[user070223]

Her logic seems reasonable but stating that the fibers "return to their original crinkled state" is missing the fact that the fiber go through the process of spinning to improve tensile strength (as well as the options of making an infinite yarn from finite fibers by twisting them together). regardless to return to original "crinckled state" they need to overcome those forces as well as the forces of the geometry of the knit(on a different scale).

BTW Rayon is also made from cellulose, cellulose II. While Cellulose I(natural) is metastable it can be converted by disolving in lye to a stable form (beta-gllocouse molecolue chain goes from being parallel to being anti parllel which increases the # of hydrogen bonds as well as helping create a more stable 3d structure) which again improve tensile strength and resist wrinkles on a different scale.