ASTM D5034-09(2013)

5.1 The grab test procedure in this test method for the determination of breaking force and elongation is considered satisfactory for acceptance testing of commercial shipments of most woven or nonwoven textile fabrics, and the modified grab test procedure is considered satisfactory for acceptance testing of commercial shipments of most woven textile fabrics, since the procedures have been used extensively in the trade for acceptance testing.

5.2 This test method is not recommended for knitted fabrics because of their high stretch.

5.3 Some modification of technique may be necessary for any fabric having a strength in excess of 200-N/cm (1140-lb/in.) width. Special precautionary measures are provided for use when necessary for strong fabrics.

5.4 All of the procedures are applicable for testing fabrics either conditioned or wet.

5.5 Comparison of results from tensile testing machines operating on different principles is not recommended. When different types of machines are used for comparison testing, constant-time-to-break at 20 ± 3 s is the established way of producing data. Even then the data may differ significantly.

5.6 Although a constant-rate-of-extension is preferred in these procedures, in cases of dispute, unless there is agreement to the contrary between the purchaser and the supplier, a constant-time-to-break (20 ± 3 s) is to be used.

5.7 The grab test procedure is applicable to the determination of the effective strength of the fabric; that is, the strength of the yarns in a specific width together with the fabric assistance from the adjacent yarns. The breaking force determined by the grab procedure is not a reflection of the strength of the yarns actually gripped between clamps and cannot be used for direct comparison with yarn strength determinations. Grab test specimens require much less time to prepare although they require more fabric per specimen. There is no simple relationship between grab tests and strip tests since the amount of fabric assistance depends on the type of fabric and construction variables.

5.8 The modified grab test procedure is applicable to the determination of the breaking force of fabrics with constructions in which the application of tensile stress on raveled strip specimens produces further unraveling. This test method is particularly applicable to high-strength fabrics.

1.1 This test method covers the grab and modified grab test procedures for determining the breaking strength and elongation of most textile fabrics. Provisions are made for wet testing.

1.2 This test method is not recommended for glass fabrics, or for knitted fabrics and other textile fabrics which have high stretch (more than 11 %).