Abstract:
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 element—obtained in a position opposite to the hole—a 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 conditions which the tubular element is submitted to due to friction, scraping and bonding forces exchanged between the cleaning member and the inner surface of the delivery duct, enabling to monitor the working conditions of the self-cleaning mixing device.
Abstract:
The invention concerns an apparatus (1) for the dispersion of an expansion gas even in supercritical conditions, e.g. carbon dioxide, in a reactive resin, of the kind in which a reaction chamber having an input (27) for gas and an input (37) for resin is provided. Advantageously, the chamber is a dispersion and containment chamber made into a casing (2) of predetermined high resistance susceptible to sustain high pressure and is divided into two sections (6,7) by a head (14) of a dispersion and mixing cylinder-piston group (4) in fluid communication between themselves by means of at least one pouring passage (31, 36, 32, 39) provided with a static mixer (38), motor means (3) being provided for piston (34) control of said mixing cylinder-piston group (4). The invention also concerns a process for the formation of a polyurethane foam starting with the dispersion of carbon dioxide, even supercritical, in a reactive resin in which at least one initial dispersion and mixing controlled phase of the two components is provided in a dispersion and containment chamber under pressure divided into two sections (6,7) by a head (14) of a cylinder-piston mixing group (4) in fluid communication between themselves by means of at least one pouring passage (31, 36, 32, 39) provided with a static mixer (38) and in which adduction, dispersion and mixing occurs under high pressure (at least greater than 75 bar).
Abstract:
A method for forming a self-regenerating seal in a mixing chamber of a high-pressure mixing apparatus for polymeric components suitable for providing a reactive mixture for a polymerizable resin. An annular sealing element is provided in a circular housing seat inside the mixing chamber, in a sealing zone downstream the injection holes for the polymeric components; worn and/or torn parts of the annular sealing element are automatically regenerated by the same reactive mixture delivered during operation of the mixing apparatus. A high-pressure mixing apparatus with self-regenerating sealing element is also claimed.
Abstract:
A method is disclosed for preparing and dispensing a mixture obtained by mixing at least one first chemically reactive component and at least one second chemically reactive component containing a dispersed solid material by a high pressure mixing device comprising a mixing chamber for mixing the components, in which a valve member is slidable, in particular a slide-valve, provided with longitudinal slots for recirculating the components to respective storage tanks. The method provides removing from at least one tank, a dosed quantity of the at least second chemically reactive second component to with filler material is added; recirculating the second component through the slots of the slide-valve for a period of time that is comparatively very reduced with respect to a recirculating step of the at least first component through the slide-valve. An apparatus for preparing and dispensing the mixture is also disclosed.
Abstract:
A high-pressure mixing device adapted to form a polymeric mixture from the reaction of two or more reactive liquid components or resins, comprises a head-body with a mixing chamber having an inner cylindrical surface with inlet and outlet openings for injecting and recirculating reactive components; a duct for delivering the mixture, a valve body with recirculation longitudinal slots; the delivery duct, of the self-cleaning type, is a single-piece tubular element, insertable into a hole passing through the head-body, having an intermediate transversal hole aligned with the mixing chamber with a diameter greater than a diameter of the mixing chamber for avoiding protrusions of the walls of the transversal hole from forming inwardly of the mixing chamber of the head-body. Sealing elements duly arranged between the coupling interfaces of the various components prevent the leakage of polymeric mixture and lubricant liquid. There is also disclosed a related method.
Abstract:
A method and high-pressure mixing device for co-injection of polymeric reactive components, in particular for polyurethane and epoxy mixtures. The polymeric components are supplied in a common pressure chamber where they flow at a same pressure and in an unmixed state into a forwardly converging fore portion of the pressure chamber, and through a settable co-injection orifice to be co-injected, in the unmixed state, into a mixing chamber transversely oriented to the pressure chamber. The settable co-injection orifice consists in an elongated restriction that longitudinally extends on a side wall of the mixing chamber orthogonally oriented to an intersecting the forwardly converging fore portion of the pressure chamber; a first cleaning member and a second cleaning member are sequentially reciprocable in the pressure chamber to eject the remaining unmixed polymeric components, respectively in the mixing chamber to eject the remaining mixture, and stop elements are provided to set an open section of the elongated restriction, by adjustably stopping the fore end of the cleaning member for the mixing chamber, in respect to the same elongated restriction of the co-injection orifice.
Abstract:
The present invention relates to a spacer for high pressure mixing head comprising a control cylinder flange, a head body flange, and a plurality of uprights adapted to interconnect the control cylinder flange and the head body flange. At least one of the plurality of uprights comprises at least one deformation detection sensor applied at at least one available deformation surface thereof and adapted to detect longitudinal deformations and/or transversal deformations of the at least one of the plurality of uprights. The present invention also relates to a related mixing and dosing head and to a related apparatus.
Abstract:
A device for mixing at high-pressure two or more reactive liquid components or resins includes 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; a valve member with longitudinal recirculation slots; the tubular element is removably inserted into a pass-through hole of the head-body, having 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 is provided such that the forces are exchanged through the annular shoulder zone; sealing and centering elements avoid leakages of polymeric mixture. Deformation-detecting elements detect the deformation conditions which the tubular element is subjected.
Abstract:
The invention relates to a high-pressure mixing, dosing and recirculation head for injection or casting reaction molding, said high-pressure mixing, dosing and recirculation head comprising a head body, a mixing chamber, obtained in the head body wherein a valve element or mixing valve slides and in fluid communication with a supply duct, and a self-cleaning element comprising a scraping portion, said self-cleaning element being structured to slide in said supply duct, as well as comprising an apparatus for controlling and commanding mixing, supply and recirculation comprising a plurality of sensors and transducers mounted on board of the head body and of the components parts of the head connected thereto to detect and transform representative physical quantities of at least one operational status of said high-pressure mixing, dosing and recirculation head into electrical signals and an electronic control and storing system adapted to synchronously control and scan said sensors and transducers and adapted to receive and process said electrical signals indicative of said at least one operational status, at the beginning and during the operational phases of said high-pressure mixing, dosing and recirculation head to compare them with each other and with electrical signals representative of a predetermined reference operational status. The invention also relates to a high-pressure mixing, dosing and recirculation method for injection or casting reaction molding.
Abstract:
A method and high-pressure mixing device for co-injection of polymeric reactive components, in particular for polyurethane and epoxy mixtures. The polymeric components are supplied in a common pressure chamber where they flow at a same pressure and in an unmixed state into a forwardly converging fore portion of the pressure chamber, and through a settable co-injection orifice to be co-injected, in the unmixed state, into a mixing chamber transversely oriented to the pressure chamber. The settable co-injection orifice consists in an elongated restriction; a first cleaning member and a second cleaning member are sequentially reciprocable in the pressure chamber to eject the remaining unmixed polymeric components, respectively in the mixing chamber to eject the remaining mixture, and stop means are provided to set an open section of the elongated restriction.