ASTM F1473 - The Polyethylene Notch Tensile (PENT) Test
This method is used in the United States to test PE Pipe grade materials that exhibit high ESCR values, as this test generally provides more timely results. Typical test conditions are 80°C air and 2.4 MPa stress. A diagram of this test method is shown in Figure 3. Specimens are machined directly from pipe or from a molded plaque. Typical samples measure 10x25x100 mm. A single notch cut into the test specimen acts as a crack initiation point. Side notches are made to facilitate the cracking in the main notch. Notch depth is dependent on sample thickness. However, typical notch depths are 138 microns on the front, and 40 microns on each side. The applied load expedites the cracking mechanism, leading to sample failure. Failure is classified as a complete separation at the notch, indicating a brittle failure. Time to failure is
recorded for each sample.