Processing effects on the surface composition of glass fiber

In this study, differences in the surface composition of commercial glass f iber have been characterized as a function of process. The two processes st udied were flame attenuation, a high-temperature combustion-assisted proces s, and continuous filament drawing through a bushing. The techniques used t o 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 vapo r pressures at the surface, during fiberization, showed significant differe nces in the behavior of Na, B, and F species in the two processes. To furth er test the models, glass fibers were produced under more closely controlle d conditions in a laboratory-scale flame attenuation system. These experime nts verified the important effect of flame temperature and residence time i n creating the surface layer.