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Relationship of leather break to grain and flesh layers stress - Strain properties / Jorge A. Vergara in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 63, N° 2 (03-04/1979)
[article]
Titre : Relationship of leather break to grain and flesh layers stress - Strain properties Type de document : texte imprimé Auteurs : Jorge A. Vergara, Auteur ; Alberto Sofia, Auteur ; José Hidalgo van Dick, Auteur ; Victor D. Vera, Auteur Année de publication : 1979 Article en page(s) : p. 25-27 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Emulsions
Homopolymères
Matériaux -- Imprégnation
Polyacrylate d'éthyle
Polyacrylate de butyle
Polyacrylate de méthyle
Polymérisation en émulsion
Polyméthacrylate de méthyleLe poly(méthacrylate de méthyle) (souvent abrégé en PMMA, de l'anglais Poly(methyl methacrylate)) est un polymère thermoplastique transparent obtenu par polyaddition dont le monomère est le méthacrylate de méthyle (MMA). Ce polymère est plus connu sous son premier nom commercial de Plexiglas (nom déposé), même si le leader global du PMMA est Altuglas International9 du groupe Arkema, sous le nom commercial Altuglas. Il est également vendu sous les noms commerciaux Lucite, Crystalite, Perspex ou Nudec.
Rigidité (mécanique)
Rupture (mécanique)Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Four impregnating resins (homopolymers) were produced from methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate monomers respectively. The emulsion polymerisation method and other chemical agents were maintained constant. Upper leathers were impregnated with these resins following a statistical design which included non-impregnated leathers as controls. Leather break and stiffness were assessed before and after the impregnating process. The elasticity modulus at 2% extension was measured for ail leathers and also in their respective grain and flesh layers after splitting. From the results obtained several concrete facts emerged. First, the leather break and stiffness increased in the following resins order: butyl acrylate < ethyl acrylate= methyl methacrylate < methyl acrylate. Relationships of the grain layer elasticity modulus to the flesh layer one for the impregnated leathers (Mi grain/Mi flesh) and for the control leathers (Mc grain/Mc flesh) were calculated. It was found that an increase in the difference between these two relationships correlated very well with the increase found in the leather break. On the other hand, when the leathers were impregnated with film forming polymers, their elasticity modulus increased proportionally to the polymer hardness increase. Note de contenu : - EXPERIMENTAL : Impregnating emulsions - Leather ande application of the impregnating resin
- RESULTS : Leather break - Stiffness - Elasticity modulus
- Table 1 : Emulsion composition
- Table 2 : Break (0 = poor ; 10 = escellent) control leather score = 5.0
- Table 3 : Stiffness (0 = soft ; 5 = extremely rigid) (control leather score = 2.0
- Table 4 : Impregnated leather elasticity modulus measured at 2% of strain (g/mm2) (control leather elasticity modulus = 1.444 g/mm2)
- Table 5 : Relative variation of elasticity modulus (ΔMR) of grain and corium layers of impregnated leather referred to the control and break increase obtained with each resin emulsionEn ligne : https://drive.google.com/file/d/1NNJQVVSKaupq3f55T1L04_U_ORQefQ0e/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34137
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 63, N° 2 (03-04/1979) . - p. 25-27[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 007120 - Périodique Bibliothèque principale Documentaires Disponible Unhairing technology involving hair protection adaptation of a recirculation technique / Carlos S. Cantera in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 79, N° 1 (01-02/1995)
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Titre : Unhairing technology involving hair protection adaptation of a recirculation technique Type de document : texte imprimé Auteurs : Carlos S. Cantera, Auteur ; Victor D. Vera, Auteur ; L. Fernà ndez Crespo, Auteur ; R. Escobar, Auteur Année de publication : 1995 Article en page(s) : p. 12-17 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux
Cuirs et peaux -- Déchets -- Recyclage
Déchets -- Réduction
Déchets industriels -- Recyclage
EpilageIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : The application of the hair-saving process has mainly resulted in a reduction of the organic content and suspended-settleable solids in the beamhouse effluent.
Aiming at decreasing the volume of effluents from unhairing and at optimizing the amount of products used in such a process in a tannery producing upholstery leather, a study concerning recycling was made of the effluents from a hair-saving "chemical unhairing" process that is in current use.
By means of trials both at laboratory scale on a pilot plant, the recirculation of an effluent ("mixed liquor") - including unhairing liquid wastes and waste water from the first discontinuous washing - was used at the stages of alkaline conditioning, hair immunization, unhairing and liming.
Fifteen unhairing trials were performed at the CITEC's pilot plant with 7 bovine hides in each cycle ; when the pelt stage was reached, the process was continued at the tannery.
The results obtained led to the following conclusions :
. An adaptation of the recycling technique to a hair-saving process is applicable at the liming, immunization and unhairing stages ;
. The features of the "re-circulated leather" are similar to those of the finished upholstery product made by the tannery ;
. This recycling technique allows for an 88 % reduction in the volume of unhairing wastes and for 43 and 20 % reduction in the consumption of lime and sodium sulphide, respectively.En ligne : https://drive.google.com/file/d/1wfqU4Ly8LnaqtRMwBcAENil7q8_14Kle/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=8229
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 79, N° 1 (01-02/1995) . - p. 12-17[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 007002 - Périodique Bibliothèque principale Documentaires Disponible