| 摘要 |
PURPOSE:To rapidly discharge air from a filter apparatus at the start time of operation, in allowing a resin to flow in the empty filter apparatus in which the resin does not yet flow, by filling the filter apparatus with the resin while the interior of the filter apparatus is held to a vacuum state from the part on the downstream side thereof. CONSTITUTION:Prior to starting operation, at first, a two-position three-way valve 15 is preliminarily set to a first position state. Thereafter, the extrusion of a resin is started from an extruder 2 and, at the point of time when the molten resin passes through a gear pump 4, the operation of a vacuum pump 14 is started to bring the region from the pump 14 to the leading end of the molten resin containing the interior of the disc filter apparatus 6 on the upstream side of the pump 14 to a vacuum state. By this method, extrusion is continued in the vacuum state and the disc filter apparatus 6 is perfectly filled with the molten resin and, at the point time when the leading end of the flow of the molten resin passes through the disc filter apparatus 6, the operation of the vacuum pump 14 is stopped to gradually return the pressure in the runner to atmospheric pressure and the two-position three-way valve 15 is changed over to the other position and the extrusion of the molten resin is continued in this state. |
