This method is suitable for use with the following range of materials: fabrics, woven fabrics, coated fabrics, fabrics coated with rubber, and fabrics coated with plastics. The two methods are used to investigate the
tensile strength of fabrics coated with rubber or plastics in dry or wet conditions.
Method 1 - The Strip Test Method is a method for the determination of tensile strength and break failure of force and extension characteristics of the product for a given rate of displacement. Specimen preparation one set in the longitudinal direction and the other in the transverse direction. In principle the test specimen is supported by clamping a test piece in the stationary jaws so that its longitudinal axis passes through the center of the front edge of each jaw.
Method 2 - The Grab Test Method is a method for the determination of tensile strength only, of force and extension characteristics of the product for a given rate of displacement. Specimen preparation one set in the longitudinal direction and the other in the transverse direction. In principle the test specimen is supported by clamping a test piece in the stationary jaws so that its longitudinal axis passes through the center of the front edge of each jaw and is perpendicular to the edges of the jaws, and so that the line drawn on the test piece coincides with the appropriate edge of each jaw.
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.
We use pneumatic action grips with rubber coated jaw faces for clamping of the material fitted to a tensile testing machine. While manual action grips will work, many of our users prefer the pneumatic action grips for ease of use, productivity, and better repeatability. Pneumatic action grips allow you to set a clamping pressure, while the manually operated grips depend on the operator's strength (which may not be so repeatable). We find that gripping pressure and specimen alignment are very important in these tests. Too much gripping pressure can produce premature breaks, while not enough gripping pressure can lead to specimen slippage or breaks at or near the jaws. We also suggest for the strip test to choose faces that are at least 10 mm wider than the specimen being tested, and at least 25 mm if not more in height. As an option two methods of strain measurement can be adopted. A contacting long travel extensometer is attached to the test specimen. This incorporate a mechanism suitable for determining the relative change in length of the appropriate part of the test specimen. Or a non-contacting video extensometer can be used as a viewing mechanism suitable for determining the relative change in length of the appropriate part of the test specimen.The testing machine is usually of a single-column or dual-column table-top 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 type, we use 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 ISO1421 to fully understand the test fixture and results requirements prior to performing any tests.