EN ISO 19403-2:2024

SLOVENSKI STANDARD
01-januar-2025
Nadomešča:
SIST EN ISO 19403-2:2020
Barve in laki - Omočljivost - 2. del: Določanje proste površinske energije površin
trdnih teles z merjenjem stičnega kota (ISO 19403-2:2024)
Paints and varnishes - Wettability - Part 2: Determination of the surface free energy of
solid surfaces by measuring the contact angle (ISO 19403-2:2024)
Beschichtungsstoffe - Benetzbarkeit - Teil 2: Bestimmung der freien Oberflächenenergie
fester Oberflächen durch Messung des Kontaktwinkels (ISO 19403-2:2024)
Peintures et vernis - Mouillabilité - Partie 2: Détermination de l'énergie libre de surface
des surfaces solides par la mesure de l'angle de contact (ISO 19403-2:2024)
Ta slovenski standard je istoveten z: EN ISO 19403-2:2024
ICS:
87.040 Barve in laki Paints and varnishes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 19403-2
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2024
EUROPÄISCHE NORM
ICS 87.040 Supersedes EN ISO 19403-2:2020
English Version
Paints and varnishes - Wettability - Part 2: Determination
of the surface free energy of solid surfaces by measuring
the contact angle (ISO 19403-2:2024)
Peintures et vernis - Mouillabilité - Partie 2: Beschichtungsstoffe - Benetzbarkeit - Teil 2:
Détermination de l'énergie libre de surface des Bestimmung der freien Oberflächenenergie fester
surfaces solides par la mesure de l'angle de contact Oberflächen durch Messung des Kontaktwinkels (ISO
(ISO 19403-2:2024) 19403-2:2024)
This European Standard was approved by CEN on 17 August 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 19403-2:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 19403-2:2024) has been prepared by Technical Committee ISO/TC 35 "Paints
and varnishes" in collaboration with Technical Committee CEN/TC 139 “Paints and varnishes” the
secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2025, and conflicting national standards shall
be withdrawn at the latest by March 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 19403-2:2020.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 19403-2:2024 has been approved by CEN as EN ISO 19403-2:2024 without any
modification.
International
Standard
ISO 19403-2
Second edition
Paints and varnishes —
2024-09
Wettability —
Part 2:
Determination of the surface
free energy of solid surfaces by
measuring the contact angle
Peintures et vernis — Mouillabilité —
Partie 2: Détermination de l'énergie libre de surface des surfaces
solides par la mesure de l'angle de contact
Reference number
ISO 19403-2:2024(en) © ISO 2024

ISO 19403-2:2024(en)
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 19403-2:2024(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and materials . 2
6 Sampling . 3
7 Procedure . 3
7.1 General for measuring on the horizontal drop .3
7.1.1 Setting up the contact angle measuring system .3
7.1.2 Test conditions .4
7.1.3 Conditioning of the test panels .4
7.2 Measurement .4
7.2.1 General .4
7.2.2 Static method .4
7.2.3 Dynamic method (progressive contact angle) .5
7.2.4 Determination of the contact angle .6
8 Ev a luat ion . 6
8.1 General .6
8.2 Owens-Wendt-Rabel-Kaelble method (OWRK method) .6
8.3 Wu method .7
9 Precision . 8
9.1 General .8
9.2 Repeatability limit, r . .8
9.3 Reproducibility limit, R .8
9.4 Calculation in accordance with the Owens-Wendt-Rabel-Kaelble method .8
10 Test report . 9
Annex A (informative) Notes on measuring practice . 10
Bibliography . 14

iii
ISO 19403-2:2024(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 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)
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 35, Paints and varnishes, Subcommittee
SC 9, General test methods for paints and varnishes, in collaboration with the European Committee for
Standardization (CEN) Technical Committee CEN/TC 139, Paints and varnishes, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 19403-2:2017), which has been technically
revised.
The main changes are as follows:
— the minimum size of the text samples has been changed to 4 cm × 4 cm;
— definition 3.1 on “recently advanced contact angle” has been added;
— the use of ethylene glycol as test liquid has been deleted;
— in 7.2.1, the information on the camera tilt angle has been added;
— the normative references have been updated.
A list of all parts in the ISO 19403 series can be found on the ISO website.
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
International Standard ISO 19403-2:2024(en)
Paints and varnishes — Wettability —
Part 2:
Determination of the surface free energy of solid surfaces by
measuring the contact angle
1 Scope
This document specifies a test method to measure the contact angle for the determination of the surface
free energy of a solid surface. The method can be applied for the characterization of substrates and coatings.
NOTE 1 For the determination of the surface free energy of polymers and coatings, it is preferred to use either the
[3],[4],[5]
method according to Owens, Wendt, Rabel and Kaelble or the method according to Wu.
NOTE 2 The morphological and chemical homogeneity have an influence on the measuring results. The procedures
indicated in this document are based on the state-of-the-art employing the drop projection method in penumbral
shadow. Other methods are not excluded.
Measuring the contact angle on powders is not part of this document.
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 4618, Paints and varnishes — Vocabulary
ISO 19403-1:2022, Paints and varnishes — Wettability — Part 1: Vocabulary and general principles
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4618, ISO 19403-1 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
recently advanced contact angle
contact angle of a droplet at rest after the three-phase contact line has advanced over a previously dry surface
Note 1 to entry: The recently advanced contact angle is thermodynamically not defined.
4 Principle
A minimum of three drops of at least two test liquids are dosed onto the flat surface of a test specimen. For
every drop, the contact angle is measured. From the averaged contact angles of every liquid, their surface

ISO 19403-2:2024(en)
tensions, as well as their polar and dispersive fractions, the surface free energy of the solid is calculated by
means of an appropriate model, divided into the polar and dispersive fractions.
5 Apparatus and materials
Ordinary laboratory apparatus, together with the following shall be used.
5.1 Contact angle measuring system, i.e. any state-of-the-art contact angle measuring device, preferably
with digital image capture and analysis for measuring the contact angle. Figure 1 shows a schematic example
of a contact angle measuring system.
Key
1 light source
2 specimen holder
3 graduated micro syringe or pressure based liquid needle dosing system
4 optical system
5 screen
NOTE 1 The image capturing system is oriented in a way that the optimal image resolution ratio (ratio of width and
height) can be used.
NOTE 2 The device used can differ from the schematic diagram in regard to light path and the arrangement of the
components.
Figure 1 — Schematic diagram of a contact angle measuring system
5.2 Dosing unit, which makes it possible to precisely apply drops in the range of microlitres to the
surface. It should facilitate a drop deposition guaranteeing that one of the contact angles (as described in
ISO 19403-1:2022, 3.1.9) can be reproducibly assessed. The recently advanced contact angle after liquid
needle drop deposition has the least human influence and is thus recommended.
5.3 Test liquids, including at least two of those suggested in Table 1. The test liquids shall have at least
purity grade “for analysis”. Water shall have a surface tension of at least 71,5 mN/m at standard climate, i.e.
(23 ± 2) °C and (50 ± 5) % relative humidity.
It is recommended to measure the surface tension of the liquids to be used in accordance with ISO 19403-3.
For guidance, the values from the literature for the surface tension, σ , are indicated in Table 1. It is also
l
possible to use an individually measured value of the surface tension as a reference value. According to

ISO 19403-2:2024(en)
experience, the measured value should not deviate more than ±2 % from the value specified in the literature
or the individually determined value.
The test liquids shall not physically or chemically affect the surface. The test liquids shall be chosen so that
they have a difference as large as possible in the polar and dispersive parts of the surface tension.
For at least one of the test liquids used, the polar fractions shall be larger than 0 mN/m (see Table 1).
In case only two test liquids are used, water and di-iodomethane are recommended.
NOTE The values in Table 1 refer to 25 °C measuring temperature. For measuring under standard atmosphere
(see 7.1.2), no significant deviations can be assumed.
Table 1 — Suggested test liquids
Test liquid Surface tension Dispersive fraction Polar fraction Source
d
p
σ
l
σ
σ
l
l
mN/m
mN/m
mN/m
Water 72,8 21,8 51,0 Reference [6]
a
Di-iodomethane 50,8 50,8 0,0 Reference [6]
1,2,3-propanetriol
63,4 37,0 26,4 Reference [6]
(glycerol)
Hexadecane 27,6 27,6 0,0 Reference [6]
1- bromo-
44,6 44,6 0,0 Reference [6]
b
naphthalene
Benzyl alcohol 38,9 29,0 9,9 Reference [6]
Decalin
30,6 30,6 0,0 Reference [6]
(isomer mixture)
cis-Decalin 32,2 32,2 0,0 ISO 19403-3
trans-Decalin 29,9 29,9 0,0 ISO 19403-3
a
Di-iodomethane is relatively instable, yellowing after a short time by splitting-off iodine. Di-iodomethane swells and
dissolves a lot of plastics and organic coatings. Di-iodomethane reacts with common metals (e.g. magnesium).
b
1-bromo-naphtalene reacts with common metals (e.g. magnesium).
1-bromo-naphtalene tends to swell and dissolve high-molecular compounds.
6 Sampling
Take a representative specimen of the substrate to be tested. The specimens shall not be contaminated
before measuring.
Preferably, the specimen should have the minimum size of 4 cm × 4 cm.
See also Annex A.
7 Procedure
7.1 General for measuring on the horizontal drop
7.1.1 Setting up the contact angle measuring system
Choose the location of the contact angle measuring system so that it is not exposed to:
— vibrations,
— intense air flows (e.g. caused by air conditioning), and

ISO 19403-2:2024(en)
— intense exposure to light from outside (e.g. windows, bright lighting).
Align the contact angle measuring system horizontally.
7.1.2 Test conditions
Carry out the test at (23 ± 2) °C and a relative humidity of (50 ± 5) % (see ISO 3270) and make sure that all
test media have this temperature.
7.1.3 Conditioning of the test panels
If not otherwise agreed, condition the test panels at a temperature of (23 ± 2) °C and a relative humidity of
(50 ± 5) % for a minimum of 16 h prior to testing. Carry out the test immediately after conditioning.
NOTE Other conditioning parameters can be necessary if the surface of the test sample changes its chemical state
at 50 % relative humidity.
7.2 Measurement
7.2.1 General
Pla
...