This study discusses a light-weight bicomponent hollow fiber that is formed from a low-density material on the inside, such as polypropylene (PP), and a regularly dyeable material outside, such as polyterephthalate (PET) or nylon. Finite elements and the Optimesh-3D remeshing approach are adopted to identify the main controlling factors of spinning the sheath-core hollow fiber without the consideration of winding actions are performed, based on a four-segmented arc spinneret design. The results indicate that the deflection of melt streams under the spinneret is a major factor that controls the gluing of the gap between arc segments. A greater mismatch between the viscosities of the sheath and the core causes a greater deflection and increases the likelihood of gluing events. Beyond deflection, die swelling under the spinneret is another issue of concern in the processing of bicomponent hollow fibers. Finally, the simulation results are compared with experimental data, and the most appropriate conditions for forming a PET/PP hollow fiber were obtained. POLYM. ENG. SCI., 51:704-711, 2011. (C) 2010 Society of Plastics Engineers