Abstract
Bending rigidity of a 2-ply multifilament yarn was derived in terms of physical and mechanical characteristics of its constituent filaments and yarn structural parameters. Experime-ntal and theoretical results were compared for the multifilament yarn and with various structural parameters. The maximum bending rigidity of 2-ply multifilament yarns was observed around ply helix angle of 15 degree for both theoretical and experimental results. Theoretical analysis shows that bending rigidity of 2-ply multifilament yarn increases with the ratio of filament torsional rigidity to its bending rigidity. The theoretical results show good agreement to experimental one when the ply helix angle is lower than 10 degree, however, experimental results show much higher value than theoretical ones when the ply helix angle is higher than 15 degree.