PRODUCTION OF PLASTIC OPTICAL FIBER

摘要

PURPOSE:To minimize the damage to be received on an optical fiber core by the heat and pressure occurring in the coating layer component in a high-temp. molten state in the stage of coating by using a melt extrusion coating device having 2.0-3.0D die diameter. CONSTITUTION:The optical fiber core 1 conducted through a fiber introducing part 4 of a diameter (d) to the die 3 contacts with a coating polymer 2 in a molten state at the point A and is taken up in the form of the coated plastic optical fiber cord 5 at a specified speed. The quantity of the heat which the core 1 receives from the coating polymer 2 in the die 3 is larger as the die diameter D' and the length L between A and B are larger. The fluid resistance of the polymer 2 increases and the pressure on the core 1 increases if the die diameter D' is small. The quantity of the heat to be transferred to the core 1 and the pressure to be exerted on the core 1 are therefore required to be decreased by controlling the die diameter D' to a specified range. The damage during coating of the fiber is thus suppressed by selecting the die diameter D' at 2.0-3.0 times the diameter D of the core 1.