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 composite can include cellulose fiber; and foam binding the cellulose fiber. A method for manufacturing a composite can comprise mixing a plurality of ingredients to form a pre-foam mixture; foaming the pre-foam mixture to produce a foam; mixing the foam with cellulose fiber to form a composite material; and curing the composite material.

A metering and application system for a moisture-curing polymer material includes a reservoir for the polymer material and a first pump and a second pump, wherein the polymer material is conveyable by the first pump from the reservoir to the second pump. In addition, a gas metering device with a defined pressure ratio is provided to bring a gas to a defined pressure, wherein the gas metering device is connected to the input of the second pump on its outlet side. In addition, a mixer for mixing the polymer material and the gas and a valve arranged downstream of the mixer for metering and a nozzle for applying the polymer material/gas mixture are provided.

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

The invention relates to a device (01, 19, 23) for foaming a viscous material (02), said viscous material (02) being conveyed through a first conveyor pipe (05) using a first conveying means (04) at a first conveying pressure, and a gas (07) being conveyed through a second conveyor pipe (08) at a second conveying pressure, and the second conveyor pipe (08) and the first conveyor pipe (05) becoming conjoined at an opening (15), and a discharge device (17) being provided downstream of the opening (15) so as to allow a pressure-relieving discharge of the mixture (14) made up of viscous material (02) and gas (07), a gas injection valve (09) being arranged at the opening (15), said gas injection valve (09) allowing to inject gas bubbles (25) into the viscous material (02).

The invention relates to a device (01, 19, 23) for foaming a viscous material (02), said viscous material (02) being conveyed through a first conveyor pipe (05) using a first conveying means (04) at a first conveying pressure, and a gas (07) being conveyed through a second conveyor pipe (08) at a second conveying pressure, and the second conveyor pipe (08) and the first conveyor pipe (05) becoming conjoined at an opening (15), and a discharge device (17) being provided downstream of the opening (15) so as to allow a pressure-relieving discharge of the mixture (14) made up of viscous material (02) and gas (07), a gas injection valve (09) being arranged at the opening (15), said gas injection valve (09) allowing to inject gas bubbles (25) into the viscous material (02).

A metering and application system for a moisture-curing polymer material includes a reservoir for the polymer material and a first pump and a second pump, wherein the polymer material is conveyable by the first pump from the reservoir to the second pump. In addition, a gas metering device with a defined pressure ratio is provided to bring a gas to a defined pressure, wherein the gas metering device is connected to the input of the second pump on its outlet side. In addition, a mixer for mixing the polymer material and the gas and a valve arranged downstream of the mixer for metering and a nozzle for applying the polymer material/gas mixture are provided.

The invention relates to a method for metering a foamed or foamable plastic (5) in a preferably discontinuous manner. At least one first component (2) for forming the plastic (5) is conveyed into a mixing chamber (11) of a mixing device (10) in which a stirring mechanism (30) that can be rotated about a rotational axis (31) is arranged. The first component (2) is loaded with a gas (4) in order to influence the formation of foam, and the plastic (4) is metered out of the mixing chamber (11) through an outlet nozzle (18). According to the invention, the pressure in the mixing chamber (11) ranges from 0.2 bar to 15 bar, the gas (4) is injected into the first component (2), preferably directly into the mixing chamber (11), by a valve device (50), and the stirring mechanism (30) disperses the gas (5) in the first component (2).