1、Designation: D 4964 96 (Reapproved 2008)1Standard Test Method forTension and Elongation of Elastic Fabrics (Constant-Rate-of-Extension Type Tensile Testing Machine)1This standard is issued under the fixed designation D 4964; the number immediately following the designation indicates the year oforigi
2、nal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEMinor editorial changes were made throughout in October 2008.1. Scope1.
3、1 This test method covers the measurement of tension andelongation of wide or narrow elastic fabrics made from naturalor man-made elastomers, either alone or in combination withother textile yarns, when tested with a constant-rate-of-extension (CRE) type tensile testing machine.NOTE 1For determinati
4、on of similar testing using the constant-rate-of-load (CRL) type tensile testing machine, refer to Test Method D 1775.1.2 The use of this test method requires the selection of, ormutual agreement upon, loop tension(s) and elongation(s) atwhich the test results will be determined.1.3 Laundering proce
5、dures require mutual agreement on theselection of temperature and number of washing cycles anddrying cycles to be used.1.4 The values stated in SI units or inch-pound units are tobe regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore each systemmu
6、st be used independently of the other, without combiningvalues in any way.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine
7、 the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D76 Specification for Tensile Testing Machines for TextilesD 123 Terminology Relating to TextilesD 1775 Test Method for Tension and Elongation of WideElastic Fabrics3D 1776 Practice for Conditioning
8、 and Testing Textiles3. Terminology3.1 Definitions:3.1.1 constant-rate-of-extension tensile testing machine(CRE), na testing machine in which the rate of increase ofspecimen length is uniform with time.3.1.2 constant-rate-of-load tensile testing machine (CRL),na testing machine in which the rate of
9、increase of the loadbeing applied to the specimen is uniform with time after thefirst 3 s.3.1.3 elastic fabric, na textile fabric made from an elas-tomer either alone or in combination with other textile mate-rials.3.1.4 elongation, nthe ratio of the extension of a materialto the length of the mater
10、ial prior to stretching.3.1.5 extension, nthe change in length of a material due tostretching.3.1.6 extension-recovery cycle, nin tension testing, thecontinuous extension of a specimen, with a momentary hold ata specified extension, followed by a controlled rate of return tozero extension.3.1.7 forc
11、e, na physical influence exerted by one body onanother which produces acceleration of bodies that are free tomove and deformation of bodies that are not free to move.3.1.8 loop tension, n in elastic material testing, the totaltension at any specified extension that is exerted on a specimenin a loop
12、formation.3.1.9 narrow elastic fabric, nan elastic fabric that is lessthan 150 mm or 6 in. wide.3.1.10 tension, na uniaxial force tending to cause thestretching of a material.1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee
13、 D13.59 on Fabric Test Methods,General.Current edition approved July 1, 2008. Published October 2005. Originallyapproved in 1989. Last previous edition approved in 2004 as D 4964 96(2004).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service
14、astm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consho
15、hocken, PA 19428-2959, United States.3.1.11 tension-recovery chart, n in tension testing,acontinuously plotted graph of tension versus extension result-ing from a tension-recovery cycle.3.1.12 tension test, n in textiles, a test designed tomeasure the tautness in a textile strand or fabric.3.1.13 wi
16、de elastic fabric, nan elastic fabric that is at least150 mm or 6 in. wide.3.1.14 For definitions of other textile terms used in this testmethod, refer to Terminology D 123.4. Summary of Test Method4.1 Loop Tension at Specified Elongation(s)A condi-tioned loop specimen is mounted in a CRE-type tensi
17、le testingmachine. The specimen is then extended at a specified rate toa specified loop tension, and returned at a specified rate to zerotension. The cycle is repeated two more times to give a total ofthree cycles. During the test, extension-recovery curves may beplotted by an automatic recorder for
18、 all or only the third cycle.The tension at specified percent elongation(s) is calculatedfrom the graph of the third cycle or obtained from theinstrument.4.2 Elongation at Specified Loop TensionA conditionedloop specimen is mounted in a CRE-type tensile testingmachine. The specimen is then loaded at
19、 a specified rate to aspecified loop tension, and unloaded at a specified rate to zeroloop tension. The cycle is repeated two more times to give atotal of three cycles. During the test, tension-recovery curvesmay be plotted by an automatic recorder for all or only the thirdcycle. The elongation at a
20、 specified loop tension is calculatedfrom the graph of the third cycle or obtained from theinstrument.5. Significance and Use5.1 This test method for testing loop tension and elongationof elastic fabrics is considered satisfactory for acceptancetesting of commercial shipments of elastic fabrics beca
21、use thetest method is used in the trade for acceptance testing.5.1.1 In case of a dispute arising from differences inreported test results when using this test method for acceptancetesting of commercial shipments, the parties should conductcomparative tests to determine if there is a statistical bia
22、sbetween their laboratories. Competent statistical assistance isrecommended for the investigation of bias. As a minimum, thetwo parties should take a group of test specimens that are ashomogeneous as possible and that are from a lot of material ofthe type in question. The test specimens should then
23、berandomly assigned in equal numbers to each laboratory fortesting. The average results from the two laboratories should becompared using students t-test for unpaired data and anacceptable probability level chosen by the two parties beforethe testing is begun. If bias is found, either its cause must
24、 befound and corrected or the purchaser and the supplier mustagree to interpret future test results with consideration to theknown bias.5.2 This test method specifies the use of the CRE-typetensile testing machine. Users of this test method are cautionedthat loop tension test data obtained using thi
25、s method are notcomparable to tension test data obtained using Test MethodD 1775 because of the differences in testing machines. TestMethod D 1775 uses a CRL-type tensile testing machine.5.3 The loop tension and extension relationship of an elasticfabric is an important criterion for judging the sui
26、tability of thefabric for various end uses, such as: foundation garments,brassieres, and swimsuits.5.4 Data from loop tension-recovery curves can be com-pared only if the tension testing machine, rate-of-extension,maximum loading (or extension), and specimen specificationsare comparable. Since diffe
27、rent machine set-ups will causedifferent results on the same fabric, machine set-ups mustalways be specified before making a test and be reported withthe test results.5.5 The test for measuring loop tension at specified elonga-tion(s) is used to determine the tension of an elastic fabricwhen subject
28、ed to a specified elongation which is less than theelongation required to rupture the fabric. The test prescribespoints of measurement on the extending (outgoing) cycle only.5.6 The test for measuring elongation at specified tension(s)is used to determine the elongation of an elastic fabric whensubj
29、ected to a specified loop tension which is less than thetension required to rupture the fabric. The test prescribes pointsof measurement on the loading (outgoing) cycle only.6. Apparatus6.1 Tensile Testing Machine, CRE-Type,4conforming toSpecification D76, equipped with an automatic recordingdevice
30、and cycling controls.6.2 Band Clamps, to hold loop specimen during testing. Thediameter of the anvils will be 13.06 0.25 mm (0.5 6 0.01 in.)or 6.56 0.25 mm (0.25 6 0.01 in.). The length of the anvil willnot be less than 76 mm (3.0 in.).6.3 Sewing Machine Single-Needle.7. Sampling7.1 Lot SampleAs a l
31、ot sample for acceptance testing,take at random the number of rolls of fabric as directed in anapplicable material specification or other agreement betweenthe purchaser and the supplier. Consider rolls of fabric to be theprimary sampling units.NOTE 2An adequate specification or other agreement betwe
32、en thepurchaser and the supplier requires taking into account the variabilitybetween rolls of fabric, and the variability between specimens from aswatch from a roll of fabric, to provide a sampling plan with a meaningfulproducers risk, consumers risk, acceptable quality level, and limitingquality le
33、vel.7.2 Laboratory SampleAs a laboratory sample for accep-tance testing, take a full width swatch,2m(2yd)long, fromthe end of each roll of fabric in the lot sample, after firstdiscarding a minimum of1m(1yd)offabric from the veryoutside of the roll.7.3 Test SpecimensTake test specimens as follows:7.3
34、.1 Wide Elastic FabricsIf the purchaser and the sup-plier agree to test the fabric in only one direction, cut five4For additional information on obtaining apparatus, equipment, or supplies thatmay be suitable for use in this standard, please visit the ASTM ManufacturersEquipment Directory at www.ast
35、m.org.D 4964 96 (2008)12specimens from each swatch in the laboratory sample with thelong dimension of the specimens parallel to the direction oftest. If the purchaser and the supplier agree to test the fabric inboth directions, from each full-width swatch in the laboratorysample, cut five specimens
36、parallel to the long dimension andfive specimens perpendicular to the long dimension. Speci-mens should be spaced along a diagonal to allow for represen-tation in each specimen of different warp and filling areas, orwale and course areas. Take no specimens nearer than one tenthof the fabric width fr
37、om the selvage.7.3.2 Narrow Elastic FabricCut five specimens fromeach swatch in the laboratory sample. For narrow knitted orwoven elastic fabrics that are more than 75 mm (3 in.) wide,the purchaser and the supplier may agree to (1) use specimensof the widths specified in 8.1.1 for wide elastic fabri
38、cs ofcomparable construction, or (2) if wide clamps are available,use full-width specimens.8. Preparation of Test Specimens8.1 Cut specimens as directed below:8.1.1 Wide Elastic FabricCut specimens 350 by 100 mm(14 by 4 in.). Trim, or ravel woven fabrics by taking yarnsalternately from the two sides
39、, to a width as near 75 6 2mm(3 6 0.05 in.), as possible. If fabrics are ravelled to obtain thespecimen width, specimens should contain the same number ofyarns in the testing direction.8.1.2 Narrow Elastic FabricCut specimens with the350-mm (14-in.) dimension parallel to the length of the fabric.8.2
40、 Preparation of Loop Specimens Draw two gage markson the specimen which are (1) 250 6 2mm(106 0.05 in.)apart, (2) approximately the same distance from the specimenends, (3) parallel to one another, and (4) perpendicular to thelong direction of the test specimen. Form a loop by folding thespecimen; t
41、hen aligning and sewing a seam along the two gagemarks. Use a single-needle stitch, sewing two rows of stitchingand making certain that the beginning and ending stitches donot come loose.9. Preparation and Verification of Apparatus9.1 Equip and set-up the CRE-type tensile testing machineaccording to
42、 the manufacturers instructions and using thefollowing information:9.1.1 Loop distance around clamps: 250 6 2mm(1060.05 in.).9.1.2 Loading crosshead speed: 500 6 15 mm/min (20 60.5 in./min).9.1.3 Unloading crosshead speed: 500 6 15 mm/min (20 60.5 in./min).9.1.4 Cycling controls: 100 N (20 lbf) forc
43、e maximum, oras agreed upon. Force must be less than that which will causethe fabric to rupture. For low elongation fabrics (below100 %), parties should agree to a slower crosshead speed forloading and unloading, such as 300 6 15 mm/min, or 12.0 60.5 in./min.NOTE 3The slower speed is recommended bec
44、ause the recordingdevices may not be able to keep up with the machine at elongations below100 %.9.2 Verification of Position of Clamps:9.2.1 Use one of the procedures described in 9.2.2 through10.2.4 to verify or set the position of the clamps.9.2.2 Use the gage supplied by tensile testing machinema
45、nufacturer.9.2.3 Make and use a paper gage as directed below.9.2.3.1 Cut a strip of flexible paper that measures 275 6 2mm by 106 2 mm, or 11.0 6 0.05 in. by 0.5 6 0.05 in.9.2.3.2 From one end of paper strip, measure a distance of250 6 2 mm, or 10.0 6 0.05 in., and draw a line perpendicularto the lo
46、ng axis.9.2.3.3 Place a strip of double-faced tape across the strip,and on the short end, coincident with the line.9.2.3.4 Curl the untaped end of the strip to form a loop,aligning the end with the 250 mm, or 10 in., line. Press downon the strip, fastening it to the double-faced tape.9.2.3.5 Place t
47、he paper loop around the testing machineclamps with the taped joint between the clamps. See Fig. 1.9.2.3.6 Adjust the clamp spacing until the loop is just snugon the clamp.9.2.3.7 Remove the loop.9.2.3.8 If the anvil diameter is 13 mm (0.5 in.), set the initialanvil spacing so that the distance from
48、 the top of the upperanvil to the bottom of the lower anvil is 118 mm or 4.7 in.9.2.3.9 If the anvil diameter is 6.5 mm (0.25 in.) set theinitial anvil setting so that the distance from the top of theupper anvil to the bottom of the lower anvil is 121 mm or 4.9in.NOTE 4The anvil spacing in 9.2.3.8 a
49、nd 9.2.3.9 will provide a loopcircumference of 250 mm or 10 in.10. Conditioning10.1 Before making any tests for loop tension or stretch,bring the samples to moisture equilibrium for testing in thestandard atmosphere for testing textiles, which is 21 6 1C(70 6 2 F) and 65 6 2 % relative humidity.Allow the samplesto relax, free of loop tension, for a minimum of 16 h. Afterexposure for this time, it may be assumed that moistureequilibrium has been reached. See Practice D 1776 for standardconditions for testing textile materials.FIG. 1 Loop Specimen
