Production manner of the high-temperature formation item, production manner of preform for precise press molding, and production mannered null continuation

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a hot-molded article (molten glass gob) in such a manner as to ensure the retention of a glass gob by suction at the front end of a suction nozzle and not to scratch the glass gob; to provide a method for producing a preform for precision molding by processing the hot-molded article obtained thereby; and to provide a method for producing an optical element by precision-press molding of the preform obtained thereby.;SOLUTION: There is provided a method for producing a hot-molded article comprising: floating a molten glass gob received by a lower mold by applying wind pressure thereto on the lower mold; meanwhile cooling it in the course of transfer of the lower mold to adjust viscosity to a prescribed value; press-molding the glass gob adjusted to a prescribed viscosity on the lower mold by using an upper mold at a specified position; thereafter cooling the press-molded article on the lower mold in the course of transfer of the lower mold; and taking out the press-molded article from the lower mold. Before taking out of the lower mold, the molded article is positioned in a noncontact manner at a prescribed position on the molding surface of the lower mold, and then is taken out. A method for producing an optical element comprising precision-press molding the preform made thereby is also provided.;COPYRIGHT: (C)2013,JPO&INPIT