ASTM D2591-07(2020)
(Test Method)Standard Test Method for Linear Density of Elastomeric Yarns (Short Length Specimens)
Standard Test Method for Linear Density of Elastomeric Yarns (Short Length Specimens)
SIGNIFICANCE AND USE
5.1 This test method is considered satisfactory for acceptance testing of commercial shipments because current estimates of between-laboratory precision are acceptable and the method is used extensively in the trade for acceptance testing.
5.1.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, use samples for such comparative tests that are as homogeneous as possible, drawn from the same lot of material as the samples that resulted in disparate results during initial testing, and randomly assigned in equal numbers to each laboratory. The test results from the laboratories involved should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If bias is found, either its cause must be found and corrected, or future test results for that material must be adjusted in consideration of the known bias.
5.2 Linear density of elastomeric yarns is used in some calculations for tensile and elastic properties.
5.3 The test method is based on elastomeric yarns in lthe “as-produced” condition, but may be used for treated elastomeric yarns provided the treatment is specified. The method does not cover the removal of finish for the determination of linear density of “finish-free” elastomeric yarns.
SCOPE
1.1 This test method covers the determination of the linear density of short lengths of “as produced” elastomeric yarns made from rubber, spandex or other elastomers.
Note 1: For the determination of linear density of elastomeric yarns using skeins, refer to Test Method D6717.
1.2 This test method is not applicable to covered, wrapped, or core-spun yarns, or yarns spun from elastomeric staple, or elastomeric yarns removed from fabrics.
1.3 This test method is applicable to elastomeric yarns having a range of 40 to 3200 dtex (36 to 2900 denier).
1.4 The values stated in either SI units or U.S. Customary units are to be regarded separately as standard. Within the test the US Customary units are in parentheses. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other.
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 the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D2591 − 07 (Reapproved 2020)
Standard Test Method for
Linear Density of Elastomeric Yarns (Short Length
Specimens)
This standard is issued under the fixed designation D2591; 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 D6717 Test Method for Linear Density of ElastomericYarns
(Skein Specimens)
1.1 This test method covers the determination of the linear
D4849 Terminology Related to Yarns and Fibers
density of short lengths of “as produced” elastomeric yarns
made from rubber, spandex or other elastomers.
3. Terminology
NOTE 1—For the determination of linear density of elastomeric yarns
3.1 For all terminology relating to D13.58, Yarns and
using skeins, refer to Test Method D6717.
Fibers, refer to Terminology D4849.
1.2 This test method is not applicable to covered, wrapped,
3.1.1 The following terms are relevant to this standard:
or core-spun yarns, or yarns spun from elastomeric staple, or
denier, elastomeric yarn, linear density, tex.
elastomeric yarns removed from fabrics.
3.2 For all other terminology related to textiles, refer to
1.3 This test method is applicable to elastomeric yarns
Terminology D123.
having a range of 40 to 3200 dtex (36 to 2900 denier).
4. Summary of Test Method
1.4 The values stated in either SI units or U.S. Customary
4.1 A pre-relaxed specimen is fastened in vertically
units are to be regarded separately as standard. Within the test
mountedapparatusunderaspecifiedtension.Aspecifiedlength
theUSCustomaryunitsareinparentheses.Thevaluesstatedin
is cut from the specimen and weighed, and the linear density
each system are not exact equivalents; therefore, each system
calculated.
shall be used independently of the other.
1.5 This standard does not purport to address all of the 5. Significance and Use
safety concerns, if any, associated with its use. It is the
5.1 This test method is considered satisfactory for accep-
responsibility of the user of this standard to establish appro-
tance testing of commercial shipments because current esti-
priate safety, health, and environmental practices and deter-
mates of between-laboratory precision are acceptable and the
mine the applicability of regulatory limitations prior to use.
method is used extensively in the trade for acceptance testing.
1.6 This international standard was developed in accor-
5.1.1 If there are differences of practical significance be-
dance with internationally recognized principles on standard-
tween reported test results for two laboratories (or more),
ization established in the Decision on Principles for the
comparative tests should be performed to determine if there is
Development of International Standards, Guides and Recom-
a statistical bias between them, using competent statistical
mendations issued by the World Trade Organization Technical
assistance. As a minimum, use samples for such comparative
Barriers to Trade (TBT) Committee.
teststhatareashomogeneousaspossible,drawnfromthesame
lot of material as the samples that resulted in disparate results
2. Referenced Documents
during initial testing, and randomly assigned in equal numbers
2.1 ASTM Standards:
to each laboratory. The test results from the laboratories
D123 Terminology Relating to Textiles
involved should be compared using a statistical test for
D2258 Practice for Sampling Yarn for Testing
unpaired data, at a probability level chosen prior to the testing
series. If bias is found, either its cause must be found and
corrected, or future test results for that material must be
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
adjusted in consideration of the known bias.
and is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.
Current edition approved Feb. 1, 2020. Published February 2020. Originally
5.2 Linear density of elastomeric yarns is used in some
approved in 1967. Last previous edition approved in 2013 as D2591 – 07(2013).
calculations for tensile and elastic properties.
DOI: 10.1520/D2591-07R20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.3 The test method is based on elastomeric yarns in lthe
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
“as-produced” condition, but may be used for treated elasto-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. meric yarns provided the treatment is specified. The method
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2591 − 07 (2020)
does not cover the removal of finish for the determination of 6.2.3.1 The slots are positioned such that the distance
linear density of “finish-free” elastomeric yarns. between the slot midlines provides a gage length of 1000 mm
when using the tex system or 900 mm when using the denier
6. Apparatus
system. If necessary, the two gage lengths can be obtained by
having the upper slot assembly adjustable, or by having two
6.1 Specimen Boards, with short pile or plush surfaces of
separate test apparatuses.
black or contrasting color, for storing specimens during relax-
ation period.
6.3 TensioningWeights, with varioius masses from 10 mg to
3gasrequired,topretensionthespecimensto1.0 60.1cN/tex
6.2 Linear Density Apparatus, mounted vertically on a wall
(0.9 6 0.09 gf/d) tension based on the nominal linear density
or in a sturdy, stable vertical support and containing the
of the yarn.
essential parts listed below. See Fig. 1 and Annex A1 for
general construction details of suitable apparatus.
6.4 Razor Blades, safety single-edge, or wood-carving type
6.2.1 Steel Plate, about 100 mm (4 in.) wide and 1.3 m (1.4
knife.
yd) long.
6.5 Balance, with an accuracy of 6 0.1% of the expected
6.2.2 Clamps, three toggle-action type with rubber tips.
mass of the specimens.
6.2.3 Brass Plates, two, with slots at right angles to be used
for controlling the alignment and length of the specimen.
7. Sampling, Test Specimens, and Test Units
7.1 LotSample—Asalotsampleforacceptancetesting,take
a random number of shipping units directed in an applicable
Components are commercially available.
NOTE 1—Drawing not to scale. For conversion to U.S. customary units,
divide mm by 25.4 to obtain inches
FIG. 1 Linear Density Apparatus
D2591 − 07 (2020)
material specification or other agreement between the pur- 9.5 After approximately 5 s, close the bottom clamp and
chaser and the supplier, such as an agreement to use Practice then the middle clamp. Cut the specimen centrally in the
D2258. Consider shipping cases or other shipping units to be bottom slot and then in the top slot, using a straight-on
the primary sampling units. perpendicular cutting action without lateral action. Lateral
action may cause stretching. The actual length of the test
NOTE 2—An adequate specification or other agreement between the
specimen after cutting is 1 m (1000 mm) 61mmor0.9m
purchaser and the supplier requires taking into account the variability
(900mm) 61mmdependingupontheyarnnumberingsystem
between shipping units, between packages or ends within a shipping unit,
and between specimens from a single package to provide a sampling with
used.
a meaningful producer’s risk, consumer’s risk, acceptable quality level
9.6 Weighthespecimenandrecorditsmasstowithin0.1%.
and limiting quality level.
9.7 Calculate the linear density as directed in 10.1, then
7.2 Laboratory Sample—As a laboratory sample for accep-
compare the calculated linear density to the nominal density
tance testing, take at random from each shipping unit in the lot
given and proceed as follows:
sample the number of packages directed in an applicable
9.7.1 If the calculated density is within5%ofthe given
material specification or other agreement between the pur-
nominal density, test 4 additional specimens as directed in 9.3
chaser and the supplier, such as an agreement to use Practice
– 9.6, for a total of five.
D2258. Preferably, take the same number of packages from
9.7.2 If the calculated density is different from the given
each of the shipping units selected. If differing numbers of
nominal density by more than 5 %, discard the result, change
packages are to be taken from the shipping units, determine at
the tension weight to meet 1.0 6 0.1 cN/tex (0.9 6 0.09 gf/d)
random which shipping units are to ha
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.