| 摘要 |
PURPOSE:To prevent the entry of a reactive material in a fiber surface and to prevent the decrease in transmittance by providing a layer having no grain boundaries at 2-10mum thickness in the depth direction from the fiber surface. CONSTITUTION:The inside of the fiber is made into a polycrystalline state 3 and the surface 2 is made into the fiber sectional structure having no grain boundaries. This surface treatment is executed by condensing light 22 which is nontransparent to the fiber 1 and is impulsive to the fiber 1 surface and scanning the same over the entire part of the surface. The thickness (d) of the surface layer 2 is preferably <=10mum at which the ratio thereof to the fiber diameter is <=10%. About the same surface roughness as the surface roughness of the fiber or below is resulted and the reactive material such as moisture is easily transmittable if the thickness (d) of the amorphous layer is <=2mum. The preferable thickness is, therefore, >=2mum. The outdoor air and grain boundaries are thus shut off by the surface layer, by which the route for the entry of the reactive gas is interrupted and the change of the transmittance with age is obviated. |
