Processing Effects on the Surface Composition of Glass Fiber

In this study, differences in the surface composition of commercial glass fiber have been characterized as a function of process. The two processes studied were flame attenuation, a high‐temperature combustion‐assisted process, and continuous filament drawing through a bushing. The techniques used to determine the surface compositions were TOF‐SIMS and XPS; the presence of a very thin, boron‐depleted silica‐enriched layer on the flame‐attenuated fibers was most significant. Thermodynamic modeling of the equilibrium vapor pressures at the surface, during fiberization, showed significant differences in the behavior of Na, B, and F species in the two processes. To further test the models, glass fibers were produced under more closely controlled conditions in a laboratory‐scale flame attenuation system. These experiments verified the important effect of flame temperature and residence time in creating the surface layer.