Titre : |
Determination of water vapour permeability of leather : A report of the VGCT commission for leather testing and evaluation |
Type de document : |
texte imprimé |
Auteurs : |
Hans-Jürgen Kellert, Auteur |
Année de publication : |
2004 |
Article en page(s) : |
p. 63-65 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Catégories : |
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. Cuir Cuir dans les automobiles Cuirs et peaux -- Analyse Perméabilité Vapeur d'eau
|
Index. décimale : |
675 Technologie du cuir et de la fourrure |
Résumé : |
This is the first report of an irregular series providing information on the performance capability of test methods used for many years in the leather industry. The reason and purpose of the series is to provide the reader with an impression of the range and variability of the measured values which result from the use of the test methods on leather.
Anyone concerned with the testing of leather over a period of time will be aware of the problem of agreement of results between two testers. Despite sampling according to DIN, the results agree only to a limited extent. Reasons for this come readily to mind, there is the variability of the leather itself or, the actual location of the specimen may not be known.
As a rule these differences are not understood by the customer. In customer specifications the requirements are often stated in the form of “greater than”, “less than” or as a range “from...to”. These do not provide a problem provided that the achieved values are markedly in excess or below the stipulated values and within the confidence limits of the test method. Problems can arise however when the average value for the delivery conforms to the requirement but is close to the defined limit. It is then possible for individual results to be outside the required values. A recheck by the customer may indicate a failure whereas the producer had achieved compliance in his tests. In order to avoid the possibility of rejection or claims for compensation, it is of considerable importance to know the likely deviations of the test method used. The determination of water vapour permeability according to DIN 53333 is one of those test methods where considerable differences in the determined values can occur. Not only are these variations due to the leather but also to the method itself and the interpretation of the method details.
In order to determine the variability of the test method, a round robin test is ideal as unrelated practitioners test a common material by the same method. The resultant standard deviations of the average values provide a good means of characterising the test method. Disadvantages of this approach are the large amount of material required, as sampling is from the official sampling position and the rapidly increasing number of samples required with an increase in the number of participants. |
Note de contenu : |
- Table 1 : Water vapour permeability values for the FOC crust leather
- Table 2 : Water vapour permeability values of the finished FOC leather |
En ligne : |
https://drive.google.com/file/d/1hvOjwJtXbm18sj0NjLS0T885yV28PfL7/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39643 |
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 88, N° 2 (03-04/2004) . - p. 63-65