1、Designation: D5169 98 (Reapproved 2004)Standard Test Method forShear Strength (Dynamic Method) of Hook and Loop TouchFasteners1This standard is issued under the fixed designation D5169; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, the year 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 measures the shear strength of hookand loop touch (CRE) fasteners using a recording c
3、onstant rateof extension tensile testing machine.1.2 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theres
4、ponsibility 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 76 Specification for Tensile Testing Machines for TextilesD 123 Terminology Relating to
5、Textiles2D 618 Practice for Conditioning Plastics and ElectricalInsulating Materials for Testing3. Terminology3.1 Definitions:3.1.1 hook and loop fastenera touch fastener, comprisedof two flexible mating strips, the surface of one mating stripbeing covered with tiny, stiff protrusions shaped like ho
6、okswhich engage the other mating strip which is covered withpliable loops.3.1.1.1 DiscussionThis fastener comprises a non-adhesive method of joining two materials where ready adjust-ment and removal is desirable and fastening is accomplishedby pressing the mating strips together and separation isacc
7、omplished by simply peeling apart. Terms herein referringto hook and loop fastening systems shall be construed toinclude other types of touch fasteners in which the fasteningstrength in the shear mode (that is, against forces applied in theplane of the fastener) substantially exceeds the fasteningst
8、rength in the peel mode (that is, against forces appliedperpendicular to the planes of the two components of thefastener).3.1.2 shear strength, nthe resistance to forces that cause,or tend to cause, two contiguous parts of a body to sliderelatively to each other in a direction parallel to their plan
9、e ofcontact.3.2 For definitions of other textile terms used in this testmethod, refer to Terminology D 123.4. Summary of Test Method4.1 An area of hook surface is applied to an area of loopsurface with controlled engagement pressure. This combina-tion is subjected to a dynamic shear force acting par
10、allel to thesurfaces of the specimens.5. Significance and Use5.1 This test method gives a measure of a key property ofhook and loop touch fasteners which is of interest to users ofsuch devices. This is a means of determining the resistance toseparation when forces are applied parallel to the plane o
11、f thefastener.5.2 In the case of a dispute arising from differences inreported test results when using this test method for acceptancetesting of commercial shipments, the purchaser and the sup-plier should conduct comparative tests to determine if there isa statistical bias between their laboratorie
12、s. Competent statis-tical assistance is recommended for the investigation of bias.As a minimum, the two parties should take a group of testspecimens which are as homogenous as possible and which arefrom a lot of hook and loop of the type in question. The testspecimens should then be randomly assigne
13、d in equal numbersto each laboratory for testing. The average results from the twolaboratories should be compared using Students t-test and anacceptable probability level chosen by the two parties beforethe testing began. If a bias is found, either its cause must be1This test method is under the jur
14、isdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.54 on Subassemblies.Current edition approved Oct. 1, 2004. Published November 2004. Originallyapproved in 1991. Last previous edition approved in 1998 as D 5169 98.2For referenced ASTM standards, visit th
15、e 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 19428-2959,
16、United States.found and corrected or the purchaser and the supplier mustagree to interpret future test results in the light of the knownbias.6. Apparatus6.1 Rollerconsisting of a smooth steel surface, approxi-mately 434 in. (21 mm) in diameter, 214 in. (57 mm) wide, andequipped with a handle, length
17、 418 in. (105 mm), for propellingthe roller back and forth without adding additional weight tothe specimen being rolled (see Fig. 1). The weight of the roller(including the handle) is 11 lbs. 614 lb (4994 6 114 g).6.2 Testing MachineA constant rate of extension (CRE)tensile tester shall be used. The
18、 tester shall have two clampswith centers in the same plane, parallel to the direction of themotion of the stressing clamp, and so aligned that they willhold the specimen ends wholly in the same plane; a means ofmoving the stressing clamp at a uniform rate of 12.0 6 0.5in./min (305 6 13 mm/min); an
19、autographic device for record-ing the maximum load.6.2.1 The instrument shall be calibrated to an accuracy of1.0 % of the full scale and the scale range used for the test shallbe such that the main test falls within 20 to 80 % of full range.7. Sampling7.1 Select the test samples so as to be as repre
20、sentative ofthe unit (a shipment, a lot, and so forth.) as possible.7.2 LotA lot shall consist of all the material of the sametype, color and width, made at the same time from the samematerials in no more than a two week period. It shall beexpressed in linear units of 10 000 yards (9144 m).7.3 Sampl
21、e RollsSelect one roll randomly from eachlinear unit 10 000 yards (9144 m). If the lot does not containfive units, additional rolls shall be selected from the lot to givea sample size of five rolls.7.4 For specification purposes, the material under test mustbe mated with material supplied by the man
22、ufacturer of thematerial being tested.8. Specimen Preparation8.1 Hook and loop material for this test shall be in the widthas supplied, not to exceed 1 in. (25.4 mm) in width. Formaterials greater than 1 in. (25.4 mm), the material shall be slitto 1 in. (25.4 mm) in width. If material is less than 1
23、 in. (25.4mm) wide as tested, test results will not be directly propor-tional to those obtained with the 1 in. (25.4 mm) wide material.8.1.1 Remove the outer lap of each roll before selecting therequired number of strips, hook and loop, 4 in. 614 in.(102 6 6 mm) long.8.1.2 Each specimen is marked wi
24、th an arrow () pointingin the direction that the specimen is unwound from the roll.This arrow is marked on the specimen on the leading end as itis unwound from the roll. The arrow () indicates the directionof the hooks and loops of the specimens.8.1.3 Select the sample consisting of the four (4) con
25、tiguousspecimens as described in 8.1.1 and mark it with the appropri-ate identification (roll number, lot number, date, and so forth).There are four (4) possible direction configurations of closureas shown in Fig. 2. The four specimens of hook and loopselected will be used to characterize the shear
26、strength of eachof the configurations.9. Conditioning9.1 Condition the specimens in an atmosphere for testing of23 6 2C (73.4F 6 3.6F) and 50 6 5 % relative humidity asdescribed in Practice D 618 for a period of 24 h or until thespecimens reach moisture equilibrium. Lay specimens flat withthe functi
27、onal side up so that the conditioning atmosphere hasfree access to them.10. Procedure10.1 Select from the four (4) specimens of hook and loop,the first closure to be tested and referring to Fig. 2, prepare thefirst closure specimen with the marked arrows as shown inSequence 1.NOTE 1The reason for te
28、sting all four possible closure configurationsis that the hook or loop material, or both, may have directionality (that is,the hooks or loops may not be perpendicular to the base fabric of whichthey are a component), and affect the shear force.10.1.1 Carefully align and superimpose the hook strip ov
29、erthe loop strip so that the hook strip covers the loop strip and themarked ends are matched as shown in Fig. 2, Sequence 1.10.1.2 Place a flat steel plate 8 in. (20 cm) long and 112 in.(4 cm) wide and weighing 4 pounds (1814 gm) (approximatelyFIG. 1 Roller for Making Closure of Hook and Loop TouchF
30、asteners Prior to TestingFIG. 2 Test Configurations for Dynamic Shear Strength of Hookand Loop Fasteners (Not to Scale)D5169 98 (2004)2equivalent to12 lbs per in.2of closure) onto the closure,completely covering it, slowly, and without adding any handpressure. After 2 s remove the plate. This initia
31、l mating of theclosure is done to create just enough hook and loop engage-ment so as to be able to continue with the test procedure.10.1.3 Securely fasten the two ends of the mated hook andloop to a hard flat surface such as a metal plate, table top, andso forth using masking tape, staples, clamps,
32、hook and loopstraps, or the like.10.1.4 Push the roller without adding weight over the entirelength of the joined strips and then pull it back over the entirelength. This constitutes one cycle; a continuous uninterruptedback and forth motion of the roller, without lifting it from thematerial. Each c
33、ycle should take about 2 s.10.1.4.1 Perform five (5) cycles with the roller withoutlifting it from the material. Remove the specimen from theholder.10.2 Prepare the second closure specimen as described in10.1.1-10.1.4.1 except with the marked ends as shown inSequence 2 of Fig. 2.10.3 Prepare the thi
34、rd closure specimen as described in10.1.1-10.1.4.1 except with the marked ends as shown inSequence 3 of Fig. 2.10.4 Prepare the fourth closure specimen as described in10.1.1-10.1.4.1 except with the marked ends as shown inSequence 4 of Fig. 2.10.5 In the sequence in which the closure specimens werep
35、repared, select them for testing in the tensile tester.10.6 Position the clamps of the tensile tester so they are3 618 in. (76 6 3 mm) apart. Place the free ends of thespecimen to be tested in the clamps of the tester with the hookstrip in the moving clamp. The mated specimen should beapproximately
36、centered and aligned approximately perpen-dicular to the clamps. Use a clamp separation speed of12.0 612 in./min (305 6 12 mm/min).10.7 Observe the chart paper produced by the autographicrecorder. Make note on the recording chart of the test specimennumber and the sequence number from diagram 2.10.8
37、 Record the force (maximum load) required to separatethe hook and loop closure.11. Calculation11.1 Convert the force (maximum load) to separate the 2 in.overlap of closure to lbs per in.2(a psi).11.2 Calculate the average force (maximum load) of thesample from the four (4) specimens tested.12. Repor
38、t12.1 Report the following information:12.1.1 State that the specimens were tested as directed inASTM Test Method D 5169.12.1.2 Describe the material or product sampled (includingtype, color, source and manufacturers code or part number),12.1.3 The width of the material tested and whether thewidth w
39、as as supplied or slit down to 1 in. (25.4 mm) asrequired in 8.1,12.1.4 The shear strength as the average separation force(maximum load) of each sample in lbs per in.2to the nearest lbper in.2(psi).13. Precision and Bias13.1 PrecisionBased on limited testing from one labora-tory, the within-laborato
40、ry or repeatability standard deviation isabout 2.51 lb or the coefficient of variation is about 0.07.Repeatability is dependent on the specific material beingtested: some materials would be expected to be higher or lowerthan this. Between-laboratory reproducibility is being deter-mined by the subcom
41、mittee.13.2 BiasThe procedure in Test Method D 5169 for mea-suring the shear strength of hook and loop touch fasteners hasno bias because the value of the shear strength of hook andloop touch fasteners can be determined only in terms of a testmethod.14. Keywords14.1 fastener; hook; hook and loop; lo
42、op; shear; shearstrength; touch fastenerASTM International takes no position respecting 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
43、 riskof infringement of such rights, are entirely their own responsibility.This 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
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45、ake your views known to the ASTM Committee on Standards, at the address shown below.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 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D5169 98 (2004)3
