Silicone- and ethylene-vinyl-acetate-coated laser-drawn silica fibres with tensile strengths >3.5 GN/m2 (500 kp.s.i.) in >3 km lengths

Tensile strength measurements have been made on fused silica fibres coated with a silicone resin or an ethylene-vinyl-acetate (e.v.a.) hot-melt adhesive. The average strength measured in 20 m guage lengths was 4.7 GN/m2 (671 kp.s.i.) for 3 km of silicone-coated fibre and 5.2 GN/m2 (743 kp.s.i.) for 3.6 km of the e.v.a.-coated fibres. Although control of many drawing and coating process parameters is required to achieve these strengths, the results suggest that under similar conditions other coating systems may perform equally well.