| 摘要 |
PURPOSE: To mold with a high pressure at a high speed and improve impact strength and tensile strength of a film by a method wherein a melting film consisting of a thermoplastic resin extruded from a plurality of die lip outlets arranged on a concentric circle is made to be in contact with a stable body attached to the front of a die so as to join integrally. CONSTITUTION: A die is connected to an extruder by a joint. A resin extruded from the extruder is made to pass through an inner annulus 1 and an outer annulus 2 and extruded from inner and outer die lip outlets so as to mold a film. At this time, an inner layer resin 7 and an outer layer resin 8 are in contact with a stable body 14 and connected at a junction 9. The inner layer resin 7, the outer layer resin 8, the junction 9 and the die face form a space 10. The volume of the space 10 is controlled according to quantity of gas to be supplied through a valve 6 and a gas communicating hole 5. The inner layer resin 7 and the outer layer resin 8 expand being cooled by an air ring and molding is performed by cooling and solidifying them. |
