Method for manufacture of three-dimensional products using microwave radiation

A three-dimensional object (7) is built up layer by layer from a powdered substrate (2) by applying a pattern of microwave-absorbent material (4) where the object is to be formed, e.g. by jet printing (3), and heating by microwaves (5). Several layers can be applied before heating, e.g. the pattern for the whole object can be laid down before heating takes place in the same or in a separate location. Independent claims are also included for the following: (1) a device for applying layers of powdered substrate (2) in layers, e.g. with a spreader, together with an applicator (3) of a pattern of microwave-absorbent material, e.g. a printer, and a microwave generator (5) in the 300 MHz to 300 GHz region; and (2) articles formed by this method, e.g. containing glass beads, silicic acid or metal particles.