ISO 17581:2025

International
Standard
ISO 17581
First edition
Rubber- or plastics-coated
2025-05
fabrics — Determination of water
absorption resistance
Supports textiles revêtus de caoutchouc ou de plastique —
Détermination de la résistance à l'absorption d'eau
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Sampling . 1
6 Test pieces . 2
6.1 Shape and dimensions .2
6.2 Number of test piece .2
6.3 Water absorption prevention treatment .2
7 Test conditions . 3
7.1 Conditioning.3
7.2 Test atmosphere .3
7.3 Time — interval between manufacture and testing .3
7.4 Water temperature .3
7.5 Immersion time .3
8 Method A . 3
8.1 Apparatus and reagents .3
8.2 Procedure .4
8.2.1 Immersion .4
8.2.2 Measurement .5
8.3 Expression of results .5
8.4 Precision . . .5
8.5 Test report .5
9 Method B . 5
9.1 Apparatus and reagents .5
9.2 Procedure .6
9.2.1 Immersion .6
9.2.2 Preparation of the test piece for water detection in measurement .6
9.2.3 Measurement .7
9.3 Expression of results . .9
9.4 Test report .9
Annex A (normative) Absorption test for ink test solution .11
Annex B (informative) Precision for Method A .13
Bibliography .15

iii
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
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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 document 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)
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rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee
SC 4, Products (other than hoses).
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.

iv
Introduction
Water absorption resistance is one of the important properties in rubber or plastics-coated fabrics used in
the construction of, for example, tents, temporary shelters or domes, as well as roofing materials. Once the
coated fabrics absorbs water, the water can be retained for a long period of time to cause stains which can
develop moulds or, occasionally, deterioration of the substrate. The absorption mainly occurs at the edge of
the fabrics exposed to water by capillary phenomenon, therefore the coated fabrics used for such products
are usually processed with antiwater absorption treatments. The test methods in this document are useful
to evaluate the water absorption resistance in quality of the coated fabrics.

v
International Standard ISO 17581:2025(en)
Rubber- or plastics-coated fabrics — Determination of water
absorption resistance
WARNING — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It
is the responsibility of the user to establish appropriate safety and health practices and to ensure
compliance with any national regulatory conditions.
1 Scope
This document specifies two test methods for the determination of water absorption resistance of rubber–
or plastics-coated fabrics:
— Method A: Using red ink, which is applied to coated fabric where water absorption phenomenon can be
visually observed;
— Method B: Using a water detection test paper.
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 2231, Rubber- or plastics-coated fabrics — Standard atmospheres for conditioning and testing
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 105-F02, Textiles — Tests for colour fastness — Part F02: Specification for cotton and viscose adjacent fabrics
3 Terms and definitions
No terms and definitions are listed in this document.
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 Principle
The lower end of a test piece is immersed into water at the controlled temperature and humidity to evaluate
the height to which water has risen, mainly due to capillary phenomenon.
5 Sampling
The sample shall be taken from the part of the roll excluding at least 1/10 of the total width from the selvedge
and 100 cm away from the terminal in the longitudinal direction of the roll. However, when it cannot be
taken in this way, it may be taken from the part of the roll that is composed of the coated fabrics.

6 Test pieces
6.1 Shape and dimensions
A test piece shall be rectangular of uniform shape and prepared by cutting from the different locations in
the longitudinal direction (L) and the transverse direction (T) as indicated in Figure 1 so that each test piece
can exclude the same warp or weft. Width of the test piece shall be (30 ± 0,5) mm, or (50 ± 0,5) mm, and the
length shall be (300 ± 0,5) mm. However, when this dimension cannot be taken, other width and length may
be used on agreement between the interested parties. Mark a line across the width of each test piece at a
distance of (5 ± 0,5) mm from the lowest end to be immersed. When implementing Method B, it is advisable
to mark the lines across the width of each test piece at intervals of 20 mm from the bottom to the top end in
advance as indicated in Figure 3 a).
Key
L test piece cut in the longitudinal direction
T test piece cut in the transverse direction
1 selvedge
2 sample width
3 (30 ± 0,5) mm, or (50 ± 0,5) mm of width
4 (300 ± 0,5) mm of length
Figure 1 — Example of the locations of test piece to be taken
6.2 Number of test piece
Three test pieces shall be prepared in each longitudinal direction (L) and transverse direction (T), unless
otherwise specified between the interested parties.
6.3 Water absorption prevention treatment
To prevent water absorption from the side cross section of the test piece, apply adhesives (8.1.9) to both
sides up to 50 mm or more from the lower end of the test piece. After that, dry at least for 1 h.
NOTE Water absorption phenomenon is likely measured incorrectly when water is absorbed from the side cross
section of the test piece.
7 Test conditions
7.1 Conditioning
Unless otherwise required in the specification, the test pieces shall be conditioned before testing for 16 h to
24 h using the method of conditioning “1” specified in ISO 2231.
7.2 Test atmosphere
The standard atmosphere of the test shall be either atmosphere “A” or “B” in accordance with ISO 2231,
unless otherwise specified. In addition, when conducting test at a temperature different from the standard
laboratory temperature, the temperature shall be agreed between the interested parties. The test
temperature shall be recorded.
7.3 Time — interval between manufacture and testing
For all test purposes, the minimum time between the manufacture and testing shall be 16 h. For non-product
tests, the maximum time between manufacture and testing shall be four weeks and for evaluations intended
to be comparable, the tests, as far as possible, shall be carried out after the same time-interval.
For products, unless otherwise agreed between the interested parties, the time between the manufacture
and testing shall not exceed three months.
7.4 Water temperature
The water temperature in the tank for testing shall be (20 ± 2) °C or (23 ± 2) °C.
7.5 Immersion time
Immersion time shall be (72 ± 1) h unless otherwise specified between the interested parties.
8 Method A
8.1 Apparatus and reagents
Apparatus, its supplementary devices and reagents are as follows. An example of the apparatus is shown in
Figure 2.
8.1.1 Water tank, with a capacity enough to store sufficient water for testing, and the size which does not
come into contact the horizontal bar supporting frame.
8.1.2 Horizontal bar supporting frame, attached with horizontal bar.
8.1.3 Horizontal bar 1, consisting of waterproofed materials with clips to hold test pieces hung.
8.1.4 Horizontal bar 2, consisting of two waterproofed bars enable test pieces to be held in the adjustable
opening without pressure between the bars.
8.1.5 Ruler, graduated in 0,5 mm.
8.1.6 Water for testing, distilled or ion-exchanged water of grade three or higher in accordance with
ISO 3696.
8.1.7 Red ink, available in the market for fountain pen use. Some inks can show the lower height when
compared to that of water in this test method. The preliminary test to select the suitable red i
...