ASTM D6644-01 (R2021) pdf free download.Standard Test Method for Tension Strength of Sew-Through Flange Buttons.
1 .1 This lest method measures the resistance of the bridge of a sew-through button to a steadily increasing strain.
1 .2 The values stated in either SI units or inch-pound units are to he regarded separately as standard. The values stated in each system are not necessarily exact equivalents: therefore, to ensure conformance with the standard, each system shall he used independently of the other, and values from the two systems shall not be combined.
4.2 Tests are made on sew through flange buttons before laundering or dry cleaning with the option of testing again after a predetermined number of launderings or dry cleanings.
5. Significance and Use
5. 1 This test measures an important property to users of sew through flange buttons. This is a means of determining the resistance of the bridge of the button to a strain which can cause it to fall off a garment to which it is attached.
5.2 If there are differences of practical significance between the reported test results for two laboratories (or more), comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, test samples should be used that are as homogeneous as pssible, that are drawn from the material from which the disparate test results were obtained, and that are randomly assigned in equal numbers to each laboratory for testing, Other materials with established test values may be used for this purpose. The test results for the two laboratories should he compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must he found and corrected, or future test results must be adjusted in consideration of the known bias.
6. Apparatus
6.1 Force Gauge—One capable of measuring 20 kg [44 IbI of tension or compression with an accuracy of ±0.1 kg [±0.22 Ib]. The gauge may be hand held or specially mounted.
6.2 Testing Machine—A constant rate of extension (CRE) Tester shall be used. The capacity of the machine must he selected for the break position on the gauge to fall within 20 % to 90 % of full scale.
6.3 Jaw Clamping Fixture—One capable of firmly holding the button, such as a long flOSC locking wrench or a 3-pronged clamping device.
6.4 commercial Sewing Machine—One capable of automatically sewing the button to. two or more layers of fabric.ASTM D6644 pdf download.