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 i.e. a filler, by a high pressure mixing device comprising a head provided with injectors and one or more interception and supply devices defined by respective nozzles for narrowing the passage of the flows and with correlated plug members that are movable axially and settable for controlling said narrowing. The injectors and the interception and supply device transform the pressure energy of the fluids into kinematic energy of the jets that clash in the mixing chamber to mix the components for turbulence induced by the jets, 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, by pumping arrangement connected to a respective hydraulic delivery line to the head, a dosed quantity of the at least second chemically reactive second component to with filler material is added; preventing, once said quantity is removed, that the second component flows back from the pumping arrangement to the tank; dosing the component with a controlled flowrate B to the delivery line to the mixing head; keeping the slide-valve closed in a recirculating position and preventing the entry of the at least second component to the head and to the respective recirculating slot and pressurizing, by a dosed quantity Vot, the delivery line to subject the at least second polymeric component to a pressure increase along the delivery line until a value is reached that is near that reached by the passage through the nozzle of the respective interception and supply device; subsequently enabling the entry of the second component into the head to make the second component recirculate to the slots of the slide-valve for a period of time that is comparatively very reduced until it is reduced virtually to zero with respect to a recirculating step of the at least first component through the slide-valve, and subsequently opening by retracting the slide-valve to permit mixing by high pressure collision of the first and at least one second components to dispense the resulting mixture through the mixing chamber and the dispensing conduit for pouring the mixture into a cavity or into a shape to make an object by reaction of the aforesaid first and second chemically reactive components. An apparatus for preparing and dispensing the mixture is also disclosed.

A melting device includes a container capable of melting a material supplied in a free-flowing state and storing the material in a liquid state. The container includes a first storage section for storing the material in the free-flowing state, a second storage section for storing the material in the liquid state, and a dividing section provided between the first storage section and the second storage section and configured to hold back the material, when the material is in a non-molten or free-flowing state and to allow passage of the material from the first storage section into the second storage section, when the material is in a molten or liquid state.

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.

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 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 provided 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, communicating with the mixing chamber; a valve body with recirculation longitudinal slots, sliding into the mixing chamber between a backward position in which it clears the inlet openings and enables to mix components, and an advanced position, in which the slots put inlet openings in communication with outlet openings for recirculating the reactive components; the delivery duct, of the self-cleaning type, is a single-piece tubular element, removably fastenedby means of fixing membersand can be inserted into a hole transversal to the mixing chamber passing through the head-body; the tubular element has an intermediate transversal hole aligned with the mixing chamber with a diameter greater than a diameter of the mixing chamber for compensating, while assembling, for possible inevitable errors of alignment and mutual positioning due to processing tolerances of the parts to be coupled and for avoiding protrusions of the walls of the transversal hole from forming inwardly of the mixing chamber of the head-body, protrusions that might interfere with the end the walls of the valve member during the movement in the hole passing through the thickness of the tubular element until the end of said hole leading into the delivery chamber and that extends the mixing chamber to the wall of the self-cleaning delivery duct. Between the tubular element and the pass-through hole in the head-body a gap is defined, i.e. a certain coupling tolerance with a clearance between the tubular element and the hole, enabling to insert and remove the tubular element into/from the pass-through hole. Sealing elements prevent the leakage of polymeric mixture and lubricant liquid in the aforesaid gap; analogously, between the surface of the cap and the second holeobtained in a opposite position with respect to the holea respective gap with clearance is defined where an elastic or elasto-plastic sealing is interposed; the valve member, in the advanced and penetrating position into the hole of the tubular element, is separated therefrom by a gap, with a sealing member interposed therebetween; the gap prevents the metal-on-metal contact on the front part of the valve element when it enters into the intermediate hole; generally, thanks to gaps, the assembly and coupling of respective components is eased, facilitating the centering and mutual angular posit

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.

A nozzle unit for a reaction molding machine, comprising an inlet channel prepared for connection to a mixing head outlet and comprising a first dispensing nozzle, which is prepared for applying a reactive mixture and which is connected to the inlet channel in a first operating state, a second dispensing nozzle being present, which is connected to the inlet channel in a second operating state and which is likewise prepared for applying a reactive mixture. Further disclosed is a mixing head device for a reaction molding machine having the nozzle unit, to a reaction molding machine having the mixing head device, and to a method for producing a plastic part.

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.

A melting device includes a container capable of melting a material supplied in a free-flowing state and storing the material in a liquid state. The container includes a first storage section for storing the material in the free-flowing state, a second storage section for storing the material in the liquid state, and a dividing section provided between the first storage section and the second storage section and configured to hold back the material, when the material is in a non-molten or free-flowing state and to allow passage of the material from the first storage section into the second storage section, when the material is in a molten or liquid state.

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.