Transmitted Off Crossed Circular Polarized Light
Rayon fiber is a cellulose derivative. Wood cellulose or cellulose from cotton linters is often used as the starting
material. It is formed by drawing the cellulose solution through a spinneret into an acid bath where it solidifies from
the outside in. This results in the crenulated cross-section because the outside polymerizes first and is drawn more rapidly
though the bath than the interior of the fiber that is still liquid. The draw-rate affects the fiber diameter and the
degree of crenulation.
Significance in the Environment:
This is a common clothing fiber.
Rayon fiber has a refractive index along its length of about 1.54 to 1.56 and perpendicular to its length of about 1.51
to 1.53. It has a birefringence of about 0.03 and a positive sign of elongation. It tends to exhibit irregular
striations along its length due to the crinulate cross-section of the fiber.
DuPont Company Techinical Bulletin X-156: IDENTIFICATION OF FIBERS IN TEXTILE MATERIALS, December 1961.