Abstract: A power management system for a selective deposition modeling apparatus for maintaining the power consumption of the apparatus within the limits of conventional power available in most all office environments. The apparatus has a plurality of power drawing components, each component having a activation power rating wherein the accumulative total of all the power ratings exceeds a baseline power consumption value for the apparatus. The system prevents a baseline power consumption value from being exceeded by determining which components can be activated while leaving others inactivated.

Abstract: In solid freeform fabrication processes that make use of a removable support material, pre-calculation of the amount of support material needed for a build is difficult (inaccurate or slow) because the digital data for generating the support material is often not generated until the build is in progress. A method is proposed that has been shown to generate rapid and accurate estimates of the amount of both build and support material needed before a build begins, to accurately predict before a build begins when replenishment materials are needed, and to track material consumptions over time.

Abstract: A ventilation and cooling system for a selective deposition modeling apparatus dispensing a curable material. The ventilation and cooling system captures airborne contaminants in the apparatus making the apparatus suitable for use in an office environment. A pressure drop is established within the apparatus to assure that all air that enters the apparatus passes through a filter which captures the airborne contaminants before the air is expelled from the apparatus. Sensors are provided to assure that the ventilation and cooling system is function properly, and if not, the apparatus is either shut down or a signal is provided to the operator indicating that the system is not functioning properly.

Abstract: A variety of support structures and build styles for use in Rapid Prototyping and Manufacturing systems are described wherein particular emphasis is given to Thermal Stereolithography, Fused Deposition Modeling, and Selective Deposition Modeling systems, and wherein a 3D modeling system is presented which uses multijet dispensing and a single material for both object and support formation.

Abstract: A detoxification process for rendering three-dimensional objects formed by solid freeform fabrication techniques biocompatible for use in long-term dermal contact applications. The process nullifies cytotoxins normally present in objects formed by solid freeform fabrication techniques rendering such techniques as viable for the production of biocompatible devices such as stents, artery valve components, bone implant supports, pacemaker shells, surgical tools, and the like. In one embodiment, a custom hearing aid shell is produced by stereolithography from an acrylate photopolymer resin that was detoxified for long-term dermal contact application. The detoxification process makes three-dimensional objects created by solid freeform fabrication techniques available for products requiring biocompatibility.

Abstract: A convection cooling technique for selective deposition modeling utilizing a venturi duct to establish a low-pressure port for drawing a second flow of air into the duct. The second flow of air is drawn across a heat generating component in the selective deposition modeling apparatus. A low-pressure zone is established at the low-pressure port sufficient to meet the head loss that results when drawing the second flow across the heat generating component and into the venturi duct. A desired flow rate is achieved at a pressure drop that is greater than that possible by the direct use of a fan. The cooling system is well suited for use in providing steady state cooling of radiation exposure systems used in selective deposition modeling to initiate curing of the layers of dispensed material.

Abstract: A method of applying highly viscous paste-like build materials in layers in a solid freeform fabrication apparatus to form three-dimensional objects. A viscosity modifier is first introduced into the build material to establish a low viscosity state and then the material is dispensed in layers on a working surface. The viscosity modifier is then removed from the build material preferably by evaporation, and the layer is selectively solidified to form the three-dimensional object. The method substantially eliminates the undesirable effects of induced shear stress imposed on lower layers when attempting to apply uniform layers of highly viscous materials in solid freeform fabrication techniques. The method allows for the use of highly viscous paste-like materials that can include upwards of 50% by weight of metallic, ceramic, mineral, or polymer powders. Preferably the binder is a photocurable resin or thermocurable material which is selectively solidified to form the three-dimensional objects.

Abstract: A flash curing system for solid freeform fabrication which generates a plurality of radiation emitting pulses that forms a planar flash. The planar flash initiates curing of a curable material dispensed by a solid freeform fabrication apparatus. The radiation emitting pulses have a high peak power value that releases a sufficient quantity of free radicals from the photoinitiator to initiate curing and overcome the problem of oxygen inhibition. Substantially less power is consumed and less heat generated by the flash curing system compared to conventional continuous emission curing systems.

Abstract: The invention relates in general to calibrating a focused beam of energy in a solid freeform fabrication apparatus, and, in particular, to a method of measuring the propagation characteristics of the beam to produce beam propagation data. The beam propagation data can be used to verify that the beam is operating within tolerance, and/or produce a response that can be used to further calibrate the beam. The invention is particularly useful in determining asymmetric conditions in the beam. The beam propagation data is produced in accord with the “M2” standard for characterizing a beam. In one embodiment, the response indicates the beam is unacceptable for use in the apparatus. In another embodiment, the response is provided to calibrate the focal position of the beam. In still another embodiment, the response is provided to an adjustable beam that eliminates the asymmetric condition.

Abstract: What is disclosed is a process for making small thermoplastic polymer particles comprising the steps of:

Abstract: A paste composition, including a binding agent charged with metallic powder, to be used in a solid freeform fabrication procedure, comprising: a) a solidifiable binding agent comprised of at least one polymerizable resin, with a viscosity of less than 4000 mPa.s, measured at 25° C.; b) at least one initiator, in a concentration greater than about 0.1% by mass with respect to the mass of the resin; and c) a mixture of at least two metallic powders, said mixture having a volumetric concentration greater than 40% with respect to the composition, wherein said mixture of metal powders is either i) a bimodal or trimodal mixture in nature, or ii) is a majority of stainless steel with an amount of NiB or NiP and combinations thereof effective to lower the sintering temperature.

Abstract: An improved stereolithographic process for forming three-dimensional objects using an improved support structure is disclosed. The support structure is formed by using differential curing of the liquid media material to form solid supports with weak points at selected locations to facilitate support removal from a three-dimensional object and minimize post-processing.

Abstract: Rapid prototyping and manufacturing (e.g. stereolithography) methods and apparatus are disclosed that form objects with enhanced accuracy and small feature retention. Techniques for offsetting cross-sectional boundary data to at least partially accommodate for solidification width induced in a medium by a beam of radiation are provided. One technique uses repeated small offsets to yield an effective offset of a desired amount. A second technique uses displacement vectors to determine where and to what extent to offset the boundary segments. The offset amount for each vertex is determined based on a combination of the (1) the vertex angle, and (2) a predefined variable offset criteria which is different for at least two predefined ranges of angles. A third technique converts a single boundary segments into a plurality of offset boundary segments when the single boundary segment can not undergo the full desired offset without violating another offsetting rule.

Abstract: An improved stereolithography system for generating a three-dimensional object by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, information defining the object being specially processed to reduce curl and distortion, and increase resolution, strength, accuracy, speed and economy of reproduction even for rather difficult object shapes, the successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: A computer-controlled apparatus and method for fabricating three-dimensional articles in layerwise fashion is disclosed. Upon dispensing a layer of a fusible powder, a laser irradiates selected locations of that layer to fuse the powder into a cross-section of the article to be formed in that layer, such that the fused cross-sections fuse together into the article. The laser is controlled in a raster scan fashion across the selected locations of the powder layer. The raster scan lines are defined, for each cross-section, to achieve an optimal fill scan time. The optimal fill scan time is determined, by the computer estimating the fill scan time by rotating the cross-section over a plurality of rotational angles, and estimating the fill scan time for each of the rotated cross-sections for at least a sample of the fill scans necessary to form the article.

Abstract: An improved process for forming photocurable three-dimensional objects using an improved curing process is disclosed. The build object is formed by using differential curing of the photocurable media material to form cured solid regions with discrete mechanical properties at selected locations to tailor a part's properties to individual needs.

Abstract: An improved selective deposition modeling method which produces a cold weld joint in an object formed by dispensing a single phase change material. The cold weld joint can be controlled so that a lower portion of the object can serve as a support structure for forming the upper portion of the object. Upon separation of the lower and upper portions along the cold weld joint, a downward facing surface is revealed on the upper portion exhibiting superior detail and quality compared to other downward facing surfaces created by conventional selective deposition modeling techniques. The method can readily be adapted for use by selective deposition modeling machines utilizing ink jet print heads dispensing a single phase change material.

Abstract: A jettable non-curable support material composition useful for three-dimensional ink jet printing comprising at least one fatty alcohol and at least one abietic rosin ester alcohol, wherein the support material has a melting point between about 50° C. to about 65° C. and a freezing point between about 45° C. to about 55° C.

Abstract: An improved layer normalizing device for use in dimensionally normalizing layers of a three-dimensional model produced by a selective deposition modeling technique. The layer normalizing device employs a wicking member having a body and a normalizing surface for dimensionally normalizing the object while the object is being built layer by layer. The body includes a plurality of interstices, and when the wicking member is sufficiently heated to cause the build material to become flowable, excess material is drawn by capillary action from the layer of the object being normalized and into the wicking member. A refreshing means is provided to remove the excess build material from the interstices of the wicking member and allow the wicking member to draw additional build material by capillary action.

Abstract: An improved stereolithographic process for forming three-dimensional objects using an improved support structure. The support structure is formed by using differential curing of the liquid media material to form solid supports with weak points at selected locations to facilitate support removal from a three-dimensional object and minimize post-processing.