The technology of war often has unexpected results. In 1918 the first sanitary napkins were introduced under the name "Celucotton" by Kimberly & Clark Co. Ernst Mahler, a German American chemist, had developed a wood-cellulose substitute for cotton to fill the need for dressings and bandages in World War I's European field hospitals. Red Cross nurses began to use Celucotton for sanitary napkins, and when the Neenah, Wisconsin, company discovered this, it began the development of the first commercial sanitary napkins, which were sols as "Kotex" beginning in 1921.

Source:

M. Patricia Donahue, Nursing, The Finest Art (Saint Louis: C. V. Mosby Company, 1985).