Die method of depositing a protective coating from a thermoplastic polymer melt onto a quartz optical fiber as it is being drawn

Abstract

This paper discusses a laboratory technology for a die method of depositing a protective coating from thermoplastic polymer melts onto a quartz fiber as it is being drawn directly on the drawing apparatus. The process of melting thermoplastic granules in a die for coating deposition was studied, and the temperature dependences of the viscosity of the melts were measured by a capillary technique. The dependences of the thickness of the deposited coating on the diameters of the drawn fiber and the inner diameter of the die were studied, and the conditions for stable deposition of the coatings were established. Samples of quartz-quartz optical fibers with a protective coating of P-12E polyimide with no intermediate buffer layer have been obtained for the first time, and certain optical parameters of the drawn samples have been measured.