| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for coating optical fibers in which the uneven thickness of the coating layer can be minimized, even when the fibers are coated at an increased speed. SOLUTION: The coating fluid from the fluid pass 30 formed between the coating die 10 and the nipple 20 is fed into the tapered hole 11 of the coating die 10 of the coating machine in combination of the coating die and the nipple 20 and the optical fiber passing via the nipple 20 into the tapered hole 11 at a speed of >=830cm/sec is coated with the coated fluid. In this process, the numerical value D represented by the following formula is set to 8,000<=D <=20,000: D=(12μQ)/(πrC<2> ) whereμ: the viscosity of the coating fluid in the dice in g/cm.sec; r: the radius of the tapered hole at the part where the optical fiber and the coating fluid meet in cm; C: the clearance at final squeeze of the fluid pass in cm; Q: the coating volume of the fluid per unit time in cm<3> /sec; additionally, Q=πV(t<2> -u<2> )/4 where V: linear velocity of the optical fiber in cm/sec; t: the diameter of the coated optical fiber; u: the diameter of the optical fiber in cm.
|
