2.5.3. Grammage, Thickness and Mechanical Properties

The grammage of the films was calculated based on the ratio between their mass and area (g/m2), according to ISO 536:1995. The thickness (μm) was measured according to ISO 534:2011 using a micrometer (Adamel Lhomargy Model MI 20, Veenendaal, Netherlands), with several random measurements being considered. Tensile strength (MPa), elongation (%) and elastic modulus (MPa) of the films were obtained using a tensile tester (Thwing-Albert Instrument Co., West Berlin, NJ, USA), at 23 ± 2 ◦C and 50 ± 5% relative humidity (RH), as per ISO 1924/1 with a single modification. The initial grip was set at 50 mm and the crosshead was set at 10 mm/min [21].
