Comparative instrumental evaluation of water-resistant upper leathers / Ludwig Seligsberger 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. 66-75 Titre : Comparative instrumental evaluation of water-resistant upper leathers Type de document : texte imprimé Auteurs : Ludwig Seligsberger, Auteur ; Richard F. Lacerte, Auteur Année de publication : 1975 Article en page(s) : p. 66-75 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux -- Analyse Evaluation Mesure -- Instruments Résistance à l'humidité:Résistance à l'eau Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The Dow Corning Tester w•as introduced as an alternative for measuring water resistance in leather hecause the number of flexes to produce a leak was found to he approximately one quarter of the number required on the Maeser Tester. An investigation was conducted to determine how three possible ways of mounting specimens in the Dow Corning 'l'ester would affect water penetration. The results show that w•ater penetration is achieved faster with the Dow Corning Tester than with the Maeser Tester only when the specimens are mounted with their walls parallel tu each other during maximum extension. The gaskets prescrihed for use with the Dow Corning Tester are not essential and need not be used. When a four-by-four inch specimen is mounted to form a pouch with a middle fold before the machine is turned on, the specimens are compressed, slowing down the rate of water penetration to the extent that no saving in time is realized, compared to the Maeser Tester. In fact, with some of the leathers tested in this manner flexing had tu he terminated after 100,000 cycles because no leakage occurred, as is frequently ohserved on the Maeser Tester. The precision of the methods in which end points were reached with unahraded samples was hetter than expected, with the coefficients of variation ranging from 29 to 67 percent, compared with 100 percent termed "not unusual" in the description of the standard method issued by the American Society of Testing and Materials. Final tabulation shows that for the water-resistant upper leathers examined the mean ratio of the number of flexes till leakage in the Maeser Tester to the number of flexes till leakage in the Dow Corning l'ester was in the vicinity of 2.5, which is somewhat lower than previously reported. Note de contenu : - Equipment - Procedure - Table 1 : Water resistance of flesh out upper leather - Table 2 : Water resistance of abraded flesh out upper leather - Table 3 : Water resistance of flesh out upper leather - Table 4 : Water resistance of grain out upper leather - Table 5 : Ratio of results on maeser and dow corning tester En ligne : https://drive.google.com/file/d/17kLLzNdF9Pdhyl6ES0QrYuI0lErjfoYT/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38780 [article]

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Determination of the surface absorption of water vapor and liquid water by leather and other sheet materials / Ludwig Seligsberger 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. 236-250 Titre : Determination of the surface absorption of water vapor and liquid water by leather and other sheet materials Type de document : texte imprimé Auteurs : Ludwig Seligsberger, Auteur Année de publication : 1974 Article en page(s) : p. 236-250 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Absorption Cuir Cuirs et peaux de moutons Esters de cellulose Filtres Gants Semelles Vapeur d'eau Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : A method developed earlier for measuring water vapor absorption of leather and other sheet materials was modified to facilitate routine determinations of this property on large numbers of specimens. The micro-porous, hydrophobic cellulose ester filter was retained as the barrier material, but individual culture dishes with moist blotting paper at the bottom were used and the water vapor absorption was not measured at regular intervals, but just once when the test was terminated. Results obtained in this manner are presented in two tables. A new method for measuring surface absorption of liquid water by leather and other sheet materials was also developed. Differences between results of surface water absorption under dynamic and static conditions could not be found. Conditions were established for using three vessels of differe'nt size interchangeably. Results are presented in four tables. Some types of insoles, whether made of leather or of cellulose, were found developing a trend toward reduced wettability after repeated wetting and drying. One cellulosic product was exceedingly wettable because it contained a water soluble surfactant, but after its removal became difficult to wet. The importance of the properties measured by the two methods for the development of functionally improved handwear and for assessing replacement materials for leather insoles is discussed. Note de contenu : - Apparatus for water vapor absorption - Determinationof water vapor absorption : Specimen size and reporting results - Apparatus for surface water absorption - Determination of surface water absorption - Table 1 : Water vapor absorption of leather insoles in grams (culture dish method) - Table 2 : Water vapor absorption of cellulosic insoles in grams (culture dish method) - Table 3 : Water absorption by grain surface of water repellent sheepskin glove leather (one specimen each from four skins representing two different experimentl lots) - Table 4 : Water absorption by degrained surface of leather insoles - Table 5 : Dynamic surface water absorption of cellulosic insoles (eight specimens from 1 sheet, 5 irons = 2.67 mm. thick) - Table 6 : Dynamic surface water absorption of cellulosic insoles (four specimens from one sheet, 5 irons = 2.67 mm. thick) - Table 7 : Comparison of siliconized and the formerly available hydrophobic type of millipore filters for the determination of water vapor absorption En ligne : https://drive.google.com/file/d/1_wCQVLcZ8atoQlTSy-3-SlaPeS1IxJsV/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41365 [article]

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Leather and technology in the age of chrome / Ludwig Seligsberger in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXXXVI, N° 7 (07/1991)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. LXXXVI, N° 7 (07/1991) . - p. 245-258 Titre : Leather and technology in the age of chrome Type de document : texte imprimé Auteurs : Ludwig Seligsberger, Auteur Année de publication : 1991 Article en page(s) : p. 245-258 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The introduction of the two-bath process was the subject of a recent paper by Stellmach. No less revolutionary was the shift in the one-bath tannage from chrome alum to basic chrome salts. The suppliers of these chrome extracts became adept at modifying them to save the tanner time and nearly to eliminated the chrome content of waste liquors. These and other changes taking place in the manufacture of leather induced governments and institutes devoted to research and engineering and to open national tanners' schools. International and national societies formed and bagan to hold annual or biennal conventions. Periodicals were founded, spreading the latest word on theory and practice of converting hides and skins into leather. These developments are reviewed with particular emphasis on the United States. Promising new technologies including "reconstitued collagen", solvent tannages and various ultra-rapid methods aimed at reducing sludge and effluent to a minimum are surveyed. Several synthetic tanning materials born out of necessity in Germany and the US during World War Il could not maintain as large a share of the market as was necessary for them to be produced in peacetime. Finally, the most recent trend toward the partial or complete elimination of chrome, for instance by replacing wet blues with aluminum-tanned wet whites, is briefly discussed. En ligne : https://drive.google.com/file/d/1VAwD7QLjbGk8TWIbUXJ5es_znQ_umERe/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=8480 [article]

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Water vapor permeability of leather and leatherlike sheet materials : a new approach / Ludwig Seligsberger 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. 98-113 Titre : Water vapor permeability of leather and leatherlike sheet materials : a new approach Type de document : texte imprimé Auteurs : Ludwig Seligsberger, Auteur Année de publication : 1975 Article en page(s) : p. 98-113 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuir Cuir synthétique Cuirs et peaux -- Analyse Essais (technologie) Perméabilité Vapeur d'eau Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Water vapor permeability can be determined by establishing a gradi-ent from zero to near 50 percent relative humidity using a desiccant like calcium chloride, or a gradient from almost 50 percent to 100 per¬cent relative humidity using water. New variants of water vapor trans¬mission methods were investigated. Common to these is the use of a turntable to control the airflow near the assembly with the specimen. The desiccant method was improved by making the hygroscopie surface next to the specimen renewable. In the method using water, a hydrophobic microporous barrier was placed between water and specimen, and the passage of water vapor through this barrier simulating the skin was accelerated by raising the water temperature through an external electric heating system. Experiments were conducted on several types of leather and on sheet materials used as leather substitutes. Water vapor transmission was measured in dynamic tests using the turntable and in static tests in which the assembly with the specimen was stationary. In additional static and dynamic tests the rate of evaporation of water in the presence or absence of the barrier material and the water pickup of the desiccant itself were determined. The results are summed up in five tables. It is concluded that the rates of water vapor transmission found at 21°C. by the new variant of the desiccant method and by the method using water next to a microporous barrier are not substantially different. Raising the water temperature to 39°C., on the other hand, raised transmission rates for three types of leather 3.3 to 8.6 times and for expanded or perforated vinyl 35 to 65 times. These unexpected differences point out the importance of simulating actual wear conditions in the assessment of water vapor permeability as a comfort factor. Note de contenu : - APPARATUS : For the desiccant method - For the method using water at 21°C - For the method using water at 390°c - Properties of FHLP filters - Equipment for additional tests - METHODS OF TEST AND REPORTING RESULTS : Deiccant method - Dynamic method using water at 21°C - Dynamic method using water at 39°C - "Blank" determinations - RESULTS : Desiccant method - Method using water at 21°C and 39°C - DISCUSSION : Desiccant method - Method using water - Table 1 : Water vapor permeability with calcium chloride as desiccant in absence or presence of leather and other sheet materials - Table 2 : Evaporation and transmission of water vapor in absence and presence of a hydrophobic microporous barrier - Table 3 : Water vapor permeability of leather and other sheet materials in presence of a hydrophobic microporous barrier - Table 4 : Comparative values for water vapor permeability on turntable and in test chamber - Table 5 : Ratios obtained by measuring evaporation, absorption, and water vapor transmission by different methods En ligne : https://drive.google.com/file/d/1DzSHvfxCdVUe6aUUqjmCmgz80erh4M8E/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38781 [article]

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