The Exchange Test Method
A-9: Breaking Strength: Grab Method
Issue Date: 30 Apr 1993
Revision Date: 09/30/2011
PURPOSE AND SCOPE:
To determine the breaking strength of a woven, non-woven or coated fabric using the grab Method. Strength of a fabric is generally considered the most obvious indicator of the service life of a fabric. Also the strength of fabric indicates its ability to resist mechanical damage due to stress of normal wear and refurbishing.
PRINCIPLE:
A continually increasing load is applied lengthwise or widthwise to the specimen, and the test is carried to fabric rupture. Values for the breaking load of the test specimen are obtained from machine scales, dials or charts.
REFERENCE:
- 3.1 ASTM D5034-09, Standard Test Method for Breaking Strength and Elongation of Textile Fabrics (Grab Test).
APPARATUS:
- 4.1 Tensile testing machine, constant rate of traverse (CRT) such as Instron Model #4206
PROCEDURE:
- 5.1 Prepare 3 specimens each 100 +/- 1 mm (4+/- 0.05 in.) wide by at least 150 mm (6 in.) long in both warp (length) and filling (width) directions.
- 5.2 Condition the specimens for a minimum of 2 hours with 21° +/- 1C (70° +/- 2F) and 65% +/-2% RH.
- 5.3 Set the crosshead speed at 30.5 cm (12 in.) per minute.
- 5.4 Set the gauge (distance between the jaws) at 76 mm (3 in.), and clamp the specimen lengthwise in both jaws. If the fabric being tested has too much stretch, the gauge length 25 mm (1 in.) may be used. Use a tension load cell with a capacity that exceeds the expected breaking strength.
- 5.5 To start the test, press "up" key on crosshead control panel.
- 5.6 Note the reading on the instrument panel when the fabric breaks, this is breaking strength.
- 5.7 Return the jaws to the original gauge length.
- 5.8 Remove the ruptured specimen from the jaws.
- 5.9 Repeat Steps 5.4 through 5.8 on the remaining test specimens.
EVALUATION:
Calculate the average of 3 readings of breaking strength in each direction, i.e., length and Width or warp and filling, to the nearest 0.1 of the unit chosen, i.e., pounds or grams.
REPORT:
Report the values calculated in Step 6 as the breaking force of the fabric tested in respective directions.