An installation for manufacturing cross-linkable polyethylene compounds which comprises a melting machine (101), a melt pump (102) and a filtration unit (103) to produce cross-linkable polyethylene compounds that may be further used for manufacturing insulating parts of medium, high and extra-high voltage power cables, and a method for manufacturing such cross-linkable polyethylene compounds.

A system and method to dispense, mix, and inject liquids and force them into a vented investment pattern mold cavity comprises a source of raw materials in fluid communication with an injection unit for metering and delivering the raw materials. A mixing and injection head receives and mixes the metered raw materials. A movable molding cart upon which an investment pattern mold is mounted is disposed adjacent the injection unit and proximate the mixing and injection head. The movable molding cart includes a fill cup that may be engaged by the mixing and injection head. A displaceable gating tray provides fluid communication with the fill cup and a sprue aligned with an investment port on a lower portion of the investment pattern mold. The system also includes a digital computer control by which the injection process may be controlled.

A gear box for a reciprocating kneader. A primary rotational gear is attached to a gear box primary shaft and rotates in concert therewith. A secondary rotational gear is engaged with the primary rotation gear and rotates therewith. A secondary shaft is attached to the secondary rotational gear and rotates therewith. A primary oscillation gear is attached to the gear box primary shaft and rotates therewith. A secondary oscillation gear is rotationally engaged with the primary oscillation gear and rotates on the secondary shaft. An eccentric is coupled to the secondary oscillation gear and rotates in concert therewith. A yoke is engaged with the eccentric and oscillates on an axis perpendicular to the secondary shaft in response to the lobe. The gearbox secondary shaft moves along its axis in concert with yoke oscillation. A housing is pivotally attached to the yoke and pivotally attached to a casing at a casing.

A gear box for a reciprocating kneader. A primary rotational gear is attached to a gear box primary shaft and rotates in concert therewith. A secondary rotational gear is engaged with the primary rotation gear and rotates therewith. A secondary shaft is attached to the secondary rotational gear and rotates therewith. A primary oscillation gear is attached to the gear box primary shaft and rotates therewith. A secondary oscillation gear is rotationally engaged with the primary oscillation gear and rotates on the secondary shaft. An eccentric is coupled to the secondary oscillation gear and rotates in concert therewith. A yoke is engaged with the eccentric and oscillates on an axis perpendicular to the secondary shaft in response to the lobe. The gearbox secondary shaft moves along its axis in concert with yoke oscillation. A housing is pivotally attached to the yoke and pivotally attached to a casing at a casing.

A device for cleaning an extruder includes a frame that supports a screw and a barrel. When driven by a driver, the screw is rotatable about a longitudinal axis of the barrel. The barrel includes a feed inlet and an outlet that opens directly into an extrusion die mounted on a support. The frame is translationally movable relative to the die and the support in a direction parallel to the longitudinal axis between a first position, in which the barrel and the die are in sealed contact, and a second position, in which the barrel is moved away from the die in order to allow cleaning to be performed. The device also includes an automatic coupling mechanism that enables quick locking and unlocking of the barrel and the die, so that the frame can move between the first and second positions when the barrel and the die are unlocked.

The devices relate to the nuclear, metallurgical, mining, machine-building and food industries and may be used in producing semi-finished products and items made via the extrusion of powders of composite, polymer and other plastic masses. A device for producing semi-finished products or items made of composite, or polymer, or plasticized powder materials includes a screw press with a housing and a screw within the housing. The housing and the screw each have at least one deformational portion with protrusions and may each be formed integrally with the protrusions or may be formed compositionally, having special insertable rings which are provided with protrusions. In carrying out all three device variants, the housing and the screw are formed compositionally, and have provided, on the deformational portions of a ring, stators, which are secured to neighboring portions of the housing, and rotors, which are secured to neighboring portions of the screw.

A device for mixing at high-pressure two or more reactive liquid components or resins comprises a head-body provided with a mixing chamber with inlet and outlet openings for the injecting and recirculating reactive components; a single-piece tubular element, for delivering the mixture, communicates, through an intermediate transversal hole with the mixing chamber and slidingly houses a cleaning member; a valve member with longitudinal recirculation slots slides in the mixing chamber between a backward position, in which the inlet openings are released, and an advanced position, in which the inlet openings are put in communication with the respective outlet openings for recirculating the respective reactive components; the tubular element is removably inserted into a pass-through hole of the head-body, transversal to the mixing chamber, and it has an annular shoulder zone, separated and distant from the transversal hole; fixing elements removably lock the annular shoulder zone at the head-body for holding the tubular element in the aforesaid hole; a clearance gap between the tubular element and the pass-through hole of the head-body limits the contact area among them and minimizes the exchange of forces inside the hole; when the valve member is in the advanced position and penetrating into the hole of the tubular element, a gap, with a sealing element interposed, separates it from the aforesaid hole; between the surface of a cap and a second hole on the tubular elementobtained in a position opposite to the holea respective gap is defined and an elastic sealing is interposed; the aforesaid gaps are provided such that the connecting and engagement forces transmitted between the tubular element, the head-body and the spacer chamber are exchanged through the annular shoulder zone; sealing and centering elements keep the tubular element axially centred and separated from the hole by means of the gap, avoiding the direct contact between the respective cylindrical surfaces, and avoid leakages of polymeric mixture towards the clearance gap; similarly the sealing elements make it possible to avoid leakages of reacting polymeric mixture and to insert the front part of the valve element keeping a gap, i.e. without direct metal contact with the transversal hole, and to assemble the front cylindrical part of the cap keeping a gap, not in direct metal contact with the respective surface of the housing cylindrical hole; this prevents a coupling with metal-on-metal contact between the respective cylindrical surfaces from transmitting engagement forces between the tubular delivery element and the head-body. Deformation-detecting elements detect locally the deformation condi

A plasticizing unit includes an injection cylinder having a dispensing opening, via which a plasticized material can be dispensed, and a plasticizing screw arranged to be rotationally and linearly movable in the injection cylinder and having an axis of rotation. A plasticizing zone is formed between the plasticizing screw and the injection cylinder in the radial direction relative to the axis of rotation of the plasticizing screw. The plasticizing screw has a dam element, and in the injection cylinder there is a first opening in the area of the plasticizing zone and/or the dam element and a second opening between the dam element and the dispensing opening.

A mixing machine (1) for the mixing of a homogeneous mixture with one or more components to obtain a viscous mixture, comprising a mixing chamber (2) which is divided in a push (A), a mixing (B) and a discharge zone (C), and wherein the mixing chamber (2) comprises the following parts: multiple walls, consisting of one or more top plates (22) with multiple inflow channels (10, 11, 12), one or more bottom plates (24) and multiple side walls (6); an outlet mouth (18); an outlet valve (13); several rotors (5); in and out sliding push and/or mixing blades (3, 4); and a self-cleaning system (16, 17); characterised in that the rotors (5) are integrated in the side walls (6) of the mixing chamber (2); the rotors are equipped with transit channels (30) for the in and out sliding push or mixing blades (3, 4); and the self-cleaning system comprises a cleaning plate (16) and a driving mechanism (17) wherein the cleaning plate (16) can move longitudinally through the mixing chamber (2).

A method for obtaining and applying a sealing gasket element on a slide-valve sliding in a cavity of an apparatus for the recirculation and mixing of chemically reactive polymeric components, comprises the steps of: obtaining from an elastic-plastic material a precursor element of the seal element, with a grid structure having a reticular shape; positioning the precursor element around the slide-valve; exerting on the precursor element, through temporary clamping elements, a radial compression and contraction action to insert it and couple it to one or more housing seats provided on the slide-valve so as to obtain the seal element well coupled to the latter; progressively removing the clamping elements to sequentially release successive parts of the gasket element and gradually free the slide-valve to gradually introduce the parts of the slide-valvefreed in successionin the housing cavity allowing the sealing gasket element to gradually expand radially due to the elastic return by adhering tightly to the inner surface of the same housing cavity. The special equipment for fitting the sealing gasket element on the slide-valve and the so obtained recirculation and mixing apparatus is also described.