Method and apparatus for flame coating tubular elements with thermoplastic powders

Method for flame coating tubular elements with thermoplastic powders, the method comprising the steps of:

• a. arranging along a longitudinal axis a said tubular element to be coated at a coating station;
• b. providing an applicator unit, operating in said coating station, in an inactive configuration, said applicator unit comprising at least one sector carrying at least one movable thermoplastic powders flame applicator device and being operable alternately between said inactive condition, wherein said sector is spaced from said tubular element and an active configuration, wherein said sector is approached radially to said tubular element;
• said at least one applicator device being operable either with flame only, to perform localized or distributed heating, or with flame and thermoplastic powders, in order to coat the surface of the said tubular element;
• c. operating in motion said applicator unit provided in said inactive configuration, towards said tubular element;
• d. operating said applicator unit in said active configuration, so that said sector engages peripherally, at least partially, said tubular element;
• e. commanding the activation of said at least one flame applicator device carried by said sector;
• f. feeding said thermoplastic powders to said at least one applicator device;
• and
• g. operating said sector of said applicator device, fed with said thermoplastic powders, in a rotary and/or translational motion according to said longitudinal axis so as to flame coat said tubular element with a flow of said thermoplastic powders.