Abstract: Apparatus for use in producing pellets including a pelletizer having an annular chamber partially defined by a pellet plate against which spring loaded knives are urged. Pellets produced by moving the knives relative to the plate to repeatedly cut plastics extruded through apertures in the plate are carried by a water stream out of the chamber. This stream enters the chamber via an inlet and performs one cycle round the chamber before exiting the chamber with the pellets via exit which is in the same plane as inlet. With this arrangement the axial extent of the pelletizer is reduced and the relatively short travel of the pellets promotes efficiency.

Abstract: An extruder (2) comprising an extruder barrel comprising a plurality of barrel modules (4), each provided with an inner lining material (16), and at least one plate (6) is described. Such an arrangement facilitates assembly and dismantling of the barrel for replacement of inner parts. In a preferred embodiment, a plate (6) having an opening (26) passing therethrough and comprising projections (30) extending into said opening, is interposed between each two adjacent barrel modules (4), the openings of the plates (6) and internal surfaces of the barrel modules forming a substantially continuous passageway which provides an extrusion chamber (3).

Abstract: Mixtures of particulate material of widely different particulate sizes segregate on storage, smaller particles falling to the bottom. In the invention mixture is supplied to a bunker in a plurality of layers and subsequently withdrawn so that mixture is taken from each layer simultaneously. Apparatus used comprises a rotor dividing the bunker into several equal compartments. During introduction of a batch of mixture to the bunker the rotor is rotated through several revolutions so that the mixture forms layers in each compartment. The bottom of the bunker is flat. An outlet slot in the bottom extends along a chord. A crew conveyor below the slot carries mixture falling through the slot away from the bunker. The rotor rotates slowly during dispensing in synchronism with the conveyor, pushing mixture to the slot at such a rate that material from every layer in a compartment falls into the slot simultaneously, the compartments being progressively emptied.

Abstract: A high intensity internal mixer for plasticizing material, having a mixing chamber comprising a plurality of interconnected mixing bores. Each bore contains a rotor for mixing material therewithin. Each rotor has at least one blade or wing with a sharp edge on its outer extremity adjacent the leading edge of the wing. The sharp edge is formed by a groove being cut along the extremity of the leading edge of the wing of the rotor blade. Each blade has a slight helical twist, and is configured to provide efficient material breakup.

Abstract: An extruder having a screw rotatable in a chamber provided with an annularly perforated end wall through which plastic material is extruded, the end of the screw being provided with a collar urged against the central portion of the wall to exclude the material therebetween.

Abstract: A through feed mixer for mixing and plasticizing a variety of materials has a pair of coaxially disposed rotors in a mixing chamber. The rotors are without helical twist but each have a mixing section which is derived from a regular n-sided polygon comprising n similar peripheral portions, n preferably being 3. Each rotor may have a gradual taper to its body portions. The mixer also includes a feeding device adapted to supply material to be mixed to an inlet portion of the mixing chamber under substantially constant pressure, and an outlet end portion transferring mixer material to an extrusion device.

Abstract: An extrusion apparatus for use with thermoplastic materials has a withdrawable rotor which is mounted on a piston motivated carriage, the carriage having anti-vibration mounting members to reduce loads on the rotor. A gaseous vent chamber is operable in conjunction with a reversible extruder screw and a waste mix ejection arrangement, to prevent undesirable contamination or incompletely mixed material from the extruded product.

Abstract: The invention relates to a chain of modules constructed to sequentially dry plastic particles each module comprises a mixing chamber having a trough formed therein, the trough having side walls inclined to the horizontal and a slot extending along the bottom thereof. The slot is covered by a grating to permit passage of air into the mixing chamber but to prevent particulate material from falling out of the trough through the slot. A pressure chamber is constructed immediately below the trough in the body portion of the module and means, are provided for delivering air to the pressure chamber thereby causing a stream of air to be forced upward into the mixing chamber through the slot in the trough. Each module is tilted to provide a flow of plastic particles through the trough.

Abstract: Plastic extruding and roll forming apparatus having a connecting passage at least partially formed by a plate which is swingable between open and closed position to conduct material from an extruder to forming rolls and to provide access and/or to release excess material in the passage. The extrusion and forming rates are controlled by the movement of the plate.