prEN ISO 6940

SLOVENSKI STANDARD
01-julij-2025
Tekstilije - Gorljivost - Ugotavljanje nagnjenosti k vnetljivosti navpično vpetih
preskušancev (ISO/DIS 6940:2025)
Textile fabrics - Burning behaviour - Determination of ease of ignition of vertically
oriented specimens (ISO/DIS 6940:2025)
Textile Flächengebilde - Brennverhalten - Bestimmung der Entzündbarkeit vertikal
angeordneter Proben (ISO/DIS 6940:2025)
Textiles - Comportement au feu - Détermination de la facilité d'allumage d'éprouvettes
orientées verticalement (ISO/DIS 6940:2025)
Ta slovenski standard je istoveten z: prEN ISO 6940
ICS:
13.220.40 Sposobnost vžiga in Ignitability and burning
obnašanje materialov in behaviour of materials and
proizvodov pri gorenju products
59.080.30 Tkanine Textile fabrics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 6940
ISO/TC 38
Textile fabrics — Burning behaviour
Secretariat: JISC
— Determination of ease of ignition
Voting begins on:
of vertically oriented specimens
2025-05-19
Textiles — Comportement au feu — Détermination de la facilité
Voting terminates on:
d'allumage d'éprouvettes orientées verticalement
2025-08-11
ICS: 13.220.40; 59.080.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
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WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 6940:2025(en)
DRAFT
ISO/DIS 6940:2025(en)
International
Standard
ISO/DIS 6940
ISO/TC 38
Textile fabrics — Burning behaviour
Secretariat: JISC
— Determination of ease of ignition
Voting begins on:
of vertically oriented specimens
Textiles — Comportement au feu — Détermination de la facilité
Voting terminates on:
d'allumage d'éprouvettes orientées verticalement
ICS: 13.220.40; 59.080.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
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NOTIFICATION OF ANY RELEVANT PATENT
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Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 6940:2025(en)
ii
ISO/DIS 6940:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Cautionary measures . 5
6.1 Construction of testing equipment . .5
6.2 Location of test apparatus.5
6.3 Health and safety of test operators .5
7 Sampling . 5
7.1 Number of specimens .5
7.2 Specimen holder pin location marks .5
7.3 Test specimen size .5
8 Conditioning and testing atmosphere. 6
8.1 Conditioning.6
8.2 Testing atmosphere .6
9 Setting up the apparatus . 6
9.1 Procedure A (surface ignition) .6
9.1.1 Mounting of the test specimen .6
9.1.2 Operating position of the burner .6
9.1.3 Flame adjustment — Horizontal reach .6
9.1.4 Flame position .6
9.2 Procedure B (bottom edge ignition) .7
9.2.1 Mounting of the test specimen .7
9.2.2 Operating position of the burner .7
9.2.3 Flame adjustment — vertical flame height .7
9.2.4 Flame position .7
10 Test procedure . 9
10.1 Surface ignition .9
10.2 Bottom edge ignition.9
11 Calculation of the mean ignition time . 10
12 Precision . 10
13 Test report . 10
Annex A (normative) Description and construction of the burner .12
Annex B (informative) Calculation of mean ignition time — worked example .13
Annex C (informative) Experimental techniques . 14
Bibliography .15

iii
ISO/DIS 6940:2025(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's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 38, Textiles.
This third edition cancels and replaces the second edition (ISO 6940: 2004), which has been technically
revised.
The main changes are as follows:
— the figure of the second edition was revised that the angular dimension line and the shape of the the
tip of the gas jet were incorrectly and it is necessary to match the Amendment of the first edition
(ISO 6940:1984/Amd.1:1993), without any structural changes;
— Figure 1b) has been revised to correctly show the angular dimension lines and the angular dimensions,
which makes the figureclear;
— Figure 1 b) has also been revised to show the shape of the tip of the gas jet shown in the second edition
to that of the the Amendment of the first edition;
— Figure 3 a) and b) have been revised to show the test specimen clear.
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
ISO/DIS 6940:2025(en)
Introduction
This method is one of two closely related methods of test for the inflammability of textile fabrics. It
determines the ease of ignition, as defined in ISO 4880; the other method measures flame spread time (see
ISO 6941).
v
DRAFT International Standard ISO/DIS 6940:2025(en)
Textile fabrics — Burning behaviour — Determination of ease
of ignition of vertically oriented specimens
1 Scope
This document specifies a method for the measurement of ease of ignition of vertically oriented textile fabrics
and industrial products in the form of single or multi-component fabrics (coated, quilted, multilayered,
sandwich constructions, and similar combinations), when subjected to a small, defined flame.
This method assesses the properties of textile fabrics in response to flame contact under controlled
conditions. There is a possibility that results do not apply the situations where there is restricted air supply
or exposure to large sources of intense heat.
The influence of seams on the behaviour of fabrics can be determined by this method, the seam being
positioned within the test specimen so as to be subjected to the test flame. Whenever practicable, trimmings
are tested as part of the fabric assembly on which they are, or will be, used.
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 4880, Burning behaviour of textiles and textile products — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4880 and the following 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/
3.1
flame application time
time for which the ignition flame is applied to the test specimen
3.2
afterflame time
length of time for which a material continues to flame under specified test conditions, after the ignition
source has been removed
Note 1 to entry: Afterflame time is measured to the nearest second and afterflame times of less than 1,0 s is recorded
as zero.
3.3
ignition
initiation of combustion
ISO/DIS 6940:2025(en)
3.4
sustained combustion
flaming of the specimen which gives an afterflame time of 5 s or more or which reaches the top or vertical
edges in less than 5 s
4 Principle
A defined flame from a specified burner is applied to the surface or bottom edge of textile specimens which
are vertically oriented.
The mean ignition time is determined as the weighted mean of the measured flame application times to
obtain ignition of the specimens.
5 Apparatus
5.1 Mounting frame, constructed to a design capable of holding the gas burner (5.2, see Figure 1) and the
test specimen holder (5.3, see Figure 2) in the specified relative orientation (see Figure 3).
5.2 Gas burner, as described in Annex A, capable of being moved from a standby position, where the tip of
the burner is at least 75 mm from the test specimen, to either the horizontal or inclined operating position
(see Figure 3).
5.3 Specimen holder, consisting of a rectangular metal frame having a specimen support pin at each
corner of a rectangle of length 190 mm by width 70 mm (see Figure 2). The pins for supporting the specimen
have a maximum diameter of 2 mm and a length of at least 26 mm.
NOTE Longer pins can be needed for mounting thick or multilayer specimens.
For the purpose of locating the specimen in a plane at least 20 mm away from the frame (see 9.1.1 and 9.2.1), a
spacer stub of 2 mm diameter and a length of at least 20 mm shall be positioned adjacent to each of the four pins.
5.4 Template, flat and rigid, made of a suitable material and a size corresponding to the size of the
specimen (200 mm × 80 mm).
Holes approximately 4 mm in diameter are drilled in each corner of the template and positioned so that the
distances between the centres of the holes correspond to the distances between the pins on the specimen
holder (see Figure 2). The holes should be located equidistant about the vertical centreline of the template.
5.5 Gas, commercial grade propane or butane or butane/propane mixtures.
NOTE Commercial grade propane is preferred.
5.6 Timing devices
5.6.1 A timing device to control and measure the flame application time, which can be set at 1 s and
adjusted at 1 s intervals to an accuracy of 0,2 s or better.
5.6.2 Three timing devices reading to 0,2 s or better are required to measure the afterflame time. This
device is started, preferably automatically, at the instant of test flame terminati
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