METHOD FOR FORMING GLASS VESSEL HAVING FLAT FACE

• Main Author: SHIBAOKA KAZUO
• Format: Patent
• Language: English
• Published: 06.02.1991
• Subjects: CHEMISTRY; GLASS; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; METALLURGY; MINERAL OR SLAG WOOL

PURPOSE:To improve the flatness of a face of a glass vessel by sucking air through small holes of a female mold to suck and fix the molded article to the female mold before releasing the molded glass article from a male mold and thereafter releasing the male mold from the molded article. CONSTITUTION:A male mold 1 for forming the upper face and a female mold 2 for forming the lower face are heated at about 550 deg.C. Each mold has a number of small holes having diameter of <=100mum. A prescribed amount of a glass gob heated at about 1000 deg.C is supplied to the female mold 2 and pressed with the male mold 1 to form a molded article having a thickness of about 5-10mm. The space in the mold is evacuated to about 3.3X10 Pa through a suction port 6. The male mold 1 for forming the upper face is moved upward, the pressure in the space is returned to atmospheric pressure through the suction port 6 and the molded article is released from the mold after cooling. Unevenness caused by the small holes is unnoticeable on the central flat face of the obtained molded article and the glass vessel having a flat face free from warpage can be produced by this process.