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 polymerisable 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 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.

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 polymerisable 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 and apparatus for feeding a polyurethane mixture suitable to form a thermally insulating layer inside hollow bodies, such as hollow walls of a refrigerator cabinet, freezer, display counter or insulating panel. A polyurethane mixture resulting from chemically reactive components, supplied by a high-pressure mixing device, is injected into a cavity of a hollow body extending in a horizontal plain. The mixture is injected at a first flow-rate and a first injection speed, to be poured into a first deposition zone farthest from the injection point. Subsequently, the flow-rate and the injection speed of the polyurethane mixture are gradually reduced in a controlled manner, to be poured in successive deposition zones towards the injection point of the polyurethane mixture, along a distribution strip, allowing the injected mixture to spread out throughout the cavity of the hollow body along isometric expansion lines.

Abstract: A high-pressure mixing apparatus for producing and discharging a composite material resulting from a reactive mixture of at least a first and a second chemical components and from a filler material. The apparatus includes a main body, provided with a discharge duct for the composite material, at least one high-pressure mixing chamber for the chemical components and a first cleaning member axially displaceable between a forward and a rearward position within the discharge duct. The apparatus also comprises a second cleaning member with a control device selectively actuable to sequentially move the first and the second cleaning member between the rearward position, in which the first cleaning member opens the discharge duct, and the forward position in which the facing annular surfaces of the discharge duct and the second cleaning member are mutually abutting to eject the residual reactive mixture and close the exit port of the mixing chamber.

Abstract: A high-pressure mixing apparatus suitable for producing a composite material from a reactive mixture of at least a first and a second chemical components and from a filler material, including a main body conformed with a discharge duct for the composite material, a high-pressure mixing chamber for the chemical components, and a first cleaning member axially displaceable between a forward position and a rearward position within the discharge duct.

Abstract: A method and apparatus for feeding a polyurethane mixture suitable to form a thermally insulating layer inside hollow bodies, such as hollow walls of a refrigerator cabinet, freezer, display counter or insulating panel. A polyurethane mixture resulting from chemically reactive components, supplied by a high-pressure mixing device, is injected into a cavity of a hollow body extending in a horizontal plain. The mixture is injected at a first flow-rate and a first injection speed, to be poured into a first deposition zone farthest from the injection point. Subsequently, the flow-rate and the injection speed of the polyurethane mixture are gradually reduced in a controlled manner, to be poured in successive deposition zones towards the injection point of the polyurethane mixture, along a distribution strip, allowing the injected mixture to spread out throughout the cavity of the hollow body along isometric expansion lines.

Abstract: A method and device for high-pressure mixing of polyurethane components, in which one of the polyurethane components is pre-mixed with a filler material and/or with an additive. The device comprises a mixing chamber into which first and second polyurethane components are radially injected, and a slide valve which moves between a fore or closure position and a rear or opening position of the mixing chamber. The slide valve at its fore end is provided with a feeding chamber for a third polyurethane component pre-mixed with the filler material and/or additive, and an outlet hole; a cleaning pin for the outlet hole slides into a longitudinal guide hole of the slide valve.

Abstract: A method and an apparatus for high-pressure mixing of reactive chemical components. The chemical components are fed into a mixing chamber, by respective injectors at least one of which comprises a nozzle and a plug member for controlling the pressure drop; the nozzle and/or the plug member are shaped to form a lobed outlet orifice having an adjustable outlet cross section and a plurality of radially extending lobed formations, to create a vortical or swirling and highly turbulent state in the fluid jet. The surfaces in contact with the fluid of the nozzle and/or of the plug member can either be smooth or have sharp edges which contribute to increase the turbulence and swirling state of the fluid jet; a highly effective mixing degree is thereby achieved in the manufacture of polyurethane resins, bi-component resins and molded articles.

Abstract: The high-pressure mixing apparatus, for reactive chemical components, comprises a device for self-lubricating and scraping the outlet duct of the chemical mixture, and flushing out the scraped residues. The self-lubricating and scraping device comprises a delivery chamber for the lubricant material axially aligned and in fluid communication with the outlet duct; the lubricant delivery chamber is connected to a storage tank by a feeding and re-circulation circuit. The lubricant is sucked into the outlet duct and subsequently returned into the delivery chamber by a cleaning member in the form of a pumping piston sliding into the outlet duct, the pumping piston being provided with scraping rings for removing the reacted mixture adhered to the inner surface of the outlet duct.

Abstract: A method and device (10) for mixing polyurethane-forming liquid chemical components for the production of polyurethane foams, in which positive use is made of the turbulency and swirling action caused by the injection of pressurized jets of chemical components, in order to provide a methodology tending to improve the mixing processes by impingement and by the turbulency induced by a pressure drop in conventional self-cleaning apparatuses.

Abstract: The high-pressure mixing apparatus, for reactive chemical components, comprises a device for self-lubricating and scraping the outlet duct of the chemical mixture, and flushing out the scraped residues. The self-lubricating and scraping device comprises a delivery chamber for the lubricant material axially aligned and in fluid communication with the outlet duct; the lubricant delivery chamber is connected to a storage tank by a feeding and re-circulation circuit. The lubricant is sucked into the outlet duct and subsequently returned into the delivery chamber by a cleaning member in the form of a pumping piston sliding into the outlet duct, the pumping piston being provided with scraping rings for removing the reacted mixture adhered to the inner surface of the outlet duct.

Abstract: A method and an apparatus for high-pressure mixing of reactive chemical components. The chemical components are fed into a mixing chamber, by respective injectors at least one of which comprises a nozzle and a plug member for controlling the pressure drop; the nozzle and/or the plug member are shaped to form a lobed outlet orifice having an adjustable outlet cross section and a plurality of radially extending lobed formations, to create a vortical or swirling and highly turbulent state in the fluid jet. The surfaces in contact with the fluid of the nozzle and/or of the plug member can either be smooth or have sharp edges which contribute to increase the turbulence and swirling state of the fluid jet; a highly effective mixing degree is thereby achieved in the manufacture of polyurethane resins, bi-component resins and molded articles.

Abstract: Method and device (10) for mixing polyurethane—forming reactive chemical components; at least first and second chemical components (A, B) are introduced into a common pressure and feeding chamber, from where the chemical components are made to flow and co-injected through one or more narrow orifices (31) into a mixing chamber. During co-injection of the chemical components (A, B) a first mixing takes place into the jet strim, while a final intimate mixing is performed by impingement and collision into the mixing chamber (24) of the device; selectively actuable cleaning members (12, 29) eject the residual chemical material remaining into the common pressure and feeding chamber (15), and the mixing chamber (24) of the mixing device (10).

Abstract: The apparatus comprises a high-pressure mixing headdevice and a manually operable valve assembly to stop the circulation of chemical components which are fed into a mixing chamber by injection nozzles, or are made to re-circulate, and to stop the pressurized oil fed to a hydraulic cylinder for controlling a cleaning member reciprocable in the mixing chamber. The mixing device is operatively and mechanically connected to the valve assembly, to enable its quick removal and replacement by closing the valves without disconnecting pipings from the valve unit, and without causing leakage of the chemical components and the oil, ensuring an extremely easy handling of the entire mixing apparatus.