SIST EN ISO 2061:1996

SLOVENSKI STANDARD
SIST EN ISO 2061:1996
01-maj-1996
7HNVWLOLMH'RORþDQMH]DYRMHYSUHMH0HWRGDQHSRVUHGQHJDãWHWMD
Textiles - Determination of twist in yarns - Direct counting method (ISO 2061:1995)
Textilien - Bestimmung der Drehung von Garnen - Direktes Zählverfahren (ISO
2061:1995)
Textiles - Détermination de la torsion des fils - Méthode par comptage direct (ISO
2061:1995)
Ta slovenski standard je istoveten z: EN ISO 2061:1995
ICS:
59.080.20 Preje Yarns
SIST EN ISO 2061:1996 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN ISO 2061:1996

---------------------- Page: 2 ----------------------

SIST EN ISO 2061:1996

---------------------- Page: 3 ----------------------

SIST EN ISO 2061:1996

---------------------- Page: 4 ----------------------

SIST EN ISO 2061:1996
INTERNATIONAL
ISO
STANDARD
2061
Second edition
1995-10-15
Textiles - Determination of twist in
yarns - Direct counting method
Textiles - Determination de Ia torsion des fils - M6 thode par camptage
direc t
Reference number
ISO 2061:1995(E)

---------------------- Page: 5 ----------------------

SIST EN ISO 2061:1996
ISO 2061:1995(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. Esch 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.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 2061 was prepared by Technical Committee
ISO/TC 38, Textiles, Subcommittee SC 5, Yarn testing.
This second edition cancels and replaces the first edition
(ISO 2061 :1972), which has been technically revised.
Annex A of this International Standard is for information only.
0 ISO 1995
All rights reserved. Unless otherwise specified, no part of this publication mag/ be reproduced
or utilized in any form or by any means, electronie or mechanical, including photocopying and
mtcrofilm, without permrssion in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-121 1 Geneve 20 0 Swrtzerland
Printed in Switzerland
ii

---------------------- Page: 6 ----------------------

SIST EN ISO 2061:1996
INTERNATIONAL STANDARD 0 ISO ISO 2061:1995(E)
Textiles - Determination of twist in yarns - Direct
counting method
b) the original twist of the plied yarn after plying,
1 Scope
but Prior to the last Stage of processing;
c) the twist of the Single yarn before plying.
1.1 This International Standard specifies a method
for the determination of the direction of twist in yarns,
the amount of twist, in terms of turns per unit length,
1.4 If desired, the twist of Single and plied yarn
and the Change in length on untwisting, by the direct
components as they lie in the final stt-ucture may be
counting method.
determined by the special procedure given in 10.5.7.
1.5 This International Standard is not applicable, ex-
1.2 This International Standard is applicable to:
cept by agreement, to yarns which stretch more than
a) Single yarns (spun or multifilament); 0,5 % when the tension increases from 0,5 to 1,O cN
per unit linear density of the yarn expressed in tex.
b) folded (plied) yarns;
Such yarns may be tested under special conditions
of tension which are accepted by all Parties interested
c) cabled yarns.
in the test results.
Separate procedures are given for each type of yarn.
1.6 This International Standard is not suitable for
The method is designed primarily for yarns in pack-
products of open-end spinning and intermingled
ages, but with special precautions the procedures tan
(interlaced) multifilament yarns.
be used for yarns taken from fabrics. lt is not suitable
for the determination of twist in a monofilament.
1.7 This International Standard is not applicable to
NOTE 1 See also ISO 1890: -11, Reinforcement yams -
yarns which are too large to permit their being placed
Determination of twist, which was prepared especially for
in the clamps of the testing apparatus without crush-
the needs of glass textile technology, and ISO 7211-4:1984,
ing or distortion severe enough to affect the test re-
Textiles - Wo ven fabrics - Construction - Methods of
sults.
analysis - Part 4: Determination of twist in yarn removed
from fabric.
2 Normative references
1.3 This International Standard covers the determi-
The following Standards contain provisions which,
nation of twist in plied and cabled yarns as follows.
through reference in this text, constitute provisions
of this International Standard. At the time of publi-
- In plied yarns: the final twist of the plied yarns and
cation, the editions indicated were valid. All Standards
the original twist of the Single yarn before plying.
are subject to revision, and Parties to agreements
based on this International Standard are encouraged
- In cabled yarns:
to investigate the possibility of applying the most re-
a) the final cabling twist of the yarn; cent editions of the Standards indicated below.
1) To be published. (Revision of ISO 1890:1986)
1

---------------------- Page: 7 ----------------------

SIST EN ISO 2061:1996
0 ISO
ISO 2061:1995(E)
cakes, bobbins, cops, cones, pirns, spools, tubes or
Members of IEC and ISO maintain registers of cur-
beams.
rently valid International Standards.
- Designation of the direction 3.7 twist factor: Measure of the spiralling orien-
ISO 2: 1973, Textiles
of twist in yams and related products. tation of the fibres in a spun yarn or of the filaments
in a filament yarn.
- Standard atmospheres for
ISO 139: 1973, Textiles
lt is related to the angle which fibres on the surface
conditioning and testing.
of the yarn make with the axis of the yarn and is a
measure of the hardness of the resulting yarn due to
ISOnR 8091:1983, Textiles - Twist factor related to
twist.
the Tex System.
4 Principle
3 Definitions
The twist in a known length of yarn is removed by
For the purposes of this International Standard, the
rotating one end of the specimen with respect to the
following definitions apply.
other until the components of the yarn being tested
are parallel. The exact number of turns required to
3.1 twist: Number of turns about the axis of a yarn
remove the twist is reported in terms of turns per unit
based on its nominal gauge length before untwisting.
length of yarn.
Twist should preferably be expressed as turns per
metre (turns/m), but it may be expressed as turns per
5 Apparatus
centimetre (turnslcm).
5.1 Twist counter, consisting of a pair of clamps,
3.2 gauge length: Distance between two effective
one of which is rotatable in either direction and posi-
clamping Points of the test specimen mounted in the
tively connected to a revolution counter. The Position
testing equipment.
of one or both clamps shall be adjustable to permit
testing yarn lengths from IO mm to 500 mm. There
3.3 initial length: Length of a test specimen under
shall be no play in the clamp which might affect the
a specified pretension at the beginning of a test.
gauge length.
3.4 Change in length on untwisting: Increase or
Means shall be provided for applying tension to the
decrease in initial length observed when the speci-
specimen and for rapidly determining the specimen
men is untwisted, expressed as the percentage ex-
length with an accuracy of + 0,5 mm or + 2 %,
-
tension, or contraction, based on the specimen initial
whichever is smaller.
length.
NOTE 2 The Iimit of 2 % is consistent with the highest
accuracy required in counting the number of turns in the
3.5 moisture equilibrium for testing: That state
specimen.
reached when the rate of increase in mass of a sam-
ple or specimen in a specified (test) atmosphere does
The counting device shall be capable of recording the
not exceed that prescribed for the material being
number of revolutions of the rotatable clamp.
tested. (See ISO 139.)
If the contraction or extension of the untwisted
A textile material is in moisture equilibrium with the
specimen is to be measured, the movable but
ambient atmosphere when it does not exchange wa-
nonrotatable clamp shall be capable of travelling with
ter with this atmosphere; its mass then remains con-
essentially no friction.
stant as lang as the experiment is carried out in an
unchanged atmosphere. For test purposes, moisture
5.2 Dissecting needle.
equilibrium is reached by absorption, starting from a
relatively low moisture content.
5.3 Means for magnifying the specimen being
3.6 yarn package: Length or lengths of yarn in a
tested.
form suitable for use, handling, storing or shipping.
Packages may be comprised of unsupported yarn, 5.4 Equipment for reeling iaboratory Sample skeins
such as balls, or supported yarn, such as skeins, (optional).
2

---------------------- Page: 8 ----------------------

SIST EN ISO 2061:1996
ISO 2061:1995(E)
0 ISO
8.1.2 Single multifilament yarns
6 Standard atmosphere
Take an initial length of 250 mm + - 0,5 mm if the
The Standard atmospheres for preconditioning, con-
nominal twist is 2 1 250 turns/m.
ditioning and testing shall be as specified in ISO 139.
Take an initial length of 500 mm + 0,5 mm if the
-
NOTE 3 The amount of twist is not affected directly by
nominal twist is < 1 250 turns/m.
changes in relative humidity, but since wide changes in hu-
midity Cause changes in length of some materials, all de-
terminations should be made on samples in equilibrium with
8.1.3 Folded and cabled yarns
the appropriate Standard atmosphere.
Take an initial length of 250 mm + 0,5 mm if the
-
Generally it is not necessary to precondition samples
nominal twist is > 1 250 turns/m.
before conditioning for twist tests.
Take an initial length of 500 mm + 0,5 mm if the
-
7 Sampling nominal twist is < 1 250 turns/m.
Samples shall be taken in one of the following ways:
8.2 Selection
a) according to directions, if any, given in the ma-
terial specification;
8.2.1 Test specimens shall be taken, at the lowest
tension practicable, from the end of the package if
b) according to procedures approved by ISO for tex-
this is the normal method of use; otherwise, take the
tile products, if directions on sampling are not in-
yarn from the side of the package. Discard the few
cluded in the material specification;
metres of yarn at the beginning and end of the pack-
age in Order to avoid damaged sections.
c) according to the method given in annex A, if nei-
ther a) nor b) is applicable. If it is desired to reel laboratory Sample skeins, the
yarn specimens shall be taken as specified in 8.2.1
1) Bulk samples shall be taken as directed in A.1
and shall be representative of the original package.
of annex A.
8.2.2 If two or more test specimens are taken from
2) Laboratory Sample packages shall be taken
an individual yarn package, they shall be taken at ran-
from the bulk Sample as directed in A.2 of
dom intervals of at least 1 m in Order to minimize the
annex A.
effects of cyclic Variation introduced during manufac-
ture. If more than two specimens are taken from an
8 Test specimens
individual package, take groups of specimens, not
more than five to a group, at intervals of several me-
8.1 Length tres.
8.1.1 Single spun yarns
8.3 Number of test specimens
The initial length of the specimen shall be as great as
possible, but shall be somewhat less than the average
8.3.1 Take the number of specimens required in the
length of the staple fibre used to spin the yarn. The
material specification, when applicable.
initial lengths of specimens listed in table 1 are com-
monly used.
8.3.2 In the absence of material specification, take
a number of specimens designed to give the precision
specified below, following the directions given in
Table 1 - Specimen lengths
8.3.3 or 8.3.4, depending on the information available
Specimen initial length
Type of yarn material on the Variation of twist results in the material being
mm
tested.
IQ and 25
Cotton
I I I
Worsted 25 and 50
I 8.3.3 If information on Variation is available, take a
I I
number of specimens, IZ, calculated by the formula
25 and 50
I- Woollen
given in table 2, to secure the precision specified at a
100 and 250
Bast fibre I I
I
probability of 95 %.

---------------------- Page: 9 ----------------------

SIST EN ISO 2061:1996
ISO 2061:1995(E)
Table 2 - Formula for number of specimens, ~1, using information on Variation
Type of yarn Range of twist Precision Formula for ~11)
Single multifilament Less than 40 turns/m + 4,0 turns/m 0,240~~
Single multifilament 40 turns/m to 100 turns/m + 5,0 turns/m 0,l 54a2
All other yarns - + 5 % 0,l 54V2
1) Where CT is the Standard deviation of individual results, determined from extensive past
records on similar material; v is the coefficient of Variation of individual test results, deter-
mined from extensive past records on similar materials.
8.3.4 If no information on Variation is available or in
9 Procedure 1 - Determination of
the case of a dispute, determine the number of
direction of twist
specimens as follows.
Hold one end of the yarn in such a Position that a
a) Take the number of specimens, n, specified in ta-
short length (at least 100 mm) is suspended in a ver-
ble3, which also indicates the Variation assurned
tical Position. Examine the vertical section of the yarn
to calculate n;
and determine if the slope
...