1、Designation: D2594 04 (Reapproved 2016)Standard Test Method forStretch Properties of Knitted Fabrics Having Low Power1This standard is issued under the fixed designation D2594; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar 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.1. Scope1.1 This test method covers the measurement of fabricstretch and fabric growth of knitted fabrics intended forapplic
3、ations requiring low-power stretch properties.1.2 This test method includes procedures for fabric growthand stretch and can be used individually when required byindividual specifications.1.3 This test method is not applicable to fabrics intended forsupport or other applications requiring high-power
4、stretchproperties.NOTE 1For information on testing high-power and woven stretchfabrics, refer to Test Methods D3107 and D6614.1.4 The values stated in either SI or inch-pound units are tobe regarded separately as the standard. Within the text, theinch-pound units are shown in parentheses. The values
5、 statedin each system are not exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in nonconformancewith the specification.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with it
6、s use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1776 Practice for Conditioning an
7、d Testing TextilesD2904 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Normally Distributed Data (With-drawn 2008)3D2906 Practice for Statements on Precision and Bias forTextiles (Withdrawn 2008)3D3107 Test Methods for Stretch Properties of Fabrics Wo-ven from Stretch Yar
8、nsD4849 Terminology Related to Yarns and FibersD4850 Terminology Relating to Fabrics and Fabric TestMethodsD6614 Test Method for Stretch Properties of Textile Fabrics CRE Method3. Terminology3.1 Definitions:3.1.1 For definition of textile terms used in this test method:bench marks, refer to Terminol
9、ogy D4849.3.1.2 For definitions of textile terms used in this testmethod: fabric growth; fabric stretch; low-power stretch andtension, refer to Terminology D4850.3.1.3 For definitions of other textile terms used in this testmethod, refer to Terminology D123.4. Summary of Test Method4.1 Fabric Growth
10、Bench marks of a known distance aremade on a fabric specimen. A specified tension is applied to afabric specimen by a prescribed cycling technique. The tensionis removed and after several specific recovery times under zerotension, the distance between the bench marks is remeasuredafter each time int
11、erval. The fabric growth is calculated fromthe length difference between the bench marks prior to appli-cation of the tension and after each respective recovery timeinterval.4.2 Fabric StretchBench marks of a known distance aremade on a fabric specimen. A specified tension is applied to afabric spec
12、imen by a prescribed cycling technique and theresulting distance between the bench marks measured. The1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.59 on Fabric Test Methods,General.Current edition approved July 1, 2
13、016. Published July 2016. Originally approvedin 1969. Last previous edition approved in 2012 as D2594 04(2012). DOI:10.1520/D2594-04R16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in
14、formation, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1fabric stretch is calculate
15、d from the length difference betweenthe bench marks prior to application of the tension and underwhile under the tension.5. Significance and Use5.1 This test method specifies test conditions for measuringthe fabric growth and fabric stretch of knitted fabrics intendedfor use in swimwear, anchored sl
16、acks, and other form-fittingapparel (also commonly known as semi-support apparel)applications, as well as test conditions for measuring the fabricgrowth of knitted fabrics intended for use in sportswear andother loose-fitting apparel (also commonly known as comfortstretch apparel) applications. The
17、applicability of this testmethod to the measurement of fabric growth and fabric stretchof knitted fabrics intended for use in slacks, sport coats, andsuits has not been determined.5.2 This test method is not recommended for acceptancetesting of commercial shipment because the between-laboratory prec
18、ision is known to be poor.5.2.1 If there are differences of practical significance be-tween reported test results for two laboratories (or more),comparative tests should be performed to determine if their isa statistical bias between them, using competent statisticalassistance. As a minimum, ensure
19、the test samples to be usedare as homogeneous as possible, are drawn from the materialfrom which the disparate test results are obtained, and areassigned randomly in equal numbers to each laboratory fortesting. The test results from the two laboratories should becompared using a statistical test for
20、 unpaired data, at aprobability level chosen prior to the testing series. If a bias isfound, either its cause must be found and corrected, or futuretest results for that material must be adjusted in considerationof the known bias.6. Apparatus6.1 Frame, suitable for supporting the hanger assemblyillu
21、strated in Fig. 1 and tension forces applied during testing.6.2 Hanger Assembly, consisting of hangers, hanger rods,and chain.6.3 Lightweight Rule, fitted with a pin hook at the zero pointof the scale for attachment to the specimen, graduated either inunits of percent of original gage length of 125
22、mm (5 in.) or inunits of 1 mm (116 in.).6.4 Tensiometer or Weights, that can be attached to thebottom hanger of the hanger assembly, capable of providingtotal tensions of 2.27 kgf (5 lbf) and 4.54 kgf (10 lbf) to thespecimen, 6 1%.6.5 Turnbuckle, or equivalent, having a length of 25 to 75mm (1 to 3
23、in.).6.6 Sanforized Marker, to establish bench marks on thespecimen.6.7 Timer, with increments of at least 1 min.7. Sampling and Test Specs7.1 Primary Sampling UnitConsider rolls of fabric orfabric components of fabricated systems to be the primarysampling unit, as applicable.7.2 Laboratory Sampling
24、 UnitAs a laboratory samplingunit take from rolls at least one full-width piece of fabric thatis2m(2yd)inlength along the selvage (machine direction),after removing a first 1 mm (1 yd) length. For fabric compo-nents of fabricated systems use the entire system.7.3 Test SpecimensFrom each laboratory s
25、ampling unit,cut 5 wale-wise (lengthwise) and 5 course-wise (widthwise)test specimens 125 6 3mm(56 0.1 in.) by 398 6 10 mm(15.5 6 0.3 in.). Cut the long dimension of the wale-wisespecimens parallel to the wale direction and the course-wisespecimens parallel to the course direction. Take specimensrep
26、resenting a broad distribution from different positionsdiagonally across the width of the laboratory sampling unit.Consider the long direction as the direction of test. Label tomaintain specimen identity.7.3.1 For fabric widths 125 mm (5 in.) or more, take nospecimen closer than 25 mm (1 in.) from t
27、he edges of thelaboratory sampling unit.7.3.2 For fabric widths less than 125 mm (5 in.), use theentire width of the laboratory sampling unit for specimens.FIG. 1 Hanger AssemblyD2594 04 (2016)27.3.3 Ensure specimens are free of folds, creases, orwrinkles. Avoid getting oil, water, grease, etc., on
28、the speci-mens when handling.7.3.4 If the fabric has a pattern, ensure that the specimensare a representative sampling of the pattern.7.3.5 After cutting, fold each specimen in half lengthwiseforming a loop and sew the edges opposite the fold together 6to 13 mm (0.25 to 0.50 in.) from the cut edges
29、and parallel tothe short direction of the specimen.7.3.6 Lay the specimen on a flat surface and place benchmarks 125 6 3mm(56 0.01 in.) apart on the central sectionof one face of the looped specimen establishing a gage lengthalong the length of the specimen. Record as measurement (A).8. Conditioning
30、8.1 Bring the test specimens to moisture equilibrium fortesting in the standard atmosphere for testing textiles asdirected in Practice D1776, or if applicable, in the specifiedatmosphere in which the testing is to be performed.9. Preparation of Test Apparatus and Calibration9.1 Verify measuring scal
31、es and tension weights are withincalibration.10. Procedure10.1 Test the test specimens in the standard atmosphere fortesting textiles, as described in Practice D1776.10.2 Handle the test specimens carefully to avoid alteringthe natural state of the material.10.3 Fabric Growth:10.3.1 Slide the specim
32、en loop over the upper hanger rodand secure the rod in the hanger such that the seam of the looplies along the rod.10.3.2 Slide the folded end of the loop over the lowerhanger rod and secure the rod to the hanger.10.3.3 Place the upper hanger in the slot in the top bar of thesupporting frame.10.3.4
33、Attach the rule to the specimen loop by inserting therule pin hook through the face of the fabric in the center of theupper bench mark.10.3.5 Attach the chain by means of the turnbuckle to thelower hanger and extend the specimen loop to the amountspecified in Table 1, that is, such that the lower be
34、nch markslines up with the specified percentage stretch point on the scale.NOTE 2If the scale is in units of measurement, it is helpful to calculatethe corresponding percentage.10.3.6 Lock the chain in the corresponding notch in thelower crossmember of the frame. Adjust the turnbuckle tomake minor a
35、djustments of the position of the lower benchmark.10.3.7 Allow the loop to remain in the extended position for2h6 5 min.10.3.8 After 2 h 6 5 min, unlock and release the chain andremove the lower hanger from the specimen loop.10.3.9 Measure the position of the lower bench markrelative to the scale on
36、 the rule to the nearest 1 % of originalgage length or 1 mm (116 in.) after recovery under no tensionas follows:10.3.9.1 After 60 6 5 s and record as measurement (B), and10.3.9.2 After 1 h 6 5 min record as measurement (C).10.3.10 Remove the tested specimens, in turn, and continueas directed in 10.3
37、 until three specimens for each the wale andcourse directions have been tested for each laboratory samplingunit.10.4 Fabric Stretch:10.4.1 Place a new specimen in the stretch testing equip-ment as directed in 10.3.1 10.3.4.10.4.2 Attach the tensiometer to the lower hanger, grasp andmanually exercise
38、 the specimen loop by cycling four timesbetween 0 to 2.27 kgf (0 to 5 lbf) for loose-fitting (comfortstretch) apparel fabrics, or between 0 and 4.54 kgf (0 and 10lbf) for form-fitting (semi-support) apparel fabrics allowing 4to6stocomplete each cycle.10.4.2.1 Weights that provide the same tension ca
39、n be usedin place of the tensiometer.NOTE 3The choice of the cycling force should be based on theintended end use of the fabric being tested. If the intended end use is notknown, the fabric growth and fabric stretch may be determined using boththe loose-fitting and the form-fitting apparel test cond
40、itions.10.4.3 Continue and begin a fifth cycle holding the tensi-ometer at the specified tension force for 5 to 10 s, then measurethe position of the lower bench mark relative to the scale on therule to the nearest 1 % of original gage length or 1 mm (116 in.)while under tension. Record as measureme
41、nt (D).10.4.4 Remove the tested specimens, in turn, and continueas directed in 10.4 until two specimens for each the wale andcourse directions have been tested for each laboratory samplingunit.11. Calculation11.1 If the scale is graduated in percent of original gagelength, read the percent fabric gr
42、owth and fabric stretchdirectly from the scale to the nearest 1 %, otherwise, use thecalculations in 11.1.1.11.1.1 Calculate the fabric growth and fabric stretch prop-erties of individual specimens to the nearest 1 % using Eq 1-3,as applicable.Fabric Growth60s,%5 100 3 B 2 A!/A (1)Fabric Growth1h,%5
43、 100 3 C 2 A!/A (2)Fabric Stretch, % 5 100 3 D 2 A!/A (3)where:A = original distance between bench marks prior to tensionforce, mm (in.) (from 7.3.6),B = distance between bench marks, mm (in.) measured afterrelease of the tension, force following 60 s recovery,(from 10.3.9.1),TABLE 1 Specimen Stretc
44、h Percentage PointsApparel Type Wale Direction Course DirectionLoose-fitting (comfort stretch) 15 30Form-fitting (semi-support) 35 60D2594 04 (2016)3C = distance between bench marks, mm (in.) measured afterrelease of the tension, force following 1 h recovery,(from 10.3.9.2), andD = distance between
45、bench marks, mm (in.) measuredwhile specimen is under tension force (from 10.4.3).11.2 Calculate the average of three specimens to the nearest1 % for the fabric growth calculated in 11.1 for the laboratorysampling unit and for the lot, as applicable.11.3 Calculate the average of two specimens to the
46、 nearest1 % for the fabric stretch calculated in 11.1 for the laboratorysampling unit and for the lot, as applicable.12. Report12.1 Report that the fabric growth and fabric stretch weredetermined as directed in Test Method D2594. Describe thematerial or product sampled and the method of sampling use
47、d.12.2 Report the following information for the laboratorysampling unit and for the lot as applicable to a materialspecification or contract order.12.2.1 Individual and average fabric growth after 60 srecovery.12.2.2 Individual and average fabric growth after 1 hrecovery.12.2.3 Individual and averag
48、e fabric stretch.12.2.4 Original distance between bench marks.12.2.5 Percent extension used for fabric growth.12.2.6 Tension used for fabric stretch.13. Precision and Bias13.1 SummaryIn comparing two averages, the differencesshould not exceed the single-operator precision values shownin Table 2 for
49、the respective number of tests in 95 out of 100cases when all the observations are taken by the samewell-trained operator using the same piece of equipment andspecimens randomly drawn from the sample of material.Larger differences likely are to occur under all other circum-stances.13.2 Interlaboratory Test Data4An interlaboratory testwas run in 19661967, in which randomly-drawn samples ofsix materials were tested in each of six laboratories. Eachlaboratory tested three specimens for fabric growth and twospecimens for fabric stretch on each material in both the
