PRODUCTION OF PREFORM FOR POF AND APPARATUS FOR PRODUCTION THEREFOR

摘要

PROBLEM TO BE SOLVED: To improve the evaporation efficiency of a gaseous solvent, to shorten a molding time and to obviate the occurrence of clogging of a raw material supply line by using a varnish polymer as a polymer material, reducing the pressure in a cylinder for centrifugal forming and further forming the raw material supply line and a pressure reduction line to a double structure. SOLUTION: The pressure reduction line is connected to the inside of a rotating body consisting of a hollow tube 13 and a heat source 9 is disposed in the outer peripheral part thereof. A chamber F and the hollow tube 13 are sealed by a rotary seal 8 via a chuck 5. While the pressure in the rotating body consisting of the hollow tube 13 is reduced, the rotating body is rotated and is subjected to internal deposition under heating at the time of producing the preform for a GI-POF to be manufactured by internal deposition by using the varnish polymer E and rotating the same in the rotating body consisting of the hollow tube 13. The raw material supply line and the pressure reduction line are made into the double structure and are connected to the hollow tube 13. The inner side is formed as the raw material line and the outer side as the pressure reduction line. The inside of the rotating body consisting of the hollow tube 13 to be subjected to the pressure reduction is purged by nitrogen as inert gas.