Ejecting Residual Material From Three-Plate Mold

The Stationary Plate with Lug

Fig 6 12 is a construction of the stationary plate with lug. The molten plastic passes into the cavity through a needle gate that the mold is in three-plate or having two parting lines. These two parting lines open one after another. This construction is more complicated than the former structures. The mold is operated in the following manner: when the nozzle of the machine moves away from the sprue bush, the belleville springs I lift the sprue bush 8 by one or two millimeters and the residual material or sprue is detached from the sprue bush 8. In the first step of the opening of sub-parting linePL I), the plastic solidified in hug 7 machined at an angle of 300 breaks off the material at the needle gate, and the residual material in the runner and sprue bush is carried along by the pullers 3 arranged in the runner. The waste is pulled out of the stationary mold (Fig. 6.12b). At a certain point in the opening path, PL Il opens for taking workpieces off also, and the intermediate plate 6 which containing the needle gate lifts the residual material or waste off the pins 3, so that the waste falls out of the mold  (Fig.6.12c) automatically.