- Applying load using hard, sharp, or angular objects is important for packaging materials. Understanding puncture resistance is necessary if films are used as packaging material for food or parts with sharp edges.
- The static puncture test to EN 14477 measures this behavior using a pointed tip with a diameter of 0.8 mm. This test is also known as the Parker Ball-Point Test.
- In this test, a strip specimen is gripped in the lower specimen holder. It is punctured from above with an exchangeable probe to measure the maximum penetration force.
- ASTM F1306 describes a method with very similar objectives for measurement of flexible barrier films and laminates. It uses an indenter with a tip radius of 1.6 mm and a conical shaft with a 6° angle. The test is performed on a film strip, which is fastened over an opening with a 35 mm diameter.
This method, which is described in ASTM D5748, requires a larger radius indenter coated with PTFE to minimize friction. Throughout the deformation process, the film is significantly stretched before the indenter causes it to fail. Therefore, in addition to the puncture force, the deformation behavior of the film is also characterized in a multi-axial stress state.