Abstract: 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.

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 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 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: 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: 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: A process and an apparatus for the production of a polyurethane mixture is described. The apparatus comprises a high-pressure mixing device provided with a mixing chamber opening onto a side of a discharge duct. An elongated cleaning member is reciprocable inside the duct and is provided with a longitudinal channel for feeding a fluidized reinforcing material, for example reinforcing fibers or a reinforcing material in powder or granulate form, to be blended with the polyurethane mixture flowing into the discharge duct. The feeding channel for the reinforcing material terminates at the front end of the cleaning member, at a point where the flow of reinforcing material impinges the polyurethane mixture which emerges from the mixing chamber under high turbulence conditions. Blowing nozzles are provided to generate air jets for repeatedly deviating the flow of blended polyurethane mixture and reinforcing material flowing out from the discharge duct.

Abstract: A process and an apparatus for the production of a polyurethane mixture is described. The apparatus comprises a high-pressure mixing device provided with a mixing chamber opening onto a side of a discharge duct. An elongated cleaning member is reciprocable inside the duct and is provided with a longitudinal channel for feeding a fluidized reinforcing material, for example reinforcing fibers or a reinforcing material in powder or granulate form, to be blended with the polyurethane mixture flowing into the discharge duct. The feeding channel for the reinforcing material terminates at the front end of the cleaning member, at a point where the flow of reinforcing material impinges the polyurethane mixture which emerges from the mixing chamber under high turbulence conditions. Blowing nozzles are provided to generate air jets for repeatedly deviating the flow of blended polyurethane mixture and reinforcing material flowing out from the discharge duct.

Abstract: A high-pressure self-cleaning mixing apparatus adapted to mix at least first and second reactive polyurethane-forming components and feed the mixed components to a mold is disclosed. The apparatus includes at least a mixing chamber, first and second feed passages, first and second recycle passages, and a cleaning member having at least first and second longitudinally-extending recycle grooves spaced from each other. The cleaning member is movable between an open position in which the first feed passage radially feeds the first polyurethane-forming component to the mixing chamber and a closed position in which the first longitudinally-extending recycle groove communicates the first feed passage with the first recycle passage to recycle the first polyurethane-forming component instead of feeding the first polyurethane-forming component to the mixing chamber.

Abstract: A process and a system for the continuous manufacture of polymeric foams. Reactive chemical components and additives comprising a low boiling blowing agent are mixed under pressure; the mixture is then frothed before chemical reaction takes place by feeding the mixture through a pressure equalizing and frothing device comprising a pressure-drop zone opening into a frothing cavity having an output aperture to discharge the froth onto a moving substrate.

Abstract: A process and a system for the continuous manufacture of polymeric foams. Reactive chemical components and additives comprising a low boiling blowing agent are mixed under pressure; the mixture is then frothed before chemical reaction takes place by feeding the mixture through a pressure equalizing and frothing device having a pressure-drop zone opening into a frothing cavity having an output aperture to discharge the froth onto a moving substrate.

Abstract: A process and a system for the continuous manufacture of polymeric foams. Reactive chemical components and additives comprising a low boiling blowing agent are mixed under pressure; the mixture is then frothed before chemical reaction takes place by feeding the mixture through a pressure equalizing and frothing device having a pressure-drop zone opening into a frothing cavity having an output aperture to discharge the froth onto a moving substrate.

Abstract: A process and a system for the continuous manufacture of polymeric foams. Reactive chemical components and additives comprising a low boiling blowing agent are mixed under pressure; the mixture is then frothed before chemical reaction takes place by feeding the mixture through a pressure equalizing and frothing device having a pressure-drop zone opening into a frothing cavity having an output aperture to discharge the froth onto a moving substrate.

Abstract: A process and a system for the continuous manufacture of polymeric foams. Reactive chemical components and additives comprising a low boiling blowing agent are mixed under pressure; the mixture is then frothed before chemical reaction takes place by feeding the mixture through a pressure equalizing and frothing device having a pressure-drop zone opening into a frothing cavity having an output aperture to discharge the froth onto a moving substrate.