EXTRUSION RAW MATERIAL FEEDING DEVICE AND METHOD OF PRODUCING OPTICAL TRANSMISSION BODY BY USING EXTRUSION RAW MATERIAL FEEDING DEVICE

摘要

The invention provides an extrusion material supply device suitable for use in melt extrusion molding, and a method for manufacturing an optical transmission body, in which a deterioration of an optical signal transmission loss is extremely small, and productivity intrinsic to an extrusion molding method is provided in combination. An extrusion material supply device 1 includes: a vertical hopper 2, which has a cooling unit 3 and a heat melting unit 4 continuous with a lower portion thereof, and houses a material rod R; cooling means 5 for cooling the cooling unit 3; an electric heater 6 that heats the heat melting unit 4; and gas pressurizing means 7 for sequentially supplying molten plastics M to a metal die by a gas pressure. The heat melting unit 4 is formed into a cylinder shape in which an inner diameter is larger than an inner diameter of the cooling unit 3 arranged above, and enables the molten plastics M to spread in the heat melting unit 4. A portion between an outer circumference of the material rod R and an outer circumference of the molten plastics M is defined as an annular gas pressurizing surface 7a.