ISO 4582:2017

Plastics — Determination of changes in colour and variations in properties after exposure to glass-filtered solar radiation, natural weathering or laboratory radiation sources

ISO 4582:2017 specifies methods to determine changes in colour and other appearance properties, and variations in mechanical or other properties, of plastics that have been exposed to glass-filtered solar radiation, to natural weathering or to simulated solar radiation from a laboratory source. The procedure used to analyse data depends on whether the test used to characterize the materials being exposed is destructive or non-destructive. The exposures are conducted under conditions described in specific exposure standards.

Plastiques — Détermination des changements de coloration et des variations de propriétés après exposition au rayonnement solaire sous verre, aux agents atmosphériques ou aux sources de rayonnement de laboratoire

General Information

• Status: Published
• Publication Date: 16-Aug-2017
• ICS: 83.080.01 - Plastics in general
• Technical Committee: ISO/TC 61/SC 6 - Ageing, chemical and environmental resistance
• Drafting Committee: ISO/TC 61/SC 6/WG 2 - Exposure to light
• Current Stage: 9092 - International Standard to be revised
• Completion Date: 20-Sep-2022

Relations

• Revises: ISO 4582:2007 - Plastics — Determination of changes in colour and variations in properties after exposure to daylight under glass, natural weathering or laboratory light sources
• Effective Date: 01-Nov-2014

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 4582
Fourth edition
2017-08
Plastics — Determination of changes
in colour and variations in properties
after exposure to glass-filtered solar
radiation, natural weathering or
laboratory radiation sources
Plastiques — Détermination des changements de coloration et des
variations de propriétés après exposition au rayonnement solaire sous
verre, aux agents atmosphériques ou aux sources de rayonnement de
laboratoire
Reference number
ISO 4582:2017(E)
©
ISO 2017

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ISO 4582:2017(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
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ISO 4582:2017(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Determination of changes in colour or other appearance attributes .2
4.1 General . 2
4.2 Changes in colour . 2
4.2.1 Principles . 2
4.2.2 Apparatus . 3
4.2.3 Test specimens. 3
4.2.4 Procedure . 3
4.3 Changes in other appearance properties . 5
5 Determination of changes in mechanical or other properties . 5
5.1 Principles . 5
5.2 Apparatus . 6
5.3 Test specimens . 6
5.4 Procedure . 6
5.4.1 Determination of initial properties . 6
5.4.2 Storage of file specimens . 6
5.4.3 Determination of properties after exposure . 7
6 Expression of results . 7
6.1 Changes in colour . 7
6.1.1 Instrumental measurements . 7
6.1.2 Visual assessment . 7
6.2 Changes in other appearance properties . 7
6.2.1 Instrumental measurements . 7
6.2.2 Visual assessment of change in appearance attributes . 8
6.2.3 Changes in mechanical and other properties . 8
7 Precision . 9
8 Test report . 9
Annex A (normative) Statistical formulae based on ISO 2602 for determination of mean
and standard deviation and procedure for determination of time to 50 % loss
of property .10
Annex B (informative) Possible effects of surface cleaning on assessment of exposure .15
Bibliography .16
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ISO 4582:2017(E)

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
constitute an endorsement.
For an explanation on 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 the following
URL: w w w . i s o .org/ iso/ foreword .html
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 6, Ageing,
chemical and environmental resistance.
This fourth edition cancels and replaces the third edition (ISO 4582:2007), which has been technically
revised. The main changes compared to the previous edition are as follows:
— due to the withdrawal of all parts of ISO 7724, the colour measurement procedure has been revised.
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ISO 4582:2017(E)

Introduction
A number of different exposure techniques can be used to provide information on the effects of
environmental stresses such as simulated solar radiation, heat and water on plastics [see ISO 877 (all
parts) and ISO 4892 (all parts)]. Each exposure test has its own particular application and relevance.
When determining changes in a particular property or attribute of a material subjected to different
exposures, the same evaluation methods should be used after all exposures to ensure meaningful
results.
Results for plastics subjected to exposure tests are strongly dependent on the type of exposure
conditions used, the type of plastic being tested and the property being evaluated. A result obtained
for one property may not be the same as that for a different property of the same material, even if the
same exposure test is used. This document is not intended to establish a fixed procedure for conducting
the exposure test, but is intended to provide a set of specific procedures used to express the results
for change in a characteristic property of the material after it has been exposed. It is up to the user
to determine which exposure conditions are most relevant to the specific material and the service
conditions being used.
Test methods should be selected to determine changes in appearance and properties of the exposed
material with its proposed application in mind. The exposure test used should be devised to
discriminate among materials based on such changes. This document suggests typical properties that
can be used to determine changes in plastics which have been subjected to exposure tests.
NOTE Because of large differences in the spectral distribution of the radiation sources used, there can
be large differences in results for the same plastics exposed in the various devices described in ISO 4892 (all
parts). Therefore, comparisons between plastics are intended to be made only based on results from exposures
in the same type of device and under the same conditions. For optimum comparisons, plastics are expected to be
exposed at the same time in the same device.
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INTERNATIONAL STANDARD ISO 4582:2017(E)
Plastics — Determination of changes in colour and
variations in properties after exposure to glass-filtered
solar radiation, natural weathering or laboratory
radiation sources
1 Scope
This document specifies methods to determine changes in colour and other appearance properties,
and variations in mechanical or other properties, of plastics that have been exposed to glass-filtered
solar radiation, to natural weathering or to simulated solar radiation from a laboratory source. The
procedure used to analyse data depends on whether the test used to characterize the materials being
exposed is destructive or non-destructive. The exposures are conducted under conditions described in
specific exposure standards.
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 105-A01, Textiles — Tests for colour fastness — Part A01: General principles of testing
ISO 105-A02, Textiles — Tests for colour fastness — Part A02: Grey scale for assessing change in colour
ISO 105-A03, Textiles — Tests for colour fastness — Part A03: Grey scale for assessing staining
ISO 291, Plastics — Standard atmospheres for conditioning and testing
ISO 2602, Statistical interpretation of test results — Estimation of the mean — Confidence interval
ISO 10640, Plastics — Methodology for assessing polymer photoageing by FTIR and UV/visible spectroscopy
ISO 11664-1, Colorimetry — Part 1: CIE standard colorimetric observers
ISO 11664-2, Colorimetry — Part 2: CIE standard illuminants
ISO 11664-3, Colorimetry — Part 3: CIE tristimulus values
ISO 11664-4, Colorimetry — Part 4: CIE 1976 L*a*b* Colour space
CIE Publication No. 15, Colorimetry
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
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3.1
control
material which is of similar composition and construction to the test material, used for comparison and
exposed at the same time as the test material
3.2
file specimen
portion of the material to be tested which is stored under conditions in which it is stable, and is used for
comparison between the exposed and the original state
3.3
test specimen
specific portion of the material upon which the testing is to be performed
3.4
replicate specimens
identical pieces of the test material being evaluated which are all exposed, conditioned and tested at
the same time
4 Determination of changes in colour or other appearance attributes
4.1 General
When a polymeric material is exposed to UV radiation and other moderate environmental stresses, the
change in most physical properties is attributable to chemical ageing, and the extent of the chemical
changes can be related to the duration of the exposure under natural outdoor weathering or artificial
weathering exposure.
Chemical changes control the degradation of mechanical properties and contribute to changes in the visual
appearance of polymer materials during photoageing. These chemical changes are analysed primarily
by IR spectroscopy, with additional analyses using UV/visible spectroscopy during the photoageing
of polymers. The analysis at this earliest stage of degradation allows the identification of the critical
oxidation products, allows the stoichiometry of reactions to be checked and, in some cases, indicates weak
points in the polymer material (e.g. a weakness in the specific structure of the polymer, such as a double
bond, an ether group or a urethane group, unstable colorant, lack of UV stabilizers, or migration of low-
molecular-mass components of formulations to the surface and their accumulation there).
The relevance of artificial ageing can be determined by comparing the chemical changes that occur
in the accelerated test to those that occur in natural weathering. It should be pointed out that, in
some cases, oxidation products can be partially eliminated by hydrolysis, or erosion caused by water
under humid climates (e.g. southern Florida) or by wind under very dry climates (e.g. Arizona). Kinetic
analysis is recommended to determine the rate of degradation under different conditions of ageing in
order to rank different formulations or to determine the range of acceleration possible for an artificial
ageing test compared to a given natural outdoor weathering exposure (without distortion of the
photodegradation mechanism of the polymer). In addition, these analyses can be used as a tool for
developing improvements in polymers and polymeric products.
Methodologies to measure chemical changes in plastics after exposure to glass-filtered solar radiation,
natural weathering or laboratory radiation sources are expressed in ISO 10640.
4.2 Changes in colour
4.2.1 Principles
Changes in colour of plastics test specimens exposed in accordance with the specific exposure standard
(see Introduction) are determined by one of the following methods:
a) an instrumental method;
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b) visual assessment using a scale.
4.2.2 Apparatus
4.2.2.1 Instruments for measuring colour or changes in colour, conforming to the following
requirements:
— CIE 1964 standard colorimetric observer (10° observer), as specified in ISO 11664-1;
— CIE standard illuminant D65 (recommended) or A (for metamerism index), as specified in
ISO 11664-2;
— CIE tristimulus values or CIE 1976 L*a*b* Colour space, as specified in ISO 11664-3 and ISO 11664-4.
For light-transmitting specimens, instruments shall conform to the requirements of CIE Publication
No. 15.
4.2.2.2 Grey scale for assessing change in colour, in accordance with ISO 105-A02 or ISO 105-A03.
In this scale, grade 1 corresponds to the strongest contrast, and grade 5 to zero contrast (two samples
with identical colour).
NOTE The dark grey scale of ISO 105-A02 is well suited to assessing the extent of fading of relatively strong
colours or deep shades. The use of the near-white grey scale of ISO 105-A03 can be found preferable for assessing
the discolouration, e.g. yellowing, of white or near-white specimens.
4.2.3 Test specimens
Specimens of test and control materials shall conform to the requirements of the appropriate
International Standard dealing with the specific exposure method used. Whenever possible, a control
material of known weathering properties shall be included in the exposure experiment. Unless
otherwise specified, at least three replicate specimens of each material being exposed shall be used.
4.2.4 Procedure
4.2.4.1 General
The specific procedure used for assessment of colour changes and any surface cleaning shall be agreed
upon by all interested parties and shall be included in the test report. Determine colour changes as
specified in the appropriate International Standard.
Typically, colour changes are determined at a series of exposure stages in order to evaluate the rate of
colour change caused by exposure. In some cases, colour change is determined after a predetermined or
specified exposure increment. Measurement or visual assessment of colour should be made as soon as
possible after specimens are removed from exposure in order to minimize the effect of dark reactions,
although in some cases it is preferable to condition the specimens for e.g. 24 h after removal from exposure
as appearance properties assessed just after removal from exposure may vary, depending whether the
specimen was removed at the end of a wet exposure period or at the end of a dry exposure period.
NOTE Because of variability in exposure results, comparison of colour changes of different materials is best
done when the materials are simultaneously exposed in a single exposure device or at the same exterior location.
4.2.4.2 Instrumental assessment
Measure colour on all specimens before exposure and after each exposure stage. If required, measure
colour on file specimens of each material when measuring colour on exposed specimens.
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For opaque specimens, both colour and gloss may change due to ageing. When measuring the colour
and determining the colour change of opaque specimens with instruments use one of the following
measuring conditions:
— to get colour values independent of surface changes, use di:8° or 8°:di, according to CIE Publication
No. 15 (often used for smooth specimens);
— to get best correlation to visual perception, use de:8°, 8°:de, or 45°:0°, according to CIE Publication
No. 15 (often used for rough or matt specimens).
NOTE 1 If the gloss changes, the diffuse part of the surface reflexion will change and consequently the colour
values measured excluding the specular reflexion change too.
NOTE 2 If the gloss changes without a visually perceptible change in colour, for example after weathering, the
colour values measured including the specular reflexion will generally not be influenced.
NOTE 3 ISO 18314-1 applies to paint films but gives useful hints on the measuring procedure.
For light-transmitting specimens, follow the procedures described in CIE Publication No. 15.
NOTE 4 ASTM E1347 also describes colour measurement of light-transmitting materials.
4.2.4.3 Visual assessment
Follow the procedure described in ISO 105-A01 when determining colour change by visual assessment.
Use a grey scale meeting the requirements of ISO 105-A02 or ISO 105-A03. Compare the contrast rating
of the exposed specimen and file specimens using the grey scale. The rating of colour change is the
grade on the grey scale which shows the same contrast as between the exposed test specimen and an
unexposed file specimen of the same material.
NOTE Current information about suppliers of grey scales can be obtained from the secretariat of
ISO/TC 38/SC 1.
If the contrast observed lies between two ratings on the grey scale, it can be characterized by an
intermediate rating. For example, a 3-4 rating signifies that, at the given exposure stage, the contrast
between the exposed test specimen and the unexposed file specimen is greater than that of rating 4 on
the grey scale, but less than that of rating 3.
Report the nature of the colour change in terms of the rating on the grey scale. In addition, the type of
colour change shall also be determined and reported. Use the following terms to describe changes in
hue, saturation, lightness or combinations of these changes:
a) for hue changes: more blue or less blue
more green or less green
more red or less red
more yellow or less yellow
b) for saturation changes: less intense
more intense
c) for changes in lightness: lighter
darker
A typical report of colour change by visual assessment would be as follows: “more yellow, less intense,
lighter, ISO 105-A02/ISO 105-A03 grey scale 2-3”.
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4.3 Changes in other appearance properties
In addition to colour change, other appearance properties of plastics may change as a result of exposure.
Determine changes in these appearance properties in accordance with the relevant International
Standards. If the method used to assess the property change is not described in an International
Standard, include a description of the method used when reporting results. Examples of tests used to
determine change in typical appearance properties are shown in Table 1.
Table 1 — Methods used to measure change in typical appearance properties
Property assessed ISO standard Quantitative data
a
Gloss retention ISO 2813 yes
Light transmission ISO 13468-1 yes
Haze ISO 14782 yes
a b
Chalking ISO 4628-6 scale
Mass yes
Dimensions yes
b
Cracking or crazing scale
b
Delamination scale
b
Warping scale
b
Growth of microorganisms scale
b
Migration of components to surface scale
a
 Methods for paints applicable to plastics.
b
 See 6.2.2 for recommended descriptive scale.
5 Determination of changes in mechanical or other properties
5.1 Principles
Surface properties of a plastic can be much more sensitive to changes caused by weathering than bulk
properties. Measurement of surface properties, or material properties greatly affected by surface
properties, may be more informative in evaluating rigid plastics. The mechanical or other properties
measured using destructive tests are determined on several sets of specimens:
a) on specimens selected as representative of the material prior to exposure (initial property
determination);
b) on test specimens exposed for a chosen period in accordance with an appropriate International
Standard for the specific exposure used;
c) (if required) on file specimens stored in the dark for the same period for which the corresponding
test specimens have been exposed.
It is very important that all tests be conducted using exactly the same test procedure and the same
specimen-conditioning environment.
Examples of mechanical-property tests which may be used to assess the effect of exposure are shown in
Table 2. Such tests yield quantitative data but are destructive so that, if it is required to follow changes
through the course of the exposure, an adequate number of replicate test pieces are needed for each
exposure increment.
If a property is measured with a non-destructive test, it is recommended that the property be measured
on each test specimen prior to exposure and after each exposure increment. Typical properties
measured using non-destructive tests include mass, dimensions, surface gloss, transmittance and haze.
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Table 2 — Typical mechanical-property tests used to assess the effect of exposure on plastics
Property assessed ISO standard
Tensile properties, particularly extension at break ISO 527
Flexural properties ISO 178
Impact strength
  Charpy impact strength ISO 179 (all parts)
  Izod impact strength ISO 180
  Non-instrumented puncture test ISO 6603-1
  Instrumented puncture test ISO 6603-2
  Tensile impact test ISO 8256
Vicat softening temperature ISO 306
Temperature of deflection under load ISO 75-1 and ISO 75-2
Dynamic mechanical thermal analysis ISO 6721-1, ISO 6721-3 and ISO 6721-5
Chemical changes (for example using infrared spectroscopy)
5.2 Apparatus
The apparatus shall conform to the appropriate International Standard for the determination of the
property being measured.
5.3 Test specimens
For measurement of the property of interest, test specimens shall conform to the appropriate
International Standard dealing with the property measurement method. Unless otherwise specified,
use at least three replicate specimens of each material being evaluated when non-destructive tests
are performed. Use at least five replicates of each material being evaluated when destructive tests are
performed.
NOTE For properties measured with destructive tests, exposed specimens can be in the form of a sheet from
which the specimens for the particular test are cut. However, there can be differences in results between tests
conducted where individual test specimens are directly exposed, and tests where individual test specimens are
cut from a larger piece that has been subjected to the exposure.
Test specimens shall be conditioned after machining (see ISO 2818). In addition, it may also be necessary
to precondition the sheets prior to machining to facilitate specimen preparation.
5.4 Procedure
5.4.1 Determination of initial properties
Unless otherwise specified in the relevant International Standards, condition the test specimens prior
to the determination of initial properties in the standard atmosphere 23/50, class 1 and the appropriate
conditioning period specified in ISO 291, or as agreed between the interested parties.
Determine the property or properties to be evaluated in accordance with the relevant International
Standards, or as agreed between the interested parties (see 5.1).
5.4.2 Storage of file specimens
Store file specimens in the dark, unless otherwise specified in the standard atmospheres 23/50, class 1
according to ISO 291.
If increased moisture sensitivity is expected, storing at low relative humidity could be more useful, to
avoid ageing processes during storage. Such conditions shall be agreed upon all parties.
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The storage conditions used for reference specimens shall be agreed upon by all interested parties and
shall be stated in the test report.
5.4.3 Determination of properties after expos
...