Abstract: A method of additive manufacturing an object featuring properties of a hard bodily tissue, comprises: dispensing and solidifying a plurality of non-biological material formulations to sequentially form a plurality of hardened layers in a configured pattern corresponding to a shape of the object. The method forms voxel elements containing different material formulations at interlaced locations to provide a three-dimensional textured region spanning over the portion. The material formulations and the interlaced locations are selected such that the textured region exhibits, once hardened, a stress variation of at most ±20% over a strain range of from about 0.1% to about 0.3%.

Abstract: A method of additive manufacturing (AM) includes dispensing a first building material formulation to form an outer region, and dispensing a second building material formulation to form an inner region, the outer region surrounding the inner region, the inner and outer regions being shaped to form a layer of the object; exposing the layer to a first curing condition, repeating the dispensing and the exposing to sequentially form a plurality of layers of the object and collectively exposing the plurality of layers to a second curing condition. The selections are such that the first building material formulation is hardened to a higher degree than the second building formulation. The outer regions form a hardened coating that at least partially encapsulates the inner regions. The second curing condition is other than the first curing condition and is selected to increase the degree that the inner region is hardened.

Abstract: A method of additive manufacturing of a three-dimensional object. The method comprises: sequentially dispensing and solidifying a plurality of layers comprising (i) a stack of model layers arranged in a configured pattern corresponding to the shape of the object and being made of a modeling material, (ii) a sacrificial structure having a stack of sacrificial layers made of an elastomeric material, and (iii) a stack of intermediate layers made of a support material having an elastic modulus less than the elastomeric material and being between the stack of model layers and the sacrificial structure; and applying a peeling force to the sacrificial structure to remove the sacrificial structure, and to expose the stack of model layers and/or the stack of intermediate layers beneath the sacrificial structure.

Abstract: A system for delivering liquid material to a nozzle array of a printing system comprises a cartridge and a vented sub-tank. The cartridge has a cartridge outlet and contains the liquid material. The sub-tank has a sub-tank inlet configured to receive the cartridge outlet to allow the liquid material to flow through the cartridge outlet by gravity, two inlet ports within the sub-tank inlet at different heights relative to a liquid level in the sub-tank, and a sub-tank outlet. The sub-tank outlet is sealingly connectable to the nozzle array by a pipe and has an outlet port below the inlet ports.

Abstract: A method of printing a three-dimensional object, comprises: for each of a plurality of arrays of nozzles, activating a subset of nozzles of the array to dispense a respective building material from the subset, so as to form an interleaved scan pattern of dispensed materials. The method comprises hardening the interleaved scan pattern, and repeating the activating and the hardening to form a stack of hardened interleaved scan patterns.

Abstract: A system for three-dimensional printing comprises an array of nozzles for dispensing building materials, a work tray (12/360) and a jig (402) configured for affixing a fabric (420) to the work tray. A computerized controller operates at least the array of nozzles to dispense a building material in a configured pattern corresponding to a shape of an object on the affixed fabric.

Abstract: A formulation usable as a modeling material formulation in additive manufacturing of a three-dimensional object and additive manufacturing methods utilizing same are provided. The formulation comprises one or more curable materials; and a radiopaque material, and features, when hardened, a CT number of at least 100 HU at 70 kV. Objects made by the additive manufacturing method utilizing the formulation are usable as radiological phantoms.

Abstract: A system for three-dimensional printing is disclosed. The system comprises: a rotary tray configured to rotate about a vertical axis; a printing head, each having a plurality of separated nozzles; and a controller configured for controlling the inkjet printing head to dispense, during the rotation, droplets of building material in layers, such as to print a three-dimensional object on the tray.

Abstract: An additive manufacturing (AM) system includes a carriage that deposits material in a defined pattern and a building platform that receives material deposited from the carriage. The carriage includes a pre-heating assembly with a plurality of pre-heating chambers and a printing block with a plurality of slots for receiving a plurality of printing heads. The carriage is equipped with more pre-heating chambers than head slots.

Abstract: Formulations usable in additive manufacturing such as 3D inkjet printing which provide a transparent material when hardened, are provided. The formulation are designed so as to provide transparent objects or parts thereof with improved transmittance and color properties such as yellowness index, compared to commercially available formulations. The formulations comprise a photoinitiator at a relatively low amount and designed mixture of curable materials.

Abstract: Formulations usable in additive manufacturing, 3D inkjet printing in particular, of a three-dimensional object that contains a polyimide material, and additive manufacturing utilizing same are provided. The formulations contain a polyimide precursor (e.g., a bismaleimide) and an additional curable material, which is a multifunctional curable material, and are devoid of an organic solvent.

Abstract: A method of additive manufacturing, comprises: dispensing from an array of nozzles an amount of building material formulation to form a layer in a configured pattern corresponding to a shape of a slice of an object, and hardening the layer. Based on the amount and a geometrical characteristic of the slice, a thermal mass of the layer is calculated. A cooling system is controlled in a closed loop control responsively to the calculated thermal mass.

Abstract: A method of three-dimensional printing, comprises: operating a printing head having a nozzle array to dispense a building material formulation, wherein the printing head is directly connected to a cartridge containing the building material formulation, and wherein the printing head comprises a channel conveying a building material formulation received from the cartridge to the nozzle array; discarding the building material formulation from the channel; and connecting a cartridge containing a building material formulation that is different from the discarded building material formulation to the channel.

Abstract: A method of three-dimensional fabrication of an object is disclosed. The method comprises: forming a plurality of layers in a configured pattern corresponding to the shape of the three-dimensional object, at least one layer of the plurality of layers being formed at a predetermined and different thickness selected so as to compensate for post-formation shrinkage of the layer along a vertical direction. In various exemplary embodiments of the invention spread of building material of one or more layers is diluted at least locally such as to maintain a predetermined thickness and a predetermined planar resolution for the layer.

Abstract: A system for additive manufacturing comprises a dispensing head for dispensing building materials on a working surface, a hardening system for hardening the building materials, a cooling system for evacuating heat away from the building materials, and a computerized controller. A thermal sensing system is mounted above the working surface in a manner that allows relative motion between the sensing system and the working surface, and is configured to generate sensing signals responsively to thermal energy sensed thereby. The controller controls the dispensing head to dispense the building materials in layers, the sensing system to generate the sensing signals only when the sensing system is above the building materials once hardened, and the heat evacuation rate of the cooling system responsively to the sensing signals.

Abstract: A method of additive manufacturing a three-dimensional object by layerwise deposition of a building material with an inkjet printing system comprising a print head and a building tray, comprises calculating a weighting value for each nozzle, then for each layer obtaining a 2-D map of the layer, comprising active pixels at building material dispensing positions; obtaining a Data Correction Filter (DCF) including a height map of the previous layer, comparing the data of the 2D map to the data of the DCF at each position and determining if the nozzle at that position should dispense, then printing the layer, updating the weighting values and adjusting the position of the print head vis a vis the printing tray. The above is repeated until the three-dimensional object is printed.

Abstract: A method of additive manufacturing comprises receiving digital data defining a shape of a three-dimensional object and based on the digital data, sequentially dispensing and solidifying a plurality of layers made of a modeling material and arranged in a configured pattern corresponding to the shape of the object. A portion of the layers forms one or more stacks, each encompassing a non-solid substance trapped between a plurality of building material pillars oriented perpendicularly to the layers.

Abstract: Formulations and methods employing these formulation for fabricating an object by additive manufacturing, such as three-dimensional inkjet printing are provided. The formulations comprise at least 50 weight percents of hydrophilic curable materials, and upon curing, provide a material that is characterized by water absorbance of at least 5%, and by high HDT and impact resistance values. Objects containing cured material made of these formulations are also provided.

Abstract: Novel support material formulations, characterized as providing a cured support material with improved dissolution rate, while maintaining sufficient mechanical strength, are disclosed. The formulations comprise a water-miscible non-curable polymer, a first water-miscible, curable material and a second, water-miscible material that is selected capable of interfering with intermolecular interactions between polymeric chains formed upon exposing the first water-miscible material to curing energy. Methods of fabricating a three-dimensional object, and a three-dimensional object fabricated thereby are also disclosed.

Abstract: A support material formulation for use in additive manufacturing of a three-dimensional object, which, when hardened, is soluble upon immersion in water, is provided. The formulation includes a hydrophilic curable mono-functional material; a polyol (e.g., a branched polyol) having a molecular weight lower than 1,000, or lower than 800 grams/mol; and a polyester material having a molecular weight higher than 400, or higher than 500, grams/mol. Additive manufacturing using the disclosed formulation and objects made thereby are also provided.