Abstract: A method and apparatus for forming three dimensional objects by laser sintering that includes depositing the required quantities of powder for two successive layers on one side of the process chamber and simultaneously spreading the first layer while transporting the second layer quantity to the opposite side of the process chamber. The invention includes steps of parking the quantities of powder in sight of the part bed heater to pre-heat the powder and flattening the powder wave before the pre-heating step to improve pre-heat efficiency. This method and apparatus can result in reduction of the mechanisms, size, cost, and increase productivity of a laser-sintering device.

Abstract: A method of forming a three-dimensional object in a layerwise manner is disclosed. The object is formed in a manner-that substantially prevents non-uniform distortion to occur during the layerwise build process as the build material forming the object solidifies and shrinks. The formed object comprises an outer surface defined by a shell structure and an internal lattice structure residing within the internal volume of the object. The object may be formed by any selective deposition modeling apparatus from a wide variety of materials.

Abstract: An apparatus and a method of using the apparatus wherein a radiation emitter is positioned adjacent a sensor apparatus within a process chamber in a laser sinter system that emits radiation to the sensor apparatus and a calibration apparatus receives readings from the sensor apparatus to compare temperature sensings received from the sensor apparatus with set emission signals from the radiation emitter to adjust the temperature sensings to calibrate the sensor apparatus during the forming of a three-dimensional article. The calibration is done repeatedly during the build process of the three-dimensional article.

Abstract: A method for removing supports from a three-dimensional object formed by solid freeform fabrication. The three-dimensional object and support structure both contain a phase change component in order to achieve the desired phase change characteristics needed for dispensing the material. The method prevents the phase change material within the three-dimensional object from migrating within the object during post processing to remove the support structure.

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 material feed system for solid freeform fabrication. The build material is delivered in discrete or quantized amounts by the feed system in a non-flowable state to the dispensing device and the material is then changed to a flowable state prior to being dispensed. The feed system can be used to build three-dimensional objects in color, if desired. In one embodiment individual cartridges with build material are loaded into a magazine on the feed system which is integrated with a waste removal system. As the build material is expelled from the cartridges, waste material is deposited into the cartridge. Once all the build material has been expelled, the waste material is hermetically sealed in the spent cartridge which is then ejected from the system. The hermetically sealed cartridges protect operators from contact with the reactive waste material making the system safe for the office environment.

Abstract: A method for the manufacture of a three-dimensional object includes the steps of forming a mixture that contains a binder, a wetting agent, and a least one of aluminum or a first aluminum-base alloy into a green composite, removing the binder from said green composite forming a porous preform structure and infiltrating the porous preform structure with a molten second aluminum base alloy to form the three-dimensional object with near theoretical density. The wetting agent assists in wetting during infiltration. The green composite may be formed by an additive process such as computer aided rapid prototyping, for example selective laser sintering. The method facilitates the rapid manufacture of aluminum components by an inexpensive technique that provides high dimensional stability and high density.

Abstract: A selective deposition modeling method and apparatus for dispensing a curable phase change material. The dispensing temperature of the material is set at or less than a thermally stable temperature value for the material in which the reactive component of the material remains substantially uncured when held at the temperature for a desired time period. The dispensed material is provided with an environment that enables the material to solidify to form layers of the object. The solidified material is normalized to a desired layer thickness and is then cured by exposure to actinic radiation. In a preferred embodiment a UV curable phase change material is dispensed at about 80° C. and has a viscosity of about 13 to about 14 centipoise at this temperature. The cured material provides substantially increased physical properties over thermoplastic phase change materials previously used in selective deposition modeling.

Abstract: A UV curable composition useful for three-dimensional inkjet printing comprising (i) at least one UV curable urethane (meth)acrylate resin; (ii) at least one wax; (iii) at least one (meth)acrylate diluent; (iv) at least one photoinitiator; and (v) at least one polymerization inhibitor; wherein the amount of wax (ii) is sufficient to phase change the UV curable composition after jetting.

Abstract: A liquid radiation-curable composition that comprises (A) at least one polymerizing organic substance; (B) at least one free-radical polymerizing organic substance; (C) at least one cationic polymerization initiator; (D) at least one free-radical polymerization initiator; (E) at least one hydroxyl-functional compound; and (F) at least one epoxy interpenetrating polymer compound;

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: A support structure is applied directly to the first side of a semiconductor work piece or wafer by a stereolithographic process layer by layer completely about and extending inwardly of the periphery of the wafer, but external to the selected area within which a desired circuitry pattern is placed, the support structure being of a desired height and of a material resistive to an acid etch process effective to seal the circuitry pattern in the selected area from acid when the work piece is subjected to an acid etch on the opposing second side and about the periphery. The support structure further strengthens the work piece against flexural failure.

Abstract: A powder blend for use in laser sintering and a method for forming tough, strong, wear-resistant, corrosion-resistant infiltrated metal products are provided. The powder blend comprises a steel alloy, a polymeric binder and a high melting temperature fine particulate which are blended together, then applied layer by layer to a working surface in a laser sintering system, exposed a layer at a time to fuse together the powder until a green part of high strength is formed, and then the green part is infiltrated with a metal infiltrant in a non-reducing gas atmosphere at an effective temperature for an effective period of time. The preferred steel is a mild steel alloy.

Abstract: A method and apparatus for forming three dimensional objects by laser sintering that utilizes a broad area thermal vision system such as an infrared camera that can measure multiple temperatures across the target area and use that temperature data as feed back to a control system that both adjusts a zoned radiant heater system and adjusts scan speed and laser power to control temperatures across the target area.

Abstract: A powder blend for use in laser sintering and a method for forming tough, strong, wear-resistant, corrosion-resistant infiltrated metal products are provided. The powder blend comprises a steel alloy, a polymeric binder and a high melting temperature fine particulate which are blended together, then applied layer by layer to a working surface in a laser sintering system, exposed a layer at a time to fuse together the powder until a green part of high strength is formed, and then the green part is infiltrated with a metal infiltrant in a non-reducing gas atmosphere at an effective temperature for an effective period of time. The preferred steel is a mild steel alloy.

Abstract: A solid freeform fabrication method and apparatus for making objects in a layer by layer manner in which the objects have special geometrical features requiring specialized control parameters. The method and apparatus automatically determines and selects the build parameters for the build process based on automatic part feature recognition. A general build style is first determined having a plurality of default parameters for building the object. Data representing the object is imported and oriented with a Z-axis. The data is then processed by slicing software that automatically identifies special build types for specific ranges of Z-values and selects the alternative parameters needed to successfully build these features. Preferably a look-up table contains special sets of values for the parameters for each special build type possible in which the slicing algorithm can select from. During slicing, operator intervention is not needed to prepare all the parameters necessary for a successful build.

Abstract: A method and apparatus for forming three dimensional objects by laser sintering that utilizes a broad area thermal vision system such as an infrared camera that can measure multiple temperatures across the target area and use that temperature data as feed back to a control system that both adjusts a zoned radiant heater system and adjusts scan speed and laser power to control temperatures across the target area.

Abstract: An improved stereolithographic process for forming three-dimensional objects using an improved support structure and the improved support structure is described. 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.