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JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) . Vol. CXIX, N° 9Mention de date : 09/2024Paru le : 26/09/2024 |
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Ajouter le résultat dans votre panierStatistical analysis and critical aspects of surface measurement using mechanical pin-wheel machines / R. Mascolo in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIX, N° 9 (09/2024)
[article]
Titre : Statistical analysis and critical aspects of surface measurement using mechanical pin-wheel machines Type de document : texte imprimé Auteurs : R. Mascolo, Auteur ; G. Calvanese, Auteur ; L. Giorleo, Auteur ; E. Scaglia, Auteur Année de publication : 2024 Article en page(s) : p. 379-386 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse de variance En statistique, l'analyse de la variance (terme souvent abrégé par le terme anglais ANOVA : ANalysis Of VAriance) est un ensemble de modèles statistiques utilisés pour vérifier si les moyennes des groupes proviennent d'une même population. Les groupes correspondent aux modalités d'une variable qualitative (p. ex. variable : traitement; modalités : programme d'entrainement sportif, suppléments alimentaires ; placebo) et les moyennes sont calculés à partir d'une variable continue (p. ex. gain musculaire).
Ce test s'applique lorsque l'on mesure une ou plusieurs variables explicatives catégorielles (appelées alors facteurs de variabilité, leurs différentes modalités étant parfois appelées "niveaux") qui ont de l'influence sur la loi d'une variable continue à expliquer. On parle d'analyse à un facteur lorsque l'analyse porte sur un modèle décrit par un seul facteur de variabilité, d'analyse à deux facteurs ou d'analyse multifactorielle sinon. (Wikipedia)
Cuir
Mesure -- Instruments
Roue à picots
StatistiqueIndex. décimale : 667.9 Revêtements et enduits Résumé : The publication of the “Measuring Instruments Directive - MID” (European Directive 2014/32/UE) has determined the inclusion of area measuring machines in the category of legal metrology devices. Leather must follow similar rules for other goods traded by means of a measurement. Finished leathers are usually sold by area and the measurement for verification purposes in commercial trades is regulated by the International Contract No 7 (1998) between the ICT and the ICHSLTA. This contract provides specific indications on commercial issues and defines rules for area checking in case of legal disputes. In general, the contract allows the use of any agreed machine between seller and buyer (mechanical or optoelectronic), but in the event of a dispute it refers exclusively to pin-wheel machines according to ISO 11646 standard. This requirement has been defined without the provision of any technical support and does not consider the deviations of the results using other devices. Furthermore, ICT and ICHSLTA agreed that official controls shall be carried out only in specific Measurement Institutes, among which only 5 around the world have a working instrument, and only one has accredited the test according to ISO/IEC 17025. In this study, 13 small batches of different leather articles were used in an interlaboratory trial that involved 8 participants, including 4 European ICT/ICHSLTA official Measurement Institutes. By means of a statistical analysis of the results, the scope of this study is the identification of critical aspects related to the use of pinwheel machines with particular reference to leather (dimension, deformability, etc) and device characteristics. Note de contenu : - Table 1 : Leather samples and statistics
- Table 2 : Variance analysis using ANOVA
- Table 3 : Grouping information using the Turkey Method and 95% confidence for sample factor
- Table 4 : Grouping information using the Turkey Method and 95% confidence for Laboratory factor
- Table 5 : Compliance to ICT requirements of the results
- Table 6 : Mechanical properties, Repeatability and Reproducibility 6 vs 2% ICT theoretical requirementsDOI : https://doi.org/10.34314/0gfn4326 En ligne : https://drive.google.com/file/d/1iwb_UqGnJkbJXbY38VO4nwsHSx0lASxY/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41456
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Code-barres Cote Support Localisation Section Disponibilité 24826 - Périodique Bibliothèque principale Documentaires Sorti jusqu'au 18/10/2024 Opuntia ficus-indica extract as a sustainable solution for skins and hides unhairing / Hafeezullah Memon in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIX, N° 9 (09/2024)
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Titre : Opuntia ficus-indica extract as a sustainable solution for skins and hides unhairing Type de document : texte imprimé Auteurs : Hafeezullah Memon, Auteur ; Eldana Bizuneh Chaklie, Auteur ; Mulugeta Muche Birhanu, Auteur ; Misganaw Hailie Tesfie, Auteur Année de publication : 2024 Article en page(s) : p. 387-395 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Chimie écologique
Cuirs et peaux -- Propriétés mécaniques
Cuirs et peaux de moutons
Enzymes végétales
Epilage
Epilage enzymatique
Figuier de Barbarie
Résistance à la déchirure
Résistance à la tractionIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : With increasing awareness of environmental repercussions stemming from the leather industry, the pursuit of plant-based unhairing methodologies has gained substantial research momentum. This study unveils an innovative strategy capable of thorough sheepskin unhairing within a remarkably brief span of 6 hours. This approach is promising because it leverages the synergistic potential of potassium/calcium thioglycolate to dismantle disulfide bonds in keratin and fortify the process with zinc substances to enhance collagen attributes and skin texture. In addition, the inherent natural antioxidants present in plants mitigate microbial proliferation. By employing various concentrations and durations, the chemical formulation was systematically applied to nine distinct samples, culminating in an optimal outcome marked by 80 mL of Opuntia ficus-indicasolution. This treatment resulted in a noteworthy enhancement in collagen integrity and skin texture, with profound penetration of the chemical into the skin matrix, thereby ensuring efficacious permeation. Critically, the inclusion of collagenase inhibitor constituents within the enzyme composition precluded collagen degradation, ultimately yielding premium-grade leather that not only adheres to but also surpasses industry benchmarks, as substantiated by meticulous tensile and tear tests. Leathers crafted via this innovative paradigm consistently demonstrated superiority, thereby underscoring the merits of this approach in fostering sustainable leather production. Note de contenu : - EXPERIMENTAL :
- Materials
- Method
- RESULTS : Unhairing agent application
- Hair removal results
- Characteristics of leather after new unhairing process
- Shrinkage temperature test
- The extent of hair removal from each sample and Shrinkage test result
- Influence of concentration and unhairing duration on tensile strength
- Influence of concentration and unhairing duration on tear strength
- Comparing conventional process and current novel process
- Table 1 : Application of the solution at different concentrations and duration
- Table 2 : The extent of hair removal from each sample and Shrinkage test result
- Table 3 : Thickness, tensile strength with its SD, percentage elongation and tear strength with its SD result of samples
- Table 4 : Comparison between conventional process and the developed novel processDOI : https://doi.org/10.34314/5x1p4465 En ligne : https://drive.google.com/file/d/1EXdOUu_NMZq0VcCA4AUvg1a8pGaSLWqr/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41457
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Code-barres Cote Support Localisation Section Disponibilité 24826 - Périodique Bibliothèque principale Documentaires Sorti jusqu'au 18/10/2024 The future of leather production based on chemicals evaluation in conjunction with modern tools for higher performing processes and lower environmental impact / R. Pasquale in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIX, N° 9 (09/2024)
[article]
Titre : The future of leather production based on chemicals evaluation in conjunction with modern tools for higher performing processes and lower environmental impact Type de document : texte imprimé Auteurs : R. Pasquale, Auteur ; T. Pellegrini, Auteur ; F. Serafini, Auteur Année de publication : 2024 Article en page(s) : p. 396-404 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Biomatériaux
Cuirs et peaux -- Finition
Cuirs et peaux -- Industrie -- Aspect de l'environnement
Cuirs et peaux -- Produits chimiques
Déchets végétaux -- Recyclage
Durée de vie (Ingénierie)
Eaux usées
Environnement -- Etudes d'impact
Evaluation
Olive et constituants
PicklageLe picklage consiste à faire absorber à la peau en tripe une quantité importante d'acide, en présence de sel neutre (NaCl) pour réprimer le gonflement que provoquerait l'acidité du milieu.
Produits de nourriture du cuir
Retannage
TannageIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : In response to rising pressure from both market forces and global institutions, the leather manufacturing sector is actively seeking solutions to minimize its environmental impact. This has triggered an increase in research and development with a particular focus on sustainable chemistry as the pillar for creating a more responsible and future-proof industry. Additionally, there’s a call for transparency and robust assessments of industry practices to empower customers and minimize environmental impact. This study explored the potential of bio-based chemicals in tanning, retanning, and finishing processes. It compared different tanning technologies based on their chemical composition, bio-based content, tanning procedures, and environmental impact using Life Cycle Assessment (LCA) methodology. The traditional chromium tanning process served as the benchmark, while the Olive oil Mill Wastewater technology (OMW) received particular attention due to its high bio-based content. The study concludes by comparing the effectiveness, safety, and environmental impact of different tanning technologies. It demonstrates that the OMW process, with its high bio-based content, produces high-quality leather with significantly less environmental impact compared to traditional methods. Note de contenu : - EXPERIMENTAL :
- Bio-based content evaluation
- Leather application
- LCA evaluation
- RESULTS AND DISCUSSION :
- Bio-based content on chemicals and leather
- LCA assessment of different tanning techniques
- LCA performance evaluation
- Safety issues and LCA performances
- CONCLUSIONS :
- Bio-based assessment and LCA as tools for transparency and decision-making
- Table 1 : Tanning technologies considered for this investigation
- Table 2 : Main chemical properties for the different tanning technologies
- Table 3 : Midpoints results for chromium and OMW technologies ; the application steps included pickling, tanning and retanning/fatliquoringDOI : https://doi.org/10.34314/kbc0jf53 En ligne : https://drive.google.com/file/d/1R1DGC11ya_BIKAJ05zOBeQVRF3eS6hr8/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41458
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Code-barres Cote Support Localisation Section Disponibilité 24826 - Périodique Bibliothèque principale Documentaires Sorti jusqu'au 18/10/2024 Impact of acrylic polymer molecular weight and groups on physicochemical properties and re-tanning effectiveness in leather manufacturing / Zhiyuan Zhu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIX, N° 9 (09/2024)
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Titre : Impact of acrylic polymer molecular weight and groups on physicochemical properties and re-tanning effectiveness in leather manufacturing Type de document : texte imprimé Auteurs : Zhiyuan Zhu, Auteur ; Chunxiao Zhang, Auteur ; Biyu Peng, Auteur ; Xu Zhang, Auteur Année de publication : 2024 Article en page(s) : p. 405-414 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Acide polyacrylique
Agents de tannage
Cuirs et peaux
Liaisons chimiques
Poids moléculaires
Potentiel zeta
Retannage
Réticulation (polymérisation)
Taille des particules
Tannage au chrome
ViscositéIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Acrylic polymers are widely employed as re-tanning agents in leather manufacturing due to their remarkable re-tanning and filling effectiveness, which is primarily attributed to the careful selection of monomers and control over molecular weight. In this study, a series of acrylic polymer re-tanning agents were characterized for their molecular weight and functional groups, followed by analysis of viscosity, particle size, the ability to form cross-linkage with chromium, penetration properties, and filling properties in chrome-tanned leather. The results demonstrated that the viscosity, particle size, surface charge intensity, and cross-linking ability with chromium increased with the increasing molecular weight of the acrylic acid re-tanning agent. The polymers with lower molecular weight exhibited uneven distribution in leather for the potential “capillary plugging” on the surface of leather. Higher molecular weights corresponded to stronger re-tanning and filling effectiveness, though the absorption was negatively affected. Additionally, non-carboxyl functional groups such as methyl group, ester group, amide group, and cyanide group, exhibited random effects on physicochemical properties and application characteristics of acrylic polymer retanning agents. Greater hydrophobicity of functional groups resulted in higher thickening rates for leather, while enhanced ability to form crosslinks with chromium led to improved compression resistance. This elucidation of the influence of basic structure on typical physical-chemical properties and application characteristics will facilitate the development of novel acrylic polymer re-tanning agents and re-tanning technology. Note de contenu : - EXPERIMENTAL :
- Materials
- Molecular weight measurement
- FT-IR analysis
- Viscosity determination
- Particle size and zeta potential determination
- Evaluation of the capacity of acrylic polymers to establish crosslinkage with chromium
- Application properties of acrylic polymers
- RESULTS AND DISCUSSION :
- FT-IR analysis and molecular weight characterization of polyacrylic acid re-tanning agent
- Viscosity analyzation of polyacrylic acid re-tanning agent
- Particle size and zeta potential measurements of polyacrylic acid re-tanning agent
- Reassessment of the crosslinking properties of chromium and acrylic polymer
- Penetration performance of polyacrylic acid re-tanning agent
- Re-tanning performance of polyacrylic acid re-tanning agent
- Table 1 : Re-tanning process
- Table 2 : Classification of acrylic polymersDOI : https://doi.org/10.34314/wgnp8v94 En ligne : https://drive.google.com/file/d/1G75OuLJJNjm2sEo7zP2w12dCgUZxHlRB/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41459
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Code-barres Cote Support Localisation Section Disponibilité 24826 - Périodique Bibliothèque principale Documentaires Sorti jusqu'au 18/10/2024
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Code-barres | Cote | Support | Localisation | Section | Disponibilité |
---|---|---|---|---|---|
24826 | - | Périodique | Bibliothèque principale | Documentaires | Sorti jusqu'au 18/10/2024 |