EN ISO 7784-2:2006

SLOVENSKI STANDARD
01-julij-2006
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Paints and varnishes - Determination of resistance to abrasion - Part 2: Rotating
abrasive rubber wheel method (ISO 7784-2:1997)
Beschichtungsstoffe - Bestimmung des Abriebwiderstandes - Teil 2: Verfahren mit
rotierendem Gummireibrad (ISO 7784-2:1997)
Peintures et vernis - Détermination de la résistance a l'abrasion - Partie 2: Méthode
utilisant une roue abrasive en caoutchouc (ISO 7784-2:1997)
Ta slovenski standard je istoveten z: EN ISO 7784-2:2006
ICS:
87.040 Barve in laki Paints and varnishes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 7784-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2006
ICS 87.040
English Version
Paints and varnishes - Determination of resistance to abrasion -
Part 2: Rotating abrasive rubber wheel method (ISO 7784-
2:1997)
Peintures et vernis - Détermination de la résistance à Beschichtungsstoffe - Bestimmung des Abriebwiderstandes
l'abrasion - Partie 2: Méthode utilisant une roue abrasive en - Teil 2: Verfahren mit rotierendem Reibrad mit
caoutchouc (ISO 7784-2:1997) Gummirädern (ISO 7784-2:1997)
This European Standard was approved by CEN on 9 March 2006.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 7784-2:2006: E
worldwide for CEN national Members.

Foreword
The text of ISO 7784-2:1997 has been prepared by Technical Committee ISO/TC 35 "Paints and
varnishes” of the International Organization for Standardization (ISO) and has been taken over
as EN ISO 7784-2:2006 by 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 October 2006, and conflicting national
standards shall be withdrawn at the latest by October 2006.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,
Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Endorsement notice
The text of ISO 7784-2:1997 has been approved by CEN as EN ISO 7784-2:2006 without any
modifications.
INTERNATIONAL IS0
STANDARD 7784-2
First edition
1997-02-15
Paints and varnishes - Determination of
resistance to abrasion -
Part 2:
Rotating abrasive rubber wheel method
Pein tures et vernis
- D&termination de la resistance P I’abrasion -
Partie 2: M&hode utiiisant une roue abrasive en caoutchouc
Reference number
IS0 7784-2:1997(E)
IS0 7784=2:1997(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies).The work of
preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard IS0 7784-Z was prepared by Technical Committee
ISOnC 35, Paints and varnishes, Subcommittee SC 9, Genera/ test
methods for paints and varnishes.
IS0 7784 consists of the following parts, under the general title Paints and
varnishes - Determination of resistance to abrasion:
Part 7: Rotating abrasive-paper-covered wheel method
- Part 2: Rotating abrasive rubber wheel method
- Part 3: Reciprocating test panel method
Annex A forms an integral part of this part of IS0 7784. Annexes B and C
are for information only.
0 IS0 1997
All rights reserved. Unless otherwise specified, no part of this publication may be
reproduced or utilized in any form or by any means, electronic or mechanical, including
photocopying and microfilm, without permission in writing from the publisher.
International Orga nization for Standardization
CH-121
Case Postale 56 l 1 Geneve 20 l Switzerland
Printed in Switzerland
II
@ IS0 IS0 7784=2:1997(E)
Introduction
This document is one of three parts of IS0 7784 dealing with the
determination of resistance to abrasion of a dried film of paint, varnish or
related product.
Parts 1 and 3 both specify a method using abrasive paper for
determination of the resistance to abrasion. In part 2, a method using
abrasive rubber wheels is described. The user of IS0 7784 should note
that the methods using abrasive paper (parts 1 and 3) are the preferred
methods.
. . .
III
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IS0 7784=2:1997(E)
INTERNATIONAL STANDARD 0 IS0
Determination of resistance
Paints and varnishes -
to abrasion -
Part 2:
Rotating abrasive rubber wheel method
1 Scope
This part of IS0 7784 is one of a series of standards dealing with the sampling and testing of paints, varnishes and
related products.
This part of IS0 7784 specifies a method for determining the resistance to abrasion of a dried film of paint, varnish
or related product, using abrasive rubber wheels and abrading by making a rotary movement.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this part
of IS0 7784. At the time of publication, the editions indicated were valid. All standards are subject to revision, and
parties to agreements based on this part of IS0 7784 are encouraged to investigate the possibility of applying the
most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently
valid International Standards.
IS0 48: 1994, Rubber - Determination of hardness (hardness between 30 and 85 IRHD).
- Sampling of products in liquid or paste form.
IS0 1512:1991, Paints and varnishes
IS0 1513:1992, Paints and varnishes - Examination and preparation of samples for testing.
IS0 1514: 1993, Paints and varnishes - Standard panels for testing.
IS0 2808:- 1), Paints and varnishes - Determination of film thickness.
IS0 6507-I :I 982, Metallic materials - Hardness test - Vickers test - Part I: HV 5 to HV 100.
3 Principle
A dried paint or varnish film is abraded, under specified conditions, with abrasive rubber wheels which are attached
to an abrasion testing machine. During the test the wheels are loaded with specified weights. The resistance to
abrasion is calculated as the loss in mass after a specified number of abrasion cycles or as the number of cycles
required to remove the coating down to the next layer or down to the substrate.
1) To be published. (Revision of IS0 2808:1991)

IS0 7784=2:1997(E) @ IS0
4 Required supplementary information
For any particular application, the test method specified in this part of IS0 7784 needs to be completed by
supplementary information. The items of supplementary information are given in annex A.
5 Apparatus
5.1 Abrasion testing machine*), consisting of the elements described in 5.1 .I to 5.1.4 (see also figure 1
peed nounted
5.1 .‘I Turntable, ca pable of rotating at a s of (60 +_ 2) rpm, on which the test panel can be centrally
and firmly attached.
51.2 Two abrasive rubber wheels*), each of thickness (12,7 * OJ) mm. The wheels shall be mounted on and
able to rotate freely about horizontal spindles. Their internal faces shall be (53,O 1: 0,5) mm apart and the
hypothetical line through the two spindles shall be (l9,l * 0,l) mm away from the central axis of the turntable. The
external diameter of the wheels shall be (5116 + OJ) mm when new, and in no case less than 44,4 mm.
The type of wheel shall be chosen by agreement between the interested parties
A slow hardening of the rubber bonding material in this type of wheel may occur. Therefore the hardness shall be
checked to agree with the specification given by the manufacturer. Wheels shall not be used after the expiration
date marked on them by the manufacturer, or more than one year after their purchase if no expiration date is given.
51.3 Counter, to record the number of cycles (turns) made by the turntable.
5.1.4 Suction device, with two nozzles. One of the nozzles shall be positioned between the two wheels and the
other placed diametrically opposite the first. The distance between the axes of the two nozzles shall be
(75 + 2) mm and the distance between them and the test panel 1 mm to 2 mm.
When the suction nozzles are in position, the air pressure in the suction devic e shall be I,5 kPa3) to I,6 kPa3) lower
pressure.
than a tmospheric
5.2 Weights, to enable the mass of each wheel to be increased by up to 1 kg.
5.3 Resurfacing medium, in the form of an abrasive disc, used for resurfacing the wheels.
54 . Calibration panel, of thickness between 0,8 mm and 1 mm, for calibration of the apparatus (see annex B).
5.5 Balance, with an accuracy of 0,l mg.
6 Sampling
Take a representative sample of the product to be tested (or of each product in the case of a multi-coat system), as
described in IS0 1512.
Examine and prepare each sample for testing, as described in IS0 1513.
2) This apparatus is commercially available from Teledyne Taber, 455 Bryant Street, North Tonawanda, NY 14120, USA.
3) 1 kPa = 10 mbar.
IS0 7784=2:1997(E)
@ IS0
7 Test panels
7.1 Substrate
Unless otherwise agreed, select the substrate from one of those described in IS0 1514, using, where possible, the
same type of material as will be used in practice. The substrate panels shall be plane and free from distortion,
otherwise the wear of the coating under test will not be uniform.
Dimensions in millimetres
d
+I
F
ti
r
-
-
N
d
+I
Ln
.
-
cv
d
+I
In
:
r
d
+I
r+-
oi
r
w
1 Abrasive wheels
2 Test specimen
3 Wear zone
4 Vacuum nozzles
0 8 + 0,5
- Diagrammatic arrangement of apparatus
Figure 1
@ IS0
IS0 7784=2:1997(E)
7.2 Shape and dimensions
The shape and dimensions of the test panels shall be such that they can be fitted correctly on the apparatus. They
shall have a central hole of diameter 6,35 mm.
NOTE - Typical dimensions for a test panel are 100 mm x 100 mm.
7.3 Preparation and coating
Unless otherwise agreed, prepare each test panel in accordance with IS0 1514 and then coat it by the specified
method with the product or system under test.
7.4 Drying and conditioning
Dry (or stove) and age, if applicable, each coated test panel for the specified time under the specified conditions.
7.5 Thickness of coating
Determine the thickness, in micrometres, of the dried coating by one of the methods specified in IS0 2808.
8 Procedure
8.1 Test conditions
Carry out the test at a temperature of (23 + 2) "C and a relative humidity of (50 1: 5) %, unless otherwise agreed.
8.2 Calibration of the apparatus
Calibrate the apparatus (an example of a calibration procedure is given in annex B).
8.3 Preparation of the abrading rubber wheels
8.3.1 Check that the abrasive rubber wheels meet the requirements specified in 5.1.2.
8.3.2 To ensure that the abrading function of the wheels is maintained at a constant level, prepare the abrasive
rubber wheels as prescribed by the manufacturer, following 8.3.2.1 to 8.3.2.4.
8.3.2.1 Mount the selected abrasive rubber wheels on their respective flange holders, taking care not to touch the
abrasive surfaces. Adjust the load on the wheels to the value agreed between the interested parties.
8.3.2.2 Mount the resurfacing-medium disc on the turntable. Lower the abrading heads carefully until the wheels
rest on the disc. Place the suction nozzle in position and adjust it to a distance of 1 mm above the surface of the
disc.
8.3.2.3 Set the counter to zero.
8.3.2.4 Start up the suction and then the turntable. Resurface the wheels by running them for a specified number
of cycles against the resurfacing-medium disc.
NOTE - A typical number of cycle is 50.

Q IS0 IS0 7784=2:1997(E)
Resurface the wheels in this manner before testing each specimen and after every 500 cycles,
...