| 摘要 |
PROBLEM TO BE SOLVED: To utilize the constant volume supply of molten resin conducted with a gear pump, reduce the pulsation of the molten resin generating in supply, manufacture an high quality insulating cable, and easily transfer a reflected standing wave ratio of a insulating cable beyond a frequency band used even in the using frequency band where the deterioration of the reflecting standing wave ratio is of concern. SOLUTION: A constant volume of molten resin is supplied to a cross head 6 with a gear pump 5, and extruded on a central conductor 7 to cover it for manufacturing an insulating cable. The pulsation frequency of the gear pump 5, based on the number of tooth and the number of revolutions of a gear in the gear pump, is set larger than the frequency in which deterioration of the reflected standing wave ratio is of concern, the height of teeth of the gear in the gear pump 5 is decreased and the number of the teeth is increased. |
