Abstract: A system and a method of mitigating color discrepancies in three-dimensional (3D) printing systems may including a plurality of printing heads may include: printing one or more samples according to one or more sample parameters; obtaining a color offset vector from the one or more samples; receiving a model representing a 3D object, the model comprising a plurality of model printing points associated with respective color; analyzing the model in view of the obtained color offset vector to produce a calibrated data structure, adapted to mitigate color discrepancies; and printing the 3D object according to the calibrated data structure.

Abstract: A method of manufacturing a conductive element is disclosed. The method being executed by an additive manufacturing system and comprises: dispensing a modeling material on a receiving medium to form a layer, and dispensing a conductive ink on the layer of modeling material to form a conductive element. In some embodiments of the invention the modeling material comprises a sintering inducing agent, and in some embodiments of the present invention a sintering inducing composition is dispensed separately from the modeling material and separately from the conductive ink.

Abstract: A three-dimensional printing system to print three-dimensional objects and a method of printed are disclosed. The system includes a printing apparatus to print three-dimensional objects and a controller to receive data from a material supply source and to control said printing apparatus.

Abstract: Methods for fabricating three-dimensional objects by 3D-inkjet printing technology are provided. The methods utilize a combination of curable materials that polymerize via ring-opening metathesis polymerization (ROMP) and curable materials that polymerize via free-radical polymerization (FRP) for fabricating the object. Systems suitable for performing these methods, kits containing modeling material formulations usable in the methods and objects obtained thereby are also provided.

Abstract: A method of processing data for additive manufacturing of a 3D object comprises: receiving graphic elements defining a surface of the object, and an input color texture to be visible over a surface of the object; transforming the elements to voxelized computer object data; constructing a 3D color map having a plurality of pixels, each being associated with a voxel and being categorized as either a topmost pixel or an internal pixel. Each topmost pixel is associated with a group of internal pixels forming a receptive field for the topmost pixel. A color-value is assigned to each topmost pixel and each internal pixel of a receptive field associated with the topmost pixel, based on the color texture and according to a subtractive color mixing. A material to be used during the additive manufacturing is designated based on the color-value.

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: Additive manufacturing or 3D printing produces considerable quantities of waste ink or resin during the course of additive manufacture. The waste ink is a hazardous substance and must be collected and disposed of accordingly. The present embodiments provide a waste ink collection device that collects the waste ink from the printing process, or from head cleaning and other incidental operations, stores the waste and cures it. The waste ink is thus rendered safe for conventional disposal. A waste ink disposal cartridge collects the waste ink and carries out curing.

Abstract: Formulation systems usable for fabricating a three-dimensional object made of a polyamide-containing material, by three-dimensional 3D inkjet printing, and methods and systems utilizing same, are provided. The formulation systems are formed of at least a first and second model formulations containing a lactam and a catalyst for inducing anionic ring opening polymerization of the lactam in the first formulation, and an activator for promoting anionic ring opening polymerization of the lactam in the second formulation, and are further characterized as: including in the first and/or second formulation a compound capable of increasing a rate of said polymerization upon exposure to said curing energy; including as an activator a lactam-blocked polyisocyanate; and/or as including in the first model formulation at least one material capable of reducing a melting point of said first model formulation. Formulation systems usable at a selected ratio are also provided.

Abstract: Methods, particularly automated methods, are provided, as well as 3D-printed composite and hollow objects and 3D-printing systems for printing them. Methods comprise deriving a central line of a hollow 3D object model, calculating reference point(s) and/or line(s) along an inner surface of the hollow 3D object model, and filling the hollow 3D object model with material that comprises a thread defined with respect to the central line and the reference point(s) and/or line(s) and with filling material surrounding the thread. The support construction thus formed may be removed from the 3D object by pulling on the thread, extracting it and the surrounding support filling from the hollow object, thus enabling 3D-printing of convoluted or elongated hollow objects and objects with narrow openings. The parameters of the thread, such as type of curve and thickness, are selected to ensure thread extraction without risk of tearing or knotting the thread.

Abstract: Novel cleaning compositions, usable for removing a cured support material from a printed object obtained by additive manufacturing such as 3D inkjet printing are provided. The cleaning compositions are aqueous alkaline compositions containing a combination of two alkaline substances: an alkali metal hydroxide and an alkali metal silicate, each at a concentration of no more than 3 weight percents of the total weight of the composition. The cleaning compositions are characterized by high and constant dissolution rate, and are particularly useful for removing a cured support material that includes cross-linked polymeric chains such as cross-linked polyacrylate chains. Kits comprising the alkaline substances, and methods of fabricating a three-dimensional model object which utilize the cleaning compositions or the kits, and a three-dimensional model object fabricated thereby, are also provided.

Abstract: A method suitable for solid freeform fabrication is disclosed. The method comprises mixing respective amounts of a plurality of materials such as to provide a building material characterized by at least one attribute, and using the building material for fabricating a three-dimensional object.

Abstract: A system and methods for solid freeform fabrication of an object is disclosed. The system comprises a solid freeform fabrication apparatus having a plurality of dispensing heads, a building material supply apparatus configured to supply a plurality of building materials to the fabrication apparatus, and a control unit configured for controlling the fabrication apparatus and the supply apparatus based on an operation mode selected from a plurality of predetermined operation modes.

Abstract: A method of printing a three-dimensional (3D) color object, layer-by-layer, comprises: obtaining a 3D CAD specification defining a 3D geometry and a surface color distribution for the color object to be printed, defining regions on a surface of the color object; defining colors for each region based on the CAD specification; determining, using the 3D geometry of the specification, conditions applying at respective regions that are liable to cause color variation, such that using the colors as defined at the respective regions may give rise to a coloration error; selecting color corrections defined for respective determined conditions; correcting the defined colors; and printing the 3D color object with the color corrections.

Abstract: The combination of 3D printing technology plus the additional dimension of transformation over time of the printed object is referred to herein as 4D printing technology. Particular arrangements of the additive manufacturing material(s) used in the 3D printing process can create a printed 3D object that transforms over time from a first, printed shape to a second, predetermined shape.

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: 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 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 system for building a three dimensional green compact comprising a printing station configured to print a mask pattern on a building surface, wherein the mask pattern is formed of solidifiable material; a powder delivery station configured to apply a layer of powder material on the mask pattern; a die compaction station for compacting the layer formed by the powder material and the mask pattern; and a stage configured to repeatedly advance a building tray to each of the printing station, the powder delivery station and the die compaction station to build a plurality of layers that together form the three dimensional green compact.

Abstract: A method of fabricating a cross-layer pattern in a layered object is disclosed. The method is executed by an additive manufacturing system and comprises: dispensing a patterning material onto a receiving medium to form a first pattern element; dispensing a first layer of modeling material onto the first pattern element while forming a first open cavity exposing at least a portion of the first pattern element beneath the first layer; and dispensing patterning material onto the exposed portion of the first pattern element and the first layer to form a second pattern element contacting the first pattern element.

Abstract: Methods for fabricating three-dimensional objects by 3D-inkjet printing technology are provided. The methods utilize curable materials that polymerize via ring-opening metathesis polymerization (ROMP) for fabricating the object, in combination with acid-activatable pre-catalyst and an acid generator activator. Kits containing modeling material formulations usable in the methods are also provided.