Abstract: A three piece, sliding ring valve for use in a plasticating screw and barrel arrangement has an extended life. The sliding ring has apertures for passing molten resin therethrough. The sliding ring also has annular contact surfaces for spreading the force driving the screw, thereby decreasing the pressure between the sliding ring and the valve retainer. The result is less valve wear and longer life.

Abstract: An extruder for plasticating and extruding an extrudate, and an extrusion screw used with the extruder form the subject of this invention. The extruder screw includes an elongated root body and a thread portion helically wound about the root body and extending along the length. The screw having a low compression ratio, flight with a reduced helical angle, and a conical, tapered front end section where at least one-half flight of the thread has a pitch associated therewith which is different from the pitch of the remainder of the thread and where the diameter is less than the diameter of the remainder of the root body.

Abstract: An extruder for plasticating and extruding an extrudate, and an extrusion screw used with the extruder form the subject of this invention. The extruder screw includes an elongated root body and a thread portion helically wound about the root body and extending along the length. The screw having a low compression ratio, flight with a reduced helical angle, and a conical, tapered front end section where at least one-half flight of the thread has a pitch associated therewith which is different from the pitch of the remainder of the thread and where the diameter is less than the diameter of the remainder of the root body.

Abstract: A plasticating apparatus including a rotating screw having a helical flight disposed within and cooperating with the inner wall of a heated barrel. Solid resinous material is introduced to a helical valley extending between said flight to be heated and plasticized by said apparatus while being advanced towards an outlet opening by the rotation of said screw. The screw has a meter section for working, melting and mixing said resinous material at high temperatures. The bottom surface of the helical valley in said metering section is divided into side by side relatively shallow and relatively deep levels. Within the metering section is a transit channel having a reverse helical direction as compared with the helical direction of the flight. Because of the reverse helical direction of the transit channel, the transit channel intersects the helical flight and helical valley with the transit channel cutting therethrough.

Abstract: A plasticating screw and method of plasticating without thermal degradation problems. Said screw having a metering section with a helical flight disposed within and cooperating with the innerwall of a heated barrel. In particular, solid resinous material is introduced to a helical valley extending between said flight. The resinous material is heated and plasticized by said apparatus while being advanced along a helical path towards an outlet opening by the rotation of said screw. The bottom surface of the helical valley in said metering section having a plurality of geometrically shaped surfaces in side-by-side relation with at least two of said shaped surfaces being sloped. During operation, the level differential between the shaped surfaces induces a continuous tumbling, variable shear and mixing action upon the molten resin as the molten resin in the metering section flows along the helical path.

Abstract: An apparatus and method for controlling thermoplastic mixing in a plastic extrusion machines used for injection molding, blow molding or other reciprocating molding process. The plastic extruder having a rotating helical screw within a cylindrical shell with an automatic shut-off and mixing valve secured to the helical screw at the downstream end of the screw. The automatic shut-off and mixing valve includes a unitary valve body with a poppet. A plurality of mixing groove pairs are arranged extending substantially longitudinally on the surface of the valve body. Select angular bores extend from the groove pairs to the poppet. The poppet is axially movable within and rotatable relative the valve body. The poppet has an axial stem extending into a longitudinal axial bore within the valve body. An elastic means is positioned on the rearward end of the poppet maintaining the valve in a normally closed position against a seating surface of the valve body when there is no rotation of the helical screw.

Abstract: A screw for use in an plasticating injection apparatus includes a plurality of interrupted primary flights. An outer surface of a primary valley is formed by the primary flights and features a plurality of plateaus. The plateaus span adjacent sections of the primary flights and define shallow levels between deeper levels of the primary valleys. This depth differential contributes to a turbulent mixing action which, along with the primary and secondary valleys, contributes to improve mixing action within a metering section of the screw. The primary flights are interrupted by secondary valleys which are of opposite hand to the primary valleys.

Abstract: A pipe coupling device wherein the connection between pipe members is made by rotating one member relative to the other member so that a plurality of radially extending surfaces of one member face corresponding radially extending surfaces of the other member. The facing surfaces can be flat and planar. The plurality of facing flat surfaces initially face each other in an interlocking arrangement which is not tight. A single threaded adapter is then tightened to draw the plurality of facing surfaces of one member tightly against the corresponding facing surfaces of the other member.

Abstract: A plastic extruder having a rotating helical screw within a cylindrical shell. An automatic shut-off valve is mounted at the forward end of the helical screw. The valve includes a unitary or integral valve body and a poppet which is axially movable and is rotatable relative to the valve body. A rearwardly extending axial bore is provided at the forward end of the screw and the valve body extends into and is secured to the screw within said bore. The poppet has an axial stem which extends through the valve body into the axial bore. A compression spring is mounted on the rearward end of the poppet stem to act cooperatively with respect to the poppet to urge the poppet against a seating surface of the valve body and maintain the valve in a normally closed position. Flow of plastic through the valve upon rotation of the screw causes the valve to open. However, the valve automtically closes upon cessation of screw rotation to prevent back-flow of plastic during the injection step.

Abstract: A method and apparatus for regulating the flow of plastic particulates to the opening of a cylinder of a plasticating screw. The particulate pass through a feed throat disposed at a feed opening of the drum. A valve mechanism disposed in the feed throat includes upper and lower members connected by pivot means. A fulcrum is located below the pivot means and the lower member bears on the fulcrum. The upper member is moved up or down which in turn causes the lower member bearing on the fulcrum to swing about the pivot means to open or close the valve. As the valve is closed, the lower member moves downwardly towards the rotating screw to prevent flooding with particulates of the feed opening of the cylinder.

Abstract: A plasticating apparatus and method for its use including a rotating screw having a helical flight disposed within and cooperating with the inner wall of a heated barrel with said barrel provided with inlet and outlet openings so that particles of resinous material are introduced through said inlet opening to a helical valley extending along said flight to be plasticated by said screw and advanced towards said outlet opening. A barrier extends along said helical valley to divide said helical valley into coextensive side by side helical valley sections. The barrier extends in a path which is non-parallel and alternating with respect to the helical flight so that the pitch of the barrier is alternately greater than and less than the pitch of the helical flight. The height of the barrier is less than the height of the flight so that the resinous material overflows the barrier due to changes in width of said side by side helical valley sections.

Abstract: A method and apparatus for cutting grooves onto the interior surface of the barrel of a plasticating machine in order to increase the friction against sliding unmelted resin particles. The helical screw is removed from the barrel without removing the barrel from its operating site. A grooving device is transported from a remote location to the plasticating operation site and mounted within the barrel with a portion protruding from the barrel. A brace is attached to the end of the barrel to help support the grooving device. Periodic adjustments are made to the grooving device by manual or automatic manipulation of the grooving device.

Abstract: A method and apparatus for cutting grooves onto the interior surface of the barrel of a plasticating machine in order to increase the friction against sliding unmelted resin particles. The helical screw is removed from the barrel without removing the barrel from its operating site. A grooving device is transported from a remote location to the plasticating operation site and mounted within the barrel with a portion protruding from the barrel. A brance is attached to the end of the barrel to help support the grooving device. Periodic adjustments are made to the grooving device by manual or automatic manipulation of the grooving device.

Abstract: Ionomers can be injection molded and extruded in wet condition using a vented, two-stage barrier screw wherein the barrier flight melt channel is operated only partially filled.

Abstract: A plasticating apparatus including a rotating screw having a helical flight disposed within and cooperating with the inner wall of a heated barrel. Resinous material is introduced to a helical valley extending along said flight to be plasticated by said screw and advanced towards an outlet opening. The screw has a metering section for working said resinous material at high temperature. The bottom surface of the helical valley in said metering section is divided into side by side relatively shallow and relatively deep levels having a depth differential therebetween. The relatively shallow and relatively deep levels extend along the bottom surface of the helical valley in side by side helical paths. The side by side helical paths have a different pitch than the pitch of the helical flight so that the helical flight periodically interrupts the helical paths.