Abstract: In a planetary extruder for extruding thermoplastics materials, a threaded main spindle is meshed with and surrounded by threaded planetary spindle. To improve pull-in of material, the planetary spindles are provided in groups, each group comprising at least three spindles. The first planetary spindle of each group corresponds in length to the main spindle and succeeding spindles, considered in an opposite direction to the direction or orbital movement of the planetary spindles, of each group are each shorter than the spindle which immediately precedes it to form receiving spaces for material fed by a feed screw, which receiving spaces in operation are continuously enlarging.In one embodiment in each group, the spindles which are successively shorter are followed by spindles which are successively longer.

Abstract: A screw extruder of the type in which a pair of counter-rotating screws of progressively increasing diameter plasticize and extrude thermoplastic resins and in which an equal ratio of power conversion in shear and convective heating to throuput of material is obtained over the length of the screws.

Abstract: Liquid-containing radioactive wastes are bound into thermoplastic material by introducing particles of thermoplastic material at a non-sticking temperature into a kneading machine, heating the thermoplastic material in the absence of radioactive wastes to at least 100.degree. C., adding the liquid-containing wastes to the heated thermoplastic material, mixing and concurrently increasing the temperature of the mixture to a temperature of about 200.degree. C. or more to vaporize liquid in the mixture, maintaining the mixture at a vaporization temperature to dry to the mixture, releasing evolved vapors and discharging the dried mixture from the kneading machine. Difficulties due to clogging of the kneading machine and fluctuations in the consistency of the dried end product are minimized.

Abstract: A screw extruder for processing rubber or plastics material, comprising a cylinder jacket with a feed hopper, a central geared shaft and geared planet shafts disposed between the central shaft and the cylinder jacket and drivably engaged with the central shaft and the cylinder jacket, wherein parts of at least some of the planet shafts are bare of gearing.Advantageously each alternate planet shaft is only partly geared, the gearing extending for only approximately half the length of the shaft, at one end or the other end or in two quarter length portions at the opposite ends. Alternatively each third planet shaft is only partly geared.Preferably each geared part of a planet shaft which is only partly geared overlaps with a geared part of the planet shaft which follows it in the direction of rotation.

Abstract: Apparatus for the preparation and extrusion of plastics material or rubber, comprising a planet rolling extruder and a feed portion disposed upstream thereof with a main shaft of the planet rolling extruder being surrounded by planet shafts and being driven jointly with a feed-screw of the feed portion, in which some of the planet shafts at their ends adjacent the feed-screw are reduced in section to form transfer shaft portions and thereby receiving chambers for material fed to the planet rolling extruder by the feed portion. The transfer shaft portions may be cylindrical with a diameter smaller than the diameter of the root circle of the planet shaft gearing or may have, adjacent the feed-screw, a diameter smaller than the root circle of the planet shaft gearing and increase in diameter in a direction away from the feed-screw until they achieve the full shaft outline.

Abstract: The screw extruder is provided with screw shafts arranged so as to intermesh in pairs and rotate in pairs in the same sense, each screw shaft of a pair containing at least one double or triple threaded pressure build-up section corresponding to that of the other screw shaft. At least part of the pressure build-up sections have at least a ratio of screw pitch t to housing inner diameter d within the range:0.7.multidot.f(h/d, .delta./d, q/nd.sup.3)<t/d<1.8.multidot.f(h/d, .delta./d, q/nd.sup.In which q is the volume throughput of one screw pair, n is the screw shaft rotational speed, h is the thread depth, measured from the screw thread base to the housing inner wall, .delta. is the radial screw clearance between the screw crest and the housing inner wall and f is a function between the above values which is specified in the description.

Abstract: A method and apparatus for feeding an additive, such as glass fibers, fillers, etc., to a plastic resin in an extruder is disclosed. The additive is fed by means of a screw type feeder into the barrel of a plastics extruder or reciprocating screw plastifier at a location where the resin is molten and the resin pressure is low.

Abstract: A multi-stage extruder apparatus comprising at least two extruder units operatively joined together in series for the progressive sequential working of plastic molding material moving continuously therethrough. The apparatus comprises an improved extrusion screw for a succeeding extruder unit of the multi-stage apparatus which prevents adverse effects attributable to an imbalance of the rate or volume of molding material moving continuously through the multi-stage apparatus.

Abstract: A twin screw extruder comprising a cylinder having twin bores therein to receive the twin screw of the extruder and a circular casing with at least one passage to permit heating or cooling fluid to flow between the cylinder and the casing, in which the cylinder has a generally circular outside contour with a first set of grooves and a second set of grooves forming parts of said at least one passage, extending obliquely to the longitudinal axis of the cylinder and formed in the outer surface of the cylinder, the bottom walls of the grooves extending parallel to a plane which includes the two longitudinal axes of the twin bores with the first set of grooves lying on one side of said plane, and the second set of grooves lying on the other side of said plane, the inclination of said first set of grooves to said axis being opposite to the inclination of said second set of grooves to said axis, and the inside of the casing containing spaced recesses forming further parts of said at least one passage and, except for

Abstract: A highly viscous mass to be homogenized is fed from a screw plasticizer into a mixing chamber, perpendicular to the plasticizer mouth, in which a mandrel rotates independently of the plasticizer screw to masticate the mass in a narrow annular clearance between itself and the chamber wall. The mass, force-fed through this clearance by the screw pressure, encounters several sets of free-floating balls or other rotary bodies loosely guided in annular grooves of the chamber wall, or of the mandrel, while revolving about the mandrel axis. The mandrel may have a screw-threaded rearward extension for admixing additional ingredients from one or more further chamber inlets with the mass to be homogenized, with exertion of a back-up pressure upon that mass. The chamber temperature may be controlled by the circulation of a cooling fluid through its wall and/or through the mandrel.

Abstract: A wear-resistant lining is provided in the work chamber of a screw extruder by providing an internal cavity in the extruder housing of a shape corresponding to the external cross-section of a wearing insert but sufficiently larger such that a gap of predetermined width is provided between the walls. A layer of soft, hardenable material is applied to the outer surface of the wearing insert to a thickness slightly greater than the gap. The extruder housing is heated until the cavity expands to a degree sufficient to allow insertion of the insert. The insert is then placed into the cavity and the material is allowed to harden, as by heat hardening due to the temperature of the extruder housing.

Abstract: A vent for a devolatilizer includes a means defining a vent opening in the cage of the devolatilizer and a vent duct which communicates with the vent opening. Gas escapes into a cylindrical vent chamber in the vent duct. The chamber is cleaned by a vent screw which is rotated in the chamber and which includes a screw body of minimal diameter and a helical screw flight portion of a pitch which is sufficiently large such that the velocity of the vapor leaving the cage through the vent duct is maintained below a predetermined maximum vapor velocity. This maximum vapor velocity is set such that the amount of fine material which is entrained in the escaping vapor is minimized. A vapor return duct is connected to the vent chamber for extracting vapor from the chamber so that it may be recycled or disposed of.

Abstract: Apparatus for separating a substantially insoluble liquid from a mixture containing a polymer or polymer mixture. The liquid is a vapor at the usual temperature and pressure of the polymer extrusion operation and is kept in liquid form by providing a high pressure region in the extruder. A liquid outlet is provided upstream of the high pressure region and the liquid is maintained under pressure and taken off as a liquid. The pressure restricting means may be a liquid outlet provided with a pressure control valve, trap or the like.

Abstract: Methods are provided for processing expandable thermoplastic materials with a typical compression relief design extruder screw having a helical flight for advancing and working a thermoplastic material. The screw is modified to shorten the feed and compression sections and to include a plurality of force-producing components in at least the compression section of the screw such that at least some portion of the components in any one turn of the flight lie in one plane essentially normal to the axis of rotation of the screw and such that the walls of the flight are uninterrupted. This arrangement controls the location of the rupturing or fragmenting of what is referred to as the solid bed and controls the manner in which it is fragmented to provide an extrudate at a die end of the extruder which has a constant temperature and which is uniform throughout each successive section of the thermoplastic material.

Abstract: A screw extruder comprises a casing connected to a bed, the casing comprising two portions connected together longitudinally by connecting elements. At least one of the casing portions is articulated with respect to the bed, and the connecting elements are adapted to release the connection between the casing portions at a predetermined casing pressure to allow the casing portion to articulate to thereby open the casing.

Abstract: An improved polymerization apparatus for finishing high viscosity synthetic polymers involves a vessel having vertical rotating elements which fully wipe the interior surface of the vessel including the top inner surface. Entrances located in the top of the vessel for feeding streams containing molten polymer downwardly into the vessel deposit fresh polymer on the walls and on the upper element surfaces which wipe the top inner surface. A reservoir formed by the leading edge of a raised portion on the upper end surface of the elements facilitates collecting and spreading a fresh supply of polymer on the top inner surface of the vessel to help eliminate stagnant polymer areas thereon during operation.

Abstract: An extruder for synthetic material is disclosed which includes an extruder housing provided with at least two worm conveyer shafts, each having one or more helices thereon. An inlet opening is provided in the housing at the extruder input for introducing the synthetic material and a degassing outlet is provided in the housing downstream of the inlet. Intermediately of the material inlet and degassing outlet, distributing members are arranged on the worm shaft peripheries, the distributing members comprising intermeshing tooth-shaped heightened parts of generally hemispherical configuration.

Abstract: An apparatus for making variegated soap bars or cakes. Said apparatus provides for co-plodding differently colored commingled sets of soap noodles having particular diameters.

Abstract: A gaseous phase disengaging apparatus for a liquid phase process material contaminated with a substance of lower boiling point comprising a twin screw extruder through which the raw feed is passed and within which the feed is repetitively spread over the apparatus inside surfaces and thereafter recombined, which apparatus is provided with paired raw material supply inlets and gaseous phase vent ports maintained in continuous communication therebetween during screw rotation.

Abstract: An internal mixer for kneading and rolling includes a mixing chamber containing two parallel spaced shafts. Kneading blades and arcuate roller surfaces are provided on the outer peripheries of the shafts. The arcuate surfaces are so disposed on the shafts such that a gap is formed therebetween when in their innermost positions. The arcuate surfaces and kneading blades are disposed serially in the peripheral direction on the shafts. The shafts rotate in opposite directions and so as to provide the same peripheral speed for the arcuate surfaces.