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The diffusion barrier within the unhairing process / Carlos S. Cantera in WORLD LEATHER, Vol. 18, N° 6 (10/2005)
[article]
Titre : The diffusion barrier within the unhairing process Type de document : texte imprimé Auteurs : Carlos S. Cantera, Auteur ; Maria Laura Garro, Auteur ; M. L. Goya, Auteur ; L. Barbeito, Auteur ; Betina Galarza, Auteur Année de publication : 2007 Article en page(s) : p. 29-32 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Epilage
Peaux brutesIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Hair-saving processes for bovine hides are being applied in tanneries in several countries to replace traditional hair burning systems. The factors that are taken into account when using this unhairing technique are :
- the need for a pelt that is suitable for the production of different types of leather
- a reduction in the effluent load arising from the beamhouse
- the recovery of the partially degraded hair as a solid waste with potential industrial applications
It is well known that the organic matter, the sulfide ion content and the presence of suspended solids in the liquid effluent is greatly dependant on the unhairing process employed. Within the sulfide unhairing system there are problems associated with toxicity, odour and effluent treatment.
Hydrogen sulfide is a highly toxic gas, and can be liberated from within the unhairing process and from effluent treatment. In extreme cases it has led to the death of workers, and in the wider environment creates an odour within the tannery surroundings which causes associated complaints. The acceptable maximum concentration in the work environment, in which a worker can remain for 8 hours/day and 5 days/a week, is 10 cm3 H2S/m3 (15 mg/m3) without suffering physical damage.
The enzymatic removal of intact hair offers a suitable alternative to destructive sulfide unhairing. However, interest in the enzyme unhairing process cornes and goes. This is because of difficulties in managing the process, mainly because the proteolysis cannot be accurately focused and controlled. Essentially, the enzyme activity is not restricted to the function of hair removal, but also affects the structure of the dermis. The grain layer is therefore partially digested hence there is a decrease in the quality of the grain structure in the final leather. Enzyme unhairing remains a fascinating concept, but is full of difficulties.
Nevertheless, the problems and costs of treating effluent to acceptable standards are considerable. If hair could be removed intact without using sulfide, then there would be a significant easing of techniques, capital equipment and power requirements to achieve discharge limits. In addition, the volume of sludge would be considerably reduced, with the hair remaining as a new clean raw material with many potential ourlets.Note de contenu : - The epidermis as a diffusion barrier
- The role of lipids within the epidermis
- The diffusion of substances across the epidermis
- Enhancers for penetration, or promoters for reactions : Sodium sulfite - Surfactants - Proteolytic enzymes - Trypsin - Urea - Organic solvents
- Phases of the unhairing processEn ligne : https://drive.google.com/file/d/14I1LkOfYwz-xkhH5GSFeR0kmgJqXd9Yb/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35688
in WORLD LEATHER > Vol. 18, N° 6 (10/2005) . - p. 29-32[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 006186 - Périodique Bibliothèque principale Documentaires Disponible The impact of different hair-removal behaviours on the biophysical and biochemical characteristics of female axillary skin in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 42, N° 5 (10/2021)
[article]
Titre : The impact of different hair-removal behaviours on the biophysical and biochemical characteristics of female axillary skin Type de document : document électronique Année de publication : 2020 Article en page(s) : p. 436-443 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Aisselles -- Soins et hygiène
Barrière cutanée
Cosmétiques
Cytokines
Epilage
Erythèmes
Evaluation
Peau -- Physiologie
Peau -- Soins et hygièneIndex. décimale : 668.5 Parfums et cosmétiques Résumé : - Objective : The impact of hair removal on the biophysical and biochemical characteristics of human axillary skin is not fully understood. This study investigated the effect of different hair-removal techniques on biophysical parameters and the concentrations of key inflammatory biomarkers in the axillae of female Thai subjects. Axillary hair was removed by shaving, plucking or waxing.
- Methods : Following a 2-week washout phase without hair removal, subjects underwent visual assessment for erythema and skin dryness in one (randomized) axilla, then, hair was removed from the axilla by shaving, plucking or waxing according to each subject’s established habit. Erythema and dryness were assessed again 30 min after hair removal, and buffer scrubs collected from depilated and non-depilated axillae and analysed for inflammatory cytokines; after a further 48 h, erythema, dryness and post-inflammatory hyperpigmentation (PIHP) were assessed in the depilated axilla. Biophysical assessments (skin hydration, barrier integrity, elasticity and roughness) were made in depilated and non-depilated axillae.
- Results : All three hair-removal techniques induced an increase in axillary erythema and skin dryness. Shaving was associated with significantly less erythema (P < 0.01), but significantly greater skin dryness (P < 0.05) versus the other techniques 30 min after hair removal. There were no between-technique differences in PIHP or biophysical parameters. Interleukins IL-1α and IL-1RA concentrations increased, and IL-8 concentration decreased following hair removal by each technique.
- Conclusion : This is the first study to identify the principal cytokines associated with the inflammatory process triggered by axillary hair removal. A single hair-removal treatment did not appear to induce PIHP or further biophysical changes to the skin.Note de contenu : - METHODS : Impact of different hair removal techniques on the biophysical and biochemical properties of axillary skin - Subjects - Study design - Assessments - Data analysis
- RESULTS : Visual and biophysical assessments - Biochemical assessmentsDOI : https://doi.org/10.1111/ics.12648 En ligne : https://drive.google.com/file/d/1DPbReUcASEA5Q6qw6TefFul7JLTc3IFJ/view?usp=shari [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35408
in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 42, N° 5 (10/2021) . - p. 436-443[article]The methods and mechanism of unhairing / D. Burton in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 100, N° 2 (03-04/2016)
[article]
Titre : The methods and mechanism of unhairing Type de document : texte imprimé Auteurs : D. Burton, Auteur Année de publication : 2016 Article en page(s) : 12 p. Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Epilage
LaineIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : In investigating the efficiencies of unhairing agents it is necessary to ascertain the effects on the old club hairs, the short undergrowth of young hairs, the follicles and the malpighian layer. These structures and the interfibrillary matter, which consists of albumins, globulins and mucoids, are affected by the times which elapse between the death of the animal, flaying and curing as well as by the methods of curing, and soaking.
The methods of Ioosening the hair by liquid air, warm water, bacteria, enzymes, alkaIine solutions, alkaline solutions with reducing or oxidising agents, acids and lyotropic salts arc discussed and compared with the methods of tightening the hair with bactéricides, moderato concentrations of caustic soda, acid solutions such as pickles or bran drenches, protein precipitants and increasing or decreasing the moisture content in the case of the woolskins.
Microscopie observations show that the unhairing agents all act on the malpighian or soft inner mucous layer. The crux of the unhairing problem is therefore to weaken or partially dissolve the mucous layer of the epidermis and to find a machine which will remove the longer hair and the undergrowth of short young hairs. The soft inner mucous layer is rich in mucoid material. It is still considered that unhairing and bating are in essence the partial removal of this material.
In the application of modern scientific researches to the practice of leather manufacture it must be realised that science is dynamic and not static. In any particular field, the scientist has established certain facts and is investigating a number of possibilities. We must be careful to confine our thoughts to the application of established facts and remember the conditions of time, temperature, concentration, movement and degree of aeration which are inherent in these facts. Conclusions for fresh skins do net necessarily apply to salted ones. Again, precision must be used in visualising the processus of leather manufacture. This is by no means as easy as it might appear to die uninitiated for the smallest details are often significant.Note de contenu : THE STRUCTURE AND GROWTH OF THE HAIR AND EPIDERMIS
- EXPERIMENTS TO INVESTIGATE THE EFFICIENCY OF VARIOUS UNHAIRING AGENTS : Methods of unhairing - Methods of tightening the hair of woolEn ligne : https://drive.google.com/file/d/1lRgGm1yQoC5xouzIahRfqI1uYxdhs5NC/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=26093
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 100, N° 2 (03-04/2016) . - 12 p.[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 17955 - Périodique Bibliothèque principale Documentaires Disponible The physical properties of leather from kangaroo skins III / L. J. Stephens in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXXXIV (Année 1989)
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Titre : The physical properties of leather from kangaroo skins III : Comparison between sirolime and conventional unhairing and between chrome and vegetable tanning Type de document : texte imprimé Auteurs : L. J. Stephens, Auteur ; D. E. Peters, Auteur ; A. C. Trajstman, Auteur Année de publication : 1989 Article en page(s) : p. 296-305 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux de kangourous
Epilage
Tannage au chrome
Tannage végétalIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The tensile strenght and elongation of leather from male and female, Red and Grey Kangaroos was used to compare the effect of unhairing by the conventional lime/sulfide process and the Sirolime process. No difference was detected between the properties of leather produced by either of the two unhairing methods. A similar comparison was made between chrome-tanned and vegetable-tanned kangaroo leather ; the vegetable-tanned leather gave lower strenght properties than the chrome-tanned leather when treated with the same levels of fatliquor. Note de contenu : - MATERIALS AND METHODS : Skins - Unhairing and tanning - Physical testing
- RESULTS : Sirolime vs. conventional unhairing - Chrome vs. vegetable tanning
- Table I : Average tensile properties. Sirolime & conventionally limed, chrome-tanned kangaroo leather
- Table II : Average tensile properties. Sirolime & conventionally limed, chrome-tanned kangaroo leather ; variation with position on the skin
- Table III : Average tensile properties. Sirolimed & conventionally limed, chrome-tanned kangaroo leather ; variation with direction of testing
- Table IV : Average tensile properties. Chrome vs vegetable-tanned kangaroo leather
- Table V : Average tensile properties. Chrome vs vegetable-tanned kangaroo leather : variation with position on the skin
- Table VI : Average tensile properties. Chrome vs vegetable-tanned kangaroo leather ; variation with direction of testingEn ligne : https://drive.google.com/file/d/1RGbWtkElTveDBbbMIT_re6yi0CrLozZU/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=17365
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXXXIV (Année 1989) . - p. 296-305[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 008089 - Périodique Bibliothèque principale Documentaires Disponible The physical properties of leather from Kangaroo skins V. Comparison of hair-on and unhaired tannage / L. J. Stephens in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXXXV (Année 1990)
[article]
Titre : The physical properties of leather from Kangaroo skins V. Comparison of hair-on and unhaired tannage Type de document : texte imprimé Auteurs : L. J. Stephens, Auteur ; D. E. Peters, Auteur Année de publication : 1990 Article en page(s) : p. 19-23 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux de kangourous
Epilage
TannageIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : A comparison is made, by means of matched sides, of the physical properties of unhaired or hair-on leather, produced from the skins of female Red Kangaroos. It is found that unhaired leather is consistently stronger than hair-on leather and, although this difference is not large, it is statistically significant. En ligne : https://drive.google.com/file/d/1Ow85AZxpqUmLyAYKl3VBFUAjjXv98fgd/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=8604
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXXXV (Année 1990) . - p. 19-23[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 008090 - Périodique Bibliothèque principale Documentaires Disponible The use of neutral protease in enzymatic unhairing / R. G. Paul in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVI, N° 5 (05/2001)
PermalinkUnhairing of goat skins by an alternative non-enzymatic and sulphide free process / Praveen Kumar Sehgal in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 80, N° 3 (05-06/1996)
PermalinkUnhairing 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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