INNER MANDREL

摘要

The object of the present invention is to provide an internal mandrel for cooling a tubular thin film where air layer is not remaining in the lower side cooler of the internal mandrel, so that the tubular thin film can be continuously and stably produced. In the internal mandrel for directly cooling the tubular thin film while using external circularly shaped cooling tank where the tubular thin film is downwardly extruded through a circular slit of the die, the internal mandrel is characterized in that coolant for cooling a lower most part of the internal mandrel is flown in such a direction as to oppose to the tubular thin film.