ASTM D1424-96
(Test Method)Standard Test Method for Tearing Strength of Fabrics by Falling-Pendulum Type (Elmendorf) Apparatus
Standard Test Method for Tearing Strength of Fabrics by Falling-Pendulum Type (Elmendorf) Apparatus
SCOPE
1.1 This test method covers the determination of the force required to propagate a single-rip tear starting from a cut in a fabric and using a falling-pendulum type (Elmendorf) apparatus.
1.2 This test method applies to most fabrics including woven, layered blankets, napped pile, blanket, and air bag fabrics, provided the fabric does not tear in the direction crosswise to the direction of the force application during the test. The fabrics may be untreated, heavily sized, coated, resin-treated, or otherwise treated. Instructions are provided for testing specimens with, or without, wetting.
1.3 This method is suitable only for the warp direction tests of warp-knit fabrics. It is not suited for the course direction of warp knit fabrics or either direction of most other knitted fabrics.
1.4 The values stated in other SI units or U.S. customary units are to be regarded as standard, but must be used independently of each other. The U.S. customary units may be approximate.
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.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D1424–96
Standard Test Method for
Tearing Strength of Fabrics by Falling-Pendulum Type
(Elmendorf) Apparatus
This standard is issued under the fixed designation D 1424; 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 Method That Produces Normally Distributed Data
D 2906 Practice for Statements on Precision and Bias for
1.1 This test method covers the determination of the force
Textiles
required to propagate a single-rip tear starting from a cut in a
D 4848 Terminology of Force, Deformation and Related
fabric and using a falling-pendulum type (Elmendorf) appara-
Properties of Textiles
tus.
2.2 ASTM Adjuncts:
1.2 This test method applies to most fabrics including
TEX-PAC
woven, layered blankets, napped pile, blanket, and air bag
fabrics, provided the fabric does not tear in the direction
3. Terminology
crosswise to the direction of the force application during the
3.1 Definitions:
test. The fabrics may be untreated, heavily sized, coated,
3.1.1 cross-machine direction, CD, n—the direction in the
resin-treated,orotherwisetreated.Instructionsareprovidedfor
plane of the fabric perpendicular to the direction of manufac-
testing specimens with, or without, wetting.
ture.
1.3 This method is suitable only for the warp direction tests
3.1.1.1 Discussion—The term cross-machine direction is
of warp-knit fabrics. It is not suited for the course direction of
used to refer to the direction analogous to coursewise or filling
warp knit fabrics or either direction of most other knitted
direction in woven fabrics, respectively.
fabrics.
3.1.2 length of tear, n—in tear testing of fabrics, the
1.4 The values stated in other SI units or U.S. customary
measured distance propagated in a specimen by a tearing force
units are to be regarded as standard, but must be used
from the initiation of the test to the termination of the test.
independently of each other. The U.S. customary units may be
3.1.3 machine direction, MD, n—the direction in the plane
approximate.
of the fabric parallel to the direction of manufacture.
1.5 This standard does not purport to address all of the
3.1.3.1 Discussion—The term machine direction is used to
safety concerns, if any, associated with its use. It is the
refer to the direction analogous to walewise or warp direction
responsibility of the user of this standard to establish appro-
in woven fabrics, respectively.
priate safety and health practices and determine the applica-
3.1.4 tearing energy, n—the work done in tearing a mate-
bility of regulatory limitations prior to use.
rial.
2. Referenced Documents 3.1.5 tearing force, n—in fabric, the force applied to propa-
gate a tear initiated under specified conditions.
2.1 ASTM Standards:
3.1.6 tear resistance, n—in textiles, the resistance to a
D 123 Terminology Relating to Textiles
2 tearing force.
D 629 Test Methods for Quantitative Analysis of Textiles
3.1.7 tearing strength, n—in fabrics, the force required to
D 689 Test Method for Internal Tearing Resistance of Pa-
propagate a tear after its initiation.
per
3.1.8 fabric, n—in textiles, a planar structure consisting of
D 1776 Practice for Conditioning Textiles for Testing
yarns or fibers.
D 2904 Practice for InterlaboratoryTesting of aTextileTest
3.1.9 For definitions of other textile terms used in this test
method, refer to Terminology D 123. For definitions of other
1 terms related to force and deformation in textiles, refer to
ThistestmethodisunderthejurisdictionofASTMCommitteeD-13onTextiles
Terminology D 4848.
and is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,
Specific.
Current edition approved May 10, 1996. Published August 1996. Originally
published as D 1424 – 56 T. Discontinued January 1995 and reinstated as
Annual Book of ASTM Standards, Vol 07.02.
D 1424 – 96. PC programs on floppy disks for analyzing Committee D-13 interlaboratory
Annual Book of ASTM Standards, Vol 07.01. data are available throughASTM. For 3 ⁄2 in. disk request PCN: 12-429040-18, for
Annual Book of ASTM Standards, Vol 15.09. a5 ⁄4 in. disk request PCN: 12-429041-18.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D1424–96
4. Summary of Test Method mm (0.1 6 0.01 in.) and are aligned such that the clamped
specimen lies in a plane parallel to the axis of the pendulum,
4.1 Aslit is centrally precut in a test specimen held between
the plane making an angle of 0.480 rad (27.5 6 0.5°) with the
two clamps and the specimen is torn through a fixed distance.
perpendicular line joining the axis and the horizontal line
The resistance to tearing is in part factored into the scale
formed by the top edges of the clamping jaws. The distance
reading of the instrument and is computed from this reading
between the axis and the top edges of the clamping jaws is
and the pendulum capacity.
1036 0.1 mm (4.055 6 0.004 in.). The clamping surface in
5. Significance and Use
each jaw is at least 25 mm (1.0 in.) wide and 15.9 6 0.1 mm
(0.625 6 0.004 in.) deep.
5.1 This test method for the determination of tearing
6.1.3 The tester may have a pointer mounted on the same
strength by the falling pendulum type apparatus is used in the
axis as the pendulum to register the tearing force, or it may be
trade for the acceptance testing of commercial shipments of
substituted by means of calculating and displaying the required
fabrics, but caution is advised since technicians may fail to get
results without the use of a pointer, such as digital display and
good agreement between results on certain fabrics. Compara-
computer driven systems. Preferably the clamps may be air
tive tests as directed in 5.1.1 may be needed.
actuated, but manual clamping is permitted.
5.1.1 In case of a dispute arising from differences in
6.1.4 The test instrument should be equipped to provide
reported test results when using this test method for acceptance
interchangeable full scale force ranges. Typical full scale
testing of commercial shipments, the purchaser and the sup-
ranges are shown in Table A3.1.
plier should conduct comparative tests to determine if there is
6.2 Calibration Weight(s) for graduation of 50 % of the full
a statistical bias between their laboratories. Statistical assis-
scale force range, or other means as described by the manu-
tance is recommended for the investigation of bias. As a
facturer of the test apparatus.
minimum, the two parties should take a group of test speci-
6.3 Cutting Die having essentially the shape and dimen-
mens that are as homogeneous as possible and that are from a
sions shown in Fig. 1(a) or (b). Either die provides the basic
lot of fabric of the type in question. The test specimens should
rectangular test specimen 100 62mm(4 6 0.05 in.) long by
then be randomly assigned in equal numbers to each laboratory
63 6 0.15 mm (2.5 6 0.005 in.) wide, along with additional
for testing. The average results from the two laboratories
fabricatthetopedgeofthespecimentohelpensurethebottom
should be compared using appropriate statistical analysis and
portion of specimen will be torn during the test. The critical
anacceptableprobabilitylevelchosenbythetwopartiesbefore
dimension of the test specimen is the distance 43.0 6 0.15 mm
the testing began. If a bias is found, either its cause must be
(1.696 0.005 in.) which is to be torn during the test.
found and corrected or the purchaser and the supplier must
agree to interpret future test results with consideration to the
NOTE 1—The improved die model shown in Fig. 1(a) has two new
known bias.
features not found in the original model, Fig. 1(b), namely a cutout for the
bottom of the specimen to aid in centering it in the clamps, and (optional)
5.2 Microprocessor systems for automatic collection of data
provision for cutting the 20.0 mm (0.75 in.) slit prior to inserting the
can provide economical and reliable results when properly
specimen in the tester. These dies can be made to order by most die
calibrated.
manufacturers.
6. Apparatus
6.4 Air Pressure Regulator, capable of controlling gage air
6.1 Falling-Pendulum (Elmendorf) Type Tester —Thetester pressure between 410 kPa and 620 kPa (60 psi and 90 psi),
includes: a stationary clamp, a clamp carried on a pendulum when applicable, for air clamps.
that is free to swing on a bearing, means for leveling as 6.5 Setting Gage for Cutting Blade that will provide a cut
applicable, means for holding the pendulum in a raised slit that leaves a 43 6 0.15 mm (1.69 6 0.005 in.) specimen
position, means for instantly releasing the pendulum, and tearing distance for a 63 6 0.15 mm (2.5 6 0.005 in.) wide
means for measuring the force to tear the test specimen. specimen, or equivalent.
6.1.1 Aknife can be mounted on a stationary post for initial
6.6 Jaw Spacing Gage 2.5 6 0.25 mm (0.1 6 0.01 in.)
slitting of the specimens centered between the clamps and width, or equivalent.
adjusted in height to give a tearing distance of 43.0 6 0.15 mm
6.7 Oil, light weight, non-gumming clock type.
(1.69 6 0.005 in.); that is, the distance between the end of the
slit made by the knife and the upper edge of the specimen is
43.0 6 0.15 mm (1.69 6 0.005 in.) when the lower edge of the
63.0-mm (2.5 6 0.005 in.) wide specimen rests against the
bottom of the clamp.
6.1.2 With the pendulum in its initial position ready for a
test, the two clamps are separated by a distance of 2.5 6 0.25
Elmendorf Tear Testers suitable for use and meeting the requirements of this
test method are available from Thwing-Albert Instrument Co., Philadelphia, PA;
Testing Machines Inc., Amityville, NY; and Schmid Corp., 40-B Ventura Blvd.,
Spartanburg, SC 24304, agent for TexTest AG, Zurich, Switzerland; Lawson-
Hemphill Sales, Inc., P.O. Drawer 6388, Spartanburg, SC 29304, agent for Shirley
Developments, LTD. FIG. 1 Die Diagram for Cutting Notched Specimens
D1424–96
NOTE 3—The reading obtained is directly proportional to the length of
6.8 Silicone Grease, when applicable, for air clamp lubri-
the material torn, therefore, it is essential that the specimen be prepared to
cation.
the exact size specified.
6.9 Vacuum Cleaner, when applicable, for cleaning dust and
fiber from sensor, or equivalent.
8. Preparation of Apparatus and Calibration
7. Sampling and Test Specimens
8.1 Select test instrument force range, such that the tear
7.1 Lot Sample—As a lot sample for acceptance testing, occurs between 20 and 80 % or 20 and 60 % of the full-scale
randomly select the number of rolls or pieces of fabric directed range as applicable. Ensure the clamps are spaced as directed
in an applicable material specification or other agreement in A1.4.
between the purchaser and the supplier. Consider the rolls or
NOTE 4—For standard test apparatus, the useable portion of the full
pieces of fabric to be the primary sampling units. In the
scale force range is 20 to 80 %. For the high capacity test instrument, the
absence of such an agreement, take the number of fabric rolls
useable portion of the full scale force range is 20 to 60 %.
or pieces specified in Table 1.
8.2 When equipped with a registering sensor, examine the
NOTE 2—An adequate specification or other agreement between the
scale and the complementary sensor, as applicable. Using care
purchaserandsupplierrequirestakingintoaccountthevariabilitybetween
and without touching the sensor, vacuum away any loose fibers
rolls or pieces of fabric and between specimens from a swatch from a roll
and dust.
orpieceoffabrictoprovideasamplingplanwithameaningfulproducer’s
8.3 Examine the knife edge for sharpness, wear, and central
risk, consumer’s risk, acceptable quality level, and limiting quality level.
alignment as directed in A1.5-A1.7.
7.2 Laboratory Sample—For acceptance testing, take a
8.4 For air clamps, set the air gage pressure to the clamps to
swatch extending the width of the fabric and approximately 1
about 550 kPa (80 psi).
m (1 yd) along the machine direction from each roll or piece in
8.4.1 Maximum gage pressure should be no more than 620
the lot sample. For rolls of fabric, take a sample that will
kPa (90 psi) and minimum gage pressure no less than 410 kPa
exclude fabric from the outer wrap of the roll or the inner wrap
(60 psi).
around the core of the roll of fabric.
8.5 When using microprocessor automatic data gathering
7.3 Test Specimens—From each laboratory sampling unit,
systems, set the appropriate parameters as defined in the
take five specimens from the machine direction and five
manufacturer’s instructions.
specimens from the cross-machine direction, for each test
8.6 Verifythecalibrationoftheselectedpendulumfullscale
condition described in 9.1 and 9.2, as applicable to a material
force range using the procedure described inAnnexA2, unless
specification or contract order.
otherwise specified.
7.3.1 Direction of Test—Consider the long direction of the
specimen as the direction of test.
9. Conditioning
7.3.2 Cutting Test Specimens—Take the specimens to be
used for the measurement of machine direction with the longer
9.1 Condition 1, Standard Testing Conditioning:
dimension parallel to the machine direction. Take the speci-
9.1.1 Precondition the specimens by bringing them to ap-
menstobeusedforthemeasurementofthecross-machinewith
proximate moisture equilibrium in the standard atmosphere for
the longer dimension parallel to the cross-machine direction.
preconditioning textiles as directed in Practice D 1776, unless
Use the cutting die described in 6.3 and shown in Fig. 1(a) or
otherwise directed in a material specification or contract order.
(b), as applicable. When specimens are to be tested wet, cut
9.1.2 After preconditioning, bring the test specimens to
from areas adjacent to the dry test specimens. Label to
moisture equilibrium for testing in the standard atmosphere for
maintain specimen identity.
testing textiles as directed in Practice D 1776 or, if applicable,
7.3.2.1 In cutting the woven fabric specimens, take care to
in the specified atmosphere in which the testing is to be
align the yarns running in the short direction parallel with the
performed,unlessotherwisedirectedinamaterialspecification
die such that when the slit is cut, the subsequent tear will take
or contract order.
placebetweentheseyarnsandnotacrossthem.Thisprecaution
9.2 Condition 2, Wet Specimen Testing Conditioning:
is most important when testing bowed fabrics.
9.2.1 When desizing treatments are specified prior to wet
7.3.2.2 Cut specimens representing a
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.