Tensile strength and elongation at break
A biodegradable composite film must withstand the normal stress encountered during its application and the subsequent shipping and handling of the food to maintain its integrity and barrier properties. Tensile strength is the maximum tensile stress sustained by the sample during the tension test. If maximum tensile stress occurs at either the yield point or the breaking point, it is designated tensile strength at yield or at break, respectively (ASTM, 1991). High tensile strength is generally required, but deformation values must be adjusted according to the intended application of the films. That is, whether it is undeformable material to provide