ASTM D7842/D7842M-12 (R2021) pdf free download.Standard Test Method for Holding Strength of Tack and Prong Fastener Attached Buttons.
1 .1 This test method covers the determination of the holding strength of a tack and prong fastener attached button using a tensile testing machine.
1 .2 This test method is applicable to attached buttons in garments or to he attached to fabrics intended for use in apparel (see Annex Al).
1.3 Units—The values stated in either SI units or inchpound units arc 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 be used independently of the other, and values from the two systems shall not be combined.
3. Terminology
3. 1 Definitions:
3.1.1 force, n—a physical influence exerted by one body on another which produces acceleration of bodies that are free to move and deformation of bodies that are not free to move.
3. 1 .2 holding strength, n—in buttons, the force required to separate the button from its attached mating part or separate from the fabric it is attached to, whichever shall fail first.
3. 1 .3 tack attached hunon, n—any button that is attached by a single post product (most commonly used to attach a non metal colleted button). (See Fig. 1.)
3. 1 .4 prong fastener attached button, n—any button that is attached by a product with 2 or more prongs (most commonly used to attach a metal colleted button). (See Fig. 2.)
3.1.5 For definitions of other textile terms used in this standard, refer to Terminology D123.
4. Summary of Test Method
4.1 A specimen. consisting of a button and tack or prong fastener attached to a fabric, is mounted in a special test fixture on a tensile testing machine. A force is applied perpendicularly until the button separates from the tack or prong fastener, or the fabric is torn. The peak force at separation is reported as the holding strength. If the fabric tears, the peak force at fabric failure is recorded and the data is reported and considered as a different category to he reported separately from the holding strength of the fasteners.
5. Significance and Use
5.1 This test method may be used for acceptance testing of commercial shipments of garments with attached buttons are attached to the fabric in the manner in which they will be used and the combined units tested.
6. Apparatus
6.1 Tensile Testing Machine, CRE type. meeting Speci(Icalion D76/D76M. (See Fig. 3.)
6. 1 . I Upper Test Fixture, Fig. 4, designed as not to malform the button specimen with interchangeable bottom plates to test a multitude of sizes of buttons.ASTM D7842/D7842M pdf download.