| 摘要 |
<p>PURPOSE:To easily prepare a resin mandrel having high outer diameter accuracy by measuring the outer diameter of a molten resin between an extrusion head and a sizing die and controlling the emitting amount of the molten resin so that the measured value always becomes a definite reference value. CONSTITUTION:The first outer diameter measuring device 10 measuring the outer diameter of a resin mandrel 8 is mounted between a cooling water tank 6 and a receiving machine 7 and the obtained outer diameter measured value is compared with the predetermined reference value predetermined in the first controller 11 and the number of rotations of the motor of the receiving machine 7 is changed on the basis of the control signal corresponding to the increase or decrease from the reference value to increase or decrease receiving speed. The second outer diameter measuring device is provided at the predetermined position between the extrusion head 3 of an extruder 1 and a sizing die 5 to measure the outer diameter of a molten resin 4. This outer diameter measured value is compared with the reference value predetermined in the second controller 13 and the number of rotations of the screw of the extruder 1 is changed on the basis of the control signal corresponding to the increase or decrease from the reference value to decrease or increase the emitting amount of the molten resin.</p> |
