| 摘要 |
PURPOSE: To obtain mesh films of various selected diameters without exchanging a device by comprising an extrusion die for extruding a synthetic resin plasticized by heat and a cooling means located in the center of the extruded tube for cooling an inner surface of the tube. CONSTITUTION: A tube 12 of a synthetic resin material plasticized by heat such as polyethylene, is extruded from an extrusion die 10. The extruded tube 12 is moved almost upward to be passed through a first cooling means 14 located in the inner central part of the extruded film tube 12 for cooling an inner surface of the tube 12. The enlargement or stretching of the tube 12 is performed after it is passed through a ring gas bearing 40. The extruded tube 12 in an area 44 after the passage of the bearing 40 can be inflated by the external gas bearing 40. By the inflation, the area 44 can be provided with a desired diameter as shown by a broken line and a solid line. |
