| 摘要 |
PURPOSE:To enable extrusion molding to be achieved under optimum condition without the occurrence of surging and vent up phenomenon by a method in which while the pressure immediately after bent zone is caused to be inside of allowable value, the feeding amount of the stock-feeding device of a constant amount type is regulated so that the deviation amount of the pressure in a discharging part is inside of allowable value. CONSTITUTION:When a controller 12 begins controlling, first, the pressure PV immediately after vent zone and discharged pressure PA are measured by resin pressure-sensors 16, 17. The pressure PV immediately after the vent zone and the allowable value of the diviation width DELTAPA of the discharged the pressure PA, are respectively set preliminarily e.g. at 20kg/cm<2> and 2kg/cm<2>, and these set values have been inputted into a controller 1. Next, when the measured value of the pressure PV immediately after the vent zone is inputted into the controller 12, the controller 12 compares this measured value with the allowable value DELTAPV. When the pressure PV is equal to 20kg/cm<2> or more, since the process is in bent up phenomena or in the tendency thereof, a command is sent to the stock-feeding device 11 of a constant amount type so that its feeding is reduced by a prescribed amount. |
