Title:
MANUFACTURE OF INFLATION FILM, DEVICE AND FORMED BODY
Document Type and Number:
Japanese Patent JP3670088
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an inflation film without unevenness in the thickness by a method wherein after extruding an ultrahigh molecular weight polyolefin molten article from a screw die of which the mandrel rotates independently from a first screw, and which has a second screw of a specified L/D ratio, a gas is blown into the tubular film.
SOLUTION: An ultrahigh molecular weight polyolefin is molten by an extruder 1, and the ultrahigh molecular weight polyolefin under a molten state is extruded from a screw die 20 of which the mandrel 23 rotates independently of the screw of the extruder 1, and L/D of which is at least 5. Then, a gas is blown into the tubular film under a molten state, which is formed by the extrusion, and both of the expansion ratio and the longitudinal draw ratio are made 7 or higher. That is, a ratio of the length from an outer die entrance 20A to a screw die exit 20C, and the internal diameter of an outer die 22 at the screw die exit 20C, i.e., L/D of the screw die is made 5 or higher, preferably 20-70.
Inventors:
Takeshi Shiraki
Suzuki Iwashun
Suzuki Iwashun
Application Number:
JP23786596A
Publication Date:
July 13, 2005
Filing Date:
September 09, 1996
Export Citation:
Assignee:
Mitsui Chemicals, Inc.
International Classes:
B29C48/33; B29C48/10; B29C48/34; B29C48/38; B29C55/28; C08F110/00; C08F110/02; B29K23/00; B29L7/00; (IPC1-7): B29C55/28; B29C47/24; B29C47/50
Domestic Patent References:
| JP61239932A | ||||
| JP60250931A | ||||
| JP2030514A | ||||
| JP6055433B2 |
Attorney, Agent or Firm:
Yukio Shoko