ISO 21915-1:2020

Textiles — Qualitative and quantitative analysis of some cellulose fibres (lyocell, cupro) and their blends — Part 1: Fibre identification using scanning electron microscopy and spectral analysis methods

This document specifies the qualitative analysis for cupro and lyocell using the two methods separately — scanning electron microscope (SEM) method based on the application of ISO 20705, and — spectral analysis method. These testing methods are applied only for cupro and lyocell, or those blends. If other fibres are present, those are identified using the test method of ISO/TR 11827 and removed using the relevant part of the ISO 1833 series. This method is not applicable for the fibre surface that is damaged during the process (e.g. chemically or physically).

Textiles — Analyses qualitative et quantitative de certaines fibres cellulosiques (lyocell, cupro) et leurs mélanges — Partie 1: Identification des fibres par des méthodes de microscopie électronique à balayage et d'analyse spectrale

General Information

• Status: Published
• Publication Date: 26-Apr-2020
• ICS: 59.060.01 - Textile fibres in general
• Technical Committee: ISO/TC 38 - Textiles
• Drafting Committee: ISO/TC 38/WG 22 - Composition and chemical testing
• Current Stage: 6060 - International Standard published
• Start Date: 27-Apr-2020
• Due Date: 02-Jun-2020
• Completion Date: 27-Apr-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 21915-1
First edition
2020-04
Textiles — Qualitative and
quantitative analysis of some cellulose
fibres (lyocell, cupro) and their
blends —
Part 1:
Fibre identification using scanning
electron microscopy and spectral
analysis methods
Textiles — Analyses qualitative et quantitative de certaines fibres
cellulosiques (lyocell, cupro) et leurs mélanges —
Partie 1: Identification des fibres par des méthodes de microscopie
électronique à balayage et d'analyse spectrale
Reference number
ISO 21915-1:2020(E)
©
ISO 2020

---------------------- Page: 1 ----------------------
ISO 21915-1:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
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: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 21915-1:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
4.1 SEM method . 2
4.2 Spectral analysis method . 2
5 Reagents . 2
5.1 SEM method . 2
6 Apparatus . 3
6.1 SEM method . 3
6.2 Spectral analysis method . 3
7 Procedure. 4
7.1 SEM method . 4
7.1.1 Prior identification . 4
7.1.2 Pre-treatment of specimens . 4
7.1.3 Cutting . 4
7.1.4 Preparation of specimen . 4
7.1.5 Observation of specimen . 5
7.1.6 Qualitative analysis . 6
7.2 Spectral analysis (IR) method . 6
7.2.1 Development of calibration model . 6
7.2.2 Measurement of test sample. 7
7.2.3 Calculation of the predicted value and judgment . 7
8 Test report . 8
Annex A (informative) Example of the observation condition by SEM . 9
Annex B (informative) Interlaboratory test results of SEM method .11
Annex C (informative) Quantitative analysis of SEM method.16
Annex D (informative) Example of optimization of calibration model .17
Annex E (informative) Interlaboratory test results of IR method .19
Bibliography .21
© ISO 2020 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 21915-1:2020(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 38, Textiles.
A list of all parts in the ISO 21915 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.
iv © ISO 2020 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 21915-1:2020(E)

Introduction
The qualitative and quantitative determination of fibres is important for the distribution of textile
products. In many countries, it is legally obligatory to attach information on the type of fibres used and
their composition to textile products.
Therefore, the standards for the fibre identification and composition test methods have been developed
on the fibres or blends of fibres as possible.
Cupro and lyocell described in this document are regenerated cellulose fibres and can be said to be
materials that contribute to a sustainable society in that raw materials are not derived from petroleum.
There is difficulty to identify if the fibre is cupro or lyocell. Because the characteristics of appearance,
chemical resistance, infrared spectroscopy (IR) spectrum, etc. are almost the same, the qualitative
property according to ISO/TR 11827 and the quantification by the ISO 1833 series cannot be performed
in some cases. The identification methods between cupro and lyocell are specified in this document
with the new technical aspects.
ISO 21915 is composed of three parts. ISO 21915-1 specifies the identification method of cupro and
lyocell by scanning electron microscope and infrared spectrum analysis. Those may be the time-
consuming methods to use the composition analysis. ISO 21915-2 and ISO 21915-3 specify the methods
for the composition analysis. The method to be used is determined by the instrument availability and
experience.
© ISO 2020 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 21915-1:2020(E)
Textiles — Qualitative and quantitative analysis of some
cellulose fibres (lyocell, cupro) and their blends —
Part 1:
Fibre identification using scanning electron microscopy
and spectral analysis methods
1 Scope
This document specifies the qualitative analysis for cupro and lyocell using the two methods separately
— scanning electron microscope (SEM) method based on the application of ISO 20705, and
— spectral analysis method.
These testing methods are applied only for cupro and lyocell, or those blends. If other fibres are present,
those are identified using the test method of ISO/TR 11827 and removed using the relevant part of the
ISO 1833 series.
This method is not applicable for the fibre surface that is damaged during the process (e.g. chemically
or physically).
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 1833 (all parts), Textiles — Quantitative chemical analysis
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 20705, Textiles — Quantitative microscopical analysis — General principles of testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
cupro
cellulose fibre obtained by the cuprammonium process
[SOURCE: ISO 2076:2013, 4.1]
© ISO 2020 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 21915-1:2020(E)

3.2
lyocell
cellulose fibre obtained by an organic solvent (3.3) spinning process (3.4) as defined in ISO 2076
[SOURCE: ISO 2076:2013, 4.2]
3.3
organic solvent
mixture of organic chemicals and water
3.4
solvent spinning
dissolving and spinning without the formation of a derivative
3.5
scanning electron microscope
SEM
electron-optical instrument that examines and analyses the physical information (such as secondary
electron, backscattered electron, absorbed electron and X-ray radiation) obtained by generating
electron beams and scanning the surface of the specimen in order to determine the structure
composition and topography of the sample
3.6
calibration model
result of calculation by using the partial least squares (PLS) regression between the IR absorption data
and dummy variables (3.7)
3.7
dummy variable
arbitrarily assigned number for cupro (3.1) and lyocell (3.2) such as 1 for cupro and 0 for lyocell to
obtain the calibration model (3.6) by using multivariate analysis
4 Principle
4.1 SEM method
Observe the fibre specimen by using SEM with specific conditions, as described in ISO 20705
(i.e. longitudinal view on SEM), and then find the difference in the shape of the surface appearance.
Identify the fibre as cupro or lyocell from the deference of the surface appearance of cupro and lyocell.
4.2 Spectral analysis method
Prepare specimen of cupro and lyocell for creation of the calibration model. Assign the dummy variable
for cupro: 1 and lyocell: 0 (these dummy variables are named reference values in Annex D). Measure the
infrared (IR) spectrum at designated condition for the calibration specimens.
Obtain the calibration model by using the software for multivariate analysis to calculate the partial
least squares regression (PLS) by using the obtained IR data and the dummy variables. Then, prepare
the testing specimen as same as the calibration specimen. Measure IR absorption and obtain IR data.
Input the data into the calibration model and obtain the result and round off the data to 1 or 0 and judge
if cupro (1) or lyocell (0).
5 Reagents
5.1 SEM method
5.1.1 Methanol, with analytical grade.
2 © ISO 2020 – All rights reserved

---------------------- Page: 7 ----------------------
ISO 21915-1:2020(E)

5.1.2 Nonionic surfactant.
5.1.3 Sodium carbonate, with analytical grade.
5.1.4 Water, grade 3 water as specified in ISO 3696.
6 Apparatus
6.1 SEM method
6.1.1 SEM, with the specification described below and in accordance with ISO 20705.
The recommended condition to obtain clear appearance of wrinkle on cupro is as follows:
— Accelerating voltage: 10 KV
— Working distance: 10 mm
— Spot size: 35
— Beam current: 30 pA to 100 pA
— Pressure in specimen chamber: 10 Pa to 8 Pa or less
— Resolution of secondary electron image: 20 nm or more
— Magnification: ×4 000 to ×5 000
The spot size and beam current setting could be differed among the manufacturers of SEM. It is
necessary to find a condition to observe the wrinkle of cupro as shown in Annex A.
6.1.2 Ventilated oven, for drying specimens at (105 ± 3) °C.
6.1.3 Microtome, in accordance with ISO 20705.
6.1.4 Razor blade.
6.1.5 Specimen stage (stub), a holder with a diameter of 13 mm made of aluminium or copper.
6.1.6 Double-sided tape.
6.1.7 Glass plate, measuring approximately 150 mm × 150 mm.
6.1.8 Test tube.
6.1.9 Stainless steel rod.
6.1.10 Sputtering device, using gold and other metals evaporation.
6.2 Spectral analysis method
6.2.1 Infrared spectroscopy (IR) instrument, capable of performing infrared spectrometry.
© ISO 2020 – All rights reserved 3

---------------------- Page: 8 ----------------------
ISO 21915-1:2020(E)

6.2.2 Software for multivariate calculation, with the following features:
— capable of calculate PLS;
— capable of cross validation of calibration model;
2
— capable of calculate standard error of calibration (SEC) and its R and standard error of cross
2
validation (SECV) and its R .
7 Procedure
7.1 SEM method
7.1.1 Prior identification
Fibres present in the sample ar
...