A dispenser for discharging a mixture of gas and paste material includes: a nozzle part (2) provided in a tip end part of a body (11) and having a tip end opening; a flow path (4) for the mixture extending from an introduction part (5) for the mixture to the tip end opening through a hollow space of the nozzle part; a needle part (3) movable in the flow path of the nozzle part to open and close the flow path; a driving part (7, 8, and 9) that drives the needle part; and a stopper part (10, 14, and 16) that limits an operation range of the needle part. The nozzle part has a tapered section in which an inside diameter of the flow path of the nozzle part relative to an operation range of a tip end of the needle part decreases toward the tip end opening.

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 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.