Effects of specimen configuration and measurement method of strain on the characterization of tensile properties of paper

Uniaxial-tension tests of copy paper were conducted to measure the tensile properties, including Young's modulus, proportional limit stress, and tensile strength in the machine direction (MD) and cross direction (CD) using straight and dog-bone-shaped specimens. In the tests using the straight specimen, the distance between the grips was varied. Additionally, the tensile strain was obtained from the crosshead movement and elongation between the lines photographed by a CCD camera. When using a straight specimen in the MD, the grip distance influenced the Young's modulus value, and the tensile strength was markedly lower than that of the dog-bone-shaped specimen. In contrast, the tensile properties in the CD could be obtained even when using the straight specimen while reducing the influence of stress concentration at the grip.