| Titre : |
Leather property : looseness |
| Type de document : |
texte imprimé |
| Auteurs : |
Karl Flowers, Auteur |
| Année de publication : |
2019 |
| Article en page(s) : |
p. 30-33 |
| Langues : |
Anglais (eng) |
| Catégories : |
Cuirs et peaux -- Propriétés mécaniques
Cuirs et peaux -- Propriétés physiques
Cuirs et peaux de bovins
Relachement (mécanique)
|
| Index. décimale : |
675 Technologie du cuir et de la fourrure |
| Résumé : |
The fine or coarse wrinkles that appear on the grain side of a leather bent concavely are known in the tanning community as looseness. A leather with the absence of wrinkles will be described as a tight-grained leather. A leather with large, coarse wrinkles that develop particularly with time will be described as loose-grained leather.
The leather technologist focusses on two main leather-maldng layers : the grain (corium minor) and the corium (corium major). The transition from the grain to the corium is hypothetically dealt with by a zone known as the grain-corium junction. Many scientists attribute this zone, in bovine leather, as the horizontal zone at the base of the hair follicles.
Many animal types exhibit differing degrees of looseness and this is often due to the presence of dermal fat. The removal of that fat during the leather-making process will leave the material porous and prone to loose-grain in the final leather article. The density and proximity of the leather fibres also plays a major role in the natural tendency/ aversion to loose-grain. The belly/axillae region of the hide and skin (a naturally loose structured area) tend to have poor grain tightness. An exaggerated opening up during the beamhouse will increase the incidence of the looseness, particularly in some animais (e.g. buffalo).
The heart of the looseness problem is twofold : the looseness can develop during wear, with extremes including delamination of the grain away from the corium; the leather is already loose - but unevenly loose - making the cutting of the leather article difficult to match (in terms of consistent visual pattern). Many leathers, such as floating grain leathers and other mill-grain effects, are intentionally loose in grain structure. |
| Note de contenu : |
- Beam theory
- Looseness testing
- Fig. 1 : Tigh-grained leathers bending in on the grain. Blue arrows showing long extension and yellow arrows showing compression of the grain. Modified from Haines and Barlow (1975)
- Fig. 2 : Loose-grained leathers bending in on the grain. Blue arrows showing lower extension and yellow arrows showing compression of the grain. Modified from Haines and Barlow (1975)
- Table 1 : An outline of some of the techniques to measure leather tightness |
| En ligne : |
https://drive.google.com/file/d/1b_KDRs5_dLuT-7RDDJlW4ZGIAgJMctkI/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33621 |
in INTERNATIONAL LEATHER MAKER (ILM) > N° 37 (09-10/2019) . - p. 30-33
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Leather property : looseness in INTERNATIONAL LEATHER MAKER (ILM), N° 37 (09-10/2019)
