ISO 2135:2017

Anodizing of aluminium and its alloys - Accelerated test of light fastness of coloured anodic oxidation coatings using artificial light

ISO 2135 specifies an accelerated test method for assessing the fastness, using artificial light, of coloured anodic oxidation coatings on aluminium and its alloys. For evaluating light fastness on exterior exposure, only outdoor exposure under conditions comparable with actual service is completely satisfactory. Accelerated testing is suitable as a quality-control test of coloured anodic oxidation coatings whose light fastness number has already been established by means of outdoor exposure testing. The method is applicable to coloured anodic oxidation coatings on aluminium and its alloys produced by any means and for any purpose. However, the method is not suitable for the measurement of coloured coatings with a light fastness number already established by means of outdoor exposure testing and of less than 6.

Anodisation de l'aluminium et de ses alliages — Essai accéléré de solidité à la lumière artificielle des couches d'oxydation anodique colorées

General Information

• Status: Published
• Publication Date: 08-Oct-2017
• ICS: 25.220.20 - Surface treatment
• Technical Committee: ISO/TC 79/SC 2 - Organic and anodic oxidation coatings on aluminium
• Drafting Committee: ISO/TC 79/SC 2/WG 15 - Anodic oxidation coatings on aluminium
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 01-Oct-2024
• Completion Date: 13-Dec-2025

Relations

• Consolidated By: ISO 8666:2020 - Small craft - Principal data
• Effective Date: 06-Jun-2022
• Revised: ISO 2135:2024 - Anodizing of aluminium and its alloys - Accelerated test of light fastness of coloured anodic oxidation coatings using artificial light
• Effective Date: 04-Nov-2023
• Revises: ISO 2135:2010 - Anodizing of aluminium and its alloys - Accelerated test of light fastness of coloured anodic oxidation coatings using artificial light
• Effective Date: 14-Nov-2015

Overview

ISO 2135:2017 - Anodizing of aluminium and its alloys - Accelerated test of light fastness of coloured anodic oxidation coatings using artificial light - specifies a laboratory procedure to assess the light fastness (colour stability) of coloured anodic oxidation coatings on aluminium using artificial light sources. It is designed as an accelerated, repeatable quality-control test for coatings whose outdoor light fastness has already been established. The method defines apparatus, specimen preparation, exposure conditions, visual and instrumental evaluation, and reporting requirements.

Key topics and requirements

• Scope and limitations: Applicable to coloured anodized coatings produced by any process; not suitable for coatings with an outdoor-established light fastness number below 6.
• Principle: Calibrate the apparatus using standard cloth samples (light fastness number 6) to define an exposure cycle. Expose test specimens until a colour change equals grade 3 of the grey scale (~25% loss of colour).
• Apparatus and light sources: Acceptable sources are xenon-arc lamps, open-frame carbon-arc, or enclosed carbon-arc lamps (specifications in Annex A). Typical cycle times cited: ~300 h for xenon-arc and ~150 h for carbon-arc (for the standard cloth).
• Specimen preparation: Sample from a representative flat area (avoid edges); standard specimen size ~150 mm × 70 mm; clean and mask part of the surface to detect colour change.
• Exposure conditions: Maintain black panel temperature at (63 ± 3) °C (or (50 ± 3) °C by agreement); ensure constant irradiance, distance and ambient conditions; rotate specimens or relocate to equalize exposure.
• Assessment:
  • Visual: assign a light fastness number based on the number of cycles needed to reach grey-scale grade 3 (Table maps cycles to numbers 6–>10).
  • Instrumental: measure colour difference as ΔE* (ISO 4582) and, if required, gloss retention (ISO 7668).
• Reporting: Must reference ISO 2135:2017 and include material, finishing, light source, test results, deviations and date.

Applications

• Routine quality control and batch acceptance for anodized aluminium finishes.
• Comparative testing in R&D and process optimization for colouring and sealing steps.
• Prequalification of finishes for architectural façades, curtain walls, signage, consumer goods and transport components where long-term colour stability is important.
• Useful for testing laboratories, anodizers, coating formulators, specifiers and façade engineers.

Related standards

• ISO 4582 (colour measurement, ΔE*)
• ISO 7583 (anodizing terms)
• ISO 105-A02 / ISO 105-B02 (grey scale and xenon-arc textile methods)
• ISO 4892-2 / ISO 4892-4 / ISO 16474-x (laboratory light sources)
• ISO 7668 (gloss measurement)
• ASTM G153 / G155 (references for lamp/filter specifications)

Keywords: ISO 2135:2017, anodizing of aluminium, light fastness, coloured anodic oxidation coatings, accelerated test, xenon-arc, carbon-arc, grey scale, ΔE*, gloss retention.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 2135
Fourth edition
2017-10
Anodizing of aluminium and its
alloys — Accelerated test of light
fastness of coloured anodic oxidation
coatings using artificial light
Anodisation de l'aluminium et de ses alliages — Essai accéléré de
solidité à la lumière artificielle des couches d'oxydation anodique
colorées
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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the requester.
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 2
6 Test specimen . 2
6.1 Sampling . 2
6.2 Size . 2
6.3 Treatment before testing . 2
7 Procedure. 2
7.1 Preparation of test specimen . 2
7.2 Exposure conditions . 2
7.3 Period of exposure . 3
8 Expression of results . 3
8.1 General . 3
8.2 Visual assessment . 3
8.3 Instrumental assessment . 4
9 Test report . 4
Annex A (normative) Various light sources . 5
Bibliography . 6
Foreword
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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
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URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 79, Light metals and their alloys,
Subcommittee SC 2, Organic and anodic oxidation coatings on aluminium.
This fourth edition cancels and replaces the third edition (ISO 2135:2010), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— the information on the test specimen has been added;
— the black panel temperature has been added;
— the instrumental assessment for colour change and gloss retention has been added;
— the specification of various light sources has been added as a new Annex A.
iv © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 2135:2017(E)
Anodizing of aluminium and its alloys — Accelerated test
of light fastness of coloured anodic oxidation coatings
using artificial light
1 Scope
This document specifies an accelerated test method for assessing the fastness, using artificial light, of
coloured anodic oxidation coatings on aluminium and its alloys.
For evaluating light fastness on exterior exposure, only outdoor exposure under conditions comparable
with actual service is completely satisfactory.
Accelerated testing is suitable as a quality-control test of coloured anodic oxidation coatings whose
light fastness number has already been established by means of outdoor exposure testing.
The method is applicable to coloured anodic oxidation coatings on aluminium and its alloys produced
by any means and for any purpose.
However, the method is not suitable for the measurement of coloured coatings with a light fastness
number already established by means of outdoor exposure testing and of less than 6.
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 4582, Plastics — Determination of changes in colour and variations in properties after exposure to
glass-filtered solar radiation, natural weathering or laboratory radiation sources
ISO 7583, Anodizing of aluminium and its alloys — Terms and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7583 apply.
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