Abstract: In a serial two-stage extruder, the first-stage extruder has a screw including a feed screw section having a length within a range of 5 to 9 the major diameter thereof, a mixing screw section having a hexagonal cross section and a pitch of 1 to 3 times the major diameter thereof, and a metering screw section having a screw groove of an appropriate depth. The second-stage extruder includes an extruding screw and a barrel. The extruding screw has a screw groove of an appropriate depth and a dulmage formed at the tip end of the screw. The dulmage has a plurality of fins cooperating with fins of the barrel. Alteratively, in the second-stage extruder, the dulmage may have a plurality of axially spaced stages of fins. Configurations of the fins in each respective stage are identical but various characteristics of the fins vary from stage to stage. In this case, the barrel does not have fins.

Abstract: In a serial two-stage extruder, the first-stage extruder has a screw including a feed screw section having a length within a range of 5 to 9 the major diameter thereof, a mixing screw section having a hexagonal cross section and a pitch of 1 to 3 times the major diameter thereof, and a metering screw section having a screw groove of an appropriate depth. The second-stage extruder includes an extruding screw and a barrel. The extruding screw has a screw groove of an appropriate depth and a dulmage formed at the tip end of the screw. The dulmage has a plurality of fins cooperating with fins of the barrel. Alteratively, in the second-stage extruder, the dulmage may have a plurality of axially spaced stages of fins. Configurations of the fins in each respective stage are identical but various characteristics of the fins vary from stage to stage. In this case, the barrel does not have fins.

Abstract: An auto-threading apparatus is disclosed. In a film processing line incorporating a transferring/receiving mechanism having a take-up unit, two pairs of cutters are moved by twos in crosswise directions of a film to cut away side narrow portions of the film by one pair of cutters. Chain clips catch the film ends to longitudinally divide the film into three parts by the other pair of cutters. The side portions of the 3-divided film are cut away by rotary cutters. The left central portion thereof is cut away by moving the other pair of cutters toward the center. The film is transferred to and received by the chain clips.

Abstract: In a film processing line incorporating a transferring/receiving mechanism having a take-up unit, two pairs of cutters are movable in crosswise directions of a film, and narrow portions of the film at sides thereof are cut away by one pair of cutters. Chain clips catch the sides of the film and the other pair of cutters longitudinally divide the film into three parts. The side parts of the divided film are cut away by rotary cutters. The central part thereof is cut away by moving the other pair of cutters toward the center of the film. A portion of the film is thus transferred to and received by the chain clips.