Effects of Reheating on Strength of Glass Fibers

Glass fibers of 12 and 22μ in diameter were drawn from the glass melt, the temperature of which were kept at 1170°C during the fiber forming process. The composition of the glass used was as follows: SiO2 67, B2O3 12, BaO 2, K2O 9, Na2O 9.5, Al2O3 0.5% (in weight).The glass fibers were repeated at different temperatures between the room temperature and the softening temperature of the glass, and then were etched with hydrofluoric acid. The tensile strength of the reheated fibers was measured before and after the etching.It was found that, although the tensile strength of fibers decreased by reheating, it regained its original value when its thin surface layer was removed by hydrofluoric acid.