Abstract: A method for selection of a print head of a three-dimensional (3D) printer includes receiving a model data element having first and second 3D shells, producing an ordered set of slice data elements corresponding to a planar slice of the 3D model, determining an overlapping region of the first and second 3D shells, attributing a property vector value (such as a colorization vector value or a printing material vector value) based on an overlap rule, and selecting a printing head based on the property vector value. A 3D printing system comprises printing heads that can be selected according to the method.

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: An apparatus for preparing a two-dimensional layer of a three-dimensional object during three-dimensional printing of the object. The apparatus may include a controller; a transparent substrate for receiving a deposited layer of liquid materials on an upper surface thereof; a selective deposition unit that deposits at least one liquid body material and a liquid support material different from the at least one liquid body material, on the transparent substrate according to signals received from the controller; and a selective curing unit that selectively solidifies, by curing irradiation, a portion of the deposited layer of liquid body materials on the transparent substrate according to signals received from the controller, such that some of the liquid body material remains uncured.

Abstract: A method of layerwise fabrication of a three-dimensional object is disclosed. The method comprises, for each of at least a few of the layers: dispensing at least a first modeling formulation and a second modeling formulation to form a core region using both the first and the second modeling formulations, and at least one envelope region at least partially surrounding the core region using one of the first and the second modeling formulations but not the other one of the first and the second modeling formulations. The method can also comprise exposing the layer to curing energy. The first modeling formulation is characterized, when hardened, by heat deflection temperature (HDT) of at least 90° C., and the second modeling formulation is characterized, when hardened, by Izod impact resistance (IR) value of at least 45 J/m.

Abstract: A method of additive manufacturing of a three-dimensional object is disclosed. The method comprises sequentially forming a plurality of layers each patterned according to the shape of a cross section of the object. In some embodiments, the formation of at least one of the layers comprises performing a raster scan to dispense at least a first building material composition, and a vector scan to dispense at least a second building material composition. The vector scan is optionally along a path selected to form at least one structure selected from the group consisting of (i) an elongated structure, (ii) a boundary structure at least partially surrounding an area filled with the first building material, and (iii) an inter-layer connecting structure.

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 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 monitoring an amount of building material in a cartridge that supplies the material to an additive manufacturing system, comprises introducing gas into the cartridge and measuring the pressure within the cartridge. When the pressure reaches a predetermined level, the amount of building material in the cartridge is determined based on a volume of gas introduced into the cartridge or based on a proxy of the volume.

Abstract: Systems and methods for calculating a time duration and an amount of material consumption required for printing a tray of one or more three-dimensional objects using a three-dimensional printing system are disclosed.

Abstract: Systems and methods for predefining at least one support structure for at least one three-dimensional object for printing thereof using a three-dimensional printing system are disclosed. Default support structures are replaced by improved support structures or not depending on the result of an assessment, based on predefined rules of the body region in the slice that needs support.

Abstract: A method for producing a three-dimensional model via additive manufacturing includes building a green block in a layerwise manner with a powder material and a solidifiable non-powder material. The green block includes a green usable model. The solidified non-powder material is removed from the green block to extract the green usable model from the green block and the density of the green usable model is increased by applying Cold Isostatic Pressing (CIP). The green usable model is then sintered to produce a three-dimensional model.

Abstract: A method for preserving the shape of an object during sintering includes filling at least one volume defined by a surface of the object with a plurality of balls, sintering the object together with the balls and separating the object from the balls post sintering. The balls have a diameter of 0.5 mm-12 mm.

Abstract: A waste curing device to cure waste generated by an additive manufacturing system, the waste curing device comprising: a container for receiving the waste; a movable cover positioned above the container; one or more waste nozzles mounted on the moveable cover and configured to deliver waste into the container; a static cover positioned above the container and below the movable cover; one or more curing sources mounted on the static cover and configured to provide curing radiation to cure the waste in the container; wherein the movable cover is configured to move relative to the static cover to provide an open position for the waste nozzles to deliver waste into the container, and subsequently to a closed position, to shield the waste nozzles from curing radiation.

Abstract: A method for sintering objects formed with aluminum powder includes forming a shape of an object with aluminum powder, selecting a sintering atmosphere and sintering the object in the sintering atmosphere. The sintering atmosphere includes Nitrogen and one or more of Argon and partial vacuum. The selection is based on a desired balance of degree of shrinkage and mechanical properties to be achieved.

Abstract: Methods of fabricating three-dimensional rubber-like objects which utilize one or more modeling material formulations which comprise an elastomeric curable material and silica particles are provided. Objects made of the modeling material formulations and featuring improved mechanical properties are also provided.

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: Modeling material formulations usable for forming a polyurea material in additive manufacturing, and methods for additive manufacturing of three-dimensional objects made of these formulations are provided. The modeling material formulation comprises at least one isocyanate-containing material and at least one amine-containing material such that at least one isocyanate-containing material comprises at least one polyisocyanate material and at least one amine-containing material comprises at least one aromatic polyamine material.

Abstract: An additive manufacturing method for printing an object includes receiving three-dimensional printing data corresponding to the object, defining an internal region of the object to be formed with a structured air pocket and printing the object with an additive manufacturing system. The object includes an internal region formed with a structured air pocket.

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: A system for maintaining a desired pressure difference between a first pressure within a chamber and a reference pressure at a reference space. The system may include a peristaltic pump located along a duct that connects the chamber with the reference space. The system may further include a pressure sensor for monitoring an actual pressure difference between the first pressure within the chamber and the reference pressure at the reference space. The system may also include a controller for receiving a signal from the pressure sensor for determining the actual pressure difference from the pressure sensor and for operating the peristaltic pump, in accordance with the actual pressure difference and the desired pressure difference, to increase, decrease or leave unchanged the pressure within the chamber so as to maintain the actual pressure difference within predetermined proximity to the desired pressure difference.