ISO 18768-1:2022

INTERNATIONAL ISO
STANDARD 18768-1
First edition
2022-06
Organic coatings on aluminium and
its alloys — Methods for specifying
decorative and protective organic
coatings on aluminium —
Part 1:
Powder coatings
Couches organiques sur l’aluminium et ses alliages — Méthodes
de spécification des revêtements décoratifs et protecteurs sur
aluminium —
Partie 1: Revêtements par poudre
Reference number
© ISO 2022
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Published in Switzerland
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Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Information to be supplied by the customer to the surface processor .3
5 Metal preparation and pretreatment . 4
5.1 Material (substrate) . 4
5.2 Pretreatment of the substrate . 4
5.2.1 General . 4
5.2.2 Degreasing, etching and rinsing. 5
5.2.3 Anodic oxidation coatings . 5
5.2.4 Chemical conversion coatings . 5
5.2.5 Alternative pretreatment . 5
6 Categories . 6
7 Tests . 7
7.1 General . 7
7.2 Appearance . 8
7.2.1 General . 8
7.2.2 Measurement . 8
7.2.3 Requirement . 8
7.3 Colour . 8
7.3.1 General . 8
7.3.2 Visual method . 8
7.3.3 Instrumental method . 9
7.4 Gloss . 9
7.4.1 General . 9
7.4.2 Visual method . 9
7.4.3 Instrumental method . 9
7.5 Thickness . 10
7.5.1 General . 10
7.5.2 Measurement . 10
7.5.3 Requirement . 10
7.6 Hardness . 10
7.6.1 General . 10
7.6.2 Pencil hardness test . . 11
7.6.3 Buchholz indentation test . 11
7.7 Adhesion . 11
7.7.1 Dry adhesion test . 11
7.7.2 Wet adhesion test.12
7.8 Impact resistance .12
7.8.1 General .12
7.8.2 Falling-weight test .12
7.8.3 DuPont test . 13
7.9 Abrasion resistance . . 13
7.9.1 Measurement . 13
7.9.2 Requirement .13
7.10 Cupping test. 14
7.10.1 Measurement . 14
7.10.2 Requirement . 14
7.11 Cylindrical mandrel bend test . 14
7.11.1 Measurement . 14
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7.11.2 Requirement . 14
7.12 Processing resistance . 14
7.12.1 Measurement . 14
7.12.2 Requirement . 14
7.13 Chemical resistance . 14
7.13.1 General . 14
7.13.2 Acid resistance . 15
7.13.3 Alkali resistance .15
7.13.4 Detergent resistance . 15
7.13.5 Mortar resistance . 16
7.14 Solvent resistance . 16
7.14.1 Measurement . 16
7.14.2 Requirement . 17
7.15 Corrosion resistance . 17
7.15.1 General . 17
7.15.2 Neutral salt spray (NSS) test . 17
7.15.3 Acetic acid salt spray (AASS) test . 18
7.15.4 Copper-accelerated acetic acid salt spray (CASS) test . 18
7.15.5 Cyclic corrosion test .
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