| 摘要 |
PURPOSE:To perform an exchange of materials or colors in a short time with a little resin, by a method wherein the first and second read valves are kept open always and a screw of an extruding machine is turned while moving an injection plunger forward or backward with short steps at a plunger position which is at a forward movement limit or its vicinity. CONSTITUTION:An injection plunger 8 performs at a forward movement limit position or its vicinity (a forward movement or a backward movement is performed within a small stroke of about 5-20mm from a forward movement limit position, for example, of an injection plunger 8) of the forward movement or the backward movement with short steps. In either case of a material exchange or a color exchange, the first and second read valves 10, 9 are made to keep open always. As for fresh resin 11 to be discharged following a continuous rotation of a screw 7 fitted into an extruding machine 4, at the time of passing of the same through a resin passage 3, a shearing action is acted upon a wall surface and old resin 11A on the wall surface is replaced with the fresh resin 11, in a method performing the exchange as the injection plunger 8 is kept under a forward movement limit state. |
