BS EN ISO 1421_{Rubber- or plastics-coated fabrics. Determination of tensile strength and elongation at break}

Test summary

A force testing stand is used to find the elongation at break and tensile strength of specimens of coated fabrics. Samples can be cut from the longitudinal and transvers direction of the material, and can be measure dry of after immersion in water. Two methods of testing are described in the standard, the ‘strip test’ to determine tensile strength and elongation at break, and the ‘grab test’ for tensile strength only.

Test method

Method 1 – strip test (Tensile strength and elongation at break)

Condition the samples according to ISO 2231. Specimens are cut 50 ± 5 mm wide, and sufficient length to allow a distance of 200 mm between the jaws of the test stand. At least 5 specimens are required from both the longitudinal and transvers direction of the material.

Set the jaws of the grips 200 mm apart, and clamp the sample in the static jaw of the test stand. Test pieces can be mounted under a pre-tension (see the standard for the settings), or if this is not suitable can be mounted in a slack condition.

Set the test stand to run in tension at 100 mm/min, and extend the test piece to the breaking point

Measure the load and extension and then report for the samples cut in the longitudinal and transverse directions:

The maximum force

The force at break

The elongation at maximum force expressed in mm and as a percentage of the distance between the jaws*

The elongation at break expressed in mm and as a percentage of the distance between the jaws*

*See the standard for determining the appropriate gauge length of the sample when using pre-tension or slack mounting of the samples

Method 2 – grab test. (Tensile strength only.)

Condition the samples according to ISO 2231. Specimens are cut 100 ± 5 mm wide, and 150 mm long. At least 5 specimens are required from both the longitudinal and transvers direction of the material.

Set the jaws of the grips 100 mm apart, and clamp the sample using the upper and lower “grab fixtures”.

Set the test stand to run in tension at 100 mm/min, and extend the test piece to the breaking point

Measure the load and then report for the samples cut in the longitudinal and transverse directions:The maximum force