Extrusion method for removing volatile contents from solid state resin materials and apparatus therefor

An extrusion method and apparatus for removing volatile contents from solid state resin materials is described. A cascade-type extruding device is used having first and second extruders. A top end portion of the first extruder 10 is directly connected to a rear side portion of a cylinder of the second extruder 100. Volatile contents of a melted resin, which is melted when the solid state resin material is supplied to the first extruder, are removed in a volatile content removing vacuum unit provided on an upstream side of the connection between the first and second extruders. The melted resin is then extruded from a nozzle provided at a top end portion of the second extruder. The volatile content removing vacuum region of the volatile content removing vacuum unit 140 extends over a first region, which is under the control of the first extruder, and a second region, which is under the control of the second extruder. The pressure and temperature of the melted resin in the first region are controlled in accordance with the properties of the melted resin.