ASTM D6479-15(R2020) pdf free download

ASTM D6479-15(R2020) pdf free download.Standard Test Method for Determining the Edgecomb Resistance of Woven Fabrics Used in Inflatable Restraints
1. Scope
1.1 This test method covers the procedures for determining the resistance to edgecombing of a woven fabric used in inflatable restraints. 1.2 Procedures and apparatus other than those stated in this standard may be used by agreement of purchaser and supplier with the specific deviations from the standard practice ac- knowledged in the report. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Terminology
3.1 For all terminology relating to D13.20, Inflatable restraints, refer to Terminology D6799. 3.1.1 The following terms are relevant to this standard: edgecombing, inflatable restraint, seam slippage, yarn slippage 3.2 For all other terms related to textiles, see Terminology D123. 3.3 Definitions: 3.4 For definitions ofother terms used in this standard, refer to Terminology D123 and Terminology D6799.
4. Summary of Test Method
4.1 One end ofa test specimen is clamped within one jaw of a CRE tensile testing machine and a special fixture pierces a row ofequally spaced needle holes through the opposite end of the specimen. In accordance with Test Method D5035, a tensile force is applied to the specimen until rupture occurs. The measurement of the force required to cause rupture is the measurement of edgecomb resistance.
5. Significance and Use
5.1 A measurement of a fabric’s edgecomb resistance indi- cates the relative tendency of a fabric to pull apart under seam stress or similar action. The related concepts of yarn slippage and seam slippage are limited to sewn seams, whereas the measurement of edgecomb resistance is made at the edge of a cut part in the absence of a sewn seam. The absence of a sewn seam in this test method eliminates the effect that a particular stitch might have on the tendency ofa yarn to slip near an edge of a cut part 5.2 This test method is useful for material design evalua- tions in such applications as airbags in which seam stress is a major concern.
6. Apparatus
6.1 Tensile Testing Machine—A constant-rate-of-extension (CRE) type, that is designed for the tensile forces anticipated, that is operated at a rate of 200 6 10 mm/min, that has a force range selected such that the anticipated break occurs between 10 and 90 % of full scale load, and that has jaws and grip faces as agreed upon by purchaser and supplier. 6.2 Clamps, jaws with smooth, flat, parallel faces a mini- mum of 60 mm wide by 25 mm tall. The jaws may be padded or coated under the jaw face area and should be mounted in the upper position in the tensile testing machine. 6.3 Fixture, compatible with tensile tester, equipped with twelve equally spaced 1 mm diameter pins with sharp points, 8 mm in length and corresponding 1.5 mm diameter holes with a stop located 5 mm from the center of the holes (Fig. 1). The fixture should be properly centered with the upper clamps and their surfaces should be aligned (not twisted). 6.4 Load Cell, whose rated capacity is between 110 and 1000 % of expected stripping load. A2000 N load cell is generally used for inflatable restraints.