ISO 5431:1999
(Main)Leather — Wet blue goat skins — Specification
Leather — Wet blue goat skins — Specification
Cuir — Peaux de caprins à l'état "bleu humide" — Spécifications
General Information
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 5431
First edition
1999-03-01
Leather — Wet blue goat skins —
Specification
Cuir — Peaux de caprins à l'état «bleu humide» — Spécifications
A
Reference number
ISO 5431:1999(E)
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ISO 5431:1999(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
International Standard ISO 5431 was prepared by Technical Committee ISO/TC 120, Leather, Subcommittee SC 2,
Tanned leather.
Annex A forms an integral part of this International Standard. Annex B is for information only.
© ISO 1999
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
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INTERNATIONAL STANDARD © ISO ISO 5431:1999(E)
Leather — Wet blue goat skins — Specification
1 Scope
This International Standard specifies requirements, methods of sampling and methods of test for wet blue leather
produced from goat skins tanned without hair and with the use of basic chromium sulfate as the primary tanning
agent.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
ISO 2418:1972, Leather — Laboratory samples — Location and identification.
ISO 3380:1975, Leather — Determination of shrinkage temperature.
ISO 4045:1975, Leather — Determination of pH.
3 Definitions
For the purposes of this International Standard, the following definitions apply.
3.1
cured
preserved temporarily from putrefaction until it can be tanned
NOTE Any method of curing, including wet or dry salting or drying, is included.
3.2
pigmentation
colouration produced by fungi growing on wet blue chrome leather
NOTE The colouration produced by fungi will normally be black, white, green or yellow but can also be pink or violet.
4 Requirements
4.1 Raw material
Wet blue goat skins shall be processed from cured or fresh goat skins.
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© ISO
ISO 5431:1999(E)
4.2 Tanning
After pretanning operations, the skins shall be tanned with basic chromium sulfate as the primary tanning agent.
The cut cross-section shall be such that the skin is completely penetrated by the bluish colour of the chromium
sulfate when examined visually. Tanning shall be carried out at a pH of 3,0 or above.
4.3 Fungicidal additives
Fungicides shall be used to inhibit mould growth in the skins.
NOTE 1 The fungicides used to inhibit mould growth and pigmentation should be effective and should not cause a health
hazard. The types of fungicide used and their dosage should preferably be agreed between the purchaser and the supplier.
NOTE 2 Fungicides should preferably be applied in quantities appropriate to ensure storage for up to 4 months at the
temperature and humidity prevailing during storage or transportation. The effectiveness of the fungicidal treatment may be
determined using one of the references given in annex B.
4.4 Presentation
Wet blue goat skins shall be well fleshed, and the grain side shall be free from hair, including short hair and fine
hair. The size and grading shall be as agreed between the interested parties.
NOTE The skins should preferably have a tight grain and be free from creases, drum folds and stains caused by iron salts.
At least 95 % of the number of pieces in a lot should be free from stains caused by chromium salts, and the aggregate of the
stained area in any one piece should not exceed 10 % of the total area of the piece.
4.5 Shrinkage temperature
The shrinkage temperature shall not be less than 95 °C, when determined using the method specified in ISO 3380.
4.6 Chemical requirements
Wet blue goat skins shall comply with the requirements given in table 1.
Table 1 — Chemical requirements
Characteristic Requirement
Moisture content, % (m/m) As agreed between the
interested parties
pH of water extract (minimum) 3,5
NOTE A minimum shrinkage temperature of 95 °C would normally require a minimum chromic oxide content of 3,0 %
relative to the dry mass, as determined by the method given in IUC 8, Determina
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