Standard Test Method for Tensile Properties of Elastomeric Yarns (CRE Type Tensile Testing Machines)

SIGNIFICANCE AND USE
This test method is considered satisfactory for acceptance testing of commercial shipments since current estimates of between-laboratory precision are acceptable and the method is used extensively in the trade for acceptance testing.
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.
The force at first filament break of elastomeric yarns may depend on its construction and manufacturing process and provides an indication of the breaking strength of fabrics made from the yarn.
Elongation is an indication of the ability of a fiber to absorb energy. The elongation of yarn or fabric must be great enough to withstand strains experienced in processing and end use, and to absorb the energies of applied forces repeatedly.
Fabric manufacturers use force and elongation information of elastomeric yarns in determining machine set-up conditions.
Other parameters such as elongation at specified force (EASF), force (or tenacity) at specified elongation (FASE, TASE), work and toughness may be calculated from force-elongation curves. EASF and FASE information is needed for tests involving cycling of yarn in determination of elastic properties.
This test method was developed using elastomeric yarns in t...
SCOPE
1.1 This test method covers the determination of the tensile properties of “as produced” elastomeric yarns made from natural rubber, spandex or other elastomers, using a constant-rate-of-extension (CRE) type tensile testing machine. The properties included in this test method are: (1) force at first filament break, (2) tenacity at first filament break, (3) elongation at first filament break, (4) work to break at first filament break, and (5) toughness at first filament break.
1.2 This test method does not apply to covered, wrapped, or core-spun yarns or yarns spun from elastomeric staple.
1.3 This test method is applicable to elastomeric yarns in the range from 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 text, the U.S. Customary units are given 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 and health practices and determine the applicability of regulatory limitations prior to use.

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Publication Date
30-Jun-2012
Technical Committee
Drafting Committee
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ASTM D2653-07(2012) - Standard Test Method for Tensile Properties of Elastomeric Yarns (CRE Type Tensile Testing Machines)
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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: D2653 − 07 (Reapproved 2012)
Standard Test Method for
Tensile Properties of Elastomeric Yarns (CRE Type Tensile
Testing Machines)
This standard is issued under the fixed designation D2653; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D4848Terminology Related to Force, Deformation and
Related Properties of Textiles
1.1 This test method covers the determination of the tensile
D4849Terminology Related to Yarns and Fibers
properties of “as produced” elastomeric yarns made from
D6717TestMethodforLinearDensityofElastomericYarns
natural rubber, spandex or other elastomers, using a constant-
(Skein Specimens)
rate-of-extension (CRE) type tensile testing machine. The
properties included in this test method are: (1) force at first
3. Terminology
filament break, (2) tenacity at first filament break, (3) elonga-
3.1 For all terminology relating to D13.58, Yarns and
tion at first filament break, (4) work to break at first filament
Fibers, refer to Terminology D4849.
break, and (5) toughness at first filament break.
3.1.1 The following terms are relevant to this standard:
1.2 Thistestmethoddoesnotapplytocovered,wrapped,or
elastomeric yarn, elongation, force, linear density, tenacity,
core-spun yarns or yarns spun from elastomeric staple.
toughness, work, work to break.
1.3 Thistestmethodisapplicabletoelastomericyarnsinthe
3.2 For definitions of other terms related to force and
range from 40 to 3200 dtex (36 to 2900 denier).
deformation, refer to Terminology D4848. For all other termi-
1.4 The values stated in either SI units or U.S. Customary
nology related to textiles, refer to Terminology D123.
units are to be regarded separately as standard.Within the text,
the U.S. Customary units are given in parentheses. The values 4. Summary of Test Method
stated in each system are not exact equivalents; therefore, each
4.1 A specimen is clamped in a CRE-type tensile testing
system shall be used independently of the other.
machine and extended to rupture. Force at first filament break
1.5 This standard does not purport to address all of the and elongation at first filament break, work and toughness are
safety concerns, if any, associated with its use. It is the
calculated from a force-elongation curve or with an interfaced
responsibility of the user of this standard to establish appro-
computer. Tenacity at first filament break can be calculated
priate safety and health practices and determine the applica-
based on the determined linear density of the yarn. Other
bility of regulatory limitations prior to use.
properties, such as force at specified elongation (FASE),
elongation at specified force (EASF), may also be calculated.
2. Referenced Documents
5. Significance and Use
2.1 ASTM Standards:
D76Specification for Tensile Testing Machines for Textiles 5.1 This test method is considered satisfactory for accep-
D123Terminology Relating to Textiles
tance testing of commercial shipments since current estimates
D1776Practice for Conditioning and Testing Textiles of between-laboratory precision are acceptable and the method
D2258Practice for Sampling Yarn for Testing
is used extensively in the trade for acceptance testing.
D2591TestMethodforLinearDensityofElastomericYarns
5.1.1 If there are differences of practical significance be-
(Short Length Specimens)
tween 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
ThistestmethodisunderthejurisdictionofASTMCommitteeD13onTextiles
assistance. As a minimum, use samples for such comparative
and is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.
teststhatareashomogeneousaspossible,drawnfromthesame
Current edition approved July 1, 2012. Published August 2012. Originally
lot of material as the samples that resulted in disparate results
approved in 1967. Discontinued 1979 and reinstated as D2653–79. Last previous
edition approved in 2007 as D2653–07. DOI: 10.1520/D2653-07R12.
during initial testing, and randomly assigned in equal numbers
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
to each laboratory. The test results from the laboratories
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
involved should be compared using a statistical test for
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. unpaired data, at a probability level chosen prior to the testing
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2653 − 07 (2012)
series. If bias is found, either its cause must be found and 7. Sampling, Test Specimens, and Test Units
corrected, or future test results for that material must be
7.1 Lot Sample—Asalotsampleforacceptancetesting,take
adjusted in consideration of the known bias.
a random number of shipping units directed in an applicable
5.2 The force at first filament break of elastomeric yarns material specification or other agreement between the pur-
maydependonitsconstructionandmanufacturingprocessand chaser and the supplier, such as an agreement to use Practice
provides an indication of the breaking strength of fabrics made D2258. Consider shipping cases or other shipping units to be
from the yarn. the primary sampling units.
5.3 Elongation is an indication of the ability of a fiber to
NOTE 1—An adequate specification or other agreement between the
purchaser and the supplier requires taking into account the variability
absorb energy. The elongation of yarn or fabric must be great
between shipping units, between packages or ends within a shipping unit,
enough to withstand strains experienced in processing and end
and between specimens from a single package to provide a sampling with
use, and to absorb the energies of applied forces repeatedly.
a meaningful producer’s risk, consumer’s risk, acceptable quality level
and limiting quality level.
5.4 Fabric manufacturers use force and elongation informa-
tion of elastomeric yarns in determining machine set-up
7.2 Laboratory Sample—As a laboratory sample for accep-
conditions.
tance testing, take at random from each shipping unit in the lot
sample the number of packages directed in an applicable
5.5 Other parameters such as elongation at specified force
material specification or other agreement between the pur-
(EASF), force (or tenacity) at specified elongation (FASE,
chaser and the supplier, such as an agreement to use Practice
TASE), work and toughness may be calculated from force-
D2258. Preferably, take the same number of packages from
elongation curves. EASF and FASE information is needed for
eachoftheshippingunits,determineatrandomwhichshipping
tests involving cycling of yarn in determination of elastic
units are to have each number of packages for testing.
properties.
7.3 Test Specimens—From each package or end in the
5.6 Thistestmethodwasdevelopedusingelastomericyarns
laboratory sample, take specimens as directed in 7.3.1.
in the “as-produced” condition, but may be used for treated
7.3.1 Remove the outer layer of yarn from the package.
elastomeric yarns provided the treatment is specified. The
Avoid any damaged areas in selecting segments for testing.
method does not cover the removal of finish for determination
Carefullyunwindyarnfromthepackagewithaslowastension
of tensile properties of “finish-free” elastomeric yarns.
as possible to avoid stretching.As test specimens, cut approxi-
6. Apparatus mately 125 mm (5 in.) long segments of yarn from each
package, taking them at intervals of at least1m(1 yd). Three
6.1 Specimen Boards, with short pile or plush surfaces or
ofthesixspecimensareusedassparetoallowforunacceptable
black or contrasting color, for storing specimens during con-
breaks, such as caused by slippage or breaking in the clamps.
ditioning.
7.4 Determine the tex (denier) of the yarn for each labora-
6.2 Tensile Testing Machine, CRE-type, conforming to
tory sample using Test Method D2591 or Test Method D6717.
Specification D76 with respect to force indication, working
range, capacity and verification of recorded elongation, and
8. Preparation of Apparatus
designed for operation at a pulling speed of 500 mm/min (20
in./min) or 1000% extension per min.
8.1 Prepare and verify the calibration of the tensile testing
machine as directed in the manufacturer’s instructions.
6.3 Clamping Assembly, pneumatically operated, with jaw
faces as described in 6.3.1 or 6.3.2.
8.2 Set up and adjust the CRE-type tensile testing machine
6.3.1 Option A, Preferred—One jaw with a flat acrylic face
as follows:
nominally 25 mm × 12.5 mm (1 in. × 0.5 in.) and the opposing
8.2.1 Examine the acrylic jaw face of the clamps for wear
jaw approximately 12.5 mm (0.5 in.) wide with a convex
and replace as needed. Position the clamp faces with their
[approximately7.1mm(0.28in.)radius],steelorchromeface.
contact line horizontal.
6.3.2 Option B—One jaw with a flat, steel or chrome face
8.2.2 Set the distance between clamps, (gage length) to 50
nominally 25 mm × 12.5 mm (1 in. × 0.5 in.) and the opposing
61mm(2 6 0.05 in.), nip to nip.
jaw approximately 12.5 mm (0.5 in.) wide with a convex
NOTE 2—A convenient technique for checking the gage length is to
[approximately 8.5 mm (0.375 in.) radius] acrylic face.
place a piece of carbon paper and white paper in the clamps and close the
clamps. The distance between the marks made on the white paper by the
6.4 Computer or Microprocessor,interfaced,withautomatic
carbon paper represents the set gage length.
data gathering system, optional.
8.2.3 Use a force measuring system such that the breaking
6.5 Tensioning Weights, with various masses from 10 mg to
force will fall between 30 and 80 percent of its full scale
3 g as required to pretension the specimen to 30 to 50 mN/tex
capacity.
(0.3 to 0.5 mgf/d) before testing.
8.2.4 Setthecrossheadspeedto500mm/min(20in./min)or
6.6 Air Supply, capable of providing 415 kPa (60 psi) to the
1000% extension per min.
pneumatic clamps.
8.2.5 Set the extension measuring system as follows:
8.2.5.1 When using a chart recorder, set the chart speed to
500 mm/min (20 in./min). Not needed with computer inter-
Apparatus and accessories are commercially available. Clamps may need to be
modified to accept jaw faces and attachment to some tensile testing machine. faced testing machines.
D2653 − 07 (2012)
8.2.5.2 When using an interfaced computer or 11.2 Tenacity at First Filament Break—CalculatetheTenac-
microprocessor, set parameters to obtain selected properties ity at First Filament break as follows:
using supplier’s directions and Specification D76.
11.2.1 Calculate the tenacity at FFB for each specimen to
8.2.6 Set air pressure for pneumatic clamps to 415 kPa (60
the nearest 0.1 cN/tex (0.01 gf/d), using Eq 1.
psi).At this pressure, the clamping force is approximately 450
T 5 F/D (1)
N (100 lb).
where:
9. Conditioning
T = tenacity at FFB, cN/tex (gf/d),
F = force at FFB, cN (gf), and
9.1 No preconditioning is required. for currently produced
D = average linear density, tex (denier).
rubber yarns and other elastomeric yarns.
11.2.2 Calculate the average breaking tenacity for each
9.2 Condition the specimens relaxed on specimen boards in
laboratory sampling unit and for the lot.
the standard atmosphere for testing textiles as directed in
Practice D1776 which is 21 6 1°C (70 6 2°F) and 65 62%
11.3 Percent Elongation at First Filament Break—Calculate
relative humidity for a minimum of 4 h.
the Percent Elongation at First Filament Break as follows:
11.3.1 Read the elongation at the force at FFB value for
10. Procedure
each specimen to the nearest 0.1% from the force-elongation
10.1 Test the relaxed specimens in the standard atmosphere
curves.
for testing textiles.
11.3.1.1 If force-extension curves are used, determine the
extension corresponding to the force at FFB and calculate the
NOTE3—Theforcemeasuringsystemshouldbezeroedpriortorunning
any specimens and periodically during the course of the test, particularly percent elongation at FFB, using Eq 2.
if drift is observed in the zero value of the force measuring system.
E 5 100 3 L/G (2)
10.2 Select the appropriate pretensioning weight based on
where:
the linear density of the yarn that will provide a 30 to 50
E = elongation at FFB, %,
mN/tex (0.3 to 0.5 mgf/d) tension to the yarn.
L = the extension (distance on the extension axis from the
10.3 Attach the selected tensioning weight (10.2)tothe
origintotheextensionlinecorrespondingtotheforceat
specimen such that when the specimen is place in the lower
FFB), mm (in.), and
clamp, the tensioning weight will hang freely.
G = the nominal gage length, mm (in.).
10.4 Position a specimen centrally between the top clamp
11.3.2 Calculate the average percent elongation at FFB for
faces and close the clamp. Ensure that the tensioning weight is
each laboratory sampling unit and for the lot.
hanging freely below the botton clamp.
11.4 Work to Break at First Filament Break (FFB)—
10.5 Close the lower clamp and remove the tensioning
Calculate the Work to Break at FFB as follows:
weight.
11.4.1 Usingtheforce-extensioncurve,drawalinefromthe
10.6 Start the tester and observe the specimen behavior.
point of first filament break of each specimen perpendicular to
Record the breaking force when the first filament break is
the extension axis. Measure the area bounded by the curve, the
observed.
perpendicular, and the extension axis. This area may be
10.6.1 If the specimen breaks within 3 mm (0.13 in.) of
estimated by counting squares, measured with a planimeter, or
eitherjaw,ortheslippageisindicatedbyalevelingintheforce
determined by electronic means.
direction with abnormally high elongation, discard the result
11.4.2 Calculate the work to break at FFB for each speci-
and test another specimen from the same package.
men to the nearest. 0.01 mJ ( 0.01 in-lbf.), or the specific work
10.6.2 If many specimens exhibit what appears to be
to break at FFB to the nearest 0.01 J/m (0.01 in-lbf./in.) using
slippage, replace the acrylic jaw face and retest.
Eq 3 or Eq 4.
10.7 Remove the specimen and continue testing until a total
W 5 A 3 F 3 E (3)
b
of 3 specimens have been tested for each laboratory sampling
W 5 A 3 F 3 E/G (4)
unit. sb
where:
11. Calculation or Interpretation of Results
W = work to break, J (gf-in.),
b
11.1 Force at First Filament Break—Calculate the Force at
W = specific work to break, J/m (gf-in/i
...

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