ASTM D1422/D1422M-13
(Test Method)Standard Test Method for Twist in Single Spun Yarns by the Untwist-Retwist Method
Standard Test Method for Twist in Single Spun Yarns by the Untwist-Retwist Method
SIGNIFICANCE AND USE
5.1 This test method is used for acceptance testing in the trade for economic reasons even though it is less accurate than the direct method, Test Method D1423.
5.1.1 If there are differences or practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if their is a statistical bias between them, using competent statistical assistance. As a minimum, the test samples should be used that are as homogeneous as possible, that are drawn from the material from which the disparate test results are obtained, and that are assigned randomly in equal numbers to each laboratory for testing. Other materials with established test values may be used for this purpose. The test results from the two laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results must be adjusted in consideration of the known bias.
5.2 The “setting” of twist in some fibers causes excessive contraction when the yarn is retwisted in the reverse direction. Therefore, the number of turns required to bring the specimen back to its original length may be less than the number of turns removed in untwisting. This effect may be partially offset by the use of higher pretensioning loads; but this increases the danger of stretching the yarn. Little information is available on the correct tensions to use for yarns made from different fibers or with different amounts of twist.
5.3 In addition to being less tedious, this test method requires fewer specimens than the direct-counting method and the results may be sufficiently accurate for certain purposes. This test method can be useful in those cases where the main objective is to measure variations from an average value. Another possible application is where a large amount of twist testing is required on yarns of similar ty...
SCOPE
1.1 This test method2 describes the determination of twist in single spun yarns when only an approximation of the true twist is required. Note 1—For a more accurate method see Test Method D1423.
1.2 This test method is applicable to spun single yarns in continuous lengths, and also to spun yarns raveled from fabrics, provided specimens at least 200 mm [8 in.] long can be obtained.
1.3 This test method has been found satisfactory for use in determining the approximate twist content in single ring spun yarns of all types and fiber contents, but not in open-end spun yarns.
1.4 This specification shows the values in both inch-pound units and SI units. The “inch-pound” units is the technically correct name for the customary units used in the United States. The “SI” units is the technically corrected name for the system of metric units known as the International System of Units. The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D1422/D1422M − 13
Standard Test Method for
1
Twist in Single Spun Yarns by the Untwist-Retwist Method
This standard is issued under the fixed designation D1422/D1422M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D1059 Test Method for Yarn Number Based on Short-
4
2
Length Specimens (Withdrawn 2010)
1.1 This test method describes the determination of twist in
D1423 Test Method for Twist in Yarns by Direct-Counting
single spun yarns when only an approximation of the true twist
D2258 Practice for Sampling Yarn for Testing
is required.
D3888 Terminology for Yarn Spinning Systems
NOTE 1—For a more accurate method see Test Method D1423.
D4849 Terminology Related to Yarns and Fibers
1.2 This test method is applicable to spun single yarns in
3. Terminology
continuous lengths, and also to spun yarns raveled from
fabrics,providedspecimensatleast200mm[8in.]longcanbe
3.1 Refer to Terminology D4849 for definitions of the
obtained.
following terms used in this standard: direction of twist, single
yarn, spun yarn, twist, twist factor, twist multiplier, and yarn.
1.3 This test method has been found satisfactory for use in
determining the approximate twist content in single ring spun
3.2 Refer toTerminology D123 andTerminology D3888 for
yarns of all types and fiber contents, but not in open-end spun
definitions of other terms used in this standard.
yarns.
4. Summary of Test Method
1.4 This specification shows the values in both inch-pound
4.1 A specimen is untwisted and then retwisted in the
units and SI units. The “inch-pound” units is the technically
opposite direction until it contracts to its original length. It is
correct name for the customary units used in the United States.
assumedthatthesameamountoftwisthasbeeninsertedaswas
The “SI” units is the technically corrected name for the system
originally present. Twist, as turns per unit length, is calculated
ofmetricunitsknownastheInternationalSystemofUnits.The
ashalfthenumberofturnsregisteredonthecounterdividedby
values stated in either SI units or inch-pound units are to be
the specimen length.
regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system
5. Significance and Use
shall be used independently of the other. Combining values
5.1 This test method is used for acceptance testing in the
from the two systems may result in non-conformance with the
trade for economic reasons even though it is less accurate than
standard.
the direct method, Test Method D1423.
1.5 This standard does not purport to address all of the
5.1.1 If there are differences or practical significance be-
safety concerns, if any, associated with its use. It is the
tween reported test results for two laboratories (or more),
responsibility of this standard to establish appropriate safety
comparative tests should be performed to determine if their is
and health practices and determine the applicability of regu-
a statistical bias between them, using competent statistical
latory limitations prior to use.
assistance.As a minimum, the test samples should be used that
2. Referenced Documents
are as homogeneous as possible, that are drawn from the
3
material from which the disparate test results are obtained, and
2.1 ASTM Standards:
thatareassignedrandomlyinequalnumberstoeachlaboratory
D123 Terminology Relating to Textiles
for testing. Other materials with established test values may be
1 used for this purpose.The test results from the two laboratories
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
and is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.
should be compared using a statistical test for unpaired data, at
Current edition approved July 1, 2013. Published August 2013. Originally
a probability level chosen prior to the testing series. If a bias is
approved in 1956. Last previous edition approved in 2008 as D1422 – 99(2008).
found, either its cause must be found and corrected, or future
DOI: 10.1520/D1422_D1422M-13.
2
test results must be adjusted in consideration of the known
This test method is commonly designated by the less precise term “Untwist-
Twist Method.”
bias.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
4
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C7
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D1422 − 99 (Reapproved 2008) D1422/D1422M − 13
Standard Test Method for
1
Twist in Single Spun Yarns by the Untwist-Retwist Method
This standard is issued under the fixed designation D1422;D1422/D1422M; the number immediately following the designation indicates
the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
2
1.1 This test method describes the determination of twist in single spun yarns when only an approximation of the true twist
is required.
NOTE 1—For a more accurate method see Test Method D1423.
1.2 This test method is applicable to spun single yarns in continuous lengths, and also to spun yarns raveled from fabrics,
provided specimens at least 200 mm (8 in.)[8 in.] long can be obtained.
1.3 The values stated in either inch-pound or SI units are to be regarded separately as standard. Within the text, the SI units are
shown in parentheses. The values stated in each system are not exact equivalents; therefore each system shall be used
independently of the other. Combining values from the two systems may result in nonconformance within this test method.
1.3 This test method has been found satisfactory for use in determining the approximate twist content in all single ring spun
yarns and 100% cotton open-end yarns. For all open-end spun yarns that are not 100 % cotton this test method has not been found
to be satisfactory for determining twist but may be used to measure deviation from an average value.of all types and fiber contents,
but not in open-end spun yarns.
1.4 This specification shows the values in both inch-pound units and SI units. The “inch-pound” units is the technically correct
name for the customary units used in the United States. The “SI” units is the technically corrected name for the system of metric
units known as the International System of Units. The values stated in either acceptable metric SI units or in other units shall
inch-pound units are to be regarded separately as standard. The values expressedstated in each system may not be exact
equivalents; therefore, each system mustshall be used independently of the other, without combining in any way. other. Combining
values from the two systems may result in non-conformance with the standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior
to use.
2. Referenced Documents
3
2.1 ASTM Standards:
D123 Terminology Relating to Textiles
4
D1059 Test Method for Yarn Number Based on Short-Length Specimens (Withdrawn 2010)
D1423 Test Method for Twist in Yarns by Direct-Counting
D2258 Practice for Sampling Yarn for Testing
D3888 Terminology for Yarn Spinning Systems
D4849 Terminology Related to Yarns and Fibers
3. Terminology
3.1 Definitions:
1
This test method is under the jurisdiction of ASTM Committee D13 on Textiles and is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.
Current edition approved Aug. 1, 2008July 1, 2013. Published October 2008August 2013. Originally approved in 1956. Last previous edition approved in 19992008 as
D1422 – 99.D1422 – 99(2008). DOI: 10.1520/D1422-99R08.10.1520/D1422_D1422M-13.
2
This test method is commonly designated by the less precise term“ Untwist-Twistterm “Untwist-Twist Method.”
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
4
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D1422/D1422M − 13
3.1.1 direction of twist, n—the right or left direction of the helix formed in a twisted strand as indicated by superimposition of
the capital letter “S” or “Z.”
3.1.1.1 Discussion—
Yarn has S twist if, when the yarn is held in a vertical position, the visible spirals or helices around its central axis conform in
direction of slope to the central portion of the letter“ S,” and Z twist if the visible spirals or helices conform in directio
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.