ASTM D2594-2004 Standard Test Method for Stretch Properties of Knitted Fabrics Having Low Power《低弹针织品弹性的标准试验方法》.pdf

1、Designation: D 2594 04Standard 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 year of last revis

2、ion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 forapplications requirin

3、g 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 stretchproperti

4、es.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, theinch-pound units are shown in parentheses. The values statedin eac

5、h 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 its use. It is

6、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 Relating to TextilesD 1776 Practice for Conditioning and Testing T

7、extilesD 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 FabricsWoven from Stretch YarnsD 4849 Terminology Relating to Yarns and Fibe

8、rsD 4850 Terminology Relating to FabricD 6614 Test Method for Stretch Properties of TextileFabrics-CRE Method3. Terminology3.1 Definitions:3.1.1 For definition of textile terms used in this test method:bench marks, refer to Terminology D 4849.3.1.2 For definitions of textile terms used in this testm

9、ethod: 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 GrowthBench marks of a known distance aremade on a fabric specimen. A s

10、pecified 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 interval. The fabric growth is calculated fromthe length difference

11、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 specimen by a prescribed cycling technique and theresulting distance

12、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 specifies test conditions for measuringthe fabric growth and fabric str

13、etch of knitted fabrics intendedfor use in swimwear, anchored slacks, 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 (a

14、lso commonly known as comfortstretch apparel) applications. The applicability of this test1This 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 Dec. 1, 2004. Publish

15、ed January 2005. Originallyapproved in 1969. Discontinued November 1997 and reinstated as D 2594 99.Last previous edition approved in 1999 as D 2594 99a2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMSta

16、ndards 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 19428-2959, United States.method to the measurement of fabric growth and fabric stretchof knitted fabrics intended for u

17、se 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 differences of practical significance be-tween reported test results for tw

18、o 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 possible, are drawn from the materialfrom which the disparate test resu

19、lts 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 the testing series. If a bias isfound, either its cause must be fo

20、und 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 testing.6.2 Hanger Assembly3, consisting of hangers, hanger rods,an

21、d 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 Tensiometer or Weights3, that can be attached to thebottom hanger of the

22、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 marks on thespecimen.6.7 Timer, with increments of at least 1 min.7.

23、 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 at least one full-width piece of fabric thatis2m(2yd)inlength alo

24、ng 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 course-wise (widthwise)test specimens 125 6 3mm(56 0.1 in.) by 500

25、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 positionsdiagonally across the width of the laboratory sampling unit.

26、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 fabric widths less than 125 mm (5 in.), use theentire width of th

27、e 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 specimensare a representative sampling of the pattern.7.3.5 After cutting

28、, 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 surface and place benchmarks 125 6 3mm(56 0.01 in.) apart on the cent

29、ral sectionof 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 as3This equipment is available commercial

30、ly.FIG. 1 Hanger AssemblyD2594042directed in Practice D 1776, or if applicable, 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 spe

31、cimens in the standard atmosphere fortesting textiles, as described in Practice 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

32、 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 Attach the rule to the specimen loop by inserting therule pin hook through the

33、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 bench markslines up with the specified percentage stretch point on the scale.NOTE

34、 2If the scale is in units of measurement, it is helpful tocalculate the corresponding 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 rema

35、in 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 the rule to the nearest 1 % of originalgage length or 1 mm (116 in.) after rec

36、overy 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 until three specimens for each the wale andcourse directions have been tested

37、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 the specimen loop by cycling four timesbetween 0 to 2.27 kgf (0 to 5 lbf) for

38、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 can be usedin place of the tensiometer.NOTE 3The choice of the cycling force shou

39、ld 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 conditions.10.4.3 Continue and begin a fifth cycle holding the tensi-ometer at the

40、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 measurement (D).10.4.4 Remove the tested specimens, in turn, and continueas directed in

41、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 growth and fabric stretchdirectly from the scale to the nearest 1 %, otherwise, u

42、se 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 1003BA!/A (1)Fabric Growth1h,%5 100 3CA!/A (2)Fabric Stretch, % 5 100 3DA!/A (3)where:A = original distance between

43、 bench marks prior to tensionforce, mm (in.) (from 7.3.6),B = distance between 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

44、 10.3.9.2), andD = distance between 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

45、 the average of two specimens to the 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 D 2594. Describe thematerial or product s

46、ampled 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.TABLE 1 Specimen Stretch Percentage PointsApparel Type Wale Direction Course DirectionLoose-fitting (comfort stretch

47、) 15 30Form-fitting (semi-support) 35 60D259404312.2.1 Individual 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 fab

48、ric 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 the respective number of tests in 95 out of 100cases when all the observations are taken by the sam

49、ewell-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 waleand course direction using Test Method D 2594. The precisionstatement is based upon a testing pl