Processes, compositions and systems for 2D and 3D printing

A method for additive 3D manufacturing of a designed object based on a 3D digital data model of said object characterized in shape and structure by a plurality of adjacent object layers of build material, by sequential application of a plurality of geometrically designed object layer patterns of build material characterizing the shape and structure of said object, comprising the steps of

• providing an aqueous dispersion of an object build material dispersed in an aqueous solution of a thermosensitive polymer in water to form an aqueous amphiphilic dispersion which undergoes phase separation from the water component of said aqueous dispersion upon heating to a phase change temperature at which said thermosensitive polymer precipitates from aqueous solution together with said build material above the lower critical solution temperature, LCST, of said aqueous amphiphilic dispersion,
• selectively extruding said aqueous amphiphilic dispersion at a temperature below its LCST precipitation phase change temperature onto a suitable substrate corresponding to a geometrically defined pattern of the first of said object layers,
• heating said extruded aqueous dispersion above its LCST to congeal and aggregate said build material of said extruded aqueous dispersion together with said thermosensitive polymer while separating and expelling liquid water to deposit the build material in the first of said object layer patterns, said heating being carried out by application of thermal energy to the extruded amphiphilic dispersion by directed laser light,
• subsequently repeating said extrusion and heating steps to form each of said adjacent layers of build material on the preceding object layer as a substrate, to form the shape and structure of said object.