The method for spraying thermoplastic powders provides to feed a flow of compressed air and/or nitrogen and a liquefied petroleum gas through respective separated discharge chambers (9, 12), shaped inside a mixing device (1) of a spray gun (100), the separated discharge chambers (9, 12) being in communication with a mixing chamber (15). Then a flame is ignited at the mixing chamber, through a flame ignition device (30) connected with the gun (100), said device comprising a spark ignition device (31, 310), and a conductor element (32) associated with the mixing device (1) and connected with the spark ignition device (31, 310). The thermoplastic powders are mixed with a transport inert gas, and fed through a further discharge chamber (7) communicating with the mixing chamber (15). Then the spray gun is operated to spray the thermoplastic powders through the flame onto the surface of the article to be coated, to cause the melting of the same powders.

A spray nozzle has a body having a flow passage. At least along a portion of the flow passage the body has a depth-wise compositional variation having: a cemented carbide first region; and a cemented carbide second region closer to the flow passage than the first region and having a higher boron content than a boron content, if any, of the first region.

Method of deposition of a coating on a surface of a workpiece, working with at least one deposition device, or torch, of Thermal Spray type, controlled by an associated motor. It is contemplated to perform the deposition step by configuring the torch so as to create two concurrent movements, of which a first movement along a linear path on the surface area to be coated; a second oscillation movement according to an axis of rotation coaxial with said advancement direction; this allows increasing the spray pattern of the thermal spray torch at each stroke resulting in a reduction of the relative movement speed of the torch itself.

The method for flame spraying thermoplastic powders provides to heat the article to be coated at a suitable working temperature and to feed the said thermoplastic powders, transported by an inert gas, a flow of compressed air and a flow of liquefied petroleum gas through respective separated discharge chambers (7, 9, 12), shaped inside a mixing device (1) of a spray gun. The thermoplastic powders are then projected, in a resulting flow (30), on the heated surface of the article to be coated, to determine the melting of the same powders at their contact with said heated surface. At least one couple of flows (31, 32) of compressed air is sprayed converging towards the resulting flow (30) flowing out of the mixing device (1), giving the resulting flow (30) a substantially flattened fan shape.

The apparatus comprises a labyrinth mixing device designed to mix a first oxidizer gas and a fuel under pressure, and to inject the mixture produced in a combustion chamber, a torch's main body (1) housing the labyrinth mixing device (2) and connectors (7) for fuel and oxidizer gases, a torch's front part (3) defining, with the labyrinth mixing device (2), the internal geometry of the combustion chamber (4) comprising several second oxidizer gas injectors (32,33) for injecting separately a second oxidizer gas upstream in the combustion chamber to promote the combustion process and connecting down-stream to a gas expanding nozzle (50) designed to receive products of combustion of said mixture and form a high-velocity gaseous jet, an ignition device (30) to start combustion of said mixture, a material delivery device (6) designed to inject an spray material axially into said high-velocity gaseous jet. The labyrinth mixing device (2) comprises one or more flanges (23,24) which define one or more mixing volumes (21,22) and holes (25,26,27), concentrically placed both on the flanges (23,24) and passing through the mixing device (2) and opening at the downstream end of the mixing device (2) for connecting a feeding section (20) of the labyrinth mixing device (2) with the combustion chamber (4). The labyrinth mixing device (2) comprises a crossing axial bore (28) to inject the spray material into the combustion chamber (4).

A coat forming apparatus 100 includes a droplet supply unit 110 and an active species supply unit 120. The droplet supply unit 110 is adapted to spray or drop a droplet for coat forming toward an object 116. The active species supply unit 120 is adapted to supply an active species to be brought into contact with the droplet moving from the droplet supply unit 110 toward the object 116. The coating is formed on a surface of the object 116 by the droplet that has been brought into contact with the active species.

The invention relates to a device for High Velocity Oxygen Fuel thermal spraying process for coating a component, especially a gas turbine component. The device includes a liquid fuel fired combustion chamber, a de-Laval section, a powder injector block with powder injectors and a barrel all arranged around and along an axis. The powder injector block includes at least four powder injectors arranged in an equal circumferential distance around the axis and an exchangeable hot gas section insert inside the powder injector block designed as a cylindrical bush with at least four openings, the openings being arranged in an equal circumferential distance around the axis in the cylinder, wherein the bush is fixed by the at least four powder injectors extending through said openings.

An object of the present invention is to provide a combustion burner which is capable of heating or melting a raw material powder efficiently by dispersing the raw material powder, and which is capable of improving a collection rate of the heated or melted raw material powder, the invention providing a combustion burner that forms flame including a dispersal member which is provided in the raw material powder outlet which spouts the raw material powder into the flame, includes first and second inclined surfaces, and which disperses the raw material powder by colliding with the raw material powder that is supplied to the raw material powder outlet.

A system for spraying a coating material to a substrate includes an optical sensor that monitors a thickness, a controller that generates a first signal corresponding to an amount of gas propellant to be heated, a second signal corresponding to a temperature to which the gas propellant is to be heated, a third signal corresponding to an amount of a solid powder composition to be mixed with the heated gas, and a fourth signal corresponding to a distance between the nozzle and the substrate, a first regulator that supplies an amount of gas propellant corresponding to the first signal, a heater that heats the gas propellant to the temperature corresponding to the second signal, a second regulator that supplies an amount of solid powder composition corresponding to the third signal, and an actuator that moves the nozzle corresponding to the fourth signal.

Methods of thermal spraying polymeric coatings are disclosed. A powder polymeric coating material is introduced into a thermal spray applicator. Particles of the polymeric coating material are heated by the thermal spray applicator, and the heated coating particles are directed toward a substrate to form a deposited coating. The deposited coating may be post-heated onto the substrate to form the polymeric coating with desirable surface characteristics. Thermal spray coating systems are also disclosed for thermally spraying the polymeric coatings. The thermal spray applicator may include a combustion chamber and an injection nozzle assembly that transfers coating powders to a heated zone generated from the combustion chamber.