Patent ID: 6434976
Filing Date: 2002-08-20
Classification: C03B,G02B

Abstract:
A manufacturing method for a glass product, comprising the steps of:placing a glass material in a cavity defined by a lower mold, an upper mold, and a side mold; molding the glass material in the cavity with pressure into the glass product in so controlling that the glass material has a viscosity range of 106.5 to 109.5 poises at the beginning of the molding operation with pressure, that the lower mold is at a temperature in a range such that the glass material indicates the above viscosity range, and that the upper and side molds are at a temperature in a range such that a converted viscosity of the glass material at the temperature of the upper and side molds is 5 to 100 times higher than the viscosity of the glass material at the temperature of the lower mold; and decreasing the temperature of the lower mold at the same time that or after the glass product begins to be molded with pressure.