1、Designation: D 2594 04 (Reapproved 2008)1Standard Test Method forStretch Properties of Knitted Fabrics Having Low Power1This standard is issued under the fixed designation D 2594; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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.1NOTEEditorial changes were made in August 2008.1. Scope1.1 This test method covers the measurement of fabricstretch and
3、fabric growth of knitted fabrics intended forapplications 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 for
4、support or other applications requiring high-power stretchproperties.NOTE 1For information on testing high-power and woven stretchfabrics, refer to Test Methods D 3107 and D 6614.1.4 The values stated in either SI or inch-pound units are tobe regarded separately as the standard. Within the text, the
5、inch-pound units are shown in parentheses. The values 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
6、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 the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology
7、Relating to TextilesD 1776 Practice for Conditioning and Testing TextilesD 2904 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Normally Distributed DataD 2906 Practice for Statements on Precision and Bias forTextilesD 3107 Test Methods for Stretch Properties of FabricsWov
8、en from Stretch YarnsD 4849 Terminology Related to Yarns and FibersD 4850 Terminology Relating to FabricD 6614 Test Method for Stretch Properties of Textile Fab-rics CRE Method3. Terminology3.1 Definitions:3.1.1 For definition of textile terms used in this test method:bench marks, refer to Terminolo
9、gy D 4849.3.1.2 For definitions of textile terms used in this testmethod: fabric growth; fabric stretch; low-power stretch andtension, refer to Terminology D 4850.3.1.3 For definitions of other textile terms used in this testmethod, refer to Terminology D 123.4. Summary of Test Method4.1 Fabric Grow
10、thBench 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 i
11、nterval. 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 sp
12、ecimen by a prescribed cycling technique and theresulting distance between the bench marks measured. Thefabric stretch is calculated 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 spec
13、ifies test conditions for measuringthe fabric growth and fabric stretch of knitted fabrics intendedfor use in swimwear, anchored slacks, and other form-fittingapparel (also commonly known as semi-support apparel)1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the d
14、irect responsibility of Subcommittee D13.59 on Fabric Test Methods,General.Current edition approved July 1, 2008. Published August 2008. Originallyapproved in 1969. Discontinued November 1997 and reinstated as D 2594 99.Last previous edition approved in 2004 as D 2594 04.2For referenced ASTM standar
15、ds, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
16、19428-2959, United States.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 applicability of this testmethod to the measurement of
17、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 precision is known to be poor.5.2.1 If there are difference
18、s 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 the test samples to be usedare as homogeneous as possib
19、le, 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 unpaired data, at aprobability level chosen prior to t
20、he 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 Frame3, suitable for supporting the hanger assemblyillustrated in Fig. 1 and tension forces applied during te
21、sting.6.2 Hanger Assembly3, consisting of hangers, hanger rods,and chain.6.3 Lightweight Rule3, fitted with a pin hook at the zeropoint of the scale for attachment to the specimen, graduatedeither in units of percent of original gage length of 125 mm (5in.) or in units of 1 mm (116 in.).6.4 Tensiome
22、ter or Weights3, 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 Turnbuckle3, or equivalent, having a length of 25 to 75mm (1 to 3 in.).6.6 Sanforized Marker, to establish bench mar
23、ks 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 UnitAs a laboratory samplingunit take from rolls
24、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 sampling unit,cut 5 wale-wise (lengthwise) and 5 co
25、urse-wise (widthwise)test specimens 125 6 3mm(56 0.1 in.) by 500 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 specimensrepresenting a broad distribution from different posi
26、tionsdiagonally 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 the edges of thelaboratory sampling unit.7.3.2 For
27、fabric widths less than 125 mm (5 in.), use theentire width of the laboratory sampling unit for specimens.7.3.3 Ensure specimens are free of folds, creases, orwrinkles. Avoid getting oil, water, grease, etc., on the speci-mens when handling.7.3.4 If the fabric has a pattern, ensure that the specimen
28、sare 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 and parallel tothe short direction of the specimen.7.3.6 Lay the specimen on a flat surf
29、ace and place benchmarks 125 6 3mm(56 0.01 in.) apart on the central section3For additional information on obtaining apparatus, equipment, or supplies thatmay be suitable for use in this standard, please visit the ASTM ManufacturersEquipment Directory at www.astm.org.FIG. 1 Hanger AssemblyD 2594 04
30、(2008)12of one face of the looped specimen establishing a gage lengthalong the length of the specimen. Record as measurement (A).8. Conditioning8.1 Bring the test specimens to moisture equilibrium fortesting in the standard atmosphere for testing textiles asdirected in Practice D 1776, or if applica
31、ble, in the specifiedatmosphere in which the testing is to be performed.9. Preparation of Test Apparatus and Calibration9.1 Verify measuring scales and tension weights are withincalibration.10. Procedure10.1 Test the test specimens in the standard atmosphere fortesting textiles, as described in Prac
32、tice D 1776.10.2 Handle the test specimens carefully to avoid alteringthe natural state of the material.10.3 Fabric Growth:10.3.1 Slide the specimen 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
33、 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 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 c
34、hain 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 bench markslines up with the specified percentage stretch point on the scale.NOTE 2If the scale is in units of measurement, it is helpful tocalculate the co
35、rresponding percentage.10.3.6 Lock the chain in the corresponding notch in thelower crossmember of the frame. Adjust the turnbuckle tomake minor adjustments 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 a
36、nd 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 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 meas
37、urement (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 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 spe
38、cimen 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 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 (
39、0 and 10lbf) for form-fitting (semi-support) apparel fabrics allowing 4to6stocomplete each cycle.10.4.2.1 Weights that provide the same tension can 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 inten
40、ded end use is notknown, the fabric growth and fabric stretch may be determined using boththe loose-fitting and the form-fitting apparel test conditions.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 lowe
41、r 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 measurement (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 t
42、ested for each laboratory samplingunit.11. Calculation11.1 If the scale is graduated in percent of original gagelength, read the percent fabric growth 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
43、stretch prop-erties of individual specimens to the nearest 1 % using Eq 1-3,as applicable.Fabric Growth60s,%5 1003BA!/A (1)Fabric Growth1h,%5 100 3CA!/A (2)Fabric Stretch, % 5 100 3DA!/A (3)where:A = original distance between bench marks prior to tensionforce, mm (in.) (from 7.3.6),B = distance betw
44、een bench marks, mm (in.) measuredafter release of the tension, force following 60 srecovery, (from 10.3.9.1),C = distance between bench marks, mm (in.) measuredafter release of the tension, force following 1 hrecovery, (from 10.3.9.2), andD = distance between bench marks, mm (in.) measuredwhile spe
45、cimen 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 nearest1 % for the fabric stretch calc
46、ulated in 11.1 for the laboratorysampling unit and for the lot, as applicable.TABLE 1 Specimen Stretch Percentage PointsApparel Type Wale Direction Course DirectionLoose-fitting (comfort stretch) 15 30Form-fitting (semi-support) 35 60D 2594 04 (2008)1312. Report12.1 Report that the fabric growth and
47、 fabric stretch weredetermined as directed in Test Method D 2594. Describe thematerial or product sampled and the method of sampling used.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
48、 and average fabric growth after 60 srecovery.12.2.2 Individual and average fabric growth after 2 hrecovery.12.2.3 Individual and average 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 a
49、nd Bias13.1 SummaryIn comparing two averages, the differencesshould not exceed the single-operator precision values shownin Table 2 for 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 e
