Thermal stereolithography

A method of forming a three-dimensional object on a substantially layer-by-layer basis, including forming a removable support structure comprising the steps;

• separately containing one of a selected one of a building material and a support material and a nonselected one of the building material and the support material wherein said selected one is normally in a solid state and which is made flowable when maintained at or above a flowable temperature;
• maintaining said building material and said support material as flowable material wherein at least said selected one is maintained at a temperature at or above said flowable temperature;
• maintaining a building environment at a temperature below said flowable temperature;
• supporting at least a portion of the object on a platform located within said building environment;
• identifying as positioning control signals, for substantially each layer, locations where said selected one is to be located;
• transmitting said positioning control signals for said identified locations;
• positioning at least one dispenser relative to said platform for substantially each layer, to allow selective dispensing of said selected one into said building environment;
• selectively dispensing said selected one from the at least one dispenser into the building environment according to said identified locations on each layer to form cross-sectional patterns;
• and
• nonselectively filling said nonselected one in regions of each layer not occupied by said selected one.

An apparatus for forming at least a portion of a three-dimensional object on a substantially cross-section-by-cross-section basis, including formation of a removable support structure comprising;

• a frame;
• at least one container for separately containing a support material and a building material wherein said support material is normally in a solid state and which is made flowable when maintained at or above a flowable temperature and said building material is capable of physical transformation upon exposure to synergistic stimulation;
• a heater for maintaining said support material at a temperature at or above said flowable temperature;
• a building environment maintained at a temperature below said flowable temperature and including a platform on which to support at least a portion of the object;
• at least one dispenser coupled to the at least one container to selectively dispense said support material into said building environment;
• means to nonselectively apply said building material into the building environment to fill regions of the cross-section not occupied by said dispensed support material;
• at least one computer programmed to identify for substantially each cross-section, locations where said support material is to be located and to transmit those locations as positioning control signals;
• and
• wherein said positioning control signals position the at least one dispenser relative to said platform to allow selective dispensing of said support material;
• means for sweeping away at least a portion of any excess building material applied to at least one cross-section;
• and
• means for solidifying the building material.