Textiles - Quantitative analysis of cashmere, wool, other specialty animal fibers and their blends - Part 2: Scanning Electron Microscopy method (ISO 17751-2:2016)

ISO 17751-2:2016 specifies a method for the identification, qualitative, and quantitative analysis of cashmere, wool, other speciality animal fibres, and their blends using scanning electron microscopy (SEM).
ISO 17751-2:2016 is applicable to loose fibres, intermediate products, and final products of cashmere, wool, other speciality animal fibres, and their blends.

Textilien - Quantitative Analyse von Kaschmir, Wolle, anderen speziellen tierischen Fasern und deren Mischungen - Teil 2: Rasterelektronenmikroskopie-Verfahren (ISO 17751-2:2016)

Der vorliegende Teil der ISO 17751 legt ein Verfahren zur Identifizierung sowie qualitativen und quantitativen Analyse von Kaschmir, Wolle, anderen speziellen tierischen Fasern und deren Mischungen mit dem Rasterelektronenmikroskop (REM) fest.
Dieser Teil der ISO 17751 gilt für lose Fasern, Halbfertigerzeugnisse und Fertigerzeugnisse aus Kaschmir, Wolle, anderen speziellen tierischen Fasern und deren Mischungen.

Textiles - Analyse quantitative du cachemire, de la laine, d'autres fibres animales spéciales et leurs mélanges - Partie 2: Méthode par microscopie électronique à balayage (ISO 17751-2:2016)

ISO 17751-2:2016 spécifie une méthode pour l'identification et l'analyse, qualitative et quantitative, du cachemire, de la laine et d'autres fibres animales spéciales, ainsi que de leurs mélanges, au moyen de la microscopie électronique à balayage (MEB).
ISO 17751-2:2016 s'applique aux fibres en vrac, aux produits intermédiaires et aux produits finaux de cachemire, de laine et d'autres fibres animales spéciales, ainsi que de leurs mélanges.

Tekstilije - Kvantitativna analiza kašmirskih, volnenih, drugih specialnih živalskih vlaken in njihovih mešanic - 2. del: Metoda štetja z elektronskim mikroskopom (ISO 17751-2:2016)

Ta del standarda ISO 17751 določa metodo za identifikacijo ter kvalitativno in kvantitativno analizo kašmirskih, volnenih, drugih specialnih živalskih vlaken in njihovih mešanic na podlagi metode štetja z elektronskim
mikroskopom (SEM).
Ta del standarda ISO 17751 se uporablja za prosta vlakna, vmesne proizvode in končne proizvode iz
kašmirja, volne, drugih specialnih živalskih vlaken ter njihovih mešanic.

General Information

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Published
Publication Date
12-Apr-2016
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
13-Apr-2016
Completion Date
13-Apr-2016

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SLOVENSKI STANDARD
SIST EN ISO 17751-2:2016
01-junij-2016

Tekstilije - Kvantitativna analiza kašmirskih, volnenih, drugih specialnih živalskih

vlaken in njihovih mešanic - 2. del: Metoda štetja z elektronskim mikroskopom
(ISO 17751-2:2016)

Textiles - Quantitative analysis of cashmere, wool, other specialty animal fibers and their

blends - Part 2: Scanning Electron Microscopy method (ISO 17751-2:2016)

Textilien - Quantitative Analyse von Kaschmir, Wolle, anderen speziellen tierischen

Fasern und deren Mischungen - Teil 2: Rasterelektronenmikroskopie-Verfahren (ISO
17751-2:2016)

Textiles - Analyse quantitative du cachemire, de la laine, d'autres fibres animales

spéciales et leurs mélanges - Partie 2: Méthode par microscopie électronique à balayage

(ISO 17751-2:2016)
Ta slovenski standard je istoveten z: EN ISO 17751-2:2016
ICS:
59.060.10 Naravna vlakna Natural fibres
SIST EN ISO 17751-2:2016 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 17751-2:2016
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SIST EN ISO 17751-2:2016
EN ISO 17751-2
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2016
EUROPÄISCHE NORM
ICS 59.060.10
English Version
Textiles - Quantitative analysis of cashmere, wool, other
specialty animal fibers and their blends - Part 2: Scanning
Electron Microscopy method (ISO 17751-2:2016)

Textiles - Analyse quantitative du cachemire, de la Textilien - Quantitative Analyse von Kaschmir, Wolle,

laine, d'autres fibres animales spéciales et leurs anderen speziellen tierischen Fasern und deren

mélanges - Partie 2: Méthode par microscopie Mischungen - Teil 2: Rasterelektronenmikroskopie-

électronique à balayage (ISO 17751-2:2016) Verfahren (ISO 17751-2:2016)
This European Standard was approved by CEN on 13 December 2015.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 17751-2:2016 E

worldwide for CEN national Members.
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SIST EN ISO 17751-2:2016
EN ISO 17751-2:2016 (E)
Contents Page

European foreword .............................................................................................................................................3

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SIST EN ISO 17751-2:2016
EN ISO 17751-2:2016 (E)
European foreword

This document (EN ISO 17751-2:2016) has been prepared by Technical Committee ISO/TC 38

"Textiles" in collaboration with Technical Committee CEN/TC 248 “Textiles and textile products” the

secretariat of which is held by BSI.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by October 2016, and conflicting national standards shall

be withdrawn at the latest by October 2016.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent

rights.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,

France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,

Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
Endorsement notice

The text of ISO 17751-2:2016 has been approved by CEN as EN ISO 17751-2:2016 without any

modification.
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SIST EN ISO 17751-2:2016
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SIST EN ISO 17751-2:2016
INTERNATIONAL ISO
STANDARD 17751-2
First edition
2016-03-15
Textiles — Quantitative analysis
of cashmere, wool, other specialty
animal fibers and their blends —
Part 2:
Scanning electron microscopy method
Textiles — Analyse quantitative du cachemire, de la laine, d’autres
fibres animales spéciales et leurs mélanges —
Partie 2: Méthode par microscopie électronique à balayage
Reference number
ISO 17751-2:2016(E)
ISO 2016
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SIST EN ISO 17751-2:2016
ISO 17751-2:2016(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland

All rights reserved. Unless otherwise specified, 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

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Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved
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SIST EN ISO 17751-2:2016
ISO 17751-2:2016(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Terms and definitions ..................................................................................................................................................................................... 1

3 Principle ........................................................................................................................................................................................................................ 2

4 Apparatus, materials, and reagents .................................................................................................................................................. 2

4.1 Apparatus .................................................................................................................................................................................................... 2

4.2 Materials ....................................................................................................................................................................................................... 2

4.3 Reagents........................................................................................................................................................................................................ 3

5 Sample drawing ..................................................................................................................................................................................................... 3

6 Preparation of test specimens ................................................................................................................................................................ 3

6.1 Number of test specimens ............................................................................................................................................................. 3

6.2 Preparation method for test specimens of various types of samples ...................................................... 3

6.2.1 Loose fibre ............................................................................................................................................................................. 3

6.2.2 Sliver ........................................................................................................................................................................................... 4

6.2.3 Yarn.............................................................................................................................................................................................. 4

6.2.4 Woven fabrics ..................................................................................................................................................................... 5

6.2.5 Knitted fabrics .................................................................................................................................................................... 5

6.3 Coating the specimens ...................................................................................................................................................................... 5

7 Test procedure ........................................................................................................................................................................................................ 5

7.1 Test on each specimen stub ......................................................................................................................................................... 5

7.2 Qualitative analysis (purity analysis) and determination of fibre content ......................................... 5

8 Calculation of test result ............................................................................................................................................................................... 6

Annex A (informative) Drawing of lot sample and laboratory sample ............................................................................. 7

Annex B (informative) Surface morphology of common animal fibres ............................................................................ 8

Annex C (normative) Density of common animal fibres ...............................................................................................................47

Bibliography .............................................................................................................................................................................................................................48

© ISO 2016 – All rights reserved iii
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SIST EN ISO 17751-2:2016
ISO 17751-2:2016(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

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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

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The committee responsible for this document is ISO/TC 38, Textiles.

ISO 17751 consists of the following parts, under the general title Textiles — Quantitative analysis of

cashmere, wool, other speciality animal fibres and their blends:
— Part 1: Light microscopy method
— Part 2: Scanning electron microscopy method
iv © ISO 2016 – All rights reserved
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SIST EN ISO 17751-2:2016
ISO 17751-2:2016(E)
Introduction

Cashmere is a high value speciality animal fibre, but cashmere and other animal wool fibres such as

sheep’s wool, yak, camel, etc. exhibit great similarities in their physical and chemical properties so that

their blends are difficult to distinguish from each other by both mechanical and chemical methods. In

addition, these fibres show similar scale structures. It is very difficult to accurately determine the fibre

content of such fibre blends by current testing means.

Research on the accurate identification of cashmere fibres has been a long undertaking. At present,

the most widely used and reliable identification techniques include the light microscopy (LM) method

and the scanning electron microscopy (SEM). The SEM method shows complementary characteristics

to those of LM method.

— The advantage of the LM method is that the internal medullation and pigmentation of fibres can be

observed; the disadvantage is that some subtle surface structures cannot be clearly displayed. A

decolouring process needs to be carried out on dark samples for testing. An improper decolouring

process can affect the judgment of the fibre analyst.

—The SEM method shows opposite characteristics to those of LM method so some types of fibres need

to be identified by scanning electron microscope.

The LM and SEM methods need be used together to identify some difficult-to-identify samples in order

to utilize the advantages of both methods.

It has been proven in practice that the accuracy of a fibre analysis is highly related to the ample

experience, full understanding, and extreme familiarity of the fibre analyst to the surface morphology

of various types of animal fibres so besides the textual descriptions, several micrographs of different

types of animal fibres are given in Annex B.
© ISO 2016 – All rights reserved v
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SIST EN ISO 17751-2:2016
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SIST EN ISO 17751-2:2016
INTERNATIONAL STANDARD ISO 17751-2:2016(E)
Textiles — Quantitative analysis of cashmere, wool, other
specialty animal fibers and their blends —
Part 2:
Scanning electron microscopy method
1 Scope

This part of ISO 17751 specifies a method for the identification, qualitative, and quantitative

analysis of cashmere, wool, other speciality animal fibres, and their blends using scanning electron

microscopy (SEM).

This part of ISO 17751 is applicable to loose fibres, intermediate products, and final products of

cashmere, wool, other speciality animal fibres, and their blends.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
specialty animal fibre
any type of keratin fibre taken from animal (hairs) other than sheep
2.2
scanning electron microscope

intermediate type of microscopic morphology observation instrument between transmitted electron

microscope and light microscope which use a focused beam of high-energy electrons to generate a

variety of physical information signals

Note 1 to entry: The principle consists of scanning a primary focused electron beam over a whole area of interest

on the surface of solid specimen and the signal derived from which is then received, amplified, and displayed in

images for full observation of surface area topography of the specimen.

Note 2 to entry: The signals obtained by a scanning electron microscope are, e.g. secondary electrons (2.3), Auger

electrons, characteristic X-ray, etc.
2.3
secondary electron

low-energy extra-nuclear electron released from and by ionization of a metal atom in the 5 nm to 10 nm

scanned region of metal layer less than 10 nm thick nearest to the outermost meta-coated surface of a

specimen under impact of the focused primary electron beam of energy in units of tens of keV

Note 1 to entry: Being surface sensitive because of the small mean free path of the electron to escape from deep

within the specimen and, therefore, the signal of which produces the highest-resolution morphological images of

the coated surface.
2.4
scale
cuticle covering the surface of animal fibres
2.5
scale frequency
number of scales (2.4) along the fibre axis per unit length
© ISO 2016 – All rights reserved 1
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SIST EN ISO 17751-2:2016
ISO 17751-2:2016(E)
2.6
scale height
height of the cuticle at the scale’s (2.4) distal edge
2.7
fibre surface morphology
sum of the physical properties/attributes characterizing the fibre surface

EXAMPLE The fibre surface morphology includes scale frequency (2.5), scale height (2.6), patterns of scale

edge, scale surface, smoothness, fibre evenness along its axis, transparency under light microscope, etc.

2.8
lot sample

portion representative of the same type and same lot of material drawn according to requirements

from which it is taken
2.9
laboratory sample

portion drawn from a lot sample (2.8) according to requirements to prepare specimens

2.10
test specimen

portion taken from fibre snippets randomly cut from a laboratory sample (2.9) for measurement

purposes
3 Principle

A longitudinal view image of fibre snippets representative of a test specimen coated with a thin layer

of gold is produced by a scanning electron microscope through scanning the side surface of the test

specimen with a focused incident beam of high-energy electrons, detecting signals of secondary

electrons emitted by the gold atoms excited when hit by the incident electron beam, and combining the

beam position with the detected signals which contain information on surface topography of the test

specimen.

All fibre types found in the test specimen are identified by comparing them with known fibre surface

morphologies for different types of animal fibres.

For each fibre type, the number and mean diameter of fibre snippets are counted and measured. The

mass fraction is calculated from the data for the number of fibre snippets counted, mean value, and

standard deviation of the snippet diameter and the true density of each fibre type.

4 Apparatus, materials, and reagents
4.1 Apparatus

4.1.1 Scanning electron microscope, comprised of a vacuum system, electronic optical system, signal

collecting and imaging system, display system, and measurement software.
4.1.2 Sputter coater with a gold cathode.
4.2 Materials
4.2.1 Microtome.
4.2.2 Glass tube, 10 mm to 15 mm in diameter.
2 © ISO 2016 – All rights reserved
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SIST EN ISO 17751-2:2016
ISO 17751-2:2016(E)
4.2.3 Stainless-steel rod, approximately 1 mm in diameter.
4.2.4 Glass plate, measuring approximately 150 mm × 150 mm.
4.2.5 Double-sided adhesive tape.
4.2.6 Tweezers, scissors.
4.2.7 Specimen stub, aluminium or brass, 13 mm in diameter.
4.2.8 Razor blade.
4.3 Reagents
4.3.1 Acetone (analytical grade)
4.3.2 Ethyl acetate (analytical grade).
5 Sample drawing

Draw the lot and laboratory samples in accordance with the sampling method given in Annex A.

6 Preparation of test specimens
6.1 Number of test specimens

Prepare five specimen stubs. The fibre snippets on the specimen stubs shall be sufficient to ensure that

at least 1 000 fibres are examined.
6.2 Preparation method for test specimens of various types of samples
6.2.1 Loose fibre

6.2.1.1 Place the laboratory sample flat on the test table, pick up approximately 500 mg of fibres

randomly on not less than 20 spots with tweezers (4.2.6) from the top and bottom sides of the sample.

Blend them homogeneously, and divide them into three equal portions. Sort those drawn fibres into

basically parallel fibre bundles.

6.2.1.2 Cut the fibre bundle in the middle with a microtome (4.2.1) to get approximately 0,4 mm long

fibre snippets. Cut only once in each of the fibre bundles.

6.2.1.3 Collect all fibre snippets in the glass tube (4.2.2) and suspend them in 1 ml to 2 ml acetone

(4.3.1) or ethyl acetate (4.3.2) by stirring the mixture with a stainless steel rod (4.2.3). Pour the

suspension onto a glass plate (4.2.4) to ensure that the fibre snippets are uniformly distributed on a spot

of approximately 10 cm in diameter on the glass plate as shown in Figure 1.

6.2.1.4 Press the double-edged adhesive (4.2.5) on the mounting stubs and use a razor blade (4.2.8)

to trim the tape away from around the mounting stubs. After all the acetone (4.3.1) or ethyl acetate

(4.3.2) in the fibre snippets suspension has evaporated, press the mounting stubs with the adhesive tape

end onto the glass plate (4.2.4) at the positions shown in Figure 2. Transfer the uniformly mixed fibre

snippets to the adhesive tape (4.2.5) on the specimen stub (4.2.7).
© ISO 2016 – All rights reserved 3
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SIST EN ISO 17751-2:2016
ISO 17751-2:2016(E)
Fibre suspension
Key
1 glass plate
2 fibre snippets
Figure 1 — Fibre suspension on glass plate
Key
1 specimen stub
Figure 2 — Positions of specimen stubs

If the fibre snippets have aggregated after the evaporation of the acetone (4.3.1) or ethyl acetate (4.3.2),

they shall be recollected by scraping them off the glass plate (4.2.4) with a razor blade (4.2.8) and repeat

procedures 6.2.1.3 and 6.2.1.4.
6.2.2 Sliver

6.2.2.1 Cut the laboratory sliver sample into three sections. Take out an appropriate amount of the

fibre bundle in the longitudinal direction from each sliver section.

6.2.2.2 Cut in the middle of each fibre bundle to obtain approximately 0,4 mm long fibre snippets with

a microtome (4.2.1). Cut only once in each fibre bundle.

6.2.2.3 Other operating procedures are the same as those stipulated in 6.2.1.3 and 6.2.1.4.

6.2.3 Yarn
6.2.3.1 Divide the laboratory sample into three equal portions.

6.2.3.2 Cut each portion in the middle with a microtome (4.2.1) to obtain approximately 0,4 mm long

fibre snippets. Cut only once in each yarn portion.
4 © ISO 2016 – All rights reserved
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SIST EN ISO 17751-2:2016
ISO 17751-2:2016(E)

6.2.3.3 Other operating procedures are the same as those stipulated in 6.2.1.3 and 6.2.1.4.

6.2.4 Woven fabrics

6.2.4.1 If the warp and weft yarn share the same composition, all the yarn segments unravelled from a

square sample of a complete pattern may be cut to obtain an appropriate test specimen. For those fabric

samples composed of different compositions of warp and weft yarns, unravel the warp and weft yarns

and weigh them separately. (If the fabrics have a definite repetition in the pattern, unravel at least the

integral multiple of a complete pattern.)

6.2.4.2 Cut once from the parallel yarn portion in the middle with a microtome (4.2.1) to obtain

approximately 0,4 mm long fibre snippets. Cut only once in each yarn segments.

6.2.4.3 Other operating procedures are the same as those stipulated in 6.2.1.3 and 6.2.1.4.

6.2.5 Knitted fabrics

6.2.5.1 Unravel at least 25 yarn segments from the laboratory sample for woollen knitted fabrics.

Unravel at least 50 yarn segments for worsted knitted fabrics. Cut each yarn portion in the middle to

obtain approximately 0,4 mm long fibre snippets. Cut only once in each yarn portion.

6.2.5.2 Other operating procedures are the same as those stipulated in 6.2.1.3 and 6.2.1.4.

6.3 Coating the specimens

Use the sputter coater (4.1.2) to apply a thin layer of gold to the specimens on specimen stub (4.2.7).

7 Test procedure
7.1 Test on each specimen stub

7.1.1 Place a stub with the specimen into the test chamber of the SEM. First, view the selected stub at a

lower magnification (for example, at ×10). Then, selecting an area near the upper left edge of the stub on

the monitor, set the magnification to ×1 000, scan the stub and observe the fibres. Identify the fibre types

according to the characteristics of the fibre morphologies (see details in Annex B) of cashmere, sheep’s

wool, and other animal fibres.

7.1.2 Return to the lower magnification after identifying all fibres in the selected area. Choose another

observation area along the vertical or horizontal direction. Repeat the above operation until finished,

scanning the entire stub before continuing on to analyse fibre snippets on another stub.

7.2 Qualitative analysis (purity analysis) and determination of fibre content

7.2.1 Examine 150 fibres on the first specimen stub (4.2.7). The following three conditions may happen.

— Case 1: If only one fibre type is found, examine another 300 fibre snippets on a second stub. If no

fibre of a second type is found, the sample is declared as pure.

— Case 2: If two fibre types are found and the amount of one type is lower than 3 % by number (less

than five fibres of the second type), it is considered as a minor component. Examine 300 further

snippets from the second stub and calculate the percentage by number of the two types of fibres.

— Case 3: If two fibre types are found and the content of each type is higher than 3 % by number, the

fibre mixture is considered to be a blend. Perform a quantitative analysis according to 7.2.2.

© ISO 2016 – All rights reserved 5
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SIST EN ISO 17751-2:2016
ISO 17751-2:2016(E)
7.2.2 Quantitative analysis of fibre blends.

If the sample is found to be a blend, examine 220 further fibres and measure the diameters of the first

25 fibres of each component identified (or all fibres of that component, if less than 20) on each of the

remaining stubs. At least 1 030 fibres shall be identified for a sample and 100 measurements of fibre

diameter made for each component. The mean fibre diameter of each component is calculated according

to the diameters measured for the 100 fibres. If the total amount of each component is less than 100,

calculate the mean fibre diameter according to the actual number of that fibre component.

This diameter is measured in a vacuum condition and is not comparable to a diameter measured by

other instruments. So the value shall only be used for calculation of fibre content of each component in

Clause 8.
8 Calculation of test result
8.1 Calculate the mass fraction of each component using Formula (1).
ND +S ρ
ii i i
w = ×100 (1)
 
ND +S ρ
∑ ii()ii
 
 
where
w is the mass fraction of the component, %;
N is the number of fibres counted for the component;

S is the standard deviation for mean diameter of the component, in micrometres (µm);

D is the mean diameter of the component, in micrometres (µm);
is the density of the component, in grams per millilitre (g/ml).
NOTE The density of various types of animal fibres is given in Annex C.

8.2 The mass fraction of a given fibre component in woven fabric samples may be calculated through

Formula (2).
wm×+wm×
iT TiWW
w = ×100 (2)
mm+
where
w is the mass fraction of the component in the woven fabric sample, %;

w is the mass fraction of the component in the warp yarns of the woven fabric sample, %;

m is the mass of the warp yarn in the woven fabric sample;

w is the mass fraction of the component in weft yarns of woven fabric sample, %;

m is the mass of the weft yarn in the woven fabric sample.
6 © ISO 2016 – All rights reserved
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SIST EN ISO 17751-2:2016
ISO 17751-2:2016(E)
Annex A
(informative)
Drawing of lot sample and laboratory sample
A.1 Loose fibre

Fifty percent of the total number of packages should be sampled. Take out a bundle of fibres from at

least three parts of each package. After blending them homogeneously, divide the sample into two equal

portions,
...

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