| 摘要 |
PURPOSE:To prevent the deformation of a spacer by pressing one side of a spiral groove to a molten resin in the same direction as the rotating direction of a rotary die by a mechanical means right after extruding the resin from the rotary die then solidifying the resin. CONSTITUTION: A device 10 is installed right under the rotary die 14 fitted to an extruder 12 for a thermoplastic resin on the same axis there of between said die 4 and a cooling tank 16. The thermoplastic resin in the molten state is supplied from the extruder 12 to the die 14 and a tensile wire 18 is supplied from above the same so as to pass through the die 14. The die 14 is rotated by a suitable means, by which a spacer 20 coated with the resin coating having the spiral groove on the outside circumference of the tensile wire 18 is continuously produced. The spacer 20 subjected to cooling and solidification of the resin in the cooling tank 16 is successively taken off perpendicularly downward. The spacer 20 having the high molding accuracy is thus obtd. |
