1、Designation: D 4032 94 (Reapproved 2001)Standard Test Method forStiffness of Fabric by the Circular Bend Procedure1This standard is issued under the fixed designation D 4032; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 of last revision. 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 determination of the stiff-ness of fabrics by the circular bend procedure.1.2 This te
3、st method is generally applicable to all types offabrics, including woven, knitted and nonwovens, of any fibercontent.NOTE 1For other methods of testing for stiffness, refer to TestMethods D 1388.1.3 The values stated in SI units are to be considered asstandard; the values in inch-pound units are in
4、cluded forinformation only.1.4 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 the applica-bility of regulatory limitations p
5、rior to use.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 1388 Test Methods for Stiffness of FabricsD 1776 Practice for Conditioning Textiles for Testing3. Terminology3.1 Definitions:3.1.1 circular bend, nsimultaneous, multidirectional de-formation of a fabric in
6、 which one face of a flat specimenbecomes concave and the other becomes convex.3.1.2 stiffness, nresistance to bending.3.1.3 stiffness, nwith regard to the circular bending oftextiles, resistance to multidirectional bending.3.2 For definitions of other textile terms used in this method,refer to Term
7、inology D 123.4. Summary of Test Method4.1 A plunger forces a flat, folded swatch of fabric throughan orifice in a platform. The maximum force required to pushthe fabric through the orifice is an indication of the fabricstiffness (resistance to bending).5. Significance and Use5.1 Test Method D 4032
8、for testing stiffness of fabrics isconsidered satisfactory for quality control testing. It may alsobe used for acceptance testing of commercial shipments sincethe test method has been used extensively in the trade field. Incases of differences in values reported by purchaser and sellerusing Test Met
9、hod D 4032 for acceptance testing, the statisticalbias, if any, between the laboratories of the purchaser and theseller should be determined with each comparison being basedon the testing of specimens taken homogeneously from a lot ofmaterial of the type being evaluated. Specimens should berandomly
10、assigned in equal numbers to each of the laborato-ries.5.2 The circular bend procedure gives a force value relatedto fabric stiffness, simultaneously averaging stiffness in alldirections. The stiffness tests in Test Methods D 1388 are of thesingle directional type.5.3 The circular bend procedure is
11、simple to perform andmay be used for knitted, woven, or nonwoven fabrics, providedgage capacity is in keeping with fabric range tested.6. Apparatus6.1 Circular Bend Stiffness Tester,3(Figs. 1 and 2), havingthe following parts:6.1.1 Platform,102by102by6mm(4by4by14 in.)smooth-polished chrome-plated st
12、eel plate with a 38.1-mm(1.50-in.) diameter orifice. The lap edge of the orifice should beat a 45 angle to a depth of 4.8 mm (316 in.) (see Fig. 3).6.1.2 Plunger, 25.4-mm (1.00-in.) diameter, mounted con-centric with orifice, 6.4 mm (0.25 in.) clearance on all sides.The bottom of the plunger should
13、be set at 3 mm (18 in.) abovethe top of the orifice plate. From this position, the downwardstroke length is 57 mm (214 in.).1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,Specific.Current edi
14、tion approved Jan. 15, 1994. Published April 1994. Originallypublished as D 4032 81. Last previous edition D 4032 93.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to
15、 the standards Document Summary page onthe ASTM website.3Available from J. A. King and Co., Inc., 2620 High Point Road, Greensboro,NC 27420.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.3 Force-Measurement Gage, dial or digital
16、 type (see9.3).6.1.3.1 Dial gages with maximum reading pointer in differ-ent capacities ranging from 1 to 50 lbf, 0.5 to 25 kgf, or 5 to200 N with 100 graduations minimum; or6.1.3.2 Digital gage with maximum reading “hold” featureand capacity of 100 lbf, 50 kgf, or 500 N, with 1000graduations minimu
17、m.6.1.4 Actuator, manual or pneumatic.6.2 Specimen Marking Template, (102 by 204 mm) 4.0 by8.0 in.6.3 Stop Watch, for checking stroke speed.7. Sampling7.1 Lot SizeFor sampling purposes, a lot is defined as asingle shipment of a single style of fabric. A lot may constituteall or part of a single cust
18、omer order.7.2 Lot SampleAs a lot sample for acceptance testing;take at random the number of rolls of fabric 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 specificat
19、ion or other agreement between thepurchaser and the supplier requires taking into account the variabilitybetween rolls of fabric and between specimens from a swatch from a rollof fabric to provide a sampling plan with a meaningful producers risk,consumers risk, acceptable quality level, and limiting
20、 quality level.7.3 Laboratory SampleAs a laboratory sample for accep-tance testing, take a full swatch1m(1yd)long from the endof each roll of fabric in the lot sample, after first discarding aminimum of1m(1yd)offabric from the very outside of therolls.8. Number and Preparation of Test Specimens8.1 U
21、sing the specimen marking template specified in 6.2,mark and cut five test specimens from staggered areas of eachswatch in the laboratory sample. The short side of the specimenmust be parallel to the machine (length) direction of the fabric.Cut no specimens closer to the selvage than one tenth of th
22、efabric width. Lay each specimen face down and fold thespecimen once to form a square 4 by 4 in. (102 by 102 mm).After folding, use the template and hand pressure to flatten thecrease. Handling of specimens must be kept to a minimum andto the edges to avoid affecting stiffness properties.NOTE 3When
23、otherwise agreed upon, as when specified in anapplicable material specification, the purchaser and the seller may changethe number of test specimens per swatch from the laboratory sample.NOTE 4Fabrics may also be tested face-to-face when the technicalFIG. 1 King Manual Operated Dial ModelD 4032 94 (
24、2001)2back is used for the outer surface or when there are significant differencesin face and back surface properties. In reporting, indicate that the fabricwas tested face-to-face.9. Conditioning9.1 Bring the specimens to moisture equilibrium, as directedin Practice D 1776.10. Procedure10.1 Test th
25、e adequately conditioned specimens in thestandard atmosphere for testing textiles which is 21 6 1C(706 2F) and 65 6 2 % relative humidity.10.2 Set the tester on a flat surface with dial at eye level.FIG. 2 King Air Operated Digital ModelFIG. 3 Platform and PlungerD 4032 94 (2001)310.3 Select a gage
26、with a capacity in which results will fallwithin 15 to 100 % of dial gage force or 1.5 to 100 % of digitalgage force.10.4 Check tester plunger speed control for full strokelength.10.4.1 Pneumatic ActuatorSet the air pressure control tothe actuator at 324 kPa (47 psi). Using a stop-watch, adjust thep
27、neumatics to provide plunger speed of 1.7 6 0.15 s under noload conditions.10.4.2 Manual ActuatorUsing a stop-watch, establish andconfirm a plunger speed of 1.7 6 0.3 s.NOTE 5The use of the pneumatic actuated tester gives a morecontrolled result than the manual actuated tester which is subject toope
28、rator variances in the speed at which the plunger is operated (see Table1 and Table 2).10.5 Center a double-ply specimen on the orifice platformbelow the plunger.NOTE 6If 3.2 mm (18 in.) clearance under plunger prevents ease ofentry of specimen due to fabric thickness, the clearance may be increased
29、to 6.3 mm (14 in.) maximum. In reporting, the results should indicate theplunger clearance, if not standard.10.6 Check the gage zero and adjust, if necessary.10.7 Set the maximum force reading switch.10.8 Actuate the plunger for the full stroke length. Avoidtouching the specimen during testing.10.9
30、Record maximum force reading to nearest gage gradu-ation.10.10 Continue as directed in 10.5-10.9, until all specimenshave been tested.11. Calculation11.1 Average the individual specimen readings and round tothe nearest gage increment.12. Report12.1 State that the specimens were tested as directed in
31、 TestMethod D 4032. Describe the material or product sampled, andthe method of sampling used.12.2 Report the following information:12.2.1 Average force in gage units.12.2.2 Number of specimens tested.12.2.3 Actuator type.12.2.4 Gage type and capacity.12.2.5 How fabric was folded, if not standard (ba
32、ck-to-back).12.2.6 Plunger clearance, if not standard 3.2 mm (18 in.).13. Precision and Bias13.1 Interlaboratory Test DataAn interlaboratory test wasconducted in 1979 in which 29 laboratories each tested 5specimens from 3 different fabrics. Eleven laboratories usedpneumatic actuated testers and 18 l
33、aboratories used manual.The first fabric was a 153 g/m2(412 oz/yd2) “pocketing,” 65 %polyester and 35 % cotton. The second was a 339 g/m2(10oz/yd2) broken twill, 50 % polyester and 50 % cotton. Thethird was a 492 g/m2(1412 oz/yd2) 100 % cotton denim. Allspecimens were cut at one laboratory from the
34、three fabricsamples. Each laboratory had one operator test each material.The critical differences for stiffness based on all laboratoriesare as specified in Table 2. The critical differences for stiffnesscomparing pneumatic versus manual actuated testers are speci-fied in Table 3.13.2 PrecisionFor t
35、he critical differences reported in 13.1,two averages of observed values should be considered signifi-cantly different at the 95 % probability level if the differenceequals or exceeds the critical differences listed in Table 2 andTable 3.13.3 BiasThe procedure in Test Method ASTM D 4032has no bias b
36、ecause the value of stiffness of fabric by thecircular bend procedure is defined in terms of this test method.14. Keywords14.1 fabric; stiffnessTABLE 1 Number of Fabric RollsIn Lot In Lot Sample1to10 111 to 20 221 to 30 331 to 40 441 or more 5D 4032 94 (2001)4ASTM International takes no position res
37、pecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This
38、standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Intern
39、ational Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown be
40、low.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555
41、 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 2 Stiffness Critical Differences (Summary of all Laboratories and Tester Models) (95 % Confidence Limits)Fabric TypeNumber ofObserva-tions in EachAverageAverage Stiffness, N(lbf)Critical Differences, N (lbf)Within-L
42、abo-ratory Preci-sionBetween Labo-ratory Preci-sion153 g/m2(412 oz/yd2) pocketing 3 6.2 (1.4) 5.3 (1.2) 7.6 (1.7)5 6.2 (1.4) 4.4 (1.0) 7.1 (1.6)339 g/m2(10 oz/yd2) twill 3 25.4 (5.7) 10.2 (2.3) 22.7 (5.1)5 24.9 (5.6) 10.2 (2.3) 21.4 (4.8)492 g/m2(1412 oz/yd2) denim 3 69.4 (15.6) 27.1 (6.1) 28.9 (6.5
43、)5 68.9 (15.5) 27.6 (6.2) 28.5 (6.4)TABLE 3 Stiffness Critical Differences (Air Tester versus Manual Tester) (95 % Confidence Limits)Fabric TypeNumber ofObservationsin eachAverageAverage Stiffness, N (lbf) Critical Differences, N (lbf)Air ManualWithin-LaboratoryPrecisionBetween-LaboratoryPrecisionAi
44、r Manual Air Manual153 g/m2(412 oz yd2) 3 6.2 (1.4) 6.7 (1.5) 53 (1.2) 4.9 (1.1) 2.7 (0.6) 9.3 (2.1)pocketing 5 5.8 (1.3) 6.7 (1.5) 4.4 (1.0) 4.9 (1.1) 2.7 (0.6) 8.9 (2.0)339 g/m2(10 oz/yd2) twill 3 21.4 (4.8) 27.6 (6.2) 9.3 (2.1) 10.7 (2.4) 11.6 (2.6) 25.4 (5.7)5 21.4 (4.8) 26.7 (6.0) 8.0 (1.8) 10.7 (2.4) 10.2 (2.3) 24.5 (5.5)492 g/m21412 oz/yd23 66.3 (14.9) 71.2 (16.0) 24.0 (5.4) 28.9 (6.5) 26.2 (5.9) 30.2 (6.8)denim 5 67.2 (15.1) 69.8 (15.7) 27.1 (6.1) 27.6 (6.2) 21.8 (4.9) 25.8 (5.8)D 4032 94 (2001)5
