Mixing device (1) for dispensing a multi-component polymeric mixture, comprising a main body (2) comprising a mixing chamber (3) for mixing a first and a second component of the mixture, the mixing chamber having a main development along a longitudinal direction (100) and comprising a respective longitudinal open end (4); a movable body (5) having a central axis (101) with longitudinal development and slidably housed in the main body (2) to alternatively assume, by sliding along the longitudinal direction (100), an occlusion position of the mixing chamber (3) and a mixing position, wherein the movable body (5) comprises a first channel (6) and a second channel (7) each comprising a respective end portion (20) both displaced from the central axis (101) of the movable body (5) and developing substantially along the longitudinal direction (100) up to a longitudinal end face (8) of the movable body (5) facing the open longitudinal end (4) of the mixing chamber (3), wherein the respective end portions (20) of the first (6) and second channel (7) develop inside the movable body (5) or they are made by respectively a first (9) and a second groove (10) obtained on a longitudinal surface (11) of the movable body (5), each groove (9, 10) having development with a component perpendicular to the longitudinal direction (100).

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-valve—freed in succession—in 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 system for generating and dispensing plural component materials includes a controller operatively connected to dispense valves and return valves. The return valves are in respective open states to allow constituent materials to circulate back to a source and are in respective closed states to block circulation. The dispense valves are in respective open states to allow mixing of the constituent materials to form the plural component material and in respective closed states to prevent generation and dispense. The controller implements a delay between closing the return valves and opening the dispense valves to build pressure in the system prior to generating and dispensing the plural component material.

A high-pressure mixing apparatus for polymeric components suitable for providing a reactive mixture for a polymerizable resin, provided with a self-regenerating seal. An annular sealing element is housed in a circular seat inside a cross hole of a bush transversely extending to and in communication with the mixing chamber, in a sealing zone downstream the injection holes for the polymeric components, between the mixing chamber and the same delivery bush; worn and/or torn parts of the annular sealing element are automatically regenerated by the reactive mixture delivered during operation of the mixing apparatus.

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 fluid dispenser (10) includes a housing (12) and a valving rod (14). The housing includes an inlet (28) that receives a fluid product, an internal chamber (26) in fluid communication with the inlet, a discharge port (20) in fluid communication with the internal chamber that dispenses fluid from the internal chamber, a dispensing fluid inlet (38) that receives a dispensing fluid, and a dispensing fluid passage system that carries the dispensing fluid to the discharge port. The valving rod is disposed in the housing and moves within the internal chamber between an open position and a closed position. The dispensing fluid passage system includes a first passageway (44) that carries the dispensing fluid in a first direction and a second passageway (48) that carries the dispensing fluid in a second direction. The second passageway has a distal end that dispenses the dispensing fluid proximate the discharge port.

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.

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.

A mixing device includes a first feed opening for a first liquid—preferably gas-laden—plastics component, a second feed opening for a second liquid plastics component, and a discharge opening for discharging a mixture of the first and the second liquid plastics component. The mixing device has a rotating agitator for mixing the first and second liquid plastics components, and a gap remains between the agitator and the discharge opening. An adjustment device is provided which either varies the gap by a relative movement between the discharge opening and the agitator, or varies the size of the discharge opening. A regulating device is connected in signal-transmitting fashion to a sensor for determining a pressure prevailing in the mixing device. The regulating device sets the gap, or the size of the discharge opening, by the adjustment device such that the pressure prevailing in the mixing device has a predetermined value.

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