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: Methods of printing a 3D object comprising depositing a building material, layer by layer, via printing heads comprising one or more nozzle arrays; and activating each of said printing heads to dispense a building material at least once within a specified period of time during printing to form a portion of said bulk region according to data provided by a CAD file, and activating said printing heads to deposit the building material to form another portion of the bulk region without relating to said data.

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 method of printing a 3D object comprising a plurality of discrete elements, the method comprising: receiving a 3D digital model of a shell group comprising one or more shells representing the plurality of discrete elements; defining, in the 3D digital model, a unifying shell to at least partly envelop one or more shells of the shell group to provide a unified digital model comprising the shell group and the unifying shell; assigning the unifying shell with at least one transparent building material that is transparent upon dispensing and solidifying thereof; assigning the one or more shells of the shell group with one or more building materials; and dispensing, in layers, the at least one transparent building material and the one or more building materials according to the unified digital model to form a 3D object comprising one or more discrete elements that are at least partly connected by a unifying element.

Abstract: Systems and methods for printing a 3D object on a 3D printer, including: receiving (i) a digital 3D model comprising a 3D geometry of the 3D object, (ii) a 2D displacement map, (iii) one or more maximal displacement values, and (iv) a printing resolution, calculating a displacement limit for each vertex of the 3D model based on the one or more maximal displacement values, applying local tessellation on the 3D model geometry in accordance with the 2D displacement map and with the printing resolution, thereby obtaining a tessellated 3D model, applying the displacement information of the 2D displacement map to the tessellated 3D model in accordance with the calculated displacement limit relative to each vertex, thereby obtaining a displaced 3D model, and printing the 3D object with the 3D printer based on the displaced 3D model.

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 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 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: Systems and methods of printing a colored 3D object, including: receiving an original 3D digital model of a colored 3D object comprising data relating to the geometry and to the color of the 3D object, receiving a printing resolution information relating to a 3D printing device connected to the processor, reducing the amount of data of the original 3D digital model in accordance with the printing resolution of the printing device, a geometric variation threshold and a color variation threshold, thereby generating an approximated 3D digital model of the colored 3D object, and printing the 3D object on the 3D printing device based on the approximated 3D digital model.

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.

Abstract: A formulation system usable in additive manufacturing of a three-dimensional object that comprises, in at least a portion thereof, a cyanate ester-containing polymeric network, and additive manufacturing processes employing the formulation system are provided. Also provided are objects obtainable by the additive manufacturing and kits containing the formulation system. The formulation system includes a first modeling material formulation which includes a first curable material which is a thermally-curable cyanate ester and a second modeling material formulation which comprises an activating agent for promoting polymerization of the cyanate ester and is devoid of the first curable material, and further includes a second curable material which is different from the first curable material, and optionally an agent for promoting hardening of the second curable material.

Abstract: A method of fabricating an object in layers, comprises, for at least one layer: dispensing a building material formulation to form a first portion of the layer, and leveling the first portion by a leveling device; increasing a vertical distance between the first portion and the leveling device; and while a topmost surface of the first portion is exposed and beneath a segment of the leveling device: dispensing a building material formulation to form a second portion of the layer, laterally displaced from the first portion along an indexing direction, and leveling the second portion by the leveling device.

Abstract: Methods and systems are disclosed for selecting a print head of a 3D printing machine to apply 3D printing material at one or more positions in a printed 3D object. Embodiments of the present invention may include, in the selection process one or more elements pertaining for example to: geometry of the received 3D model; colorization of the received 3D model; transparency of the received 3D model; properties of the 3D printing material; and constraints of the 3D printing machine.

Abstract: Modeling material formulation systems usable in additive manufacturing, 3D inkjet printing in particular, of three-dimensional objects, are provided. The formulations comprise two or more curable materials, such that an average molecular weight of the curable materials in each formulation is no more than 500 grams/mol, such that each formulation features a viscosity of no more than 50 centipoises at a temperature of 35° C. Kits comprising the formulations or formulation systems and additive manufacturing processes utilizing same are also provided.