ISO/FDIS 17232

IUP 38
ISO/IULTCS SC ##/WG #
Secretariat: ISO
Date: 2025-07-1409-01
Leather — Physical and mechanical tests — Determination of heat
resistance of patent leather
Cuir — Essais physiques et mécaniques — Détermination de la résistance à la chaleur des cuirs vernis
FDIS stage
ISO #####-#:####(X/FDIS 17232:2025(en)
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© ISO #### 2025 – All rights reserved
ii
IUP 38:2025(en)
Contents
Foreword . iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Method A — Lastometer method . 1
4.1 Principle . 1
4.2 Apparatus . 1
4.3 Specimen and test piece preparation . 2
4.4 Procedure . 2
4.5 Test report . 3
5 Method B — Zwik method . 3
5.1 Principle . 3
5.2 Apparatus . 3
5.3 Specimen and test piece preparation . 6
5.4 Procedure . 6
5.5 Test report . 6
Annex A (informative) Sources of apparatus . 8

iii
ISO #####-#:####(X/FDIS 17232:2025(en)
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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO'sISO’s adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
IULTCS, originally formed in 1897, is a world-wide organization of professional leather societies to further the
advancement of leather science and technology. IULTCS has three Commissions, which are responsible for
establishing international methods for the sampling and testing of leather. ISO recognizes IULTCS as an
international standardizing body for the preparation of test methods for leather.
This document was prepared by the Physical Test Commission of the International Union of Leather
Technologists and Chemists Societies (IUP Commission, IULTCS), in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 289, Leather, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
It is based on IUP 38 published in J. Soc. Leather Tech. Chem., 84 (7), p. 403, (2000),, and declared an official
method of the IULTCS in March 2001.
This third edition cancels and replaces the second edition (ISO 17232:2017), which has been technically
revised.
The main changes are as follows:
— — alignment with the changes and revised terminology in ISO 2418:2023 and ISO 2419:2024;
— — modification of the testing conditions (4.3(4.3 and 5.35.3).).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
© ISO #### 2025 – All rights reserved
iv
FINAL DRAFT International Standard ISO/FDIS 17232:2025(en)
IUP 38:2025(en)
Leather — Physical and mechanical tests — Determination of heat
resistance of patent leather
1 Scope
This document specifies two methods for determining the heat resistance of patent leather.
Method A makes use of a modified lastometer, while Method B uses the “Zwik” apparatus. Both methods are
applicable to patent leathers for all end uses.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 2418:2023, Leather — Chemical, physical, mechanical and fastness tests — Position and preparation of
specimens for testing
ISO 2419:2024, Leather — Physical and mechanical tests — Specimen and test piece conditioning
ISO 15115, Leather — Vocabulary
EN 15987, Leather — Terminology — Key definitions for the leather trade
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 15987 and ISO 15115 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
4 Method A — Lastometer method
4.1 Principle
A perforated test piece is distended by a specified amount. The surface is heated and any damage to the patent
finish is noted.
4.2 Apparatus
4.2.1 4.2.1 Test machine, including the parts described in 4.2.1.14.2.1.1 to 4.2.1.44.2.1.4.
NOTE An example of a suitable apparatus available commercially is given in Annex AAnnex A.
4.2.1.1 4.2.1.1 Clamp, capable of holding the test piece around its edge leaving free a central
circular area of diameter (25,0 ± 0,1) mm. The design of its clamping system shall ensure that the test piece
does not slip under the test conditions and neither stretches nor compresses the central area as it is clamped.
The boundary between the free and clamped area shall be sharply defined.
4.2.1.2 4.2.1.2 Plunger, terminating in a steel ball of diameter (21,0 ± 0,1) mm.
4.2.1.3 4.2.1.3 Mechanism for thrusting the steel ball, without rotation against the test
piece.
4.2.1.4 4.2.1.4 Mechanism for monitoring the distension of the test piece, (travel from
zero) to an accuracy of ±0,05 mm.
4.2.2 4.2.2 Press knife, conforming to the requirements of ISO 2419:2024 for cutting test pieces of
suitable dimensions for the test machine.
4.2.3 4.2.3 Sewing machine needle, sharp and undamaged, PCL size 80, either fitted into holder suitable
for use by hand or into sewing machine.
NOTE Other sized needles are used if they are more appropriate to the sewing used in the shoe production.
4.2.4 4.2.4 Hot air blower, capable of maintaining a temperature of (100 ± 5) °C or (125 ± 5) °C.
4.2.5 4.2.5 Temperature measuring device, reading to 1 °C.
4.2.6 4.2.6 Stopwatch, reading to 1 s.
4.2.7 4.2.7 Soft rubber mat, minimum thickness 10 mm.
4.3 Specimen and test piece preparation
4.3.1 4.3.1 Select the specimen in accordance with ISO 2418:2023. Cut three test pieces by applying the
press knife (4.2.2(4.2.2)) to the patent surface.
If there is a requirement for two or more hides or skins to be tested in one batch, then only one or two test
pieces need to be taken from each hide or skin, provided that the overall total is not less than three test pieces.
4.3.2 4.3.2 If the test piece is to be perforated by hand, place the test piece on the soft rubber mat
(4.2.7(4.2.7)) with the patent surface uppermost. Using the sewing machine needle (4.2.3(4.2.3)) fitted into
a holder, pierce a hole vertically through the centre of the test piece so that the hole is within 1,0 mm of the
centre. Pierce four further holes through the test piece with each hole (5,0 ± 0,5) mm from the first hole so
that the first holes form a simple (Greek) cross. Ensure that the needle penetrates through the leather into the
soft rubber mat.
4.3.3 4.3.3 If the test piece is to be perforated by machine, perforate through the centre using the needle
fitted into a sewing machine (4.2.3(4.2.3)) running at normal speed but without the thread and set at
6 stitches/10 mm.
4.3.4 4.3.4 Condition the test piece in accordance with ISO 2419:2024 and, if removed from the
conditioning atmosphere, the test procedure shall be started within 10 min. There is no need to carry out the
test (4.4(4.4)) in a conditioned atmosphere.
4.4 Procedure
4.4.1 4.4.1 Set the instrument so that the plunger (4.2.1.2(4.2.1.2)) is set at zero or minimum distension.
4.4.2
4.4.34.4.2 4.4.2 Tightly clamp the test piece into the instrument so that the ball end of the
plunger (4.2.1.2(4.2.1.2)) acts on the reverse side of the test piece.
© ISO #### 2025 – All rights reserved
IUP 38:2025(en)
4.4.44.4.3 4.4.3 Force the ball end of the plunger into the test piece until the test piece is
distended by (7,5 ± 0,05) mm as shown on the distension scale (4.2.1.4(4.2.1.4).). Examine the test piece and
note any damage.
4.4.54.4.4 4.4.4 Place the sensor of the temperature measuring device (4.2.5(4.2.5)) at a
distance of (1,5 ± 0,5) mm above the dome of the distended test piece. Using the hot air blower (4.2.4(4.2.4),),
raise the temperature of the test piece to (100 ± 5) °C for (180 ± 5) s for the standard test conditions or to
(125 ± 5) °C for (300 ± 5) s for the extended test conditions. Check the temperature using the temperature
measuring device (4.2.5(4.2.5)) and maintain this temperature for the time given above. If the temperature
goes out of the limits, reject the test piece and repeat using a fresh test piece.
4.4.64.4.5 4.4.5 Maintain the test piece in the distended state and re-examine. Record any
damage to the patent finish or the leather grain.
4.4.74.4.6 4.4.6 Repeat steps 4.4.14.4.1 to 4.4.54.4.5 for the remaining test pieces.
4.5 Test report
The test report shall include the following:
a) a) a reference to this document, i.e. ISO 17232:20XX;:—;
b) b) a reference to the method used;
c) c) details of any damage to the patent finish or leather grain when the test piece is first distended;
d) d) details of any damage to the patent finish or leather grain when the test piece is heated;
e) e) the test temperature and time (i.e. 100 °C for 180 s or 125 °C for 300 s);
f) f) the standard atmosphere used for conditioning as given in ISO 2419:2024;
g) g) any deviations from the method specified in this document;
h) h) full details for identification of the specimen and any deviations from ISO 2418:2023 with
respect to specimen preparation;
i) any unusual features observed;
h)j) the date of the test.
5 Method B — Zwik method
5.1 Principle
A perforated test piece is distended by a specified amount. The surface is heated and any dama
...