ISO 527-3 is a common international standard that is used to determine the tensile properties of plastic film or sheeting - a plastic test specimen with a thickness less than 1 mm. The tensile properties include
tensile strength,
yield strength, yield strain, strain at break, and in some cases
Young's Modulus. Due to the flexible, delicate nature of these plastic specimens, both gripping and strain measurement can be a challenge.
We often recommend pneumatic grips with rubber grip faces that match the width of the gripped or tabbed end of the specimen. The most common face size for this type of material is 25 mm x 25 mm (1 in x 1 in). The matching width allows for ease of specimen alignment, which is critical for good breaks and accurate test results.
For extensometry, we find that
non-contacting video extensometry is the best solution, as typical clip-on extensometers weigh down the specimen, while knife edges tear at the specimen - both affecting test results. Our video extensometers allow for ease of marking these thin specimens with paint pens and marking templates, which are provided with the instrument.