ISO 28340:2013

INTERNATIONAL ISO
STANDARD 28340
First edition
2013-02-15
Combined coatings on aluminium —
General specifications for combined
coatings of electrophoretic organic
coatings and anodic oxidation
coatings on aluminium
Revêtements combinés sur aluminium — Spécifications générales
pour les revêtements combinés appliqués sur l’aluminium composés
d’un revêtement organique obtenu par électrophorèse appliqué sur
un revêtement obtenu par anodisation
Reference number
©
ISO 2013
© ISO 2013
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ii © ISO 2013 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Classes . 2
5 Quality . 3
5.1 General . 3
5.2 Appearance . 3
5.3 Colour . 3
5.4 Gloss . 3
5.5 Thickness of anodic oxidation coating . 3
5.6 Corrosion resistance . 3
5.7 Resistance to accelerated weathering . . 4
5.8 Resistance to cyclic corrosion/UV light . 4
5.9 Outdoor exposure . 4
5.10 Hardness of the organic coating . 4
5.11 Adhesion of the organic coating . 4
5.12 Solvent resistance of the organic coating . 4
5.13 Chemical resistance . 4
5.14 Abrasion resistance . 5
6 Test specimen . 5
6.1 Sampling procedure . 5
6.2 Size of the test specimen . 5
6.3 Cleanliness of the test specimen . 5
7 Test . 5
7.1 General condition . 5
7.2 Test methods . 5
8 Expression of results .12
9 Test report .12
Annex A (informative) Recommended characteristics and performance .13
Annex B (normative) Rating number charts for evaluation of the corrosion rate .15
Annex C (normative) Rating number charts for evaluation of the alkali resistance test.16
Bibliography .17
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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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.
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.
ISO 28340 was prepared by Technical Committee ISO/TC 79, Light metals and their alloys, Subcommittee
SC 2, Organic and anodic oxidation coatings on aluminium.
iv © ISO 2013 – All rights reserved

INTERNATIONAL STANDARD ISO 28340:2013(E)
Combined coatings on aluminium — General specifications
for combined coatings of electrophoretic organic coatings
and anodic oxidation coatings on aluminium
1 Scope
This International Standard gives specifications for the combined coatings of electrophoretic organic
coatings and anodic oxidation coatings on aluminium used for architecture.
It specifies the characteristic properties of combined coatings on aluminium, outlines the test methods
for checking these characteristic properties and specifies their required performance.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method
ISO 2360, Non-conductive coatings on non-magnetic electrically conductive basis materials — Measurement
of coating thickness — Amplitude-sensitive eddy-current method
ISO 2409, Paints and varnishes — Cross-cut test
ISO 2810, Paints and varnishes — Natural weathering of coatings — Exposure and assessment
ISO 2813, Paints and varnishes — Determination of specular gloss of non-metallic paint films at 20 degrees,
60 degrees and 85 degrees
ISO 2859-10, Sampling procedures for inspection by attributes — Part 10: Introduction to the ISO 2859
series of standards for sampling for inspection by attributes
ISO 4628-1, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity
and size of defects, and of intensity of uniform changes in appearance — Part 1: General introduction and
designation system
ISO 4892-4, Plastics — Methods of exposure to laboratory light sources — Part 4: Open-flame carbon-arc lamps
ISO 7599, Anodizing of aluminium and its alloys — General specifications for anodic oxidation coatings on
aluminium
ISO 7668, Anodizing of aluminium and its alloys — Measurement of specular reflectance and specular gloss
of anodic oxidation coatings at angles of 20 degrees, 45 degrees, 60 degrees or 85 degrees
ISO 8251, Anodizing of aluminium and its alloys — Measurement of abrasion resistance of anodic
oxidation coatings
ISO 8993, Anodizing of aluminium and its alloys — Rating system for the evaluation of pitting
corrosion — Chart method
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 11341, Paints and varnishes — Artificial weathering and exposure to artificial radiation — Exposure to
filtered xenon-arc radiation
ISO 11507, Paints and varnishes — Exposure of coatings to artificial weathering — Exposure to fluorescent
UV lamps and water
ISO 15184, Paints and varnishes — Determination of film hardness by pencil test
AAMA 612-02, Voluntary specification, performance requirements, and test procedures for combined
coatings of anodic oxide and transparent organic coatings on architectural aluminum
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
combined coatings
superimposed electrophoretic organic coating and anodic oxidation coating on aluminium
3.2
significant surface
part of the article covered or to be covered by the coatings, and for which the coatings are essential for
service and/or appearance
3.3
standard sample
limit sample
sample which defines the criteria for acceptable appearance
Note 1 to entry: This may be agreed between the surface processor and the customer.
4 Classes
The combined coatings are classified by corrosion resistance, which is specified in 5.6, resistance to
accelerated weathering specified in 5.7, and resistance to cyclic corrosion/UV light specified in 5.8.
Performance requirements are given in Table 1.
To test the corrosion resistance, the acetic acid salt spray (AASS) test (method A) or copper-accelerated
acetic acid salt spray (CASS) test (method B) shall be carried out.
To test the resistance to accelerated weathering, the xenon-arc lamp exposure test (method A) or the
open-flame carbon-arc lamp exposure test (method B) shall be carried out.
To test the resistance to cyclic corrosion/UV light, the AASS test (method A) shall be carried out or the
CASS test (method B) after the ultraviolet (UV) lamp exposure test specified in 5.8. The selection of the
test method should be agreed between the surface processor and the customer.
NOTE Classes and applied environments are given in Table A.1.
2 © ISO 2013 – All rights reserved

Table 1 — Classes of combined coatings on aluminium
Characteristic prop- Corrosion resist- Resistance to acceler- Resistance to cyclic corrosion/
erty ance ated weathering UV light
Test method A B A B A B
AASS CASS Xenon-arc Carbon-arc UV AASS UV CASS
lamp lamp
Testing Class 4 1 500 120 4 000 3 000 240 1 500 240 120
time
Class 3 1 500 120 2 000 1 500 240 1 500 240 120
h
Class 2 1 000 72 1 000 750 240 1 000 240 72
Class 1 — 24  350 250 —- —- —- —-
Criteria Corrosion: No remarkable colour Corrosion:
RN 9,5 or more change and chalking RN 9,0 or more
Gloss retention: 75 % or
more
5 Quality
5.1 General
The required quality for the applied products shall be chosen from the performances specified in 5.2 to
5.14 which should be agreed between the surface processor and the customer.
5.2 Appearance
The appearance shall be examined by the method specified in 7.2.1, and any visual surface defects, such
as scratches, unevenness, peeling, which are unacceptable for the application, shall not be permitted.
The quality should be agreed between the surface processor and the customer.
5.3 Colour
The colour and its tolerance level shall be examined by the method specified in 7.2.2, and the quality
should be agreed between the surface processor and the customer.
5.4 Gloss
The specular gloss of the electrophoretic organic coating shall be examined by the method specified in
7.2.3, and the quality should be agreed between the surface processor and the customer.
5.5 Thickness of anodic oxidation coating
The thickness of anodic oxidation coating shall be measured by the method specified in 7.2.4, and the quality
should be agreed between the surface processor and the customer. The average thickness of anodic oxidation
coating, as specified in ISO 7599, shall be more than 5 μm. Furthermore, the minimum local thickness shall
not be less than 80 % (4 μm) of the average thicknesses at three or more measurement points.
The total thickness of the combined coatings is not specified because specification is based on performance.
5.6 Corrosion resistance
The corrosion resistance of the combined coatings shall be tested by the AASS test specified in 7.2.5.2
or the CASS test specified in 7.2.5.3 and shall be evaluated by the degradation in appearance and the
corrosion rate [rating number(RN)] for the test specimens. The selection of the test method should
be agreed between the surface processor and the customer. The testing time and the quality of the
combined coatings shall conform to Table 1.
5.7 Resistance to accelerated weathering
The accelerated weathering resistance shall be tested by the xenon-arc lamp exposure test specified in
7.2.6.2 or the open-flame carbon-arc lamp exposure test specified in 7.2.6.3. The performance shall be
evaluated by the visual degradation, such as colour change, chalking, and gloss-retention of the organic
coating. The testing time and the quality of the combined coatings shall conform to Table 1.
5.8 Resistance to cyclic corrosion/UV light
The resistance to cyclic corrosion/UV light shall be tested by the AASS test specified in 7.2.5.2 or the
CASS test specified in 7.2.5.3, after having been tested by UV lamp exposure, as specified in 7.2.7. The
performance shall conform to Table 1.
5.9 Outdoor exposure
If required by the customer, the resistance to outdoor exposure shall be tested, and the exposure site,
the testing time and the required performance should be agreed between the surface processor and the
customer. This test shall be carried out by the method specified in 7.2.8, and the deterioration of the test
specimens shall be evaluated by the change in appearance, gloss-retention and corrosion rate (RN). A
recommended example of the outdoor exposure test and fastness are given in Table A.2.
5.10 Hardness of the organic coating
The surface hardness of the electrophoretic organic coating shall be tested by the method specified
in 7.2.9, and shall be evaluated by the degree of pencil hardness to be scratched. The hardness of the
electrophoretic organic coating shall be more than 3 H in all classes.
5.11 Adhesion of the organic coating
The adhesion between the anodic oxidation coating and the electrophoretic organic coating shall
be tested by the cross-cut test specified in 7.2.10.2 and the cross-cut test after immersion in boiling
water specified in 7.2.10.3, and the performance shall be evaluated by the degree of exfoliation of
the electrophoretic organic coating. The required adhesion of the organic coatings of all classes shall
conform to Table 2.
Table 2 — Required adhesion of the organic coating
Cross-cut test Cross-cut test after immersion in boiling water
Adhesion Appearance Adhesion
25/25 Without wrinkles, cracks and remark- 25/25
able colour change on the significant
surface
5.12 Solvent resistance of the organic coating
The solvent resistance of the electrophoretic organic coating shall be evaluated by using the method
specified in 7.2.11. The change in hardness of the electrophoretic organic coating of all classes after the
solvent resistance test shall be within Δ1H without swellings, cracks and peeling on the significant surface.
5.13 Chemical resistance
If required by the customer, the chemical resistance of the combined coatings shall be tested.
This test shall be carried out with the alkali resistance test specified in 7.2.12.2 and/or the acid resistance
test specified in 7.2.12.3, and evaluated by the appearance and corrosion rate (RN) of the test specimens.
Recommended testing time and qualities of the combined coatings are given in A3.1 and/or A3.2.
4 © ISO 2013 – All rights reserved

In case of the combined coatings contact with mortar, the alkali resistance test should be implemented.
5.14 Abrasion resistance
If required by the customer, the abrasion resistance of the combined coatings shall be tested. The
performance requirements should be agreed between the surface processor and the customer.
This test shall be carried out by the abrasive jet test specified in 7.2.13.2 or the falling sand abrasion test
specified in 7.2.13.3, and the performance should be evaluated by the degree of abrasion as given in A.4.
The substitute test specimens shall be produced in the same way as the products, using the same
semiproduct (i.e. sheet, profile), alloy and temper.
6 Test specimen
6.1 Sampling procedure
The test specimens shall be cut from the significant surfaces of the products. However, if they cannot
be taken from production, substitute test specimens produced together with the real products may be
used for testing. The sampling lot size should be agreed between the surface processer and the customer
in accordance with ISO 2859-10, taking into consideration the kind of products, size and quantity.
6.2 Size of the test specimen
The size of test specimens should be chosen from the following sizes if there is no consensus:
150 mm x 70 mm, or 150 mm x 75 mm
6.3 Cleanliness of the test specimen
The surface of test specimens shall be wiped clean using soft wet cloths with deionized water or ethanol.
Use deionized water if the coating can be attacked by ethanol.
7 Test
7.1 General condition
The temperature of the testing environment shall be room temperature and the relative humidity should
be under 65 %. It shall be free from direct sunlight, gas, steam dust and wind, which all can influence
the test results.
7.2 Test methods
7.2.1 Visual test
The visual test of the significant surface shall be carried out under artificial light or diffuse daylight
specified in ISO 4628-1. The light source C (or D65) or high colour fidelity light (colour fidelity AAA) on
the test specimens shall be over 600 lx. The distance and observing angle should be agreed between the
surface processer and the customer. The background of the test specimens should be monochrome grey
or black. The distance between the inspector and the test specimens should be 5 m when the inspection
is done outdoors, and 3 m when it is indoors.
7.2.2 Inspection of colour
The inspection of colour and colour tolerance of the significant surface shall be carried out as specified in
7.2.1. The test specimens and standard specimen shall be placed on the same plane stand. Unless otherwise
agreed between the surface processer and the customer, in the case of artificial light, the light source shall
be placed behind the inspector and the test specimens
...