de collagène Prétannage 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 : Collagen hydrolysates obtained from shavings of chrome tanned sheep skins were used in a pretanning process for sheepskins and the effect on the efficiency of chrome tanning was observed. Various physical tests and chemical analyses were applied to tanned sheepskins and the results were evaluated statistically. Wet-blue leathers pretanned with 5% protein by-product (collagen hydrolysates) showed increased chromium take-up and had better physical characteristics. Note de contenu : - EXPERIMENTAL PROCEDURE : Extraction of collagen hydrolysates - Determination of some chemical characteristics of collagen hydrolysates - PROCESSING OF SKINS : Determination of physical and chemical characteristics of tanned leathers - Table 1 : Amino acid contents of collagen hydrolysates - Table 2 : Certain chemical characteristics of collagen hydrolysates - Table 3 : Production recipe used on skins - Table 4 : Physical and chemical test results - Table 5 : Colour values of wet-blue leathers pretanned with collagen hydrolysates En ligne : https://drive.google.com/file/d/1hL_nkvmDqKqoYYPK-P2Ps5sbFi48z_DN/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39057 [article]

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Modifying products of enzymatic breakdown of chrome-tanned leather wastes with glutaraldehyde / F. Langmaier in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 87, N° 2 (03-04/2003)  

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The separation of hydrolysate of enzyme-soluble pigskin by chromatography and sodium dodecyl sulphate-polyacrylamide gel electrophoresis / Dai Hong in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 87, N° 3 (05-06/2003)  

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Toxicity evaluation of collagen hydrolysates from chrome shavings and their potential use in the preparation of amino acid fertilizer for crop growth / Li Zhao in JOURNAL OF LEATHER SCIENCE AND ENGINEERING, Vol. 4 (Année 2022)  

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