ASTM D2524-95(2008)
(Test Method)Standard Test Method for Breaking Tenacity of Wool Fibers, Flat Bundle Method- 1/8-in. (3.2-mm) Gage Length
Standard Test Method for Breaking Tenacity of Wool Fibers, Flat Bundle Method- 1/8-in. (3.2-mm) Gage Length
SIGNIFICANCE AND USE
Test Method D 2524 for testing wool fibers for tenacity is considered satisfactory for acceptance testing when the participating laboratories, using a reference wool, have shown acceptable between-laboratory precision. It is recommended that any program of acceptance testing be preceded by an interlaboratory check in the laboratory of the purchaser and the laboratory of the seller on replicate specimens of samples of the material to be evaluated. In cases of dispute, the statistical bias, if any, between the laboratory of the purchaser and the seller should be determined with each comparison being based on testing randomized specimens from one sample of material of the type being evaluated.
Values obtained from flat bundle tenacity show a good correlation with values obtained from single fiber tests and require much less time.
The basic differences between the procedures described in Test Method D 2524 and those described in Test Method D 1294 lie in the manner of clamping the bundles and the shorter gage length employed. The special clamps used in this method allow quicker and easier bundle preparation; however, for Test Method D 1294 no special clamps are required. Closer agreement with single fiber tenacity is also obtained with Test Method D 2524 than when using the procedure in Test Method D 1294.
As the observed tenacity of fibers depends in part on the type of tensile testing machine used and the time required to break the specimen, results obtained with the different types of machines which may be used in this method will not necessarily agree. The machines specifically designed for bundle testing are CRL testers which operate at a loading rate of 1 kgf/s and therefore reach the breaking force at variable times in the order of 5 s. CRE and CRT type machines would be expected to produce somewhat different results not only because of the inherent difference in operation but because CRE and CRT type machines are to be operated at a rate to achieve the bre...
SCOPE
1.1 This test method covers the determination of the breaking tenacity of wool fibers as a flat bundle with a 1/8-in. (3.2-mm) clamp separation.
1.2 This test method is especially adapted to the fiber bundle clamps and strength testing instruments specified, but may be used on other tensile testing machines when equipped with appropriate adapters to accommodate the prescribed clamps.
1.3 This test method is applicable to wool in any form which can be hand-combed into small bundles of parallelized fibers.
Note 1—Other test methods for measuring breaking tenacity of fiber bundles include Test Methods D 1294, D 1445, and D 540.
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.
1.5 The values stated in inch-pound units are to be regarded as the standard. The SI units in parentheses are provided for information only.
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Designation: D2524 − 95(Reapproved 2008)
Standard Test Method for
Breaking Tenacity of Wool Fibers, Flat Bundle Method— ⁄8-
in. (3.2-mm) Gage Length
This standard is issued under the fixed designation D2524; 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 D1445 TestMethodforBreakingStrengthandElongationof
Cotton Fibers (Flat Bundle Method)
1.1 This test method covers the determination of the break-
D1776 Practice for Conditioning and Testing Textiles
ing tenacity of wool fibers as a flat bundle with a ⁄8-in.
D2525 Practice for Sampling Wool for Moisture
(3.2-mm) clamp separation.
1.2 Thistestmethodisespeciallyadaptedtothefiberbundle
3. Terminology
clamps and strength testing instruments specified, but may be
3.1 Definitions:
used on other tensile testing machines when equipped with
3.1.1 breaking tenacity, n—thetenacitycorrespondingtothe
appropriate adapters to accommodate the prescribed clamps.
breaking load.
1.3 This test method is applicable to wool in any form
3.1.1.1 Discussion—Breaking tenacity is commonly ex-
which can be hand-combed into small bundles of parallelized
pressed as grams-force per tex (gf/tex), grams-force per denier
fibers.
(gf/den), millinewtons per tex (mN/tex), or millinewtons per
NOTE 1—Other test methods for measuring breaking tenacity of fiber denier (mN/den). Millinewtons are numerically equal to the
bundles include Test Methods D1294, D1445, and D540.
grams-force times 9.81.
1.4 This standard does not purport to address all of the
3.1.2 constant-rate-of-extension (CRE) type tensile testing
safety concerns, if any, associated with its use. It is the
machine, n—in tensile testing, an apparatus in which the
responsibility of the user of this standard to establish appro-
pulling clamp moves at a uniform rate, and the force-
priate safety and health practices and determine the applica-
measuring mechanism moves a negligible distance with in-
bility of regulatory limitations prior to use.
creasing force, less than 0.13 mm (0.005 in.).
1.5 The values stated in inch-pound units are to be regarded
3.1.3 constant-rate-of-loading (CRL) type tensile testing
as the standard. The SI units in parentheses are provided for
machine, n—in tensile testing,anapparatusinwhichtherateof
information only.
increase of the force is uniform with time after the first3sand
the specimen is free to elongate, this elongation being depen-
2. Referenced Documents
dent on the extension characteristics of the specimen at any
2.1 ASTM Standards:
applied force.
D123 Terminology Relating to Textiles
3.1.4 constant-rate-of-traverse (CRT) type tensile testing
D540 Methods of Testing Man-Made Staple Fibers; Re-
machine, n—in tensile testing, an apparatus in which the
placed by D 3660 (Withdrawn 1973)
pulling clamp moves at a uniform rate and the force is applied
D1294 Test Method for Tensile Strength and Breaking Te-
through the other clamp, which moves appreciably to actuate a
nacity of Wool Fiber Bundles 1-in. (25.4-mm) Gage
force-measuring mechanism, producing a rate of increase of
Length
force or extension that is usually not constant and is dependent
on the extension characteristics of the specimen.
3.1.5 gage length, n— in tensile testing, the length of a
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
specimenmeasuredbetweenthepointsofattachmenttoclamps
and is the direct responsibility of Subcommittee D13.13 on Wool and Felt.
while under uniform tension.
Current edition approved Aug. 1, 2008. Published October 2008. Originally
approved in 1966. Last previous edition approved in 2003 as D2524 – 95 (2003).
3.1.6 tenacity, n—in a tensile test, the force exerted on the
DOI: 10.1520/D2524-95R08.
specimens based on the linear density of the unstrained
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
specimen.
Standards volume information, refer to the standard’s Document Summary page on
3.1.6.1 Discussion—In textiles, tenacity is considered a
the ASTM website.
property of fabrics and yarns, and tensile strain is the comple-
The last approved version of this historical standard is referenced on
www.astm.org. mentary property of fabrics. In direct yarn numbering systems,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2524 − 95 (2008)
tenacity is force divided by linear density. In indirect yarn kgf/sandthereforereachthebreakingforceatvariabletimesin
numbering systems, tenacity is force times the reciprocal linear the order of 5 s. CRE and CRT type machines would be
density. expected to produce somewhat different results not only
because of the inherent difference in operation but because
3.1.7 wool, n—the fibrous covering of sheep, Ovis species.
CRE and CRT type machines are to be operated at a rate to
3.1.7.1 Discussion—For the purposes of this method, the
achieve the breaking load in 20 s.
word wool is used in the generic sense, and includes repro-
cessed and reused wool as well as wool as defined in the Wool
6. Apparatus and Materials
Products LabelingActof1939:“thefiberfromthefleeceofthe
sheep or lamb, or hair of the Angora goat or Cashmere goat
6.1 Tensile Testing Machine, having a capacity of at least 7
(and may include the so called specialty fibers from the hair of
kgf (70 N), equipped to accommodate the specified flat bundle
the camel, alpaca, llama, and vicuna) which has never been
clamps. For CRL testing machines, the rate of loading is
reclaimed from any woven or felted wool product.”
specified as 1 kgf/s (10 N/s). For CRE and CRT machines,
select a rate of operation which will reach the breaking force in
3.1.8 For definitions of other textile terms used in this test
an average time of 20 63s.
method, refer to Terminology D123.
6.1.1 IncasetheCREorCRTtestingmachineisnotcapable
4. Summary of Test Method
of operating as specified in 6.1, select a rate so as to reach the
breaking force in an average time as close to 20 s as possible
4.1 Abundle of fibers is combed until parallel, placed under
and report the average time to break.
a uniform tension sufficient to remove as much crimp as
possible without stretching the fibers, and secured in special
NOTE 2—There may be no overall correlation between the results
clamps.Thefibersarethencuttoaknownlength,brokeninthe
obtainedwiththeCRE,CRTorCRLtypetestingmachines.Consequently,
tensile testing machine, removed from the clamps, and these three machines cannot be used interchangeably.
weighed. Breaking tenacity is calculated from the ratio of
6.2 Balance, suitable for weighing 2 to 6 mg with a
breaking force to bundle linear density. The length measured
sensitivity of 0.02 mg.
under the applied tension is the basis for computing linear
6.3 Flat Bundle Clamps and Accessories, including the
density from bundle mass.
following components:
5. Significance and Uses
NOTE 3—Pressley clamps and accessories have been found satisfactory
5.1 Test Method D2524 for testing wool fibers for tenacity for this purpose. Adapters to fit the clamps to various tensile testing
instruments are also available or can be fabricated.
is considered satisfactory for acceptance testing when the
participating laboratories, using a reference wool, have shown
6.3.1 Clamps, having a total thickness of 0.465 6 0.001 in.
acceptable between-laboratory precision. It is recommended
(11.8 6 0.03 mm) and a 0.125 6 0.001-in. (3.2 6 0.03-mm)
that any program of acceptance testing be preceded by an
spacer.
interlaboratory check in the laboratory of the purchaser and the
6.3.2 Clamp Vise, with a device to indicate approximately 8
laboratory of the seller on replicate specimens of samples of
lbf·in. (0.9 N·m) torque.
the material to be evaluated. In cases of dispute, the statistical
6.3.3 Clamp Wrench.
bias, if any, between the laboratory of the purchaser and the
6.4 Coarse Comb, approximately 8 teeth per in. (3 per 10
seller should be determined with each comparison being based
mm).
on testing randomized specimens from one sample of material
of the type being evaluated.
6.5 Fine Comb, approximately 50 teeth per in. (20 per 10
mm).
5.2 Values obtained from flat bundle tenacity show a good
correlation with values obtained from single fiber tests and
6.6 Black Paper, to hold bundles.
require much less time.
6.7 Shearing Knife or Razor Blade.
5.3 The basic differences between the procedures described
6.8 Tweezers.
in Test Method D2524 and those described in Test Method
D1294 lie in the manner of clamping the bundles and the
6.9 Torque Wrench or Friction Disk Wrench, to indicate
shorter gage length employed. The special clamps used in this
approximately 8 lbf·in. (0.9 N·m) torque (optional).
method allow quicker and easier bundle preparation; however,
for Test Method D1294 no special clamps are required. Closer
agreement with single fiber tenacity is also obtained with Test
The sole source of supply for the Stelometer known to the committee at this
Method D2524 than when using the procedure in Test Method
time is Special Instruments Laboratory, Inc., 312W.Vine St., Knoxville,TN 37901.
D1294.
If you are aware of alternative suppliers, please provide this information to ASTM
International Headquarters. Your comments will receive careful consideration at a
5.4 As the observed tenacity of fibers depends in part on the 1
meeting of the responsible technical committee, which you may attend. The
type of tensile testing machine used and the time required to
Clemson Tester (no longer available) have been found satisfactory for this purpose.
The sole source of supply of the apparatus known to the committee at this time
break the specimen, results obtained with the different types of
is J. M. Doebrich and Co., P. O. Box 2789, Tucson,AZ 85702. If you are aware of
machines which may be used in this method will not neces-
alternative suppliers, please provide this information to ASTM International
sarily agree. The machines specifically designed for bundle
Headquarters.Your comments will receive careful consideration at a meeting of the
testing are CRL testers which operate at a loading rate of 1 responsible technical committee, which you may attend.
D2524 − 95 (2008)
6.10 Standard Wool Top Sample ,havinganassignedbreak- 10.2 Grasp the tuft about one-fourth the distance from the
ing tenacity of 11.4 gf/tex (112 mN/tex). end of the tuft with the thumb and forefinger or a fiber hand
vise and comb the protruding end with the coarse comb to
NOTE 4—The standard wool top sample, USDA Lot 58-27, has a
remove loose fibers and foreign material and to secure partial
breaking tenacity (based on single fiber tests) of 11.4 6 0.6 gf/tex, at the
parallelization of the fibers. Reverse the tuft and repeat the
95 % probability level.
combing on the other end.
7. Sampling
10.3 Grasp the partially parallelized tuft at both ends using
7.1 Division into Lots—Treat a single shipment of a single the fingers of one hand, thumb and ring finger holding one end
fiber type as a lot. and middle and index fingers holding the other end. Complete
the parallelization of the fibers in the tuft by combing with the
7.2 LotSample—Asalotsampleforacceptancetesting,take
fine comb; with each pass of the comb release the end of the
at random the number of shipment containers directed in an
tuft toward which the comb is moving and grasp again
applicable material specification or other agreement between
immediately after the comb passes the holding position. To
the purchaser and the supplier, such as an agreement to use
avoidmoisturetransferfromfingerstofibers,donothandlethe
Practice D2525. Consider shipping containers to be the pri-
middlesectionofthetuft.Ifthespecimenisestimatedtobetoo
mary sampling units.
heavy, remove fibers during the combing operation from either
7.3 Laboratory Sample—For acceptance testing, take a
side with the tip of the comb to obtain the correct specimen
laboratory sample from each shipping container in the lot
size. The specimen is now ready to be placed in the clamps.
sample as follows:
7.3.1 For loose fiber, grease, and scoured wool, reduce the
11. Procedure
mass of clean fiber submitted for testing to approximately 15 g
11.1 Test the conditioned specimens in the standard atmo-
by randomly selecting pieces throughout the mass. Form into a
sphere for testing.
loose sliver by hand.
11.2 Inspect the leather faces of the clamps frequently to
7.3.2 For card sliver and top, cut a length of sliver about 20
ensure that they are in good condition. Keep the inner edges of
in. (500 mm) long from each ball submitted for testing.
the leathers trimmed flush with the metal surfaces and replace
7.3.3 For roving, cut a length about 20 in. (500 mm) long
the leathers as soon as grooves become evident to the touch.
from each spool submitted for testing and include all ends.
11.3 Place the parallelized specimen (10.3) in the clamps in
7.4 Test Specimens—Scour or solvent-extract the laboratory
the following manner: Using a Pressley type vise, lock the
sample until residual contamination is 1 % or less of the
clamps with a ⁄8-in. (3.2-mm) spacer separating the clamps of
laboratory mass, as established by further cleaning of a part of
the vise and open the jaws of the clamps. Hold both ends of the
thelaboratorysample.Fromeachunitinthelaboratorysample,
specimen as directed in 10.3, keeping the specimen approxi-
prepare five test specimens as directed in 10.1.
mately ⁄4in.(6mm)wide,andplaceitinthecentralpartofthe
open clamps. Maintain sufficient tension on the specimen to
8. Preparation, Calibration, and Verification of
hold the fibers straight while the jaws of the clamps are
Apparatus
lowered and tightened in place by applying an 8 lbf·in. (0.9
8.1 Tensile Testing Machine—Check the calibration of the
N·m) torque. The torque may be controlled by either a
instrument according to the manufacturer’s instruction.
vise-mounted, torque-indicating instrument or by a friction
8.2 Balance—Check the zero reading and the sensitivity in
disk wrench.
the range to be used.
11.4 Remove the clamps from the vise. Shear off the
protruding ends of the specimen with the shearing knife or
9. Preconditioning and Conditioning
razor blade, cutting downward and away from the leather face
9.1 Bring the laboratory sample to moisture equilibrium for
of the clamps and flush with the surface.
testing in the standard atmosphere for testing as directed in
11.5 Insert the loaded clamps in the tensi
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D2524–95 (Reapproved 2003) Designation: D 2524 – 95 (Reapproved 2008)
Standard Test Method for
Breaking Tenacity of Wool Fibers, Flat Bundle Method— ⁄8-
in. (3.2-mm) Gage Length
This standard is issued under the fixed designation D 2524; 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
1.1 This test method covers the determination of the breaking tenacity of wool fibers as a flat bundle with a ⁄8-in. (3.2-mm)
clamp separation.
1.2 This test method is especially adapted to the fiber bundle clamps and strength testing instruments specified, but may be used
on other tensile testing machines when equipped with appropriate adapters to accommodate the prescribed clamps.
1.3 This test method is applicable to wool in any form which can be hand-combed into small bundles of parallelized fibers.
NOTE 1—Other test methods for measuring breaking tenacity of fiber bundles include Test Methods D 1294, D 1445, and D 540.
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.
1.5 The values stated in inch-pound units are to be regarded as the standard. The SI units in parentheses are provided for
information only.
2. Referenced Documents
2.1 ASTM Standards:
D 123 Terminology Relating to Textiles
D 540 Testing Man-Made Staple Fibers Method of Testing Man-Made Staple Fibers
D 1294 Test Method for Tensile Strength and Breaking Tenacity of Wool Fiber Bundles— 1-in. (25.4-mm). Gage Length
D 1445 Test Method for Breaking Strength and Elongation of Cotton Fibers (Flat Bundle Method)
D 1776 Practice for Conditioning Textiles for Testing Practice for Conditioning and Testing Textiles
D 2525 Practice for Sampling Wool for Moisture
3. Terminology
3.1 Definitions:
3.1.1 breaking tenacity, n—the tenacity corresponding to the breaking load.
3.1.1.1 Discussion—Breaking tenacity is commonly expressed as grams-force per tex (gf/tex), grams-force per denier (gf/den),
millinewtons per tex (mN/tex), or millinewtons per denier (mN/den). Millinewtons are numerically equal to the grams-force times
9.81.
3.1.2 constant-rate-of-extension (CRE) type tensile testing machine, n—in tensile testing, an apparatus in which the pulling
clamp moves at a uniform rate, and the force-measuring mechanism moves a negligible distance with increasing force, less than
0.13 mm (0.005 in.).
3.1.3 constant-rate-of-loading (CRL) type tensile testing machine, n—in tensile testing, an apparatus in which the rate of
increase of the force is uniform with time after the first 3 s and the specimen is free to elongate, this elongation being dependent
on the extension characteristics of the specimen at any applied force.
3.1.4 constant-rate-of-traverse (CRT) type tensile testing machine, n—in tensile testing,anapparatusinwhichthepullingclamp
moves at a uniform rate and the force is applied through the other clamp, which moves appreciably to actuate a force-measuring
mechanism, producing a rate of increase of force or extension that is usually not constant and is dependent on the extension
characteristics of the specimen.
This test method is under the jurisdiction of ASTM Committee D13 on Textiles and is the direct responsibility of Subcommittee D13.13 on Wool and Felt.
Current edition approved April 10, 2003. Published August 1995. Originally published as D2524–66T. Last previous edition D2524–94.
Current edition approved Aug. 1, 2008. Published October 2008. Originally approved in 1966. Last previous edition approved in 2003 as D 2524 – 95 (2003).
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 07.01.volume information, refer to the standard’s Document Summary page on the ASTM website.
Withdrawn. The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 2524 – 95 (2008)
3.1.5 gage length, n—in tensile testing, the length of a specimen measured between the points of attachment to clamps while
under uniform tension.
3.1.6 tenacity, n—in a tensile test, the force exerted on the specimens based on the linear density of the unstrained specimen.
3.1.6.1 Discussion—In textiles, tenacity is considered a property of fabrics and yarns, and tensile strain is the complementary
property of fabrics. In direct yarn numbering systems, tenacity is force divided by linear density. In indirect yarn numbering
systems, tenacity is force times the reciprocal linear density.
3.1.7 wool, n—the fibrous covering of sheep, Ovis species.
3.1.7.1 Discussion—For the purposes of this method, the word wool is used in the generic sense, and includes reprocessed and
reused wool as well as wool as defined in the Wool Products Labeling Act of 1939: “the fiber from the fleece of the sheep or lamb,
or hair of the Angora goat or Cashmere goat (and may include the so called specialty fibers from the hair of the camel, alpaca,
llama, and vicuna) which has never been reclaimed from any woven or felted wool product.”
3.1.8 For definitions of other textile terms used in this test method, refer to Terminology D 123.
4. Summary of Test Method
4.1 Abundle of fibers is combed until parallel, placed under a uniform tension sufficient to remove as much crimp as possible
without stretching the fibers, and secured in special clamps. The fibers are then cut to a known length, broken in the tensile testing
machine, removed from the clamps, and weighed. Breaking tenacity is calculated from the ratio of breaking force to bundle linear
density. The length measured under the applied tension is the basis for computing linear density from bundle mass.
5. Significance and Uses
5.1 Test Method D 2524 for testing wool fibers for tenacity is considered satisfactory for acceptance testing when the
participatinglaboratories,usingareferencewool,haveshownacceptablebetween-laboratoryprecision.Itisrecommendedthatany
program of acceptance testing be preceded by an interlaboratory check in the laboratory of the purchaser and the laboratory of the
seller on replicate specimens of samples of the material to be evaluated. In cases of dispute, the statistical bias, if any, between
the laboratory of the purchaser and the seller should be determined with each comparison being based on testing randomized
specimens from one sample of material of the type being evaluated.
5.2 Values obtained from flat bundle tenacity show a good correlation with values obtained from single fiber tests and require
much less time.
5.3 The basic differences between the procedures described in Test Method D 2524 and those described in Test Method D 1294
lie in the manner of clamping the bundles and the shorter gage length employed. The special clamps used in this method allow
quicker and easier bundle preparation; however, for Test Method D 1294 no special clamps are required. Closer agreement with
single fiber tenacity is also obtained with Test Method D 2524 than when using the procedure in Test Method D 1294.
5.4 As the observed tenacity of fibers depends in part on the type of tensile testing machine used and the time required to break
the specimen, results obtained with the different types of machines which may be used in this method will not necessarily agree.
ThemachinesspecificallydesignedforbundletestingareCRLtesterswhichoperateataloadingrateof1kgf/sandthereforereach
the breaking force at variable times in the order of 5 s. CRE and CRT type machines would be expected to produce somewhat
different results not only because of the inherent difference in operation but because CRE and CRT type machines are to be
operated at a rate to achieve the breaking load in 20 s.
6. Apparatus and Materials
6.1 Tensile Testing Machine, having a capacity of at least 7 kgf (70 N), equipped to accommodate the specified flat bundle
clamps. For CRL testing machines, the rate of loading is specified as 1 kgf/s (10 N/s). For CRE and CRT machines, select a rate
of operation which will reach the breaking force in an average time of 20 63s.
6.1.1 In case the CRE or CRT testing machine is not capable of operating as specified in 6.1, select a rate so as to reach the
breaking force in an average time as close to 20 s as possible and report the average time to break.
NOTE 2—TheremaybenooverallcorrelationbetweentheresultsobtainedwiththeCRE,CRTorCRLtypetestingmachines.Consequently,thesethree
machines cannot be used interchangeably.
6.2 Balance, suitable for weighing 2 to 6 mg with a sensitivity of 0.02 mg.
6.3 Flat Bundle Clamps and Accessories, including the following components:
NOTE 3—Pressley clamps and accessories have been found satisfactory for this purpose. Adapters to fit the clamps to various tensile testing
instruments are also available or can be fabricated.
6.3.1 Clamps, having a total thickness of 0.465 6 0.001 in. (11.8 6 0.03 mm) and a 0.125 6 0.001-in. (3.2 6 0.03-mm) spacer.
6.3.2 Clamp Vise, with a device to indicate approximately 8 lbf·in. (0.9 N·m) torque.
The Stelometer, manufactured by the Special Instruments Laboratory, Inc., 312 W. Vine St., Knoxville, TN 37901; and the Clemson Tester (no longer available) have
been found satisfactory for this purpose.
Available from J. M. Doebrich and Co., P. O. Box 2789, Tucson, AZ 85702.
D 2524 – 95 (2008)
6.3.3 Clamp Wrench.
6.4 Coarse Comb, approximately 8 teeth per in. (3 per 10 mm).
6.5 Fine Comb, approximately 50 teeth per in. (20 per 10 mm).
6.6 Black Paper, to hold bundles.
6.7 Shearing Knife or Razor Blade.
6.8 Tweezers.
6.9 Torque Wrench or Friction Disk Wrench, to indicate approximately 8 lbf·in. (0.9 N·m) torque (optional).
6.10 Standard Wool Top Sample , having an assigned breaking tenacity of 11.4 gf/tex (112 mN/tex).
NOTE 4—The standard wool top sample, USDA Lot 58-27, has a breaking tenacity (based on single fiber tests) of 11.4 6 0.6 gf/tex, at the 95 %
probability level.
7. Sampling
7.1 Division into Lots—Treat a single shipment of a single fiber type as a lot.
7.2 Lot Sample—As a lot sample for acceptance testing, take at random the number of shipment containers directed in an
applicable material specification or other agreement between the purchaser and the supplier, such as an agreement to use Practice
D 2525. Consider shipping containers to be the primary sampling units.
7.3 Laboratory Sample—For acceptance testing, take a laboratory sample from each shipping container in the lot sample as
follows:
7.3.1 For loose fiber, grease, and scoured wool, reduce the mass of clean fiber submitted for testing to approximately 15 g by
randomly selecting pieces throughout the mass. Form into a loose sliver by hand.
7.3.2 For card sliver and top, cut a length of sliver about 20 in. (500 mm) long from each ball submitted for testing.
7.3.3 For roving, cut a length about 20 in. (500 mm) long from each spool submitted for testing and include all ends.
7.4 Test Specimens—Scour or solvent-extract the laboratory sample until residual contamination is 1 % or less of the laboratory
mass, as established by further cleaning of a part of the laboratory sample. From each unit in the laboratory sample, prepare five
test specimens as directed in 10.1.
8. Preparation, Calibration, and Verification of Apparatus
8.1 Tensile Testing Machine—Check the calibration of the instrument according to the manufacturer’s instruction.
8.2 Balance—Check the zero reading and the sensitivity in the range to be used.
9. Preconditioning and Conditioning
9.1 Bring the laboratory sample to moisture equilibrium for testing in the standard atmosphere for testing as directed in Practice
D 1776.
10. Preparation of Specimens
10.1 Prepare each specimen by drawing small groups of fibers from at least five locations in a unit of the laboratory sample.
Parallelize and combine them in a bundle which may be held conveniently between the thumb and forefinger. Depending on fiber
entanglement, take a sufficient number of fibers so that, after combining, an aligned specimen of 2 to 6 mg is available for testing.
10.2 Grasp the tuft about one-fourth the distance from the end of the tuft with the thumb and forefinger or a fiber hand vise
and comb the protruding end with the coarse comb to remove loose fibers and foreign material and to secure partial parallelization
of the fibers. Reverse the tuft and repeat the combing on the other end.
10.3 Grasp the partially parallelized tuft at both ends using the fingers of one hand, thumb and ring finger holding one end and
middleandindexfingersholdingtheotherend.Completetheparallelizationofthefibersinthetuftbycombingwiththefinecomb;
with each pass of the comb release the end of the tuft toward which the comb is moving and grasp again immediately after the
comb passes the holding position. To avoid moisture transfer from fingers to fibers, do not handle the middle section of the tuft.
If the specimen is estimated to be too heavy, remove fibers during the combing operation from either side with the tip of the comb
to obtain the correct specimen size. The specimen is now ready to be placed in the clamps.
11. Procedure
11.1 Test the conditioned specimens in the standard atmosphere for testing.
11.2 Inspect the leather faces of the clamps frequently to ensure that they are in good condition. Keep the inner edges of the
leathers trimmed flush with the metal surfaces and replace the leathers as soon as grooves become evident to the touch.
11.3 Place the parallelized specimen (10.3) in the clamps in the following manner: Using a Pressley type vise, lock the clamps
with a ⁄8-in. (3.2-mm) spacer separating the clamps of the vise and open the jaws of the clamps. Hold both ends of the specimen
Available from the Wool and Mohair Laboratory, Livestock and Seed Division, AMS, U.S. Department of Agriculture, 711 “O” Street, Greeley, CO 80631.
The hand vise supplied with the Suter Sorter wool fiber stapling apparatus is suitable for this purpose.Available from theAlfred Suter Co., Inc
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D2524–95 (Reapproved 2003) Designation: D 2524 – 95 (Reapproved 2008)
Standard Test Method for
Breaking Tenacity of Wool Fibers, Flat Bundle Method— ⁄8-
in. (3.2-mm) Gage Length
This standard is issued under the fixed designation D 2524; 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
1.1 This test method covers the determination of the breaking tenacity of wool fibers as a flat bundle with a ⁄8-in. (3.2-mm)
clamp separation.
1.2 This test method is especially adapted to the fiber bundle clamps and strength testing instruments specified, but may be used
on other tensile testing machines when equipped with appropriate adapters to accommodate the prescribed clamps.
1.3 This test method is applicable to wool in any form which can be hand-combed into small bundles of parallelized fibers.
NOTE 1—Other test methods for measuring breaking tenacity of fiber bundles include Test Methods D 1294, D 1445, and D 540.
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.
1.5 The values stated in inch-pound units are to be regarded as the standard. The SI units in parentheses are provided for
information only.
2. Referenced Documents
2.1 ASTM Standards:
D 123 Terminology Relating to Textiles
D 540 Testing Man-Made Staple Fibers Discontinued 1974; Methods of Testing Man-Made Staple Fibers; Replaced by D3660
D 1294 Test Method for Tensile Strength and Breaking Tenacity of Wool Fiber Bundles— 1-in. (25.4-mm). Gage Length
D 1445 Test Method for Breaking Strength and Elongation of Cotton Fibers (Flat Bundle Method)
D 1776 Practice for Conditioning Textiles for Testing Practice for Conditioning and Testing Textiles
D 2525 Practice for Sampling Wool for Moisture
3. Terminology
3.1 Definitions:
3.1.1 breaking tenacity, n—the tenacity corresponding to the breaking load.
3.1.1.1 Discussion—Breaking tenacity is commonly expressed as grams-force per tex (gf/tex), grams-force per denier (gf/den),
millinewtons per tex (mN/tex), or millinewtons per denier (mN/den). Millinewtons are numerically equal to the grams-force times
9.81.
3.1.2 constant-rate-of-extension (CRE) type tensile testing machine , n—in tensile testing, an apparatus in which the pulling
clamp moves at a uniform rate, and the force-measuring mechanism moves a negligible distance with increasing force, less than
0.13 mm (0.005 in.).
3.1.3 constant-rate-of-loading (CRL) type tensile testing machine , n—in tensile testing, an apparatus in which the rate of
increase of the force is uniform with time after the first 3 s and the specimen is free to elongate, this elongation being dependent
on the extension characteristics of the specimen at any applied force.
3.1.4 constant-rate-of-traverse (CRT) type tensile testing machine , n—in tensile testing, an apparatus in which the pulling
clamp moves at a uniform rate and the force is applied through the other clamp, which moves appreciably to actuate a
force-measuring mechanism, producing a rate of increase of force or extension that is usually not constant and is dependent on
the extension characteristics of the specimen.
This test method is under the jurisdiction of ASTM Committee D13 on Textiles and is the direct responsibility of Subcommittee D13.13 on Wool and Felt.
Current edition approved April 10, 2003. Published August 1995. Originally published as D2524–66T. Last previous edition D2524–94.
Current edition approved Aug. 1, 2008. Published October 2008. Originally approved in 1966. Last previous edition approved in 2003 as D 2524 – 95 (2003).
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 07.01.volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 2524 – 95 (2008)
3.1.5 gage length, n— in tensile testing, the length of a specimen measured between the points of attachment to clamps while
under uniform tension.
3.1.6 tenacity, n—in a tensile test, the force exerted on the specimens based on the linear density of the unstrained specimen.
3.1.6.1 Discussion—In textiles, tenacity is considered a property of fabrics and yarns, and tensile strain is the complementary
property of fabrics. In direct yarn numbering systems, tenacity is force divided by linear density. In indirect yarn numbering
systems, tenacity is force times the reciprocal linear density.
3.1.7 wool, n—the fibrous covering of sheep, Ovis species.
3.1.7.1 Discussion—For the purposes of this method, the word wool is used in the generic sense, and includes reprocessed and
reused wool as well as wool as defined in the Wool Products Labeling Act of 1939: “the fiber from the fleece of the sheep or lamb,
or hair of the Angora goat or Cashmere goat (and may include the so called specialty fibers from the hair of the camel, alpaca,
llama, and vicuna) which has never been reclaimed from any woven or felted wool product.”
3.1.8 For definitions of other textile terms used in this test method, refer to Terminology D 123.
4. Summary of Test Method
4.1 Abundle of fibers is combed until parallel, placed under a uniform tension sufficient to remove as much crimp as possible
without stretching the fibers, and secured in special clamps. The fibers are then cut to a known length, broken in the tensile testing
machine, removed from the clamps, and weighed. Breaking tenacity is calculated from the ratio of breaking force to bundle linear
density. The length measured under the applied tension is the basis for computing linear density from bundle mass.
5. Significance and Uses
5.1 Test Method D 2524 for testing wool fibers for tenacity is considered satisfactory for acceptance testing when the
participatinglaboratories,usingareferencewool,haveshownacceptablebetween-laboratoryprecision.Itisrecommendedthatany
program of acceptance testing be preceded by an interlaboratory check in the laboratory of the purchaser and the laboratory of the
seller on replicate specimens of samples of the material to be evaluated. In cases of dispute, the statistical bias, if any, between
the laboratory of the purchaser and the seller should be determined with each comparison being based on testing randomized
specimens from one sample of material of the type being evaluated.
5.2 Values obtained from flat bundle tenacity show a good correlation with values obtained from single fiber tests and require
much less time.
5.3 The basic differences between the procedures described in Test Method D 2524 and those described in Test Method D 1294
lie in the manner of clamping the bundles and the shorter gage length employed. The special clamps used in this method allow
quicker and easier bundle preparation; however, for Test Method D 1294 no special clamps are required. Closer agreement with
single fiber tenacity is also obtained with Test Method D 2524 than when using the procedure in Test Method D 1294.
5.4 As the observed tenacity of fibers depends in part on the type of tensile testing machine used and the time required to break
the specimen, results obtained with the different types of machines which may be used in this method will not necessarily agree.
ThemachinesspecificallydesignedforbundletestingareCRLtesterswhichoperateataloadingrateof1kgf/sandthereforereach
the breaking force at variable times in the order of 5 s. CRE and CRT type machines would be expected to produce somewhat
different results not only because of the inherent difference in operation but because CRE and CRT type machines are to be
operated at a rate to achieve the breaking load in 20 s.
6. Apparatus and Materials
6.1 Tensile Testing Machine, having a capacity of at least 7 kgf (70 N), equipped to accommodate the specified flat bundle
clamps. For CRL testing machines, the rate of loading is specified as 1 kgf/s (10 N/s). For CRE and CRT machines, select a rate
of operation which will reach the breaking force in an average time of 20 63s.
6.1.1 In case the CRE or CRT testing machine is not capable of operating as specified in 6.1, select a rate so as to reach the
breaking force in an average time as close to 20 s as possible and report the average time to break.
NOTE 2—TheremaybenooverallcorrelationbetweentheresultsobtainedwiththeCRE,CRTorCRLtypetestingmachines.Consequently,thesethree
machines cannot be used interchangeably.
6.2 Balance, suitable for weighing 2 to 6 mg with a sensitivity of 0.02 mg.
6.3 Flat Bundle Clamps and Accessories , including the following components:
NOTE 3—Pressley clamps and accessories have been found satisfactory for this purpose. Adapters to fit the clamps to various tensile testing
instruments are also available or can be fabricated.
Discontinued—See 1973 Annual Book of ASTM Standards , Part 25.
The Stelometer, manufactured by the Special Instruments Laboratory, Inc., 312 W. Vine St., Knoxville, TN 37901; and the Clemson Tester (no longer available) have
been found satisfactory for this purpose.
The Stelometer, manufactured by the Special Instruments Laboratory, Inc., 312 W. Vine St., Knoxville, TN 37901; and the Clemson Tester (no longer available) have
been found satisfactory for this purpose.
Available from J. M. Doebrich and Co., P. O. Box 2789, Tucson, AZ 85702.
D 2524 – 95 (2008)
6.3.1 Clamps, having a total thickness of 0.465 6 0.001 in. (11.8 6 0.03 mm) and a 0.125 6 0.001-in. (3.2 6 0.03-mm) spacer.
6.3.2 Clamp Vise, with a device to indicate approximately 8 lbf·in. (0.9 N·m) torque.
6.3.3 Clamp Wrench.
6.4 Coarse Comb, approximately 8 teeth per in. (3 per 10 mm).
6.5 Fine Comb, approximately 50 teeth per in. (20 per 10 mm).
6.6 Black Paper, to hold bundles.
6.7 Shearing Knife or Razor Blade .
6.8 Tweezers.
6.9 Torque Wrench or Friction Disk Wrench, to indicate approximately 8 lbf·in. (0.9 N·m) torque (optional).
6.10 Standard Wool Top Sample , having an assigned breaking tenacity of 11.4 gf/tex (112 mN/tex).
NOTE 4—The standard wool top sample, USDA Lot 58-27, has a breaking tenacity (based on single fiber tests) of 11.4 6 0.6 gf/tex, at the 95 %
probability level.
7. Sampling
7.1 Division into Lots—Treat a single shipment of a single fiber type as a lot.
7.2 Lot Sample—As a lot sample for acceptance testing, take at random the number of shipment containers directed in an
applicable material specification or other agreement between the purchaser and the supplier, such as an agreement to use Practice
D 2525. Consider shipping containers to be the primary sampling units.
7.3 Laboratory Sample—For acceptance testing, take a laboratory sample from each shipping container in the lot sample as
follows:
7.3.1 For loose fiber, grease, and scoured wool, reduce the mass of clean fiber submitted for testing to approximately 15 g by
randomly selecting pieces throughout the mass. Form into a loose sliver by hand.
7.3.2 For card sliver and top, cut a length of sliver about 20 in. (500 mm) long from each ball submitted for testing.
7.3.3 For roving, cut a length about 20 in. (500 mm) long from each spool submitted for testing and include all ends.
7.4 Test Specimens—Scour or solvent-extract the laboratory sample until residual contamination is 1 % or less of the laboratory
mass, as established by further cleaning of a part of the laboratory sample. From each unit in the laboratory sample, prepare five
test specimens as directed in 10.1.
8. Preparation, Calibration, and Verification of Apparatus
8.1 Tensile Testing Machine—Check the calibration of the instrument according to the manufacturer’s instruction.
8.2 Balance—Check the zero reading and the sensitivity in the range to be used.
9. Preconditioning and Conditioning
9.1 Bring the laboratory sample to moisture equilibrium for testing in the standard atmosphere for testing as directed in Practice
D 1776.
10. Preparation of Specimens
10.1 Prepare each specimen by drawing small groups of fibers from at least five locations in a unit of the laboratory sample.
Parallelize and combine them in a bundle which may be held conveniently between the thumb and forefinger. Depending on fiber
entanglement, take a sufficient number of fibers so that, after combining, an aligned specimen of 2 to 6 mg is available for testing.
10.2 Grasp the tuft about one-fourth the distance from the end of the tuft with the thumb and forefinger or a fiber hand vise
and comb the protruding end with the coarse comb to remove loose fibers and foreign material and to secure partial parallelization
of the fibers. Reverse the tuft and repeat the combing on the other end.
10.3 Grasp the partially parallelized tuft at both ends using the fingers of one hand, thumb and ring finger holding one end and
middleandindexfingersholdingtheotherend.Completetheparallelizationofthefibersinthetuftbycombingwiththefinecomb;
with each pass of the comb release the end of the tuft toward which the comb is moving and grasp again immediately after the
comb passes the holding position. To avoid moisture transfer from fingers to fibers, do not handle the middle section of the tuft.
If the specimen is estimated to be too heavy, remove fibers during the combing operation from either side with the tip of the comb
to obtain the correct specimen size. The specimen is now ready to be placed in the clamps.
11. Procedure
11.1 Test the conditioned specimens in the standard atmosphere for testing.
Available from J. M. Doebrich and Co., P. O. Box 2789, Tucson, AZ 85702.
Available from the Wool and Mohair Laboratory, Livestock and Seed Division, AMS, U.S. Department of Agriculture, 711 “O” Street, Greeley, CO 80631.
Available from the Wool and Mohair Laboratory, Livestock and Seed Division, AMS, U.S. Department of Agriculture, 711 “O” Street, Greeley, CO 80631.
The hand vise supplied with the Suter Sorter wool fiber stapling apparatus is suitable for this purpose.Available from theAlfred Suter Co., Inc., Prel Plaza, Orangeburg,
NY 10962.
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