| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for producing an optical fiber strand by forming an optical fiber bare wire made of quartz glass, and forming a coating layer of a thermosetting silicone resin on the optical fiber bare wire, which can suppress fluctuation of film thickness in a lengthwise direction and fluctuation of film thickness in a radial direction even when the film thickness of the coating layer is increased or linear velocity is increased.SOLUTION: A method for producing an optical fiber strand includes formation of a coating layer 71 comprising a thermosetting silicone resin on an optical fiber bare wire 16. Formation of the coating layer comprises: preliminary coating layer forming steps b and c of (b) coating a thermosetting silicone resin 51 on the optical finer bare wire 16 and (c) curing the coating completely by heating to form a preliminary coating layer 52 having a film thickness of T12 which is smaller than a coating thickness T3 of a product optical fiber strand 24, followed by; main coating layer forming steps d and e of coating an uncured thermosetting silicone resin liquid 61 on the preliminary coating layer 52, curing the silicone resin by heating to obtain the main coating layer 62 integrated with the preliminary coating layer.</p> |
