This ISO method is used to test a range of fabrics, including woven fabrics, coated fabrics, rubber-coated fabrics, and plastic-coated fabrics. There are two sub-methods used in ISO 1421, differentiated by the specimen type being used and the desired results.
Method 1, called the Strip Test, uses strip-type specimens, and is used to determine the tensile strength and elongation at break. In the strip method, the full width of the test piece is gripped in the jaws.
Method 2, called the Grab Test, is a method for the determination of tensile strength only, and only the central part of the width of the test piece is gripped in the jaws.
For both tests, it is important to have a test data sampling rate to the PC for analysis as high as 100 Hz to ensure the capture a high number of data points.
The challenges of testing to this standard are:
- Data capture
- Specimen gripping
- Rapid data capture rate with Instron's 5900 controller allows data peaks and valleys to be captured accurately at up to 2,500 points per second
- Instron pneumatic side action grips with wave profile faces are well-suited to gripping stronger fabric specimens for this test while maintaining high throughput
It is important to review ISO 1421:1998 in order to fully understand the test setup, procedure, and results requirements.