Numerical simulation of the diameter of E-glass fiber in forming process

Electronic products with higher signal transmission efficiency and smaller dimensions require fine and uniform E‑Glass fibers. However, owing to the dramatic temperature change and the consequent rapid variation in viscosity of the glass melt during spinning, individual fiber diameters may differ substantially, making direct and accurate prediction of each fiber’s diameter difficult. In this study, the finite element method was employed to simulate the E‑Glass fiber forming process and to predict its diameter. Given that the glass composition, spinning equipment, and cooling‑fin positions are fixed, the fiber diameter was simulated by examining the following factors: (1) the volume flow rate of the melt through the nozzle orifice, which is governed by the melt temperature and viscosity; (2) the temperatures of the cooling environment, the glass melt in the bushing, the nozzle outlet, and the spinning chamber; (3) the winding speed; and (4) the nozzle position within the bushing. The calculated fiber diameter was validated as reasonable by measuring the temperature with a thermal imager and the diameters under a microscope for G75 glass fibers. This study can be further applied to control the uniformity of glass fibers or to design the bushing.