ASTM D2261-96

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 2261 – 96
Standard Test Method for
Tearing Strength of Fabrics by the Tongue (Single Rip)
Procedure (Constant-Rate-of-Extension Tensile Testing
Machine)
This standard is issued under the fixed designation D 2261; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope D 76 Specification for Tensile Testing Machines for Tex-
tiles
1.1 This test method covers the measurement of the tearing
D 123 Terminology Relating to Textiles
strength of textile fabrics by the tongue (single rip) procedure
D 629 Test Methods for Quantitative Analysis of Textiles
using a recording constant-rate-of-extension-type (CRE) ten-
D 1776 Practice for Conditioning Textiles for Testing
sile testing machine.
D 2904 Practice for Interlaboratory Testing of a Textile Test
1.1.1 The CRE-type tensile testing machine has become the
Method That Produces Normally Distributed Data
preferred test apparatus for determining tongue tearing
D 2906 Practice for Statements on Precision and Bias for
strength. It is recognized that some constant-rate-of-traverse-
Textiles
type (CRT) tensile testing machines continue to be used. As a
D 4848 Terminology of Force, Deformation and Related
consequence, these test instruments may be used when agreed
Properties of Textiles
upon between the purchaser and the supplier. The conditions
2.2 ASTM Adjuncts:
for use of the CRT-type tensile tester are included in Appendix
TEX-PAC
X1.
1.2 This test method applies to most fabrics including
3. Terminology
woven fabrics, air bag fabrics, blankets, napped fabrics, knit
3.1 Definitions—For definitions of other textile terms used
fabrics, layered fabrics, pile fabrics. The fabrics may be
in this test method, refer to Terminology D 123. For definitions
untreated, heavily sized, coated, resin-treated, or otherwise
of other terms related to force and deformation in textiles, refer
treated. Instructions are provided for testing specimens with or
to Terminology D 4848.
without wetting.
3.2 Definitions of Terms Specific to This Standard:
1.3 Tear strength, as measured in this test method, requires
3.2.1 cross-machine direction, CD, n—the direction in the
that the tear be initiated before testing. The reported value
plane of the fabric perpendicular to the direction of manufac-
obtained is not directly related to the force required to initiate
ture.
or start a tear.
3.2.1.1 Discussion—This term is used to refer to the direc-
1.4 Two calculations for tongue tearing strength are pro-
tion analogous to crosswise or filling direction in woven
vided: the single-peak force and the average of five highest
fabrics.
peak forces.
3.2.2 fabric, in textiles, n—a planar structure consisting of
1.5 The values stated in either SI units or inch-pound units
yarns or fibers.
are to be regarded as the standard. The inch-pound units may
3.2.3 machine direction, MD, n—the direction in the plane
be approximate.
of the fabric parallel to the direction of manufacture.
1.6 This standard does not purport to address all of the
3.2.3.1 Discussion—This term is used to refer to the direc-
safety concerns, if any, associated with its use. It is the
tion analogous to lengthwise or warp direction in woven
responsibility of the user of this standard to establish appro-
fabrics.
priate safety and health practices and determine the applica-
3.2.4 peak force, in tear testing of fabrics, n—the maximum
bility of regulatory limitations prior to use.
force required to break one or more yarn components in a
2. Referenced Documents woven or knitted fabric specimen, or break the fiber, the fiber
bonds, or fiber interlocks in other manufactured fabric forms.
2.1 ASTM Standards:
This test method is under the jurisdiction of ASTM Committee D-13 on Textiles
Annual Book of ASTM Standards, Vol 07.01.
and is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,
Specific. Annual Book of ASTM Standards, Vol 07.02.
Current edition approved Feb. 10, 1996. Published April 1996. Originally A PC program on floppy disk for analyzing Committee D-13 interlaboratory
published as D 2261 – 64 T. Discontinued November 1995 and reinstated as data are available from ASTM Headquarters. For a 3 ⁄2-in. disk, request PCN:12-
D 2261. 429040-18. For a 5 ⁄4-in. disk, request PCN:12-429041-18.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 2261
3.2.4.1 Discussion—The peak force may consist of a single peak or peaks. The highest peaks appear to reflect the strength
peak or a series of peaks depending upon the nature of the of the yarn components, fiber bonds, or fiber interlocks,
fabric. Typically for woven fabrics, if a small decrease in force individually or in combination, needed to stop a tear in a fabric
occurs at a time when the force is increasing, it is not of the same construction. The valleys recorded between the
considered to peak unless the indicated force exceeds the force peaks have no specific significance. The minimum tearing
required to break a yarn. Lower shifts corresponding to yarn force, however, is indicated to be above the lowest valleys.
movement do not qualify as peaks since no yarns are broken. 5.4 Most textile fabrics can be tested by this test method.
3.2.5 tearing force, in fabric, n—the force required to Some modification of clamping techniques may be necessary
propagate a tear initiated under specified conditions. for a given fabric due to its structure. Strong fabrics or fabrics
3.2.5.1 Discussion—The tongue tearing force may be cal- made from glass fibers usually require special adaptation to
culated from a single-peak or a multiple-peak force-extension prevent them from slipping in the clamps or being damaged as
curve. a result of being gripped in the clamps.
3.2.6 tearing strength, in fabrics, n—the capacity of a fabric 5.5 The CRE-type is the preferred tensile testing machine.
to withstand the tearing force required to propagate a tear after This test method allows the use of the CRT-type tensile
its initiation. machine when agreed upon between the purchaser and the
supplier. There may be no overall correlation, however, be-
4. Summary of Test Method
tween the results obtained with the CRT-type machine and the
4.1 A rectangular specimen, cut in the center of a short edge
CRE-type machine. Consequently, these two tensile testers
to form a two-tongued (trouser shaped) specimen, in which one
cannot be used interchangeably unless the degree of quantita-
tongue of the specimen is gripped in the upper jaw and the tive correlation has been established between the purchaser and
other tongue is gripped in the lower jaw of a tensile testing
the supplier. In any event, the CRE-type machine shall prevail.
machine. The separation of the jaws is continuously increased
6. Apparatus
to apply a force to propagate the tear. At the same time, the
6.1 Tensile Testing Machine, of the CRE-type conforming to
force developed is recorded. The force to continue the tear is
the requirements of Specification D 76 with autographic re-
calculated from autographic chart recorders or microprocessor
corder, or automatic microprocessor data gathering system.
data collection systems.
6.2 Clamps, having all jaw surfaces parallel, flat, and
5. Significance and Use capable of preventing slipping of the specimen during a test,
and measuring at least 25 by 75 mm (1 by 3 in.) with the longer
5.1 This test method is considered satisfactory for accep-
dimension perpendicular to the direction of application of the
tance testing of commercial shipments since current estimates
force.
of between-laboratory precision are acceptable, and the test
6.2.1 The use of hydraulic pneumatic clamping systems
method is used extensively in the trade for acceptance testing.
with a minimum of 50 by 75-mm (2 by 3-in.) serrated or rubber
5.1.1 In case of a dispute arising from differences in
jaw faces having a clamping force at the grip faces of 13 to 14
reported test results when using this test method for acceptance
kN (2900 to 3111 lbf) is recommended. Manual clamping is
testing of commercial shipments, the purchaser and the sup-
permitted providing no slippage of the specimen is observed.
plier should conduct comparative tests to determine if there is
6.2.2 For some materials, to prevent slippage when using
a statistical bias between their laboratories. Competent statis-
jaw faces other than serrated, such as rubber-faced jaws, the
tical assistance is recommended for the investigation of bias.
jaw faces may be covered with a No. 80 to 120 medium-grit
As a minimum, the two parties should take a group of test
emery cloth. Secure the emery cloth to the jaw faces with
specimens that are as homogeneous as possible and that are
pressure-sensitive tape.
from a lot of fabric of the type in question. Test specimens then
6.3 Cutting Die or Template, having essentially the shape
should be randomly assigned in equal numbers to each
and dimensions shown in Fig. 1.
laboratory for testing. The average results from the two
laboratories should be compared using the appropriate statis-
7. Sampling and Test Specimens
tical analysis and an acceptable probability level chosen by the
7.1 Lot Sample—As a lot sample for acceptance testing,
two parties before 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 consid-
eration to the known bias.
5.2 The force registered in a tear test is irregular, and as a
consequence, empirical methods have had to be developed to
obtain usable values related to tear strength. In spite of the
empirical nature of the reported values, the values are consid-
ered to reflect comparative performance of similar fabrics
tested and measured in the same way. No known procedure is
available that can be used with all fabrics to determine the
minimum tearing strength.
5.3 Depending on the nature of the specimen, the data
FIG. 1 Template for Marking and Cutting Tongue Tear Specimens,
recording devices will show the tearing force in the form of a All Tolerances 60.5 %
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 2261
randomly select the number of rolls or pieces of fabric directed test at 75 6 1 mm (3.0 6 0.05 in.).
in an applicable material specification or other agreement 8.2 Select the full-scale force range of the testing machine
between the purchaser and the supplier. Consider the rolls or such that the maximum force occurs between 10 and 90 % of
pieces of fabric to be the primary sampling units. In the full-scale force.
absence of such an agreement, take the number of fabric rolls 8.3 Set the testing speed to 50 6 2 mm/min (2 6 0.1
specified in Table 1. in./min). When agreed upon between the purchaser and the
supplier, the testing speed may be set to 300 6 10 mm/min (12
NOTE 1—An adequate specification or other agreement between the
6 0.5 in./min).
purchaser and the supplier requires taking into account the variability
8.4 Verify calibration of the tensile testing machine as
between rolls or pieces of fabric and between specimens from a swatch
from a roll or piece of fabric to provide a sampling plan with a meaningful directed in the manufacturer’s instructions.
producer’s risk, consumer’s risk, acceptable quality level, and limiting
8.5 When using microprocessor automatic data gathering
quality level.
systems, set the appropriate parameters as specified in the
manufacturer’s instructions and Specification D 76.
7.2 Laboratory Sample—For acceptance testing, take a
swatch extending the width of the fabric and approximately 1
9. Conditioning
m (1 yd) along the machine direction from each roll or piece in
9.1 Condition 1, Standard Testing Conditioning:
the lot sample. For rolls of fabric, take a sample that will
9.1.1 Precondition the specimens by bringing them to ap-
exclude fabric from the outer wrap of the roll or the inner wrap
proximate moisture equilibrium in the standard atmosphere for
around the core of the roll of fabric.
preconditioning textiles as specified in Practice D 1776, unless
7.3 Test Specimens—From each laboratory sampling unit,
otherwise specified in a material specification or contract order.
take five specimens from the machine direction and five
9.1.2 After preconditioning, bring the test specimens to
specimens from the cross-machine direction, for each test
moisture equilibrium for testing in the standard atmosphere for
condition described in 9.1 and 9.2, as applicable to a material
testing textiles as specified in Practice D 1776 or, if applicable,
specification or contract order.
in the specified atmosphere in which the testing is to be
7.3.1 Direction of Test—Consider the short direction as the
performed, unless otherwise specified in a material specifica-
direction of test.
tion or contract order.
7.3.2 Cutting Test Specimens—Cut rectangular specimens
9.2 Condition 2, Wet Specimen Testing Conditioning:
75 by 200 mm (3 by 8 in.). Use the cutting die or template
9.2.1 When desizing treatments are specified prior to wet
described in 6.3 and shown in Fig. 1. Take the specimens to be
testing, use desizing treatments that will not affect the normal
used for the measurement of machine direction with the longer
physical property of the fabric as specified in Test Method
dimension parallel to the cross-machine direction. Take the
D 629.
specimens to be used for the measurement of the cross-
9.2.2 Submerge the specimens in a container of distilled or
machine direction with the longer dimension parallel to the
deionized water at ambient temperature until thoroughly
machine direction. Make a preliminary cut 75 mm (3 in.) long
soaked (see 9.2.2.1).
at the center of the 75-mm (3-in.) width as shown in Fig. 1.
9.2.2.1 The time of immersion must be sufficient to wet out
When specimens are to be tested wet, take the specimens from
the specimens as indicated by no significant change in tearing
areas adjacent to the dry test specimens. Label to maintain
force followed by longer periods of immersion. For most
specimen identity.
fabrics this time period will be about 1 h. For fabrics not
7.3.2.1 In cutting the specimens, take care to align the yarns
readily wet out with water, such as
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