ISO 20920:2018

INTERNATIONAL ISO
STANDARD 20920
First edition
2018-09
Textiles — Man-made fibres —
Determination of dye uptake of cationic
dyeable modified polyester fibres
Textiles — Fibres fabriquées — Détermination de l’absorption des
colorants par les fibres de polyester à pression normale
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents  Page
Foreword .iv
Introduction .v
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  Principle . 2
5  Reagents and materials . 2
6  Apparatus . 2
7  Test preparation . 2
7.1 Pre-treatment of samples . 2
7.2 Conditioning of samples . 3
7.3 Preparation of dye stock solutions . 3
8  Procedure. 3
9  Calculation and expression of the results . 3
10  Precision of the method . 4
11  Test report . 4
Annex A (informative) Precision experiment. 5
Bibliography . 6
Foreword
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This document was prepared by Technical Committee ISO/TC 38, Textiles, Subcommittee SC 23, Fibres
and yarns.
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iv © ISO 2018 – All rights reserved

Introduction
Typical polyester fibres as sold on the market can be dyed at temperatures above 100 °C and high
pressures by using disperse dye. As part of the highly modified polyester products, cationic dyeable
polyester (CDP) can be dyed at lower temperatures by using cationic dye. For some modified species in
particular, easy cationic dyeable polyester (ECDP) can be dyed under 100 °C at normal pressure. Due to
this key improvement, cationic dyeable modified polyester fibres are becoming more and more popular
on the market. This test method is used to evaluate the dye uptake rate of cationic dyeable modified
polyester fibres by using cationic dye.
INTERNATIONAL STANDARD ISO 20920:2018(E)
Textiles — Man-made fibres — Determination of dye
uptake of cationic dyeable modified polyester fibres
WARNING — The use of this document can involve hazardous materials, operations, and
equipment. It does not purport to address all of the safety risks associated with its use.
1  Scope
This document specifies a method for determining the dye uptake of cationic dyeable modified polyester
fi
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