PURPOSE: To obtain the titled film excellent in the balance of strength without using a core or the like, by cooling a high-density polyethylene melt resin tubular body extruded from an annular extrusion die by an air ring apparatus having a specified action.
CONSTITUTION: After a high-density polyethylene melt resin that has been melted and kneaded in an extruder is extruded from an annular slit 2 of an annular die 1, the melt resin tubular body is cooled by an air ring apparatus 7 that has a blowing outlet 6 directed outward and upward with respect to the direction of the extrusion of the resin to obtain the intended film. Preferably, the direction of the blowing outlet 6 is tilted 5W60° outward and upward with respect to the direction of the extrusion of the resin.
EFFECT: High speed molding becomes possible, and a blown film can be produced inexpensively.
KOMATSU HITOSHI
MIHARA YOSHIYUKI
| JPS5874322A | 1983-05-04 | |||
| JPS57115320A | 1982-07-17 | |||
| JPS53137261A | 1978-11-30 |