Organic coatings on aluminium and its alloys — Methods for specifying decorative and protective organic coatings on aluminium — Part 1: Powder coatings

This document specifies methods for specifying decorative and protective powder coatings on aluminium and its alloys. It defines the characteristic properties of powder coatings and provides testing methods with minimum performance requirements, with reference to the application and the aggressiveness of the environment in which the coated aluminium exists. This document does not apply to coil coatings on aluminium.

Couches organiques sur l’aluminium et ses alliages — Méthodes de spécification des revêtements décoratifs et protecteurs sur aluminium — Partie 1: Revêtements par poudre

General Information

Status
Published
Publication Date
31-May-2022
Current Stage
4060 - Close of voting
Start Date
02-Jul-2021
Completion Date
01-Jul-2021
Ref Project

Buy Standard

Standard
ISO 18768-1:2022 - Organic coatings on aluminium and its alloys — Methods for specifying decorative and protective organic coatings on aluminium — Part 1: Powder coatings Released:6/1/2022
English language
29 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

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 18768-1:2022(E)
© ISO 2022
---------------------- Page: 1 ----------------------
ISO 18768-1:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on

the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below

or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
© ISO 2022 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 18768-1:2022(E)
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

iii
© ISO 2022 – All rights reserved
---------------------- Page: 3 ----------------------
ISO 18768-1:2022(E)

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 ..................................................................................................................................................... 19

7.15.6 Filiform corrosion resistance .............................................................................................................................. 19

7.15.7 Resistance to humid atmosphere containing sulfur dioxide ................................................... 19

7.16 Humidity resistance .......................................................................................................................................................................20

7.16.1 Measurement ...................................................................................................................................................................... 20

7.16.2 Requirement ........................................................................................................................................................................20

7.17 Boiling water resistance .............................................................................................................................................................20

7.17.1 Measurement ...................................................................................................................................................................... 20

7.17.2 Requirement ........................................................................................................................................................................ 21

7.18 Weathering resistance .................................................................................................................................................................. 21

7.18.1 General ..................................................................................................................................................................................... 21

7.18.2 Outdoor exposure test................................................................................................................................................ 21

7.18.3 Accelerated weathering resistance ................................................................................................................ 22

7.19 Sealing compounds adhesion ................................................................................................................................................. 23

7.19.1 Measurement ......................................................................................................................................................................23

7.19.2 Requirement ........................................................................................................................................................................23

Annex A (informative) Summary of information to be supplied by the customer to the

surface processor .............................................................................................................................................................................................24

Annex B (informative) Coating powders ......................................................................................................................................................27

Annex C (informative) Categories for architectural application ........................................................................................28

Bibliography .............................................................................................................................................................................................................................29

© ISO 2022 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 18768-1:2022(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 of 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

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.
A list of all parts in the ISO 18768 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
© ISO 2022 – All rights reserved
---------------------- Page: 5 ----------------------
ISO 18768-1:2022(E)
Introduction
There are three major surface treatments on aluminium and its alloys:
a) anodic oxidation coatings;
b) organic coatings;
c) combined coatings of anodic oxidation coatings and organic coatings.

This document and ISO 18768-2 provide the performance requirements and test methods for b) organic

coatings.

Performance requirements and test methods for a) anodic oxidation coatings are given in ISO 7599 and

for c) combined coatings of anodic oxidation coatings and organic coatings in ISO 28340.

It is assumed that users are familiar with other relevant international and regional standards. Those

standards should be respected, and this document adopts optional systems in such cases.

© ISO 2022 – All rights reserved
---------------------- Page: 6 ----------------------
INTERNATIONAL STANDARD ISO 18768-1:2022(E)
Organic coatings on aluminium and its alloys — Methods
for specifying decorative and protective organic coatings
on aluminium —
Part 1:
Powder coatings
1 Scope

This document specifies methods for specifying decorative and protective powder coatings on

aluminium and its alloys. It defines the characteristic properties of powder coatings and provides

testing methods with minimum performance requirements, with reference to the application and the

aggressiveness of the environment in which the coated aluminium exists.
This document does not apply to coil coatings on aluminium.
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 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method

ISO 1519, Paints and varnishes — Bend test (cylindrical mandrel)
ISO 1520, Paints and varnishes — Cupping test

ISO 2360, Non-conductive coatings on non-magnetic electrically conductive base metals — 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 gloss value at 20°, 60° and 85°

ISO 2815, Paints and varnishes — Buchholz indentation test

ISO 3892, Conversion coatings on metallic materials — Determination of coating mass per unit area —

Gravimetric methods

ISO 4623-2, Paints and varnishes — Determination of resistance to filiform corrosion — Part 2: Aluminium

substrates

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 4628-2, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity

and size of defects, and of intensity of uniform changes in appearance — Part 2: Assessment of degree of

blistering
© ISO 2022 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 18768-1:2022(E)

ISO 4628-10, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity

and size of defects, and of intensity of uniform changes in appearance — Part 10: Assessment of degree of

filiform corrosion

ISO 6270-1, Paints and varnishes — Determination of resistance to humidity — Part 1: Condensation

(single-sided exposure)

ISO 6270-2, Paints and varnishes — Determination of resistance to humidity — Part 2: Condensation (in-

cabinet exposure with heated water reservoir)

ISO 6270-3, Paints and varnishes — Determination of resistance to humidity — Part 3: Condensation (in-

cabinet exposure with heated, bubbling water reservoir)

ISO 6272-1, Paints and varnishes — Rapid-deformation (impact resistance) tests — Part 1: Falling-weight

test, large-area indenter

ISO 6272-2, Paints and varnishes — Rapid-deformation (impact resistance) tests — Part 2: Falling-weight

test, small-area indenter

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 15184, Paints and varnishes — Determination of film hardness by pencil test

ISO 16474-2, Paints and varnishes — Methods of exposure to laboratory light sources — Part 2: Xenon-arc

lamps

ISO 16474-3, Paints and varnishes — Methods of exposure to laboratory light sources — Part 3: Fluorescent

UV lamps

ISO 22479, Corrosion of metals and alloys — Sulfur dioxide test in a humid atmosphere (fixed gas method)

ISO 28340:2013, Combined coatings on aluminium — General specifications for combined coatings of

electrophoretic organic coatings and anodic oxidation coatings on aluminium
ASTM C207, Standard Specification for Hydrated Lime for Masonry Purposes

ASTM D2794, Standard Test Method for Resistance of Organic Coatings to the Effects of Rapid Deformation

(Impact)

ASTM D7869, Standard Practice for Xenon Arc Exposure Test with Enhanced Light and Water Exposure for

Transportation Coatings
ASTM G85-19, Standard Practice for Modified Salt Splay (Fog) Testing

GSB International, GSB QR AL 631-7 ST 663-7, International Quality Regulations For the Coating of

Building Components
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
© ISO 2022 – All rights reserved
---------------------- Page: 8 ----------------------
ISO 18768-1:2022(E)
3.1
powder coating

continuous layer of coating powder applied to the aluminium or aluminium alloy substrate, which is

protective and/or decorative
3.2
reference sample
reference specimen
sample which defines the criteria for acceptable properties

Note 1 to entry: This may be agreed between the customer and the surface processor.

3.3
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
3.4
test specimen
single sample of the final product to be used for testing
4 Information to be supplied by the customer to the surface processor

In order to coat the product correctly and depending on the application, the following information

should be supplied by the customer to the surface processor, if necessary, in consultation with the

aluminium supplier and/or the surface processor.
A summary of the references to this information is given in Annex A.
a) a reference to this document, i.e. ISO 18768-1;
b) the intended service use of the article to be coated;
c) the environmental categories of the intended service (see Clause 6);

d) the specification of the aluminium (chemical composition and temper designations) to be coated;

e) an indication of the significant surface(s) of the product to be coated;
f) the preferred position and maximum size of contact marks;
g) details of any formal sampling plans required;
h) the type of pretreatment;
i) mass loss by etching;

j) thickness of the anodic oxidation coating or mass of the chemical conversion coating used for

pretreatment;
k) the type of coating process to be used;
l) the quality of appearance required;
m) the acceptable limits of colour variation by agreed reference samples;

n) the colour difference of the coating between the test specimen and the reference samples using a

colour difference meter;
o) the acceptable limits of gloss variation by agreed reference samples;
p) the value range of the gloss measured by equipment;
© ISO 2022 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 18768-1:2022(E)
q) the thickness of coating;
r) the hardness of coating;
s) the dry adhesion of coating;
t) the wet adhesion of coatings (boiling water resistance);
u) the impact resistance (excluding anodic oxidation coating for pretreatment);
v) the abrasion resistance of coating;
w) the cupping resistance (excluding anodic oxidation coating for pretreatment);

x) the flexibility of coating (excluding anodic oxidation coating for pretreatment);

y) the processing resistance, such as cutting, milling or drilling;
z) the solvent resistance of coating;
aa) the humidity resistance;
bb) the type of chemical resistance to be used;
cc) the detergent resistance;
dd) the alkali resistance;
ee) the mo
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.