Comparative physical properties of leather from young bull hides and steerhides / E. H. Bitcover in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXIX (Année 1974)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXIX (Année 1974) . - p. 508-522 Titre : Comparative physical properties of leather from young bull hides and steerhides Type de document : texte imprimé Auteurs : E. H. Bitcover, Auteur ; A. L. Everett, Auteur ; W. E. Palm, Auteur ; W. Windust, Auteur ; J. Naghski, Auteur Année de publication : 1974 Article en page(s) : p. 508-522 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Boeufs domestiques 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 -- Propriétés physiques Cuirs et peaux de bovins Etudes comparatives Taurillon Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The potential economic advantage of raising young bulls for beef may soon result in a significant increase in the proportional numbers of such hides on the market. A detailed study was therefore undertaken to indicate whether any important differences in leather properties might be expected from this new material compared with conventional steerhides. A total of 38 bull sides and 30 steer sides in the crust were evaluated by means of five different test procedures at each of 12 anatomical locations. The buil sides were found to be significantly stronger by every test except the experimental penetrometer test, which showed no real difference. Distribution of strength by location was essentially similar in all cases. Sorting of finished sides revealed a trend towards visible neck wrinkles in the bull hide leather. Since the experimental hides came from an inbred line of Hereford cattle, the incidence of the vertical fiber defect, which is thought to be genetically controlled, was of special concern. Six hides from bulls and vine from steers were definitely defective and were excluded from the strength comparisons. This is the first known report of the defect in bulls. Note de contenu : - EXPERIMENTAL : Hide source - Leather processing - Physical testing - Statistical analysis - RESULTS AND DISCUSSION : Sorting characteristics - Physcal properties - Statistical interpretation - Strength distribution - Incidence of vertical fiber defect En ligne : https://drive.google.com/file/d/1bkc85ko90spJ5qJbgKN8w095Ic9eJkVk/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41373 [article]

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008508	-	Périodique	Archives	Documentaires	Exclu du prêt

Correlation of differential thermal analysis data with the shrinkage temperature of collagen and leather / J. Naghski in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXI (Année 1966)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXI (Année 1966) . - p. 64-74 Titre : Correlation of differential thermal analysis data with the shrinkage temperature of collagen and leather Type de document : texte imprimé Auteurs : J. Naghski, Auteur ; A. Wisnewski, Auteur ; Edward H. Harris, Auteur ; Lee P. Witnauer, Auteur Année de publication : 1966 Article en page(s) : p. 64-74 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse thermique Collagène -- Analyse Statistique Température de retrait Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Shrinkage temperture data obtained on suspended specimens of raw hide substance and a variety of commercial leathers are compared with values obtained by measuring the thermodynamic changes using differential thermal analysis. In every instance the correlation between the data of these two methods was statistically highly significant, and it is concluded that they measure the same basic phenomenon. It is suggested that the absolute values for the phase transition measured by DTA be used at the reference for the thermal behavior of collagen and its products. Use of suspended specimens offers a simplified procedure, which could be defined as a method for the measurement of shrinkage temperatures. The use of pressurized equipment permitted the extension of the temperature range to include products shrinking above the boiling point of water (100°C). Note de contenu : - Instrumentation - Sample preparation - Typical leather-water thermogram - Table 1 : Data from DTA and suspension shrinkage temperature measurements - Table 2 : Summary of statistical analysis En ligne : https://drive.google.com/file/d/1SauL0CaRzgRUUDvVv4mq8YD0ZOlxD3f2/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37874 [article]

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A matched-side comparative study of the unsplit blue stock and crust leather made from uncured and pit-cured hides / Stephen H. Feairheller in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXX (Année 1975)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXX (Année 1975) . - p. 464-480 Titre : A matched-side comparative study of the unsplit blue stock and crust leather made from uncured and pit-cured hides Type de document : texte imprimé Auteurs : Stephen H. Feairheller, Auteur ; A. L. Everett, Auteur ; J. Naghski, Auteur ; F. J. Poats, Auteur ; D. F. Holloway, Auteur Année de publication : 1975 Article en page(s) : p. 464-480 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Chimie analytique 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 de bovins Echantillonnage Essais dynamiques Etudes comparatives Microscopie Wet-blue (tannage) Peau tannée au chrome (le chrome donne une couleur bleue) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : A matched-side study of 300 heavy steerhides was conducted jointly by Spencer Foods, Inc. and two agencies of the USDA to reexamine the economics of processing fresh, uncured hides into side upper leather in the light of efforts being made to eliminate salt from tannery and packing house effluents. In this report we present a comparison of the chemical and physical properties of leather made from uncured vs. cured sides at the wrung, unsplit blue stage and again at the dry crust stage, designed to indicate any potential quality advantage of one type of product over the other. A further effort was made to determine whether any other commercially important differences occurred, in response to processing, between the two types of stock. Analysis of the blue stock revealed that the uncured sides had a significantly higher chrome and ash content and a higher shrinkage temperature, while microscopic examination showed no difference in chrome distribution or extent of opening up of the fibers. Physical tests showed a higher tensile strength and penetrometer strength for the uncured sides but a lower ball burst extension value. The crust leather from uncured sides was equivalent to that from cured sides in sorting characteristics but had a significantly higher tensile strength. Processing differences were noted at the liming and chrome-tanning steps that appear advantageous to the processing of fresh hides. Furthermore, there was a slightly higher yield of crust leather from the uncured sides. it was concluded that it is possible, and perhaps economically advantageous, to process uncured hides by conventional processes into quality leather that is essentially indistinguishable from leather made from cured hides. Note de contenu : - Processing - Blue sort - Sampling - Chemical analysis - Microscopical evaluations - Physical tests - Crust sort - Table 1 : Pack and averge side weights at different stages of processing - Table 2 : Blue sort results - Table 3 : Chemical analyses and shrinkage temperature measurements - Table 4 : Results of physical tests on wrung unsplit blue stock - Table 5 : Results of physical tests on 5 1/2 oz. crust stock En ligne : https://drive.google.com/file/d/1IUHYNcE1Jh9veK6vuRuzeA7agnLkmK0X/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38792 [article]

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008509	-	Périodique	Archives	Documentaires	Exclu du prêt

Microscopic study of leather defects / A. L. Everett in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXI (Année 1966)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXI (Année 1966) . - p. 112-127 Titre : Microscopic study of leather defects : I. Veininess in glazed calfskin Type de document : texte imprimé Auteurs : A. L. Everett, Auteur ; H. J. Willard, Auteur ; J. Naghski, Auteur Année de publication : 1966 Article en page(s) : p. 112-127 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux -- Défauts Défaut de veine (cuir) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Prominent blood vessel pattern on the grain surface of leather is an esthetic defect which has long been troublesome and costly to the industry. In spite of numerous attempts to solve the problem, as summarized from the literature, the basic cause of the defect remains unknown. Inadequate curing and drastic processing were most frequently suspected, but so far there has been no conclusive proof. Therefore a continuing search for preventive measures would seem less practical than systematic testing of corrective treatments. Microscopic examination of cross-sections, improved by a suitable aqueous embedding technique, is shown to be helpful in guiding such a program. Studies of blood vessel distribution have established that they are typically arranged in three layers. The deepest and largest vessels, especially the arteries, are the principal offenders in this problem, but it is shown that their depth can be so variable that shaving is not a dependable solution. More significantly, there is almost always a large void space around the deep vessels in veiny leather but not in non-veiny samples, even from skins processed together in the same tannery pack. Thin skins are an especially difficult problem. The suggested approach for correction would be to fill there voids, either by plumping the fibers with a suitable retannage or by the use of impregnating materials. Cross-sections illustrating an experimental zirconium retannage indicate a definite reduction in void space and in consequent veininess. Likewise a resin treatment, being studied elsewhere, seems quite promising af ter preliminary trials. Note de contenu : - EXPERIMENTAL METHODS : Sectioning - Gelatin embedding - Microscopy - RESULTS AND DISCUSSION : Veiny vs. non-veiny skins - Veiny thin skins -Veniness without void space - Veniness reduced by retannage En ligne : https://drive.google.com/file/d/1kS5RRAvgc4pKf9T4XiHF_7NrLb0vAQTw/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37939 [article]

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008496	-	Périodique	Archives	Documentaires	Exclu du prêt

A study of freeze branding : influence of branding conditions on legibility and leather damage / A. L. Everett in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXX (Année 1975)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXX (Année 1975) . - p. 188-205 Titre : A study of freeze branding : influence of branding conditions on legibility and leather damage Type de document : texte imprimé Auteurs : A. L. Everett, Auteur ; N. W. Hooven, Auteur ; J. Naghski, Auteur ; Robert G. Koeppen, Auteur Année de publication : 1975 Article en page(s) : p. 188-205 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Animaux -- Marquage Azote Cuirs et peaux -- Détérioration Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Traditional hot-iron branding of cattle produces large economic losses of leather, marginal legibility for ranchers, and excessive cruelty to animals. Substitution of irons chilled in a dry ice-alcohol mixture or liquid nitrogen produces permanent, white-haired brands that are relatively painless and show greatly improved legibility. Furthermore, when properly performed, freeze branding induces minimal scarring of hide tissue and therehy reduces the leather wastage produced hy conventional branding. To provide further guidelines for improving the technique of freeze branding, a comprehensive, three-year test was performed on 23 dairy cattle and nine beef animals at three geographic locations. The two refrigerants mentioned above were compared in parallel on opposite sides of each animal to evaluate three other primary variables : age at branding, anatomical area, and exposure time. Legibility of each brand was scored after regrowth of hair. Cuttability (usability) of resultant leathers was judged mostly in corrected grain finish, but partially in full grain and in splits after close inspection of crusted sides. It was shown that exposure time, age at branding, and breed type are all critical variables. Although both refrigerants gave equally good legibility, liquid nitrogen (as used after clipping) produced many more bald brands and too much tissue damage for acceptability in leather. Cuttability of the dry-ice hrands ranged from about 25 percent in grain leather to over 50 percent in splits. Note de contenu : - EXPERIMENTAL : Test design - Test cattle - Branding procedures - Legibility scores - Leather scores - Acceptable brands - RESULTS AND DISCUSSION : Brand legibility - Bald brands - Leather effects - Minor factors - Optimum branding conditions - Table 1 : Controlled variables in freeze brand test - Table 2 : Test cattle used at each location - Table 3 : Influence of time and refrigerant on baldness and legibility of freeze brands on 22 dairy cattle En ligne : https://drive.google.com/file/d/1sbMCEUuTMHwhV0n-340pPke6ChSD05K0/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38786 [article]

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008509	-	Périodique	Archives	Documentaires	Exclu du prêt

Washability of glutaraldehyde-chrome tanned garment and glove leathers / S. J. Viola in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXI (Année 1966)  

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