Method and system for removing a coating from a substrate using radiant energy and a particle stream

A method for removing material from a structure comprising the steps of:

• (1) irradiating a target area on the surface of a structure having at least one layer of material formed on a substrate with radiant energy having an intensity sufficient to pyrolyze the material, weakening chemical bonds in the material and between the material and the substrate without permanently changing the modules of elasticity, shear strength, and tensile strength of said substrate;
• (2) impinging said pyrolyzed material with a particle stream having a temperature below ambient temperature in order to prevent overheating of the substrate to remove said pyrolyzed material from said structure;
• (3) collecting said removed pyrolyzed material;
• and
• (4) scanning said radiant energy and said particle stream over said structure to advance the target area to remove said material along a path on said structure.

A method for removing material form a structure comprising the steps of:

• (1) irradiating a target area on the surface of a structure having at least one layer of material formed on a substrate with radiant energy having an intensity sufficient to pyrolyze said material, weakening chemical bonds in the material and between said material and said substrate;
• (2) impinging said pyrolyzed material with a particle stream having a temperature below ambient temperature in order to prevent overheating of the substrate to remove said pyrolyzed material from said substrate;
• (3) scanning said surface of said structure with said radiant energy and said particle stream along a predetermined path at a scan speed;
• (4) detecting the optical character of said surface of said structure along said scanned surface of said structure and generating an electronic output signal corresponding to said optical character;
• (5) determining an updated scan speed functionally related to said electronic output signal;
• (6) directing said scan speed to be equal to said updated scan speed;
• and
• (7) repeating steps (1)-(6) if said radiant energy and said particle stream have not scanned the entirety of said predetermined path.

A method for removing material from a structure having at least one layer of material formed on a substrate, the method comprising the steps of:

• providing a source of pulsed light;
• scanning the light source at a selected scan speed along a path on the structure to apply pulsed light to successively advancing target areas in the path to substantially pyrolyze the material in the target area without substantially ablating the material from the substrate;
• and
• impinging the pyrolyzed material in the path with a particle stream having a temperature below ambient temperature in order to prevent overheating of the structure to remove the pyrolyzed material from the path.