ASTM D6612-00(2011)
(Test Method)Standard Test Method for Yarn Number and Yarn Number Variability Using Automated Tester
Standard Test Method for Yarn Number and Yarn Number Variability Using Automated Tester
SIGNIFICANCE AND USE
Test Method D6612 for yarn number and yarn number variability is satisfactory for acceptance of commercial shipments and is used in the trade.
If there are differences of practical significance between the reported test results for two or more laboratories, comparative tests should be performed by those laboratories to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, samples used for each comparative tests should be as homogeneous as possible, drawn from the same lot of material as the samples that results in disparate results during initial testing, and randomly assigned in equal numbers to each laboratory. Other fabrics with established tests values are used for this purpose. The test results from the laboratories involved should be compared appropriate statistical analysis and a probability level chosen by the two parties before testing begins, 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 adjusted in consideration of the known bias.
The average results from the two laboratories should be compared using appropriate statistical analysis and a probability level chosen by the two parties before the testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.
Test Method D6612 also is used for the quality control of filament yarns.
Indices of Variability:
Coefficient of Variation—%CV is a standard statistical calculation and is the most common index of yarn unevenness. For most textile applications in the 80–330 dtex (70–300 denier) range, a 1.0–1.3 %CV is adequate. %CV of yarns coarser than 666 dtex (600 denier) is not routine and usually not meaningful. %CV is less discriminating that %DS.
Bad/Good Test—%BGT, which will normally be up to 20 % greater than %D...
SCOPE
1.1 This test method covers the measurement of yarn number up to 4000 dtex (3600 denier) and related variability properties of filament and spun yarns using an automated tester with capability for measuring mass variability characteristics.
1.2 Yarn number variability properties include percent density spread (%DS), coefficient of variation (%CV), density frequency variation.
Note 1—For determination of yarn number by use of reel and balance, refer to Test Method D1907. For another method of measuring variability (unevenness) in yarn, refer to Test Method D1425.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are 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 inaccuracies of results.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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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: D6612 − 00(Reapproved 2011)
Standard Test Method for
Yarn Number and Yarn Number Variability Using Automated
Tester
This standard is issued under the fixed designation D6612; 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 D4849 Terminology Related to Yarns and Fibers
1.1 This test method covers the measurement of yarn
3. Terminology
number up to 4000 dtex (3600 denier) and related variability
propertiesoffilamentandspunyarnsusinganautomatedtester
3.1 For all terminology relating to D13.58, Yarns and
with capability for measuring mass variability characteristics. Fibers, refer to Terminology D4849.
3.1.1 The following terms are relevant to this standard:
1.2 Yarn number variability properties include percent den-
cottoncount,coefficientofvariation,denier,lineardensity,tex,
sity spread (%DS), coefficient of variation (%CV), density
yarn number, yarn numbering system, bad/good test, density
frequency variation.
frequency variability, density spread.
NOTE 1—For determination of yarn number by use of reel and balance,
3.2 For all other textile terms used in this test method, see
refer to Test Method D1907. For another method of measuring variability
(unevenness) in yarn, refer to Test Method D1425. Terminology D123.
1.3 The values stated in either SI units or inch-pound units
4. Summary of Test Method
are to be regarded separately as standard. Within the text, the
inch-pound units are in parentheses. The values stated in each
4.1 A specified length of yarn (specimen) is stripped auto-
system are not exact equivalents; therefore, each system shall
matically directly from the package, cut, and weighed. The
be used independently of the other. Combining values from the
yarnnumberiscalculatedbyinterfacedcomputer,displayedon
two systems may result in inaccuracies of results.
a monitor, and may be printed. The yarn number can be
reported in tex, denier, or cotton count units.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4.2 Simultaneously, by means of a capacitance cell, the
responsibility of the user of this standard to establish appro-
massofthespecimenismeasuredinsubsectionsandfrequency
priate safety and health practices and determine the applica-
of mass value crossovers are counted for calculation of
bility of regulatory limitations prior to use.
variability properties: %DS, %CV, %BGT and %DFV.
2. Referenced Documents
5. Significance and Use
2.1 ASTM Standards:
5.1 Test Method D6612 for yarn number and yarn number
D123 Terminology Relating to Textiles
variability is satisfactory for acceptance of commercial ship-
D1425 TestMethodforUnevennessofTextileStrandsUsing
ments and is used in the trade.
Capacitance Testing Equipment
5.1.1 If there are differences of practical significance be-
D1776 Practice for Conditioning and Testing Textiles
tween the reported test results for two or more laboratories,
D1907 Test Method for Linear Density of Yarn (Yarn Num-
comparative tests should be performed by those laboratories to
ber) by the Skein Method
determine if there is a statistical bias between them, using
D2258 Practice for Sampling Yarn for Testing
competent statistical assistance. As a minimum, samples used
for each comparative tests should be as homogeneous as
possible, drawn from the same lot of material as the samples
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
that results in disparate results during initial testing, and
and is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.
randomly assigned in equal numbers to each laboratory. Other
CurrenteditionapprovedMay1,2011.PublishedJuly2011.Originallyapproved
ε1
fabrics with established tests values are used for this purpose.
in 2000. Last previous edition approved in 2006 as D6612–00(2006) . DOI:
10.1520/D6612-00R11.
The test results from the laboratories involved should be
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
compared appropriate statistical analysis and a probability
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
level chosen by the two parties before testing begins, at a
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. probability level chosen prior to the testing series. If a bias is
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
D6612 − 00 (2011)
found, either its cause must be found and corrected, or future 6.2 Density Variability Accessory (DVA), with yarn number
test results adjusted in consideration of the known bias. ranges:
5.1.2 The average results from the two laboratories should 6.2.1 Low (9.7-mm slit), up to 30 dtex (up to 27 denier).
be compared using appropriate statistical analysis and a prob- 6.2.2 Medium (1.2-mm slit), 31–239 dtex (25–215 denier).
ability level chosen by the two parties before the testing is 6.2.3 High (2.2-mm slit), 240–1333 dtex (216–1200 denier).
begun. If a bias is found, either its cause must be found and 6.2.4 Ultra-High (3.2-mm slit), 1334–4000 dtex
corrected or the purchaser and the supplier must agree to (1201–3600 denier).
interpret future test results with consideration to the known
6.3 Calibration Weights, 2-g and others as needed to cover
bias.
the tex (denier) ranges of interest.
5.2 Test Method D6612 also is used for the quality control
7. Sampling
of filament yarns.
7.1 LotSample—Asalotsampleforacceptancetesting,take
5.3 Indices of Variability:
at random the number of shipping units directed in an
5.3.1 Coeffıcient of Variation—%CV is a standard statistical
applicable material specification or other agreement between
calculation and is the most common index of yarn unevenness.
the purchaser and the supplier, such as an agreement to use
For most textile applications in the 80–330 dtex (70–300
Practice D2258. Consider shipping cases or other shipping
denier) range, a 1.0–1.3 %CV is adequate. %CV of yarns
units to be the primary sampling units.
coarser than 666 dtex (600 denier) is not routine and usually
not meaningful. %CV is less discriminating that %DS.
NOTE 2—An adequate specification or other agreement between the
5.3.2 Bad/Good Test—%BGT, which will normally be up to
purchaser and the supplier requires taking into account the variability
between shipping units, between packages or ends within a shipping unit,
20 % greater than %DS value, emphasizes the greatest spread
and between specimens from a single package to provide a sampling plan
in the entire length tested, (%DS is an average). If the value is
with a meaningful producer’s risk, consumer’s risk, acceptable quality
greaterthan50 %ofthe%DS,itsuggeststhatthereisaprocess
level, and limiting quality level.
that needs to be investigated.
7.2 Laboratory Sample—As a laboratory sample for accep-
5.3.3 Density Spread—%DS is equivalent to the Uster %
tance testing, take at random from each shipping unit in the lot
unevenness (Test Method D1425) and is an indication of
sample the number of packages directed in an applicable
short-term variability. Yarns with extreme values are more
material specification or other agreement between the pur-
likely to cause trouble in subsequent yarn processes, which
chaser and the supplier, such as an agreement to use Practice
makes this perhaps the most useful index. The minimum
D2258. Preferably, the same number of packages should be
achievable and maximum tolerance spread for a yarn product
taken from each shipping unit in the lot sample. If differing
will depend on the yarn manufacturing process and end use.A
numbers of packages are to be taken from shi
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