ISO 36 is used for measuring the force required to separate, by stripping, two plies of fabric bonded with rubber or a rubber layer and a fabric ply bonded together. This test is used for the determination of median peak force and the adhesion strength characteristics of the product for a given rate of displacement.
This method is applicable when the ply surfaces are approximately plane or when they are in the form of a cylinder having an internal diameter greater than approximately 50 mm. It is not applicable when the ply surfaces contain sharp bends, angles or other gross irregularities that cannot be excluded when cutting out test pieces.
In principle, the test specimen is clamped in the jaws of the testing machine, ensuring the test specimen is properly gripped. A force is applied at a constant rate of displacement - tearing the specimen until fracture. The tear force is calculated from the force peaks.To record the test it is important to have a high speed intelligent test data logging rate. This is the transfer rate to the PC of 100Hz or more to capture and record all the peaks and troughs.
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. These grips are usually fitted to either a single-column or dual-column design. Using testing software, such as the Bluehill® 2 test method, is ideal for inputting specimen details, setting the desired test control, automatically calculating the desired results and statistics, and producing a test report all in accordance with the standard.
We suggest reviewing ISO36 to fully understand the test fixture and results requirements.