ISO 527-3, ASTM D 882
This test allows to determine properties as tensile strength, yield strength, yield strain, strain at break, and modulus of elasticity. Due to the flexible, delicate nature of these plastic specimens, both gripping and strain measurement can be a challenge
Specimens are easily produced by a cutting press or a film cutting device. Dumbbell specimens are often used for quality control and require a direct measuring extensometer for strain acquisition directly on the specimen. For tests on strips the results for strain at break depend on the shape and the clamping type of the specimen. 25 mm x 25 mm rubber grip face size is commonly used for this material, that matches the width of the gripped or tabbed end of the specimen. The matching width allows for ease of specimen alignment, which is critical for good breaks and accurate test results. The gripping must prevent slipping of the material at relatively high loads but not tear into the material and cause premature specimen failure