In an air-operated plural component mixing and dispensing assembly, including a sliding mixing and dispensing element that forms, with a pair of component inlet blocks, the valves controlling the mixing and dispensing of the plural component materials, the mixing and dispensing element includes a rearward part and a forward part which together form a mixing chamber, with admission passages for the plural components to be mixed in the rearward part and a dispensing orifice for mixed plural component material in the forward part, also including a shaping air assembly with an air inlet, a nozzle air manifold with internal air passageways to one or more impinging air outlets, wherein the shaping air assembly is configured to shape the spray pattern of the dispensed plural component material hydrostatically.

A spray gun for a plural component system is provided. The spray gun includes a first component delivery line and a second component delivery line. The spray gun also includes a nozzle, configured to receive and mix a first component received from the first component delivery line with a second component received from the second component delivery line. The spray gun also includes an air purge system configured to, when the spray gun is in a non-actuated position, purge the nozzle of the first and second components and, when the spray gun is in an actuated position, aid in atomization of the mixture of the first and second components.

The application relates to a mixing head including a head part and a mixing chamber device which is arranged in the head part. The mixing chamber device has a mixing chamber, which includes at least two inlets for introducing a starting material into the mixing chamber, and an outlet, via which the starting material mixture can be discharged out of the mixing chamber. A control piston is movably arranged in the mixing chamber. The mixing chamber device is releasably arranged in the head part in order to be exchangeable, wherein a transition fit and/or a clearance fit is formed between the head part and the mixing chamber device. The application additionally relates to a production method.

An injector device for supplying a chemically reactive component to a mixing head includes a modular structure defined by a hollow housing and guiding body extending around a longitudinal symmetry axis and having one or more supply openings for supplying the chemically reactive component; in the hollow body a nozzle orifice is obtained arranged to face and communicate with a mixing chamber obtained in the mixing head; a pin-shaped partialization and control element, which is housed and slidably movablealong the longitudinal symmetry axisin the hollow body and configured to vary a narrowed active section of the nozzle orifice; on the partialization and control element a tip portion is obtained that is conformed to receive pressure from the respective polymer component delivered to said hollow body so as to move away said partialization and control element from said nozzle orifice to vary the area of said narrowed active section; a modular adjusting and contrasting unit, which is removably couplable with the hollow body and with the partialization and control element and configured to exert an axisymmetric thrust action on the partialization and control element to arrange the partialization and control element in an initial position and preload condition to adapt the narrowed active section to a reference flowrate and pressure of the polymer component and subsequently to vary the position of said partialization and control element to adjust the narrowed active section according to the flowrate variation, exerting the contrasting force that is suitable for balancing the pressure exerted by the polymer component; the modular adjusting and contrasting unit includes a series of interchangeable elastic elements of conical disc shape, configured to exert a non-linear elastic action that is such as to contain the retracting stroke of the partialization and control element, limiting as much as possible the pressure variation at the variation of the flowrate of the respective polymer component entering the hollow housing and guiding body; the modular adjusting and contrasting unit, the tip portion and the nozzle orifice cooperate mutually to confer to the injector device a geometric conformation with high section gain, corresponding to a high ratio between the variation of the area of narrowed active section and the longitudinal shift of the partialization and control element.

A rubber composition manufacturing method comprises an operation in which at least rubber, silica, and silane coupling agent are kneaded in an internal kneader at not less than a temperature lower limit for a coupling reaction between the silica and the silane coupling agent to proceed. For at least a portion of time during which that operation is being carried out, a compressed gas is delivered to the kneading chamber while the ram is in a nonpressing state.

A high pressure mixing head for continuously producing polymeric foam comprises a body including a mixing chamber and injectors for injecting two polymeric liquids. The mixing head also includes a delivery duct which is disposed transversely to the mixing chamber, wherein a rod is slidably received in an internal passageway of the delivery duct. An alternate delivery duct is also included. The delivery duct and the alternate delivery duct are in flow communication with the mixing chamber via a switchable flow connection, and a control unit is configured to control the switchable flow connection and the positions of the rods in the delivery duct and the alternate delivery duct such that flow from the output opening of the mixing chamber can be selectively directed either to the delivery duct or to the alternate delivery duct.