ISO 20567-4:2023
(Main)Paints and varnishes — Determination of stone-chip resistance of coatings — Part 4: Mobile multi-impact testing on a small testing area
Paints and varnishes — Determination of stone-chip resistance of coatings — Part 4: Mobile multi-impact testing on a small testing area
This document specifies a mobile method for evaluating the resistance of automotive finishes to chilled-iron grit projected onto the surface under test to simulate the effect of stone chipping. Results from the test specified in this document are not comparable with results specified in ISO 20567-1.
Peintures et vernis — Détermination de la résistance des revêtements aux impacts de cailloux — Partie 4: Essais de chocs multiples par projection sur une petite surface d’essai
Le présent document spécifie une méthode pour évaluer la résistance des finitions des carrosseries de voitures à la projection de grenaille angulaire en fonte trempée contre la surface soumise à l’essai, cette projection étant destinée à simuler l’impact de cailloux. Les résultats de l’essai spécifié dans le présent document ne sont pas comparables aux résultats spécifiés dans l’ISO 20567-1.
General Information
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 20567-4
First edition
2023-03
Paints and varnishes — Determination
of stone-chip resistance of coatings —
Part 4:
Mobile multi-impact testing on a small
testing area
Reference number
© ISO 2023
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and test equipment . 2
5.1 Stone-chip resistance tester . 2
5.2 Consumables . . . 5
5.2.1 Chilled-iron grit . 5
6 Apparatus functional test . 6
7 Procedure .6
8 Ev a luat ion . 7
9 Test report . 8
Annex A (normative) Pictorial reference standards for evaluating stone-chip resistance.9
Annex B (informative) Examples of suitable methods for removing loose coating .10
Bibliography .11
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 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
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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.
A list of all parts in the ISO 20567 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
Introduction
The stone-chip resistance of the body finish is an important quality characteristic. A standard
procedure for testing this characteristic is the method according to ISO 20567-1, which is performed
with a stationary tester on a large test area. The method described here can be used in mobile form.
v
INTERNATIONAL STANDARD ISO 20567-4:2023(E)
Paints and varnishes — Determination of stone-chip
resistance of coatings —
Part 4:
Mobile multi-impact testing on a small testing area
1 Scope
This document specifies a mobile method for evaluating the resistance of automotive finishes to chilled-
iron grit projected onto the surface under test to simulate the effect of stone chipping.
Results from the test specified in this document are not comparable with results specified in
ISO 20567-1.
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 565, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes
of openings
ISO 2808, Paints and varnishes — Determination of film thickness
ISO 4618, Paints and varnishes — Vocabulary
ISO 11124-2, Preparation of steel substrates before application of paints and related products —
Specifications for metallic blast-cleaning abrasives — Part 2: Chilled-iron grit
ISO 11125-2, Preparation of steel substrates before application of paints and related products — Test
methods for metallic blast-cleaning abrasives — Part 2: Determination of particle size distribution
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4618 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 Principle
The stone-chip resistance of the coating is tested with many small, sharp-edged impact bodies, which
impact in portions and are largely independent of one another. The material used in the test is chilled-
iron grit, which is projected onto the coating at an angle of 90° using compressed air. The extent of the
damage depends on the working pressure, the grit, the projection duration and the design of the tester.
Loose fragments of coating material are removed. The degree of damage is evaluated by comparison
with pictorial reference standards.
5 Apparatus and test equipment
Ordinary laboratory apparatus, together with the following shall be used.
5.1 Stone-chip resistance tester
5.1.1 Tester including pressure regulator, hoses, connections and connection adapters (see Figures 1
and 2).
The dosing device shall be designed such that chilled-iron grit for the test (see 7.2) can be delivered in
(10 ± 1) s.
The compressed air supply for the tester (compressed air line system or compressor) shall have an oil
separator and water separator and shall meet the following requirements:
— output pressure min. 400 kPa;
— inner diameter of the connection hose min. 9,52 mm (3/8 inch);
— the connection hose between the compressed air supply and the tester shall be dimensioned (inside
diameter, length) such that the correct working pressure can be set (see 6.1).
Key
1 sample
2 projection window
3 a
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