1、Designation: D7842/D7842M 12 (Reapproved 2016)Standard Test Method forHolding Strength of Tack and Prong Fastener AttachedButtons1This standard is issued under the fixed designation D7842/D7842M; the number immediately following the designation indicates theyear of original adoption or, in the case
2、of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the holdingstrength of a tack and prong fastener
3、 attached button using atensile testing machine.1.2 This test method is applicable to attached buttons ingarments or to be attached to fabrics intended for use in apparel(see Annex A1).1.3 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard. Theval
4、ues stated in each system may not be exact equivalents;therefore, each system shall be used independently of the other.Combining values from the two systems may result in non-conformance with the standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated wit
5、h 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:2D76 Specification for Tensile Testing Machines for TextilesD123 Ter
6、minology Relating to TextilesD1776 Practice for Conditioning and Testing Textiles2.2 Federal Document:316 CFR Parts 1500.48-1500.53 and 1501.4 Engineering TestManual for Childrens Toys3. Terminology3.1 Definitions:3.1.1 force, na physical influence exerted by one body onanother which produces accele
7、ration of bodies that are free tomove and deformation of bodies that are not free to move.3.1.2 holding strength, nin buttons, the force required toseparate the button from its attached mating part or separatefrom the fabric it is attached to, whichever shall fail first.3.1.3 tack attached button, n
8、any button that is attached bya single post product (most commonly used to attach a nonmetal colleted button). (See Fig. 1.)3.1.4 prong fastener attached button, nany button that isattached by a product with 2 or more prongs (most commonlyused to attach a metal colleted button). (See Fig. 2.)3.1.5 F
9、or definitions of other textile terms used in thisstandard, refer to Terminology D123.4. Summary of Test Method4.1 A specimen, consisting of a button and tack or prongfastener attached to a fabric, is mounted in a special test fixtureon a tensile testing machine. A force is applied perpendicularlyun
10、til the button separates from the tack or prong fastener, or thefabric is torn. The peak force at separation is reported as theholding strength. If the fabric tears, the peak force at fabricfailure is recorded and the data is reported and considered as adifferent category to be reported separately f
11、rom the holdingstrength of the fasteners.5. Significance and Use5.1 This test method may be used for acceptance testing ofcommercial shipments of garments with attached buttons.5.2 This test method may be used to determine the compat-ibility of tack attached buttons or prong fastener attachedbuttons
12、 to fabrics used in apparel. In which case, the buttonsare attached to the fabric in the manner in which they will beused and the combined units tested.6. Apparatus6.1 Tensile Testing Machine, CRE type, meeting Specifica-tion D76. (See Fig. 3.)6.1.1 Upper Test Fixture, Fig. 4, designed as not to mal
13、formthe button specimen with interchangeable bottom plates to testa multitude of sizes of buttons.1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.54 on Subassemblies.Current edition approved Oct. 1, 2016. Published Oct
14、ober 2016. Originallyapproved in 2012. Last previous edition approved in 2012 as D7842/D7842M 12.DOI: 10.1520/D7842-12R16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, ref
15、er to the standards Document Summary page onthe ASTM website.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consh
16、ohocken, PA 19428-2959. United States17. Sampling, Test Specimens, and Test Units7.1 Lot Sample:7.1.1 For acceptance testing, randomly select the number ofshipping cartons or other containers of garments as directed inan applicable material specification, contract or other agree-ment between the pur
17、chaser and the supplier. Consider thecartons or containers to be the primary sampling units.7.2 Laboratory Sample:7.2.1 For acceptance testing, take necessary number ofgarments to obtain ten attachments. Button fly attachmentsshould be tested separately from waste band attached buttons.7.3 Test Spec
18、imens:7.3.1 Test ten specimens from each garment. A test speci-men consists of the button, fabric, and product (tack or prongfastener) used to attach button to fabric. The locations of thespecimens must allow for secure clamping in the fixtures. Extratests may need to be performed if fabric fails be
19、fore reachingeither the force specification agreed upon by the purchaser andsupplier or 69 N 15.5 lb. If the fabric fails before reaching 69N, it is recommended to try a thicker application (more layersof fabric) if possible, until ten tested specimens have no fabricfailures.8. Preparation of Appara
20、tus8.1 Preparation:8.1.1 Set up and verify the tensile testing machine accordingto the manufacturers instructions and 8.1.2 8.1.4.8.1.2 Attach the upper fixture to the testing machine andcheck the alignment.8.1.3 Select a force range for separation to occur between 10and 90 % of full scale force.8.1
21、.4 Set the loading rate for 300 6 10 mm/min 12.0 6 0.5in./min.9. Calibration and Standardization9.1 Testing equipment should be calibrated on a regularbasis as recommended by manufacturers instructions.10. Conditioning10.1 Condition the specimens by bringing them from thedry side to approximate mois
22、ture equilibrium for testing in thestandard atmosphere for testing textiles as directed in PracticeD1776.11. Procedure11.1 The attached button is placed in the test fixture. Thetest fixture is clamped to the top jaws of the Tensile Testingmachine and the fabric is clamped to the bottom jaws. (See Fi
23、g.5.)11.2 Initiate the test by applying force to the machine untilthe button disengages from the fastener or the fabric tears.11.3 Record the force to disengage the button from thefastener as the holding force to the nearest 0.1 N 0.5 lbf.12. Calculation or Interpretation of Results12.1 If the fabri
24、c tears before the fastener and buttondisengage, record the specimen as failing. The value of thefabric failure specimen is recorded separate from the recordingof the values of the fastener holding strength.13. Report13.1 State that the tests were made as directed in TestMethod D7842. Describe the m
25、aterial or product beingsampled and the method of sampling used. Describe thematerial and end product.13.2 Report the following information:13.2.1 Type of testing machine and load range used.13.2.2 Individual and average results.13.2.3 Note of any fabric or tack/fastener failure besideresults with F
26、F for fabric and T/F for tack/fastener. Disregardfabric failures. Use photos if needed to show the differencebetween fabric failure and tack/fastener failure.13.2.4 Report the units of force in newtons (N) or poundsforce lbf.13.2.5 Report thickness of fabric using compressed founda-tion thickness.14
27、. Precision and Bias14.1 The value for holding strength of a button, either tackattached or prong attached, in garments can only be defined bya test method. Within this limitation, Test Method D7842 hasno known biases.15. Keywords15.1 button; prong fastener; strength; tackFIG. 1 Tack AttachedFIG. 2
28、Prong Fastener AttachedD7842/D7842M 12 (2016)2FIG. 3 Tensile Test Machine and Clamped Test SpecimenFIG. 4 Upper Test FixtureD7842/D7842M 12 (2016)3ANNEX(Mandatory Information)A1. SELECTION OF BUTTON (TACK OR PRONG ATTACHED) FOR USE IN GARMENTSA1.1 Button (Tack or Prong attached) and FabricA1.1.1 But
29、tonSize appropriate to the type of fabric to beused in the garment. Some fabrics may require Tack attachmentand some may require Prong attachment.A1.1.2 FabricFor which the particular button is beingassessed for suitability.A1.1.3 Interliner FabricAs needed in garment construc-tion.A1.2 Number of Sp
30、ecimensA1.2.1 Test until ten buttons have passed the specifiedrequirement by the purchaser and supplier or 69 N 15.5 lb.A1.3 Preparation of Setup SpecimensA1.3.1 Use fabric supplied by the purchaser or supplier withthe same thickness as the actual garment that the button isbeing applied. If an inter
31、liner is to be in the area of the garmentin which the button is to be used, be sure to include betweenthe fabrics. Please note that some garments may be processedbefore or after the attachment of the button. Chemicals used toprocess the garment could affect the results of this test.A1.3.2 Attach the
32、 buttons to the manufacturers instruc-tions. Additional equipment may be needed to attach thebuttons or the supplier or purchaser may attach the buttonsusing their equipment.A1.4 TestingA1.4.1 Test the specimens as directed in Section 11.A1.5 ReportA1.5.1 Report the applicable information as stated
33、in Sec-tion 13.FIG. 5 Specimen Clamping ConfigurationD7842/D7842M 12 (2016)4ASTM 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 validit
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37、es) 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 12 (2016)5
