This die/di the airing which concentrically possesses the annular spit hole of top and bottom 2 step is provided in the vicinity of the annular emission opening

摘要

PROBLEM TO BE SOLVED: To enable steady and high-speed forming with low pressure loss by improving two-stage blowing-off air ring structure. ;SOLUTION: An outer lip of a lower-stage ring-shaped blow-off port 20 near a ring-shaped discharging port 11 is formed on a lower end part 31a of bubble- side inclined inner surface 31 of a high ring-shaped block body 30. The bubble- side inclined inner surface 31 has a ring-shaped inner surface with diameters gradually increasing upward, where air stream is guided along an entire outer periphery of a bubble B. An inner lip 23 of an upperstage ring-shaped blow-off port 21 is formed on the upper end of the ring-shaped block body 30. On an outer periphery of an outer lip 24 of the upper-stage blow-off port 21, an auxiliary lip 25, which can be adjusted by moving vertically, is provided. A ring-shaped pressure chamber 26 of variable capacity is formed for opening toward the bubble B side between the outer lip 24 and the auxiliary lip 25.;COPYRIGHT: (C)1998,JPO