Dr. Sean Teller offered an on-demand presentation titled "Tensile Specimen Preparation Method Impacting Failure Behavior" at ANTEC Classic 2021, which took place online May 10-21, 2021.
Sample preparation for polymer testing is an overlooked portion of the test plan and execution. Characterizing and testing polymers typically involves creating samples from raw materials – the vendor may not be able to supply samples in the specified sizes needed for testing. This is often the case for specialized testing, including high strain rate testing.
For thermoplastic or thermoset materials, material vendors often provide raw pellets or molded plaques in set sizes. When samples are provided in plaque form, they need to be processed to their final shape, e.g., tensile dogbones or compression cylinder. Veryst investigated the effect of the sample creation process on the results from standard tensile tests. We compared samples by injection molding raw pellets, CNC (computer numerical control) machining samples from injection molded plaques, waterjet cutting samples from injection molded plaques, and die-cutting with a manual arbor press. Dr. Teller discussed the stress vs. strain response of all sample preparation methods as well as their implications.
This presentation was pre-recorded and available to attendees on-demand.