Abstract: Viscous heating becomes significant in the high speed
resin coating process of glass fibers for optical fiber manufacturing.
This study focuses on the coating resin flows inside the capillary
coating die of optical fiber coating applicator and they are numerically
simulated to examine the effects of viscous heating and subsequent
temperature increase in coating resin. Resin flows are driven by fast
moving glass fiber and the pressurization at the coating die inlet, while
the temperature dependent viscosity of liquid coating resin plays an
important role in the resin flow. It is found that the severe viscous
heating near the coating die wall profoundly alters the radial velocity
profiles and that the increase of final coating thickness by die
pressurization is amplified if viscous heating is present.