Abstract: A plasticating apparatus adapted to handle a wide variety of synthetic resinous materials without predrying. The plasticating apparatus includes a two-stage screw rotatably and reciprocably mounted within a barrel. A surge suppressor is provided between the first and second stages and is comprised of an integral protrusion of the screw root and a deep channel section immediately preceding the protrusion. The surge suppressor prevents the surge of molten material into the vent area following the holding portion of an injection molding cycle, thereby allowing faster recovery and preventing bleeding of plasticized material from the vent opening.

Abstract: A multichannel wave screw with a slush channel barrier section adapted to provide a consistent mixture of 50% solids and 50% melt to both channels of the double wave metering section. The screw includes a barrier flight having a relatively large initial clearance which allows solids to enter the newly formed slush channel. The barrier flight gradually decreases in clearance to a final barrier flight clearance which allows some dispersed solids to enter the slush channel. At the terminal end of the barrier section, the barrier flight abruptly increases its pitch, thereby abruptly narrowing the solids channel and therefore forcing solid material over the barrier flight and into the slush channel. In this manner, a uniform mixture of solid and melt is provided to the multi-channel wave metering section.

Abstract: A multichannel wave plasticating screw having a feed section, barrier melting section, and metering section wherein solid material is transitioned from the trailing side of the primary flight to the push side of the primary flight at the terminal end of the barrier melting section. The solids transition is accomplished by interchanging, or "reversing" the diameter and width of the primary and secondary flights at the terminal end of the transition section. Alternatively, the barrier flight includes a short section of increased pitch at the terminal end of the barrier melt section which abruptly narrows the solids channel and thereby forces solid material over the barrier flight into the melt channel and on the pushing side of the primary flight. Transferring solid material from the trailing side to the push side of the primary flight increases the shear and pressure applied thereto and more quickly and efficiently melts solids.