Abstract: In one aspect, build materials operable for use in 3D printing systems are described herein. In some embodiments, a build material comprises an oligomeric curable material, a reactive component that is solid at 25° C., and at least one diluent, wherein the reactive component comprises at least one chemical moiety that is polymerizable with a chemical moiety contained in the oligomeric curable material and/or the at least one diluent.

Abstract: In one aspect, support materials operable for use in 3D printing systems are described herein. In some embodiments, a support material comprises a wax component comprising at least one ethoxylated fatty alcohol and a viscosity modifying agent, wherein the support material is water dispersible. In some embodiments, the wax component comprises a mixture of at least one fatty alcohol and at least one ethoxylated fatty alcohol.

Abstract: Systems and methods for calibrating a solid-imaging system (10) are disclosed. A calibration plate (110) having a non-scattering surface (140) with a plurality (150) of light-scattering fiducial marks (156) in a periodic array is disposed in the solid-imaging system. The actinic laser beam (26) is scanned over the fiducial marks, and the scattered light (26S) is detected by a detector (130) residing above the calibration plate. A computer control system (30) is configured to control the steering of the light beam and to process the detector signals (SD) so as to measure actual center positions (xA, yA) of the fiducial marks and perform an interpolation that establishes a calibrated relationship between the angular positions of the mirrors and (x,y) locations at the build plane (23). The calibrated relationship is then used to steer the laser beam in forming a three-dimensional object (50).

Abstract: The present invention provides a clear, low viscosity photocurable composition including (i) a cationically curable compound (ii) an acrylate-containing compound (iii) a polyol-containing mixture (iv) a cationic photoinitiator and (v) a free radical photoinitiator. The photocurable composition can be cured using rapid prototyping techniques to form opaque-white three-dimensional articles having ABS-like properties.

Abstract: A solid imaging apparatus is provided that includes a replaceable cartridge containing a source of build material and an extendable and retractable flexible transport film for transporting the build material layer-by-layer from the cartridge to the surface of a build in an image plane. An operator using the device needs merely to remove a spent cartridge and replace it with a fresh cartridge to continue solid imaging virtually uninterrupted. The apparatus also includes the capability of withdrawing and inserting an imager without the operator having to perform a separate alignment step. A brush attached to the transport film and forming part of the cartridge provides for intra-layer removal of excess uncured build material. If desired, the apparatus can produce a fully reacted build. A high intensity UV source cures the build between layers. An injection molded build pad is designed to hold a build in an inverted position for improving the build.

Abstract: There is provided methods and apparatus for improving the accuracy of three-dimensional objects formed by additive manufacturing. By depositing or hardening build material within the interior of the layers in certain patterns, the stresses that lead to curl in the object can be isolated and controlled. Similarly, certain patterns for depositing or hardening the build material provide for reduced layer thicknesses to improve the sidewall quality of the object being formed. The patterns within the interior of the layers can include gaps or voids for particular layers being deposited or hardened, and the gaps or voids can be partially filled, fully filled, or not filled at all when subsequent layers are deposited or hardened. Accordingly, the accuracy of three-dimensional objects formed by additive manufacturing is improved.

Abstract: A method of controlling the flow of unbound powder in a build chamber. A build surface for receiving the powder is provided, with the build surface including a first plate defining holes and a second plate defining a plurality of openings spaced apart and offset from the plurality of holes in the first plate. The second plate is disposed below and spaced from the first plate. A vacuum source is provided below the build surface.

Abstract: A method of making a 3-D object from a photocurable composition, including (a) a cationically curable monomer; (b) a radically curable monomer; (c) reactive particles comprising a crosslinked polysiloxane core and a shell of reactive groups on an outer surface of the core, wherein the reactive groups comprise epoxy groups, ethylenically unsaturated groups, or hydroxy groups; (d) a radical photoinitiator; and (e) a cationic photoinitiator; the method comprising (1) forming a first layer of the photocurable composition; (2) exposing the first layer to actinic radiation sufficient to harden the first layer; (3) forming a second layer of the photocurable composition above the hardened first layer; (4) exposing the second layer to actinic radiation sufficient to harden the second layer; and (5) repeating steps (3)-(4) as needed to form a 3-D object.

Abstract: The invention relates to apparatus and methods for producing three-dimensional objects and auxiliary systems used in conjunction with the aforementioned apparatus and methods. The apparatus and methods involve 3D printing and servicing of the equipment used in the associated 3D printer.

Abstract: A materials system and methods are provided to enable the formation of articles by three dimensional printing. The materials system includes particulate mixtures having a whitening agent and a solid particulate additive comprising an acid, the latter adapted for modifying a cure rate of an infiltrant. The materials system also includes aqueous fluids including optical brightening agents.

Abstract: A materials system and methods are provided to enable the formation of articles by Three Dimensional Printing. The materials system includes a transition metal catalyst that facilitates the reaction of an acrylate-containing binder with a particulate material.

Abstract: A part cake defining a build produced by laser sintering and the surrounding unfused powder is contained in an enclosure, and the enclosure includes displaceable wall portions for compressing the part cake to support the build against distortion during rapid cooling from a cooling fluid. The enclosure enables the part cake to be quickly and reliably cooled either within the laser sintering system or outside the laser sintering system. A source of cooling fluid connects to the enclosure and a lid holds the part cake in place as cooling fluid is forced through the pore volume of the cake. An inert gas blanket apparatus is also provided to reduce or prevent oxidation of the part cake and/or to cool the part cake. Once the part cake is cooled, the build produced by laser sintering may be removed from the part cake.

Abstract: The invention relates to an illumination unit for point illumination of a medium comprising a plurality of light emitters in the form of light guides, which are arranged to illuminate at least one illumination face via a light valve arrangement, said light valve arrangement comprising a plurality of electrically controlled light valves, at least one of the light emitters (1) being arranged to illuminate a plurality of light valves.

Abstract: A three-dimensional printer adapted to construct three dimensional objects is disclosed. In an exemplary embodiment, the printer includes a first surface adapted to receive a bulk layer of sinterable powder, a polymer such as nylon powder; a radiant energy source, e.g., an incoherent heat source adapted to focus the heat energy to sinter an image from the layer of sinterable powder; and a transfer mechanism adapted to transfer or print the sintered image from the first surface to the object being assembled while fusing the sintered image to the object being assembled. The transfer mechanism is preferably adapted to simultaneously deposit and fuse the sintered image to the object being assembled. The process of generating an image and transferring it to the object being assembled is repeated for each cross section until the assembled object is completed.

Abstract: A solid imaging apparatus is provided that includes a replaceable cartridge containing a source of build material and an extendable and retractable flexible transport film for transporting the build material layer-by-layer from the cartridge to the surface of a build in an image plane. An operator using the device needs merely to remove a spent cartridge and replace it with a fresh cartridge to continue solid imaging virtually uninterrupted. The apparatus also includes the capability of withdrawing and inserting an imager without the operator having to perform a separate alignment step. A brush attached to the transport film and forming part of the cartridge provides for intra-layer removal of excess uncured build material. If desired, the apparatus can produce a fully reacted build. A high intensity UV source cures the build between layers. An injection molded build pad is designed to hold a build in an inverted position for improving the build.

Abstract: A stereolithography apparatus having a resin vat with resupply containers in one-way flow communication and a leveling container in two-way how communication, an automatic offload cart to remove and replace build support platforms, an elevator assembly for supporting and releasably retaining a build platform removably attached to the stereolithography apparatus frame such that elevator forks supporting the build platform can be released into the vat and removed from the stereolithography apparatus with the vat, and a recoater assembly and recoater blade for mapping the resin surface in the vat and applying a fresh coating of resin to a cross-section being built in the vat.

Abstract: An optical moulding process is disclosed comprising the sequential steps of: (a)(y) forming a layer of a photocurable composition; and (bXz) irradiating selected areas of the composition in the layer with radiation from a radiation source, thereby curing the composition in said selected areas and repeating the steps a) and b) on top of an earlier cured layer to form a three dimensional structure, wherein the radiation source used in step b) is a non-coherent source of radiation and wherein the photocurable composition comprises at least two curable components: (i) 45%-95% (and preferably at least 50%, more preferably at least 60%, e.g.

Abstract: There are provided method and apparatus for the forming of three-dimensional objects in a layered fashion, wherein improvements are made to the support structure to improve the quality of the resulting three-dimensional objects. The support structure may include encapsulation along the interface boundary of the support-object interface to prevent or reduce the likelihood of separation of the build material, that forms the three-dimensional object, from the support material, that forms the support structure, or vice versa. The support structure may also or alternatively include both a porous support structure and a solid support structure to prevent or reduce the likelihood of, separation of the support structure from the build platform and to improve the quality of the down-facing surfaces of the three-dimensional object. Methods are also provided for selectively depositing the support material and build material and for encapsulating the interface boundary with support material.

Abstract: There is provided methods and apparatus for compensation of intensity profiles of imagers used in three-dimensional modelers. The intensity profile of the actinic radiation projected from the imager is determined by a variety of techniques, including but not limited to manually operated sensors, exposed and scanned actinic radiation-sensitive paper, and intensity profilers. Once the intensity profile of the imager is determined, each layer of the solidifiable liquid material is cured by projecting a plurality of patterns (as opposed to a single pattern) defining the two-dimensional cross-section of the part being cured. The patterns vary in duration, number, and/or shape to correlate to the intensity profile so that a single layer of selectively cured solidifiable liquid material is cured with a substantially equivalent (or otherwise controlled) amount of actinic radiation per unit of surface area to provide generally controlled and consistent part quality.

Abstract: Methods for generating supports (30) for parts (50) produced by solid freeform fabrication (“SFF”) are disclosed. The method includes defining a plurality of layers (L) that make up the part, and for each layer, determining those regions (R) that require support. The method also includes merging the regions for the different layers (L) into one or more common regions that require support, and providing at least one support for each of the one or more common regions. The result is that fewer supports are used as compared to conventional SFF fabrication methods.