The ISO9073-4 test method is used to investigate the tear resistance of nonwovens by the trapezoid specimen shape method. This method provides valuable information about a fabric's ability to resist a continuous tear from sharp objects.
This test method is suitable for use with nonwoven materials. Although nonwovens are classified within the textile industry, it should be recognised that nonwovens technologically share characteristics with textile products and paper and/or plastic products.
In principle, the test specimen is cut in the shape of an isosceles trapezoid and then a small cut is made on one side of the trapezoid. This specimen is then supported as defined in the standard by clamping of the non-parallel sides of the trapezoid in the jaws of a tensile testing machine. The application is to pull at a continuous increasing extension (constant rate of Extension) the test piece in such a way that a tear propagates across the specimen width as the jaws move apart. The result determination is the average maximum tear resistance in Newton’s. For this test it is important to have a test data sampling rate to the PC for analyis as high as 500 Hz to ensure the capture of instantaneous peaks
.
We use screw action grips or pneumatic action grips with rubber coated jaw faces for clamping of the material fitted to a tensile
testing machine.
This is usually of single-column or dual-column tabletop
design. Testing software, such as Bluehill® 2,
is used to input specimen details, set the desired test control, automatically calculate the desired results and statistics, and produce a test report all in accordance with the standard. For this test types, we used the preload feature of Bluehill software to eliminate any slack in the specimen when loading into the clamping grips prior to test.
We suggest reviewing ISO 9073-4 to fully understand the test fixture and results requirements prior to performing any tests.