| 摘要 |
PURPOSE:To produce multiple optical fiber with precoat layers having improved thin film properties, by drawing a preform bundle to give multiple optical fiber, passing the optical fiber through a bath of varnish dissolved in a solvent, and drying it. CONSTITUTION:One end of the bundle of preform 1 for optical fiber having 100mum-1mm diameter is heated and softened by the furnace 2, and drawn in a state where neighboring preforms for optical fiber are fused mutually. The prepared multiple optical fiber 3 is passed through the bath 4 of varnish in a solvent so that a coated layer of the varnish is formed on the outer periphery of the optical fiber 3. The bath 4 of varnish in a solvent is obtained by dissolving polyimide varnish wax, etc. in an organic solvent to give 15-50wt% solid content concentration and used. The multiple optical fiber 5 coated with the varnish is then passed through the drying furnace 6 to dry the varnish, wound, and heated by the furnace 10 to form the precoat layer with <=200mum thickness. |
