OPTICAL FIBER CABLE AND ITS PRODUCTION

PROBLEM TO BE SOLVED: To obtain a central core optical fiber cable of a low cabling loss having a stack of longitudinally twisted ribbons. SOLUTION: Plural optical fiber ribbons are stacked in an array form and are arranged within a tube existing at the center of the cable. A lubricating material is applied between the adjacent ribbons of the stack 200 in order to integrally holds the plural ribbons and to make the slip movement between the ribbons easy. The stack 200 of the ribbons is twisted along the longitudinal direction of the cable. The lubricant is alpha olefin oil. The stack 200 of the ribbons is twisted to one direction during a first prescribed distance and is then twisted in a reverse direction during a second prescribed distance. These distances are nearly equal to each other. An electrostatically charged powder is otherwise used as the lubricant.