EN ISO 11341:1997

SLOVENSKI STANDARD
SIST EN ISO 11341:1998
01-januar-1998
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Paints and varnishes - Artificial weathering and exposure to artificial radiation - Exposure
to filtered xenon-arc radiation (ISO 11341:1994)
Beschichtungsstoffe - Künstliches Bewittern und künstliches Bestrahlen -
Beanspruchung durch gefilterte Xenonbogenstrahlung (ISO 11341:1994)
Peintures et vernis - Vieillissement artificiel et exposition aux radiations artificielles -
Exposition aux radiations filtrées d'une lampe a arc au xénon (ISO 11341:1994)
Ta slovenski standard je istoveten z: EN ISO 11341:1997
ICS:
87.040 Barve in laki Paints and varnishes
SIST EN ISO 11341:1998 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 11341:1998

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SIST EN ISO 11341:1998

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SIST EN ISO 11341:1998

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SIST EN ISO 11341:1998

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SIST EN ISO 11341:1998

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SIST EN ISO 11341:1998
INTERNATIONAL
IS0
STANDARD
11341
First edition
I 994-09-01
Paints and varnishes - Artificial weathering
and exposure to artificial radiation -
Exposure to filtered xenon-arc radiation
Pein tures et vemis - Vieillissemen t artificiel et exposition aux radiations
artificielles - Exposition aux radiations filtr6es d’une lampe 8 arc au x&non
g-E
-
-
-
-
-
iso-
+gg#/lG
Reference number
IS0 11341 :I 994(E)

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SIST EN ISO 11341:1998
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 11341 was prepared by Technical Committee
ISODC 35, Paints and varnishes, Subcommittee SC 9, General test
methods for paints and varnishes.
Annex A forms an integral part of this International Standard. Annex B is for
information only.
0 IS0 1994
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 Organization for Standardization
11 Geneve 20 l Switzerland
Case postale 56 l CH-12
Printed in Switzerland

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SIST EN ISO 11341:1998
0 IS0 IS0 11341:1994(E)
Introduction
Coatings of paints, varnishes and similar materials (subsequently referred
to simply as coatings) are exposed to artificial weathering, or to artificial
radiation, in order to simulate in the laboratory the ageing processes which
occur during natural weathering or during exposure tests under glass
cover.
In contrast to natural weathering, artificial weathering involves a limited
number of variables which can be controlled more readily and which can
be intensified to produce accelerated ageing.
The ageing processes which occur during artificial and natural weathering
cannot be expected to correlate with each other because of the large
number of factors which influence these processes. Definite relationships
can only be expected if the important parameters (distribution of the
irradiance over the photochemically relevant part of the spectrum,
temperature of the specimen, type of wetting and wetting cycle, and
relative humidity) are the same in each case or if their effect on the
coatings is known.
. . .
III

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SIST EN ISO 11341:1998
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SIST EN ISO 11341:1998
IS0 11341:1994(E)
INTERNATIONAL STANDARD o IS0
Paints and varnishes - Artificial weathering and exposure
to artificial radiation - Exposure to filtered xenon-arc
radiation
IS0 4628-l :1982, Paints and varnishes - Evaluation
1 Scope
of degradation of paint coatings - Designation of
intensity, quantity and size of common types of de-
This International Standard is one of a series of
fect - Part I: General principles and rating schemes.
standards dealing with the sampling and testing of
paints, varnishes and related products.
IS0 4628-2:1982, Paints and varnishes - Evaluation
It specifies a test method for assessing either the
of degradation of paint coatings - Designation of
resistance of paint coatings to artificial weathering or
intensity, quantity and size of common types of
the resistance to light by exposure to artificial
defect - Part 2: Designation of degree of blistering.
radiation.
IS0 4628-3:1982, Paints and varnishes - Evaluation
The standard describes the most important para-
of degradation of paint coatings - Designation of
meters and specifies the conditions to be used in the
intensity, quantity and size of common types of
exposure apparatus.
defect - Part 3: Designation of degree of rusting.
Provided the test conditions specified are strictly re-
IS0 4628-4:1982, Paints and varnishes - Evaluation
spected, reproducibility is improved and an improved
of degradation of paint coatings - Designation of
correlation is obtained between natural-weathering
intensity, quantity and size of common types of
and artificial-weathering tests.
defect - Part 4: Designation of degree of cracking.
IS0 4628-5: 1982, Paints and varnishes - Evaluation
2 Normative references
of degradation of paint coatings - Designation of
intensity, quantity and size of common types of
The following standards contain provisions which,
defect - Part 5: Designation of degree of flaking.
through reference in this text, constitute provisions of
this International Standard. At the time of publication,
IS0 4628-6: 1990, Paints and varnishes - Evaluation
the editions indicated were valid. All standards are
of degradation of paint coatings - Designation of
subject to revision, and parties to agreements based
intensity, quantity and size of common types of
on this International Standard are encouraged to in-
defect - Part 6: Rating of degree of chalking by tape
vestigate the possibility of applying the most recent
method.
editions of the standards indicated below. Members
of IEC and IS0 maintain registers of currently valid
CIE Publication No. 85: 1989, Solar spectra/ irradiance.
International Standards
IS0 1512:1991, Paints and varnishes - Sampling of
3 Definitions
products in liquid or paste form.
For the purposes of this International Standard, the
IS0 1513:1992, Paints and varnishes - Examination
following definitions apply:
and preparation of samples for testing.
3.1 ageing behaviour: The change in properties of
IS0 1514:1993, Paints and varnishes - Standard
a coating during artificial weathering or exposure to
panels for testing.
artificial radiation until a certain ageing criterion (see
IS0 2808:1991, Paints and varnishes - Determi- 3.3) is satisfied.
nation of film thickness.
NOTE 1 One measure of ageing is the radiant exposure H
IS0 3696: 1987, Water for analytical laboratory use -
in the wavelength range below 400 nm or at a specified
Specification and test methods. wavelength, e.g. 340 nm. The ageing behaviour of coatings
1

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SIST EN ISO 11341:1998
0 IS0
IS0 11341:1994(E)
exposed to artificial weathering, or to artificial radiation, other filter, it matches the spectral distribution, in the
depends on the type of coating, the conditions of exposure
ultraviolet and visible regions, of solar radiation
of the coating, the property selected for monitoring the
filtered by 3-mm-thick window-glass (method 2).
progress of the ageing process and the degree of change
of this property.
Two spectral energy distributions are used to
describe the irradiance values and permitted de-
viations of the filtered test radiation in the ultraviolet
3.2 radiant exposure, H: A measure of the radiant
range below 400 nm. In addition, CIE Publication
energy to which a test panel has been exposed, given
No. 85 is used for the specification of the irradiance in
by the formula
the range up to 800 nm because only in that range
can the xenon-arc radiation be adapted to match solar
N=JEdt
radiation sufficiently well.
where
During testing in exposure apparatus, the irradiance E
may change due to ageing of the xenon-arc lamp and
E is the irradiance, in watts per square metre;
the optical-filter system. This occurs particularly in the
ultraviolet region which is photochemically important
t is the exposure time, in seconds.
for polymeric materials. Therefore, measurements are
made not only of the duration of the exposure, but
H is therefore expressed in joules per square metre. also of the radiant exposure H in the wavelength
range below 400 nm, or at a specific wavelength, e.g.
340 nm, and used as reference values for the ageing
If the irradiance E is constant throughout the whole
exposure time, the radiant exposure H is given simply of coatings.
by the product of E and t.
It is impossible to simulate accurately every aspect of
the way in which the weather acts on coatings.
3.3 ageing criterion: A given degree of ageing, cor-
Therefore, in this International Standard, the term
responding to a specified or agreed degree of change
artificial weathering is used as distinct from natural
in a se.lected property of the coating under test.
weathering. Testing using simulated solar radiation
filtered by window-glass is referred to in this Inter-
national Standard as exposure to artificial radiation.
4 Principle
5 Required supplementary information
Artificial weathering of coatings or exposure of
For any particular application, the test method
coatings to filtered xenon-arc radiation is carried out in
specified in this International Standard needs to be
order to obtain the degree of change in a selected
completed by supplementary information. The items
property after a certain radiant exposure H, and/or the
of supplementary information are given in annex A.
radiant exposure which is required to produce a
certain degree of ageing. The properties selected for
monitoring should preferably be those which are
important for the practical use of the coatings. The
6 Apparatus
properties of the coatings exposed are compared with
those of unexposed coatings prepared from the same
6.1 Test chamber
coating materials at the same time and in the same
way (control specimens) or with those of coatings
The test chamber shall consist of a conditioned
exposed at the same time whose behaviour during
enclosure made from corrosion-resistant material,
testing in exposure apparatus is already known
capable of housing the radiation source, including its
(reference specimens).
filter system, and the test-panel holders.
During natural weathering, solar radiation is con-
sidered to be the essential cause for the ageing of
6.2 Radiation source and filter system
coatings. The same is valid for exposure to radiation
under glass. Therefore, in artificial weathering and One or more xenon-arc lamps shall be used as the
exposure to artificial radiation, particular importance is optical radiation source. The radiation emitted by
attached to the simulation of this parameter. The them shall be filtered by a system of optical radiation
xenon-arc radiation source used is therefore fitted filters so that the relative spectral distribution of the
with one of two different filter systems, designed to irradiance (relative spectral energy distribution) in the
plane of the test-panel holders is sufficiently similar
modify the spectral distribution of the radiation
either to solar ultraviolet and visible radiation
produced so that, with one of the filters, it matches
the spectral distribution, in the ultraviolet and visible (method 1) or to solar ultraviolet and visible radiation
regions, of solar radiation (method 1) and, with the filtered by 3-mm-thick window-glass (method 2).

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SIST EN ISO 11341:1998
IS0 11341:1994(E)
0 IS0
In order to accelerate ageing further, deviations from
The conditions specified in table shall be used for
method 1. the above specifications concerning relative spectral
energy distribution and irradiance may be agreed
between the interested parties provided that, for the
The conditions specified in table 2 shall be used for
property selected for the particular coating to be
method 2.
tested, the correlation with natural weathering is
known. Such further accelerated-ageing may be car-
ried out either by increasing the irradiance or by shift-
Table 1 - Relative spectral energy distribution
ing the short-wavelength end of the spectral energy
for artificial weathering (method 1)
distribution band in a defined manner to shorter
wavelengths. Details of any such deviations from the
Wavelength, A Relative irradiance’ )
methods specified shall be stated in the test report.
nm %
Ageing of the xenon-arc lamps and filters causes the
a < 290 0
relative spectral energy distribution to change during
0,6 of= 0,2*)
290 s as320
operation and the irradiance to decrease. Renewal of
320 < a~360 4,2 zt 0,5
the lamps and filters will keep the spectral energy
distribution and the irradiance constant. The irradiance
360 c a~400 6,2 A I,0
may also be kept constant by adjustment of the
290 e as800 100
apparatus. Follow the manufacturer’s instructions.
I) Relative to the irradiance in the wavelength range
from 290 nm to 800 nm (as given in CIE Publication
6.3 Test-chamber conditioning system
No. 85:1989). See annex B, table B.I.
2) Products that have absorption bands below 300 nm
To maintain the test chamber at the black-standard
are affected more than under natural weathering con-
temperature specified in 9.2, humidity- and tempera-
ditions if specimens prepared from them are exposed
ture-controlled dust-free air shall be circulated through
to radiation below 300 nm.
the test chamber. The temperature and relative
humidity of the air in the test chamber shall be
Table 2 - Relative spectral energy distribution
monitored using temperature and humidity sensors
for exposure to artificial radiation under window-
protected against direct radiation. To maintain the
glass (method 2) relative humidity at the level specified in 9.4, only
distilled or demineralized water shall be used.
Wavelength, A Relative irradiance’)
NOTE 2 When the test chamber is fed continuously with
nm
%
fresh air, the operating conditions of the apparatus may
differ, for example, in the summer from those in the
0 0
a< a< 300 300
winter, because the moisture content of the air in the
300 300 s s as320 as320 s s 0,l 0,l summer is higher than in the winter. This may influence
the test results. The reproducibility of the test may be im-
* * 0,5 0,5
320 320 < < as360 as360 3,0 3,0
proved by circulating the air in an essentially closed circuit.
360 360 < < as400 as400 6,0 6,0 * * I,0 I,0
300 s as800 100
I
I
6.4 Device for wetting the test panels (for
1) Relative to the irradiance in the wavelength range
use in method 1)
from 300 nm to 800 nm. See annex B, table B.2.
I
I
NOTE 3 Method 1 includes wetting of the test panels;
this is intended to simulate the effects of rain and
condensation in an outdoor environment.
The radiant flux shall be chosen so that the time-
averaged irradiance E between 290 nm and 800 nm in
The device for wetting the test panels shall be de-
the plane of the test-panel holders is 550 W/m*. In
signed so that, during the whole of the wetting period
the case of a discontinuous run (see 9.3) this value
specified in 9.4, the surface under test of all the test
shall include the radiation reflected from the inside
panels shall be wetted in one of the following ways:
walls of the test chamber which reaches the plane of
the test-panel holders.
a) the surface is sprayed with water;
The irradiance E at any point over the area used for
b) the test chamber is flooded with water.
the test panels shall not vary by more than * 10 % of
the arithmetic mean of the total irradiance for the
If the test panels rotate around the radiation source,
whole area. Any ozone formed by the operation of the
the water-spray nozzles shall be arranged so that the
xenon-arc lamps shall not enter the test chamber but
requirements of 9.4 are met for each test panel.
shall be vented separately.
3

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SIST EN ISO 11341:1998
0 IS0
IS0 11341:1994(E)
5 The surface temperature of a test panel depends on a
Distilled or demineralized water meeting the require-
number of factors, including the amount of radiation ab-
ments of IS0 3696, grade 2, having a conductivity
sorbed, the amount of radiation emitted, thermal-con-
below 2 us/cm but a residue on evaporation of less
duction effects within the test panel and heat transfer
than 1 ppm, shall be used for wetting.
between the test panel and the air and between the test
panel and the holder, and cannot therefore be predicted
Recycled water shall not be used unless filtered to
with any accuracy.
give water of IS0 3696 grade 2 purity since there is a
danger of deposits forming on the test-panel sur-
In order to be able to determine the range of surface
faces. Such deposits may lead to false results.
temperatures of the test panels during exposure, and
to control better the exposure conditions in the
The supply tanks, supply pipes and spray nozzles for
apparatus, the use of an analogously
...