Additive manufacturing apparatus

Abstract

SOLUTION: To provide an additive manufacturing apparatus, in which an electronic control unit is configured to cause one or a plurality of IP lamps to discharge energy when a print assembly or a recoat assembly crosses a build zone, receive a temperature value from one or a plurality of temperature sensors, determine whether the temperature value is within a prescribed range, and adjust the intensity of the one or plurality of IP lamps or the flow gas rate of the one or plurality of IP lamps when the temperature value is not within the prescribed range.SELECTED DRAWING: Figure 1B

Description

[Technical field]

[0001] The present specification relates generally to additive manufacturing devices, and more particularly to additive manufacturing device operations and methods for using same. [Background technology]

[0002] Additive manufacturing machines may be utilized to "build" objects layer by layer from build materials such as organic or inorganic powders. Early iterations of additive manufacturing machines were used for prototyping three-dimensional objects. However, as additive manufacturing technology improves, there is growing interest in utilizing additive manufacturing machines for large-scale commercial production of objects. One challenge in scaling additive manufacturing to commercial manufacturing is improving the throughput of additive manufacturing machines to meet commercial demand while maintaining and increasing machine reliability. Summary of the Invention [Problem to be solved by the invention]

[0003] Therefore, there is a need for alternative additive manufacturing devices and components thereof that improve manufacturing throughput and reliability. [Means for solving the problem]

[0004] A first embodiment A1 includes a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone, the zones being sequentially arranged in distinct portions along the length of the process chamber, a support extending along the length of the process chamber in a first vertical plane, and a print assembly including a plurality of nozzles for dispensing a binder within the build zone, the print assembly being movably coupled to the support via a first actuator configured to move in a forward or reverse direction along the length of the support and disposed in a second vertical plane parallel to the first vertical plane, and a vision system configured to image the dispensed binder pattern in the build zone, the print assembly, the first actuator, and an electronic control unit communicatively coupled to the vision system, the electronic control unit configured to: cause the print assembly to traverse the build zone in a forward or reverse direction while dispensing binder according to a programmed deposition pattern; receive image data from the vision system of the dispensed binder pattern resulting from the programmed deposition pattern; analyze the image data to determine whether there is an anomaly in the dispensed binder pattern; and if it determines the presence of an anomaly in the dispensed binder pattern, adjust the programmed deposition pattern for a subsequent traverse of the print assembly over the build zone to address the anomaly.

[0005] A second aspect A2 includes an additive manufacturing apparatus according to first aspect A1 that captures image data of the dispensed binder pattern as the print assembly traverses the build zone in a forward or reverse direction.

[0006] A third aspect A3 includes an additive manufacturing apparatus as described in any of first aspect A1 to second aspect A2, wherein the anomaly is an area of ​​a build layer of a build produced in the build zone where less than a predetermined amount of binder is present based on a comparison of the image data to the programmed deposition pattern.

[0007] A fourth aspect A4 includes an additive manufacturing apparatus as described in any of first aspect A1 to third aspect A3, wherein the anomaly is an area of ​​a build layer of a build produced in the build zone where a greater than predetermined amount of binder is present or binder is detected at one or more locations where binder should not be deposited based on a comparison of the image data to the programmed deposition pattern.

[0008] A fifth aspect A5 includes an additive manufacturing apparatus described in any of the first aspect A1 to fourth aspect A4, wherein the programmed deposition pattern map selects one of a plurality of the nozzles to select a pixel of a build layer of a build to be produced in the build zone.

[0009] A sixth aspect A6 includes the additive manufacturing apparatus of fifth aspect A5, wherein adjusting the programmed deposition pattern for a subsequent traverse of the printed assembly over the build zone includes updating an amount of binder defined for a selected nozzle of the plurality of nozzles to dispense.

[0010] A seventh aspect A7 includes the additive manufacturing apparatus of fifth aspect A5, wherein adjusting the programmed deposition pattern for a subsequent traverse of the print assembly over the build zone includes updating mapping of selected nozzles of the plurality of nozzles to select pixels for a subsequent build layer, and a first nozzle mapped to dispense binder to a first selected set of pixels during a first traverse of the print assembly is mapped to dispense binder to a second selected set of pixels during a second traverse of the print assembly over the build zone.

[0011] Eighth aspect A8 includes an additive manufacturing apparatus as described in any of first aspect A1 to seventh aspect A7, wherein adjusting the programmed deposition pattern for a subsequent traverse of the print assembly over the build zone includes performing a sub-pixel shift in alignment of the pixels defined in the programmed deposition pattern with a plurality of jet nozzles.

[0012] A ninth aspect A9 includes an additive manufacturing apparatus according to any of first aspect A1 to eighth aspect A8, further comprising a cleaning station disposed in the cleaning zone, the cleaning station configured to clean a plurality of the nozzles of the print assembly, and the electronic control unit further configured to cause the print assembly to interface with one or more cleaning elements of the cleaning station if the electronic control unit determines the presence of an anomaly in the dispensed binder pattern.

[0013] A tenth aspect A10 includes an additive manufacturing apparatus as described in any of the first aspect A1 to the ninth aspect A9, wherein the electronic control unit is further configured to cause the print assembly to perform a purge operation in the cleaning zone if the electronic control unit determines the presence of an anomaly in the distributed binder pattern.

[0014] An eleventh aspect A11 comprises an additive manufacturing apparatus according to any of the first aspect A1 to tenth aspect A10, wherein the vision system comprises at least one of an electromagnetic radiation source, a camera, an infrared camera, or an X-ray imaging device.

[0015] A twelfth embodiment A12 includes a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone, sequentially arranged in separate portions along the length of the process chamber; a support extending along the length of the process chamber in a first vertical plane; and a doctor for distributing build material within the build zone. and a recoat assembly including at least one of a blade and a roller, the recoat assembly being movably coupled to the support via a second actuator configured to move in a forward or reverse direction along a length of the support and disposed in a second vertical plane parallel to the first vertical plane; a vision system configured to image a dispensed layer of build material in the build zone; and an electronic control unit communicatively coupled to the recoat assembly, the second actuator, and the vision system, the electronic control unit configured to: cause the recoat assembly to traverse the build zone to dispense build material to form a new layer of build material in the build zone according to predetermined build material input parameters; receive image data from the vision system of the dispensed build material in the build zone; analyze the image data to determine whether there is an anomaly in the dispensed build material; and implement corrective action for subsequent dispenses of build material by the recoat assembly upon determining the presence of an anomaly in the new layer of dispensed build material.

[0016] A thirteenth aspect A13 comprises the additive manufacturing apparatus of the twelfth aspect A12, wherein the corrective action comprises adjusting predetermined build material input parameters.

[0017] A fourteenth aspect A14 includes an additive manufacturing apparatus as described in A13, wherein the predetermined build material input parameters are at least one of a build material thickness, an over-input amount, a recoat assembly speed for traversing the build zone, a rotational speed of the rollers of the recoat assembly, and a rotational direction of the rollers of the recoat assembly.

[0018] A fifteenth aspect A15 includes the additive manufacturing apparatus of any of the twelfth aspect A12 to the fourteenth aspect A14, wherein the corrective action includes causing the recoat assembly to redistribute build material onto the new layer before the print assembly dispenses binder onto the new layer of build material.

[0019] A sixteenth aspect A16 includes the additive manufacturing apparatus according to any one of the twelfth aspect A12 to the fifteenth aspect A15, wherein the corrective action includes stopping a build.

[0020] Seventeenth aspect A17 comprises an additive manufacturing apparatus according to any of twelfth aspect A12 to sixteenth aspect A16, further comprising a cleaning station disposed in the cleaning zone or the supply zone, the cleaning station configured to clean at least one of the doctor blade and the roller of the recoat assembly, and the electronic control unit further configured to cause the recoat assembly to interface with one or more cleaning elements of the cleaning station if the electronic control unit determines the presence of an anomaly in the new layer of dispensed build material.

[0021] An 18th aspect A18 includes an additive manufacturing apparatus described in any of the 12th aspect A12 to the 17th aspect A17, wherein the electronic control unit receives a current draw value of a motor driving the roller of the recoat assembly, determines whether the roller is operating in accordance with the predetermined build material input parameters, and if it determines that the roller is not operating in accordance with the predetermined build material input parameters, determines the presence of an abnormality in the roller of the recoat assembly.

[0022] A nineteenth aspect A19 comprises an additive manufacturing apparatus according to any of twelfth aspect A12 to eighteenth aspect A18, wherein the vision system comprises at least one of a camera, an infrared camera, and an X-ray imaging device.

[0023] A twentieth aspect A20 includes a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone, the zones being sequentially arranged in distinct portions along a length of the process chamber; a support extending along the length of the process chamber in a first vertical plane; a print assembly movably coupled to the support via a first actuator configured to move in a forward or reverse direction along the length of the support and disposed in a second vertical plane parallel to the first vertical plane; a recoat assembly movably coupled to the support via a second actuator configured to move in a forward or reverse direction along the length of the support and disposed in the second vertical plane parallel to the first vertical plane; and a print assembly and a recoat assembly configured to apply energy to build material and binder in the build zone to stimulate a curing reaction, the print assembly and the recoat assembly being ... and an electronic control unit communicatively coupled to the print assembly, the first actuator, the recoat assembly, the second actuator, the one or more IR lamps, and the one or more temperature sensors, wherein the electronic control unit is configured to: cause the one or more IR lamps to emit energy when the print assembly or the recoat assembly traverses the build zone; receive temperature values ​​from the one or more temperature sensors; determine whether the temperature values ​​are within a predetermined range; and adjust an intensity of the one or more IR lamps or a flow gas rate of the one or more IR lamps when the temperature value is not within the predetermined range.

[0024] A twenty-first aspect A21 comprises an additive manufacturing apparatus as described in twentieth aspect A20, wherein if the temperature value is determined to be below the predetermined range, an intensity of one or more of the IR lamps is increased.

[0025] A twenty-second aspect A22 includes an additive manufacturing apparatus as described in any of the twentieth aspect A20 to the twenty-first aspect A21, wherein if the temperature value is determined to exceed the predetermined range, the intensity of one or more of the IR lamps is reduced.

[0026] A twenty-third aspect A23 includes an additive manufacturing apparatus described in any of the twenty-first aspect A20 to the twenty-second aspect A22, wherein a first IR lamp of the one or more IR lamps is coupled to the print assembly and a second IR lamp of the one or more IR lamps is coupled to the recoat assembly.

[0027] A twenty-fourth aspect A24 comprises an additive manufacturing apparatus according to any of the twentieth aspect A20 to the twenty-third aspect A23, wherein the electronic control unit controls a flow gas rate around one or more of the IR lamps.

[0028] A twenty-fifth aspect A25 includes an additive manufacturing apparatus according to any of the twentieth aspect A20 to the twenty-fourth aspect A24, wherein the one or more temperature sensors are gas temperature sensors, and the electronic control unit is further configured to adjust a flow rate of gas around one or more of the IR lamps if it is determined that the surface temperature value of the build material is not within the predetermined range.

[0029] A twenty-sixth aspect A26 includes an additive manufacturing apparatus as described in any of the twentieth aspect A20 to the twenty-fifth aspect A25, wherein the additive manufacturing apparatus increases the flow gas rate around one or more of the IR lamps if the surface temperature value is determined to be below the predetermined range.

[0030] In the 27th aspect A27, when it is determined that the surface temperature value exceeds the predetermined range, 1 The additive manufacturing apparatus of any of twentieth aspect A20 to twenty-sixth aspect A26 reduces the flow gas rate around one or more of the IR lamps.

[0031] A twenty-eighth aspect A28 is an additive manufacturing apparatus according to any of the twentieth aspect A20 to the twenty-seventh aspect A27, further comprising an environmental control system fluidly coupled to the process chamber, wherein the environmental control system delivers heated gas to the process chamber when it determines that the process chamber temperature value is not within a predetermined process chamber range.

[0032] A 29th aspect A29 includes an additive manufacturing apparatus described in any of Aspects 20 A20 to 28 A28, further including a build plate heater thermally coupled to a build platform in the build zone, and when the temperature value of the surface temperature of the build material surface is determined to be below the predetermined range, the electronic control unit causes the build plate heater to increase the amount of energy delivered to the build material in the build zone and the build plate.

[0033] A thirtieth aspect A30 includes an additive manufacturing apparatus including a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone sequentially disposed in distinct portions along a length of the process chamber; an environmental control system connected to the process chamber and including one or more subsystems for controlling environmental conditions within the process chamber; one or more sensors configured to monitor at least one of a temperature, a vapor content, and a process gas concentration within the process chamber; and an electronic control unit communicatively connected to the environmental control system and one or more of the sensors, wherein the electronic control unit is configured to receive sensor data from one or more of the sensors, determine whether the sensor data from one or more of the sensors corresponds to a predetermined set of environmental conditions for the process chamber during a build, and automatically adjust one or more environmental control settings of the environmental control system if the sensor data is determined not to be within the predetermined set of environmental conditions.

[0034] Thirty-first aspect A31 includes the additive manufacturing apparatus of thirtieth aspect A30, wherein the electronic control unit is further configured to cause the environmental control system to start flow to the process chamber through a heat exchanger of the environmental control system when the sensor data indicates that the temperature of the process chamber is below the set of predetermined environmental conditions, and to cause the environmental control system to stop flow to the process chamber through the heat exchanger of the environmental control system when the sensor data indicates that the temperature of the process chamber is above the set of predetermined environmental conditions.

[0035] Thirty-second aspect A32 includes an additive manufacturing apparatus as described in any of thirtieth aspect A30 to thirty-first aspect A31, wherein the electronic control unit is further configured to cause the environmental control system to start flow through a heat exchanger, dehumidifier, or condenser of the environmental control system when the sensor data indicates that the vapor content is above the set of predetermined environmental conditions, and to cause the environmental control system to stop flow through a heat exchanger, dehumidifier, or condenser of the environmental control system when the sensor data indicates that the vapor content is below the set of predetermined environmental conditions.

[0036] A thirty-third aspect A33 is a method for controlling the electronic control unit to cause the environmental control system to initiate a flow from a process gas supply of the environmental control system when the sensor data indicates that the process gas concentration is below the predetermined environmental condition set, and to cause the environmental control system to stop a flow from the process gas supply of the environmental control system when the sensor data indicates that the process gas concentration is above the predetermined environmental condition set. The additive manufacturing apparatus according to any of thirtieth aspect A30 to thirty-second aspect A32, further configured to stop

[0037] A thirty-fourth aspect A34 comprises an additive manufacturing apparatus according to any of the thirtieth aspects A30 to A33, further comprising a particulate sensor configured to sense a concentration of airborne build material in the process chamber, and wherein the electronic control unit is further configured to: cause an environmental control system to start an air filtration system of the environmental control system if the sensor data indicates that the concentration of airborne build material is above the set of predetermined environmental conditions; and cause the environmental control system to stop flow from the air filtration system of the environmental control system if the sensor data indicates that the concentration of airborne build material is below the set of predetermined environmental conditions.

[0038] A thirty-fifth embodiment A35 includes a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone, the zones being sequentially arranged in distinct portions along a length of the process chamber; a support extending along the length of the process chamber in a first vertical plane; a print assembly including a plurality of nozzles for dispensing a binder within the build zone, the print assembly being movably coupled to the support via a first actuator configured to move in a forward or reverse direction along the length of the support, and disposed in a second vertical plane parallel to the first vertical plane; a recoat assembly including at least one of a doctor blade and a roller for dispensing build material within the build zone, the recoat assembly being movably coupled to the support via a second actuator configured to move in a forward or reverse direction along the length of the support, and disposed in the second vertical plane parallel to the first vertical plane; and a vision system configured to image the build zone, the vision system including a print assembly, a recoat assembly, the first actuator, the second actuator, and a front actuator. and an electronic control unit communicatively coupled to the vision system, the electronic control unit causing the print assembly to traverse the build zone in the forward direction while dispensing a binder according to a programmed deposition pattern during a first interval, receiving image data from the vision system of a dispensed binder pattern during a second interval after the first interval and analyzing the image data to determine whether there is an anomaly in the binder pattern dispensed during the second interval, causing the print assembly to traverse the build zone in the reverse direction while dispensing a binder according to the programmed deposition pattern during the second interval, causing the recoat assembly to traverse the build zone in the reverse direction dispensing build material supplied to the supply zone to form a new layer of build material in the build zone according to predetermined build material input parameters, the recoat assembly following the print assembly traversing the build zone during the second and third intervals, and causing the print assembly to:and configured to cause at least one of a purging process and a wiping process to be performed while traversing the cleaning zone in a forward and reverse direction during the third interval.

[0039] Thirty-sixth aspect A36 includes an additive manufacturing apparatus as described in thirty-fifth aspect A35, wherein during a fourth interval, the electronic control unit causes the recoat assembly to traverse the build zone in the forward direction while dispensing binder according to a programmed deposition pattern on the new layer of build material, and causes the print assembly to traverse the build zone in the forward direction following the recoat assembly traversing the build zone.

[0040] In a thirty-seventh aspect, A37, when the electronic control unit determines the presence of the anomaly in the dispensed binder pattern, the electronic control unit changes the programmed deposition pattern for a subsequent traverse of the print assembly over the build zone to address the anomaly. The additive manufacturing apparatus according to any of thirty-fifth aspects A35 to A36 further configured to adjust.

[0041] A thirty-eighth aspect A38 includes an additive manufacturing apparatus according to any of the thirty-fifth aspects A35 to A37, wherein the electronic control unit is further configured to implement corrective action for subsequent dispensing of build material by the recoat assembly if the electronic control unit determines the presence of the anomaly in the new layer of dispensed build material.

[0042] A 39th aspect A39 includes an additive manufacturing apparatus described in any of the 35th aspects A35 to A38, wherein the electronic control unit is further configured to cause the print assembly to perform sub-pixel indexing of the plurality of nozzles between the first interval and the second interval.

[0043] A fortieth aspect A40 includes an additive manufacturing apparatus according to any of the thirty-fifth aspects A35 to A39, wherein a delay is implemented before the recoat assembly begins to traverse the build zone in the reverse direction following the print assembly traversing the build zone during the second and third intervals.

[0044] A forty-first aspect A41 includes an additive manufacturing apparatus according to any of the thirty-fifth aspects A35 to A40, wherein the print assembly traverses the build zone in the forward and reverse directions at a first speed.

[0045] A forty-second embodiment A42 includes an additive manufacturing apparatus described in any of the thirty-fifth embodiment A35 to the forty-first embodiment A41, wherein the print assembly traverses the cleaning zone in a forward and reverse direction at a second speed, the second speed being slower than the first speed.

[0046] A forty-third embodiment A43 includes an additive manufacturing apparatus described in any of the thirty-fifth embodiment A35 to the forty-second embodiment A42, further including one or more IR lamps configured to apply energy to the binder and build material in the build zone to stimulate a curing reaction, the one or more IR lamps being coupled to at least one of the print assembly and the recoat assembly.

[0047] Forty-fourth embodiment A44 includes an additive manufacturing apparatus as described in forty-third embodiment A43, wherein two IR lamps are coupled to the recoat assembly, a first IR lamp being coupled to a forward-facing surface of the recoat assembly and a second IR lamp being coupled to a rear-facing surface of the recoat assembly. [Brief description of the drawings]

[0048] [Figure 1A] FIG. 1A depicts an example process flow chart for building a component using a manufacturing apparatus and method according to one or more embodiments shown and described herein. [Figure 1B]FIG. 1B is a schematic diagram of a manufacturing apparatus according to one or more embodiments shown and described herein. [Diagram 2] FIG. 2 illustrates a schematic diagram of an exemplary architecture of a manufacturing apparatus according to one or more embodiments shown and described herein. [Diagram 3] FIG. 3 illustrates a flowchart of an exemplary method directed to a printing method for improving reliability, according to one or more embodiments shown and described herein. [Figure 4] FIG. 4 illustrates a flowchart of an exemplary method directed to a recoating method for improving reliability, according to one or more embodiments shown and described herein. [Diagram 5] FIG. 5 illustrates a flowchart of an exemplary method directed to a curing method for improving build speed according to one or more embodiments shown and described herein. [Figure 6] FIG. 6 illustrates a flowchart of an exemplary method directed to a method of operating a climate control system to improve reliability, according to one or more embodiments shown and described herein. [Figure 7] FIG. 7 depicts an example schematic diagram of the movement of a print assembly and a recoat assembly in a build block according to one or more embodiments shown and described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] Additional features and advantages of the manufacturing apparatus described herein, and components thereof, are set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description, or will be learned by practicing the embodiments described herein, including the following detailed description, the claims, and the accompanying drawings.

[0050] It should be understood that both the foregoing general description and the following detailed description are intended to describe various embodiments and provide an overview or framework for understanding the nature and features of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter.

[0051] Reference will now be made in detail to embodiments of a manufacturing apparatus and components thereof, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts.

[0052] An embodiment of an additive manufacturing tool comprises a process chamber defining a volume having a height, a length, and a width. The length is defined by a plurality of processing zones. The process chamber includes a cleaning zone, a build zone, and a supply zone arranged sequentially in separate portions along the length of the process chamber. The process chamber includes an actuator assembly for dispensing the build material and depositing the binder material in the additive manufacturing device. The actuator assembly can generally include a support extending along the length of the process chamber in a first vertical plane. The actuator assembly can further include a recoat assembly for dispensing the build material and a print assembly for depositing the binder material. The print assembly includes a plurality of nozzles for dispensing the binder 50 in the build zone. The print assembly is movably coupled to the support via a first actuator configured to move back and forth along the length of the support. The print head actuator can include a print actuation axis, where the print head actuator is bidirectionally actuable along the print actuation axis, thereby resulting in bidirectional movement of the print head. The print assembly is disposed in a second vertical plane parallel to the first vertical plane.

[0053] The recoat assembly includes one or more doctor blades and / or one or more rollers 142 for dispensing the build material 40 within the build zone BZ. The recoat assembly is movably coupled to the support via a second actuator configured to move back and forth along the length of the support. The recoat assembly can include a recoat actuation shaft, where the recoat assembly is bidirectionally actuable along the recoat actuation shaft, thereby providing bidirectional movement of the recoat head. The recoat assembly is configured to move in a first vertical plane, The actuator assembly may be disposed in a parallel second vertical plane. The recoat actuation axis and the print actuation axis may share the same axis or may be parallel to each other and may be vertically spaced apart from each other. The print assembly and recoat assembly embodiments may further include a curing system, such as an infrared lamp, for applying energy to the build material and binder in the build zone to stimulate a curing reaction. Various embodiments of an additive manufacturing device including an actuator assembly, an actuator assembly for an additive manufacturing device and methods for using the same are described in further detail herein with specific reference to the accompanying drawings.

[0054] The embodiments further include an environmental control system configured to control environmental conditions within the process chamber. The environmental control system can include one or more subsystems for controlling environmental conditions within the process chamber. The one or more subsystems can include a heat exchanger, a dehumidifier, a condenser 182 or similar system capable of removing vapors from the environment of the process chamber, a process gas supply source, an air filtration system (e.g., a cyclone separator), and the like. The environmental control system is coupled to the process chamber via one or more ports, valves, ventilation conduits, and the like. In some embodiments, the environmental control system is adapted to maintain environmental conditions within the process chamber that are favorable for a particular build. For example, the environmental control system can regulate the environment within a set of predetermined environmental conditions that can include operating ranges for pressure, process gas concentration, relative humidity, concentration of vapors in the air, concentration of build material in the air, temperature of the process chamber, and the like.

[0055] Moreover, the embodiments described herein more specifically disclose systems and methods for operating the print assembly, recoat assembly, curing system, environmental control system, and their interactions to improve the reliability and speed of the build process. To improve the reliability and speed of the build process, the manufacturing apparatus disclosed herein further implements one or more sensors and control systems configured to operate in a closed control loop.

[0056] Various embodiments of the manufacturing apparatus are described in further detail herein with particular reference to the accompanying drawings. It should be understood that the embodiments of the manufacturing apparatus shown and described herein may be configured and operable to build three-dimensional and / or non-three-dimensional objects or parts.

[0057] Ranges can be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. The beginning and end points of a range each have a significant meaning in relation to the other point (the end point and the beginning point), and each have a significant meaning independently of the other point.

[0058] Directional terms used herein, such as up, down, right, left, front, rear, top, upward, bottom, forward, reverse, and back, are made solely with reference to the figures as depicted and are not intended to imply an absolute orientation, unless expressly stated otherwise.

[0059] Unless expressly stated otherwise, it is in no way intended that any method described herein be construed as requiring that its steps be performed in a particular order, or as requiring any particular orientation of any apparatus. Thus, to the extent that a method claim does not actually recite an order in which its steps should be followed, or any apparatus claim does not actually recite an order or orientation with respect to individual components, it is not intended that the steps should be limited to a particular order or that any particular orientation with respect to the apparatus components should be construed as requiring that its steps be performed in a particular order, or as requiring any particular orientation with respect to the apparatus components. Unless otherwise specifically stated in the claims or description that a particular order or orientation is not recited, no order or orientation is intended to be inferred in any respect. This applies to any possible implicit basis for interpretation, including questions of logic regarding the arrangement of steps, operational flow, order of components, or orientation of components, plain meaning derived from grammatical organization or punctuation, and the number or type of embodiments described herein.

[0060] As used herein, the singular forms "one," "a," and the like include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "one" component 70 includes aspects having two or more such components unless the context clearly dictates otherwise.

[0061] The embodiments described herein are directed to manufacturing apparatus (e.g., additive manufacturing apparatus) and components for manufacturing apparatus, specifically, a print assembly for depositing binder 50, a recoat assembly for dispensing build material, an environmental control system for controlling the environment in the process chamber, and one or more sensors configured to provide operational feedback to an electronic control unit to improve the reliability and speed of the build process. The embodiments described herein can implement machine vision, pattern testing, printhead maintenance, printhead index-based redundancy, and the like to establish a closed-loop reliability and speed improvement process. The control loops described herein generally include steps to detect, analyze, and compensate for build operations. Although the technology developed and described herein relates to manufacturing, it is understood that aspects of the technology may be applied to related industries such as 2D printing.

[0062] 1A, an exemplary process flow chart for building a component 80 using a manufacturing apparatus 100 and manufacturing method is shown. FIGURE 1A is intended to provide a non-limiting overview of the manufacturing apparatus 100 and manufacturing method shown and described in detail herein. The apparatus 100 is configured to perform one or more predefined operations as specified by build instructions executed by a control system 10.

[0063] As used herein, "build instructions" refer to control commands for manipulating the operation of the apparatus 100 to build the component 80. The build instructions are defined, for example, by a design deposition pattern for each layer of the component 80 to be built and a plurality of motion controls that define instructions that define the sequenced operation of the motors, actuators, print assemblies, jet nozzles, and various other components of the apparatus 100 to build the component 80. The build instructions may be defined based on the component design or model and mechanical specifications of the apparatus 100. For example, the apparatus 100 may include a predetermined fixed spacing between jet nozzles in a printhead, referred to herein as "jet spacing."

[0064] The apparatus 100 further receives build material 40 and binder 50, which may be deposited layer-by-layer and drop-by-drop, respectively, according to build instructions to build the component 80. For example, the apparatus 100 may use a recoat assembly 140 (FIG. 1B) to form a layer of powder 60 (also referred to herein as a layer of build material 40) on a build plate 120 (FIG. 1B), and then use a print assembly 150 (FIG. 1B) to deposit one or more drops of binder 50 within pixel 31, thereby forming voxel 30. The "build material" may include one or more organic and / or inorganic materials that, when combined with binder 50 and, optionally, an energy source, harden to form part of the component 80.

[0065] As used herein, a "pixel" refers to a two-dimensional spatial portion of an object or part being printed by the apparatus 100, specifically a current slice or layer of a three-dimensional part relative to its positioning along the build plate 120. Each pixel corresponds to an image pixel defined in the design deposition pattern of the build instructions. An image pixel is a digital representation of a pixel. An image pixel includes a width defined by the jet spacing of the jet nozzles of the apparatus 100. As used herein, a "voxel" refers to a three-dimensional spatial portion of powder in the build plate 120 defined by one or more drops of binder 50 deposited within the pixel that form the current slice or layer of the three-dimensional part (e.g., component 80). It is understood that a voxel need not be a cube, as the shape of the voxel depends on the wicking and curing behavior of the binder 50 with the build material 40 (e.g., the layer of powder in which the binder 50 is deposited).

[0066] The binder 50 may be deposited in various amounts at various locations within a layer of powder 60 (e.g., build material 40) in the form of drops. The location and amount of the drops are defined in a "design deposition pattern," which refers to a collection of image pixels that form the pattern of a desired slice of a build file, and which, when applied to a layer of powder 60 by the apparatus 100, defines an "applied deposition pattern." While the design deposition pattern defines the amount (e.g., "drop volume") and location (e.g., location of the center of the drop of binder 50 on the layer of powder 60), the applied deposition pattern refers to the distribution of the binder 50 through the layer of powder, which may include overlapping onto adjacent pixels or underlying layers of powder. As used herein, "drop volume" refers to the volume of a binder drop that is emitted from the jet at one time. Multiple drops can be emitted for a pixel, and the drops vary in volume. After the formation of one or more layers of powder 60 and the deposition of one or more drops of binder 50, the apparatus 100 forms the component 80. More specific methods and embodiments of the apparatus 100 for forming the component 80 are now described in detail.

[0067] 1B, one embodiment of a manufacturing apparatus 100 is shown in schematic form. The apparatus 100 includes a process chamber 101. The process chamber 101 may be a hermetically sealed chamber and / or otherwise a pressurized or depressurized (e.g., maintained at or near vacuum) chamber for building the component 70 under specific environmental conditions as controlled by an environmental control system 180 (FIG. 2). The process chamber 101 is defined by a volume having a height, a length, and a width. The length is defined by a number of processing zones. The processing zones include a cleaning zone "CZ," a build zone "BZ," and a supply zone "SZ" sequentially arranged in separate portions along the length of the process chamber 101 (along + / - X-axis). The apparatus 100 includes a cleaning station 108, a build plate 120, a supply platform 130, a recoat assembly 140, and a print assembly 150. The cleaning zone "CZ" can include elements of the manufacturing apparatus 100, such as the cleaning station 108 and the jet test / purge area 109. The build zone "BZ" can include elements of the manufacturing apparatus 100, such as the build plate 120, the build plate heater 121, the build platform actuator 122, and the build receptacle 124. The supply zone "SZ" can include elements of the manufacturing apparatus 100, such as the lower build material hopper 172 (FIG. 2), which can receive build material 40 from the upper build material hopper 170 (FIG. 2), and the supply platform 130, which can receive build material 40 from the lower build material hopper 172 (FIG. 2).

[0068] The recoat assembly 140 and the print assembly 150 are coupled to the support 104 of the apparatus 100 and are adapted to move in response to actuation of the first and second actuator assemblies 102, 103. The rail 104 is configured to translate along the support 104 by a force of 100 / 102 / 100 / 100 / 200 / 250 / 100 / 150 / 200 / 250 / 100 / 150 / 250 / 100 / 250 / 150 / 100 / 150 / 250 / 100 / 250 / 150 / 100 / 150 / 250 / 100 / 250 / 150 / 100 / 150 / 250 / 100 / 150 / 250 / 100 / 250 / 150 / 100 / 150 / 250 / 100 / 150 / 250 / 150 / 100 / 250 / 150 / 150 / 250 / 100 / 150 / 2 ... This allows recoat assembly 140 and print assembly 150 to traverse actuation axis 116 of apparatus 100 in the same and / or opposite directions, and allows recoat assembly 140 and print assembly 150 to traverse actuation axis 116 of apparatus 100 at different and / or the same speed. Independent actuation and control of recoat assembly 140 and print assembly 150 allows at least some steps of a manufacturing process (e.g., an additive manufacturing process) to be performed simultaneously, thereby making the total cycle time of the manufacturing process shorter than the sum of the cycle times for each individual step. In other embodiments, apparatus 100 can include additional actuator assemblies coupled to recoat assembly 140, print assembly 150, etc.

[0069] In some embodiments, the third actuator assembly 105 may be built to facilitate independent control of the print assembly 150 along a lateral axis (e.g., extending along a + / -Y axis as shown in the figures) generally perpendicular to a longitudinal axis (e.g., actuation axis 116 as shown in the figures, + / -X axis). As described in more detail herein, the third actuator assembly 105 may provide fine movement of the print assembly 150 along the lateral axis, referred to herein as index. The first actuator assembly 102 and the third actuator assembly 105 are generally referred to as a printing head position control assembly. That is, the printing head position control assembly includes the first actuator assembly 102 configured to move the printing head along a longitudinal axis and the third actuator assembly 105 configured to move the printing head along a lateral axis. The printing head position control assembly may be controlled via signals generated by a control system 10, such as an electronic control unit 10. The electronic control unit 10 may include a processor 10a and a non-transitory computer-readable memory 10b.

[0070] In some embodiments, the first actuator assembly 102 includes a position sensor 102a and the second actuator assembly 103 includes a position sensor 103a that provides position information of the recoat assembly 140 and / or the printing assembly 150 in a feedback control signal to the electronic control unit 10 such that the electronic control unit 10 can track the position of the recoat assembly 140 and / or the printing assembly 150 in response to the provided control signal. In some examples, the electronic control unit 10 can adjust the control signals provided to the first actuator assembly 102 and the second actuator assembly 103 based on the position information provided by the position sensors 102a, 103a. In embodiments, the position sensors 102a, 103a can be encoders, ultrasonic sensors, light-based sensors, magnetic sensors, etc. embedded in or coupled to the first actuator assembly 102, the second actuator assembly 103, and / or the support 104.

[0071] As mentioned above, in the embodiments described herein, the recoat assembly 140 and the print assembly 150 are both mounted on the actuation axis 116 of the apparatus 100 (e.g., on a second vertical plane 116). Thus, movement of the recoat assembly 140 and the print assembly 150 on the actuation axis 116 occurs along the same axis and is therefore collinear. In this configuration, the recoat assembly 140 and the print assembly 150 can occupy the same space (or portions of the same space) along the actuation axis 116 of the apparatus 100 at various times during a single build cycle. In other embodiments, the components of the manufacturing apparatus 100 that traverse the actuation axis 116, such as the recoat assembly 140, the print assembly 150, etc., need not be centered about the actuation axis 116. In this case, at least two of the components of the manufacturing apparatus 100 are positioned relative to the actuation axis 116 such that the components can occupy the same or overlapping volumes along the actuation axis 116 as they traverse the actuation axis 116.

[0072] The recoat assembly 140 is configured to facilitate dispensing of the build material 40 onto the build plate 120 from a supply source of the build material 40 provided on the supply platform 130. As described in more detail herein, the print assembly 150 is configured to facilitate deposition of the binder material 50 and / or other jettable build materials (e.g., ink, flow media, nanoparticles, fluorescent particulates, sintering aids, anti-sintering aids, etc.) onto the build plate 120 as the print assembly 150 traverses the BZ along the actuation axis 116 of the apparatus 100. In the embodiment of the apparatus 100 described herein, the actuation axis 116 of the apparatus 100 is parallel to the + / -X axis of the coordinate system shown in the figures. In the embodiment described herein, the cleaning station 108, the build plate 120, and the supply platform 130 are arranged in series along the actuation axis 116. The recoat assembly 140 and the print assembly 150 are also disposed in series along the operating axis 116 of the apparatus 100 and in parallel within the cleaning station 108, the build plate 120, and the supply platform 130. Furthermore, the recoat assembly 140 and the print assembly 150 are also disposed in series along the operating axis 116 of the apparatus 100 between a home position 151 of the print assembly 150 disposed adjacent to the −X end of the operating axis 116 and a home position 153 of the recoat assembly 140 disposed adjacent to the +X end of the operating axis 116. That is, the home position 151 of the print assembly 150 and the home position 153 of the recoat assembly 140 are spaced apart in a lateral direction parallel to the + / −X axis of the coordinate system shown in the figure, with at least the build plate 120 and the supply platform 130 located therebetween. In an embodiment, the build plate 120 (eg, BZ) is positioned along the actuation axis 116 of the apparatus 100 between the cleaning station 108 (eg, CZ) and the supply platform 130 (eg, SZ).

[0073] 1B , the cleaning station 108 is disposed proximate one end of the actuation axis 116 of the apparatus 100 and is located in the same position as the home position 151 in which the print assembly 150 is located or "parked" before or after depositing binder material 50 onto the build material 40 disposed on the build plate 120. The cleaning station 108 may include one or more cleaning sections to facilitate cleaning of the print assembly 150, and in particular, cleaning of the multiple printheads 156 of the print assembly 150 between deposition operations. The cleaning stations 108 may include, for example, but are not limited to, a soak station containing a cleaning fluid for dissolving excess binder material 50 from the multiple printheads 156, a wiping station for removing excess binder material 50 and / or cleaning fluid from the multiple printheads 156, a jet test / purge area 109 for testing the binder deposition pattern and / or purging binder material 50 and / or cleaning fluid from the multiple printheads 156, a capping station for maintaining moisture of the multiple jet nozzles 158 of the multiple printheads 156, or various combinations thereof. The print assembly 150 is actuated between cleaning stations by the first actuator assembly 102. In some embodiments, the apparatus 100 may include a jet test / purge region 109 disposed proximate one end of the actuation axis 116 adjacent the cleaning station 108 and / or the home position 151. It should be appreciated that the jet test / purge region 109 of the apparatus 100 may be configured to facilitate material deposition by the print assembly 150 prior to deposition along the build plate 120. When the jet test / purge region 109 functions as a jet test region, the print assembly 150 may dispense binder 50 material in a predetermined pattern. The dispensed pattern may then be captured by the vision system 14 and analyzed by the electronic control unit 10 to determine if there is an anomaly in the nozzles 158 or print heads 156 of the print assembly 150.

[0074] The build plate 120 is coupled to a build platform actuator 122 to facilitate raising and lowering the build plate 120 in a direction perpendicular to the actuation axis 116 of the apparatus 100 (e.g., parallel to the + / -Z direction of the coordinate axes shown in the figures). The build platform actuator 122 can be, for example, without limitation, a mechanical actuator, an electromechanical actuator, a pneumatic actuator, a hydraulic actuator, or any other actuator suitable for imparting linear motion to the build plate 120 in a vertical direction. Suitable actuators include, but are not limited to, worm drive actuators, ball screw actuators, pneumatic pistons, hydraulic pistons, electromechanical linear actuators, and the like. The build plate 120 and the build platform actuator 122 are positioned within a build receptacle 124 located below the actuation axis 116 of the apparatus 100 (i.e., in the -Z direction of the coordinate axes shown in the figures). During operation of the apparatus 100, the build plate 120 is retracted into the build receptacle 124 by operation of the build platform actuator 122 after each layer of binder material 50 is deposited onto the build material 40 disposed on the build plate 120. In some embodiments, the build plate 120 can further include a build plate heater 121 coupled thereto. The build plate heater 121 applies energy to the build material 40 and / or binder 50 on the build plate 120 to facilitate the deposition and / or curing process. The faster the binder 50 and build material 40 in a layer cures, the higher the throughput the apparatus 100 can achieve since new layers can be printed in rapid succession. As described herein, the apparatus 100 can also include other sources and forms of energy that are directed to the build material 40 and binder 50 in the build zone to accelerate the curing block.

[0075] 1B, the supply platform 130 is coupled to a supply platform actuator 132 to facilitate raising and lowering the supply platform 130 relative to the actuation axis 116 of the device 100 in a vertical direction (i.e., parallel to the + / -Z direction of the coordinate axes shown in the figure). The supply platform actuator 132 can be, for example, without limitation, a mechanical actuator, an electromechanical actuator, a pneumatic actuator, a hydraulic actuator, or any other actuator suitable for imparting linear motion to the supply platform 130 in a vertical direction. Suitable actuators include, but are not limited to, worm drive actuators, ball screw actuators, pneumatic pistons, hydraulic pistons, electromechanical linear actuators, and the like. The supply platform 130 and the supply platform actuator 132 are disposed within a supply receptacle 134 located below the actuation axis 116 of the device 100 (i.e., in the -Z direction of the coordinate axes shown in the figure). During operation of the apparatus 100, the supply platform 130 is raised relative to the supply receptacle 134 toward the actuation axis 116 of the apparatus 100 by action of the supply platform actuator 132 after a layer of build material 40 has been dispensed from the supply platform 130 onto the build plate 120, as described in further detail herein. It should be understood that in this embodiment, the apparatus 100 does not include a supply platform 130 such as, for example and without limitation, in embodiments in which the build material 40 is supplied to the build plate 120 using a build material hopper.

[0076] An embodiment of the additive manufacturing apparatus 100 includes one or more energy sources 160 for heating and / or curing the build material 40 and the binder 50. In an embodiment, the recoat assembly 140 and / or the print assembly 150 can include one or more energy sources 160 for facilitating the curing and / or phase change of the build material 40 and the binder 50. The one or more energy sources 160 can include infrared lamps (IR lamps 160), ultraviolet light sources, and / or other types of energy sources. The intensity, exposure duration, and other parameters of the one or more energy sources 160 can be controlled by the electronic control unit 10 and associated hardware components such as power circuits, control circuits, etc. As shown, a first IR lamp 160A is coupled to a forward-facing (e.g., facing in a +X direction) surface of the print assembly 150, a second IR lamp 160B is coupled to a reverse-facing (e.g., facing in a -X direction) surface of the recoat assembly 140, and a third IR lamp 160C is coupled to a forward-facing surface of the recoat assembly 140.

[0077] The manufacturing apparatus 100 further includes sensors for monitoring the operation and environmental conditions of the components of the apparatus 100. The sensors 20 are communicatively coupled to the electronic control unit 10. The electronic control unit 10 is configured to receive sensor data from the sensors, analyze the sensor data, and implement control functions such as build parameter compensation on the fly, as well as adjustments to environmental conditions within the process chamber 101. The sensors 20 can include one or more temperature sensors 21 (e.g., pyrometers, thermocouples, thermistors, or other types of temperature sensors configured to measure surface or bulk temperatures of liquids or solids or gases), relative humidity sensors 22, process gas concentration sensors 23, current sensors 24, particulate sensors 25, force sensors 26, lower explosive limits (LEL) monitors 27, volatile organic compound (VOC) sensors 28, or similar solvent vapor concentration sensors, oxygen sensors (O2 sensors) 29, and other sensors. It should be appreciated that the sensor 20 may be statically mounted within the process chamber 101 or may be movably coupled to one or more moveable assemblies therein (e.g., the print assembly 150, the recoat assembly 140, etc.). A moveable sensor 20 may provide the advantage of a sensing area of ​​the process chamber 101 when a build process is in operation where sensing would be obstructed by moving components of the manufacturing apparatus 100. The operation of the sensor 20 is described in more detail with reference to the flow charts disclosed herein.

[0078] FIG. 1B shows at least two implementations of the vision system 14 (e.g., 14A and 14B). It should be understood that the vision system 14 is not limited to these two locations and configurations. The manufacturing apparatus 100 can include a vision system 14A coupled to the support 104. The vision system 14A can be an on-site monitoring system utilized to capture image data of the build zone during the build process. The vision system 14A can alternatively be movably coupled to the support 104 such that it can move along the support as the print assembly 150 and the recoat assembly 140 also move along the support 104. The vision system 14A is used to capture various angles and views of the zones (e.g., CZ, BZ, SZ) within the process chamber 101, more specifically the BZ (e.g., the components being built on the build plate 120). The BZ may be panned, tilted, and / or zoomed to capture image data of the print assembly 150 or recoat assembly 140 (component 70). Images may be taken while the print assembly 150 or recoat assembly 140 passes through the BZ to determine if there are any anomalies with the dispensed binder pattern or the new layer of dispensed build material 40.

[0079] In some embodiments, the vision system 14 may be a vision system 14B coupled to either or both of the print assembly 150 and the recoat assembly 140. In such an example, the vision system 14B may be configured to capture image data of the BZ as the print assembly 150 and the recoat assembly 140 complete a pass of the BZ. As the speed at which the print assembly 150 and the recoat assembly 140 traverse the BZ increases, the stationary mounted vision system 14A has to capture a complete field of view image of the build plate 120 for less time or no time at all. However, by implementing a vision system 14 (14A or 14B) that can move with and / or around the movement of the print assembly 150 and the recoat assembly 140, the vision system 14A or 14B may be able to take continuous, unobstructed images of the BZ during the passage of the print assembly 150 and / or the recoat assembly 140 over the BZ. The captured image data may then be combined together to develop a complete image of the active build on the build plate 120.

[0080] The vision system 14 is communicatively coupled to the electronic control unit 10. The vision system 14 can be any device having an array of sensing devices (e.g., pixels) capable of detecting radiation in the ultraviolet, visible, or infrared wavelength bands. The vision system 14 can implement one or more cameras or other imaging devices, such as an x-ray device. The vision system 14 can include one or more cameras sensitive to detecting electromagnetic radiation in the visible, infrared, and / or ultraviolet spectrums. Thus, the vision system 14 can include an electromagnetic radiation excitation source, such as a lamp, an infrared emitter, an ultraviolet light source, etc., that directs electromagnetic radiation onto surfaces, such as the build material 40 and binder 50 in the build zone BZ, which are reflected from the build zone BZ to one or more cameras and captured by the one or more cameras of the vision system 14. In some embodiments, reflected light from a visible spectrum light source, such as a lamp, can illuminate powder gouges, short diffusion, missing areas, etc., of the binder 50 through contrast analysis of the captured image data. Generally, image data captured with visible light is useful for detecting large defective areas, but other electromagnetic radiation sources can be used to detect small defective areas. In some embodiments, a vision system 14 configured to detect and capture infrared radiation can be used to develop a thermal contrast image of the build material 40 and binder 50 in the build zone BZ. In such a case, the thermal contrast image can be analyzed to determine the depth of penetration of the binder 50 into the build material 40 and / or other defects not visible through visible light inspection of the build zone BZ. In some embodiments, the vision system 14 can be configured to detect and capture image data of the build material 40 and binder 50 in the build zone BZ excited by, for example, ultraviolet light. The sensitivity of the vision system 14 to ultraviolet light provides image data with enhanced contrast between the binder 50 and the build material 40 in the build zone BZ.The image data with enhanced contrast between the binder 50 and the build material 40 includes a higher signal-to-noise ratio as compared to other image data captured with various illumination sources. Although the above-described embodiments are described for the purposes of capturing image data and determining anomalies in the build from the image data, the above-described embodiments may be used in machine vision enabled automated depowdering to determine if a part is fully depowdered (e.g., fluorescent surface intensity is greater than a threshold when powder is present).

[0081] The one or more cameras can have any resolution. The one or more cameras can be omnidirectional or panoramic cameras. In some embodiments, one or more optical components, such as mirrors, fisheye lenses, or any other type of lens, can be optically coupled to each of the one or more cameras. In the embodiments described herein, , one or more cameras may provide image data to the electronic control unit 10 .

[0082] The electronic control unit 10 can perform one or more image analysis processes to determine the presence of anomalies in the dispensed binder pattern or the dispensed new layer of build material 40. The processes can include machine vision analysis, machine learning algorithms, artificial intelligence AI, and the like. In some embodiments, the electronic control unit 10 can determine the anomalies based on a light level (e.g., light intensity) discrepancy or contrast difference in the image data of the build material 40 on the build plate 120. The light amount discrepancy may indicate a defect in the recoat layer, such as, for example, a short spread of binder 50, gouging, missing areas, and the like. With respect to the binder deposition pattern, the light amount difference can also be used to identify the deposited binder pattern, and the electronic control unit 10 can compare the identified deposited binder pattern to an expected or predefined binder pattern for a particular layer of the build.

[0083] In some embodiments, the electronic control unit 10 maintains a log of feedback parameters from various sensors and systems of the machine 100. The log can be compiled and analyzed by the electronic control unit 10 along with examples of when an anomaly is detected to develop predictive analytics. Thus, over time, the electronic control unit 10 can predict when an anomaly will occur based on the sequence of events or sensor readings that precede the anomaly. For example, if a layer-by-layer increase in current associated with the rollers of the recoat assembly 140 is present before an anomaly is detected in the image data, the electronic control unit 10 can implement preventative maintenance or other corrective measures before the anomaly occurs. For example, if the system detects a defect, the first action is to record the defect and record the sensor data set of the machine 100 for the instant layer and a predetermined number of previous layers. This recorded data can be used later for the development of predictive analytics.

[0084] The print assembly 150 includes, among other features, a support bracket 152, a printing head 154, and a plurality of printheads 156. The support bracket 152 is movably coupled to the support 104 and a first actuator assembly 102 of the apparatus 100, while the printing head 154 is movably coupled thereto via a third actuator assembly 105 disposed along an opposing end of the support bracket 152 and configured to operatively index the printing head along a lateral direction. As described in more detail herein, the printing head 154 of the print assembly 150 can include two or more rows of the plurality of printheads 156, at least one of which, in some embodiments, is movable relative to another row of the plurality of printheads 156. This allows for at least a material deposition step of a manufacturing block to be performed with increased jetting reliability and jetting resolution by varying the relative position of at least one movable row of printheads 156.

[0085] However, in some embodiments, the print assembly 150 includes a plurality of printheads 156 including a plurality of jet nozzles 158. The plurality of jet nozzles 158 are spaced apart from one another transverse to the longitudinal axis, such that a distance from a first jet nozzle to a second jet nozzle disposed adjacent to the first jet of the plurality of jets defines a jet spacing.

[0086] 1B, the manufacturing apparatus 100 may include a control system communicatively coupled to the first actuator assembly 102, the third actuator assembly 105 (collectively referred to herein as printing head position control assemblies), the recoat assembly 140, the second actuator assembly 103, and / or the print assembly 150. The control system 10 may further include a controller 10. In some embodiments, the controller (system) 10 may be specifically coupled to one or more actuators of the print assembly 150. While the control system 10 is coupled to the apparatus 100 in this example via a communication conduit 12, it should be understood that in other embodiments, the control system 10 may be communicatively coupled to the apparatus 100 via various other means or systems, such as, for example, via a wireless connection. The control system 10, sometimes referred to as an electronic control unit 10, comprises a processor 10a and a non-transitory memory 10b including stored computer readable and executable instructions. Any operation of the apparatus 100, including the operations described herein, may be performed by the computer readable and executable instructions stored in the non-transitory memory 10b of the electronic control unit 10 when executed by the processor 10a of the electronic control unit 10 (e.g., build instructions defining sliced ​​files and / or deposition patterns for layers of the component 70 to be built, predefined build material input parameters, a set of predefined environmental conditions, etc.).

[0087] For example, one or more actuators (e.g., mechanical actuators, electromechanical actuators, pneumatic actuators, hydraulic actuators, worm drive actuators, ball screw actuators, pneumatic pistons, hydraulic pistons, electromechanical linear actuators, etc.) of the first actuator assembly 102 may be actuated by computer readable and executable instructions stored in a non-transitory memory of the control system 10 when executed by the processor 10a of the electronic control unit 10 to move the print assembly 150 and / or the recoat assembly 140 in the manner described herein. Additionally, as described in more detail below, the computer readable and executable instructions stored in the non-transitory storage device 10b when executed by the processor 10a may cause the electronic control unit 10 to perform various operations to move the print assembly 150, actuate one or more actuators 105 of the print assembly 150 to move the array of print heads 156, deposit material onto the build material 40 (e.g., powder or other material) in the build plate 120, etc.

[0088] In some embodiments, the electronic control unit 10 may further be communicatively coupled to a computing device 15, optionally via a network 16 or directly via a communication link such as a wired or wireless connection. The computing device 15 may include a display 15a, a processing unit 15b (e.g., having at least a processor 10a and a memory), and an input device 15c, each of which may be communicatively coupled together and / or to the network 16. The computing device 15 may be configured to perform processes such as generating executable instructions for building a component 70 using the apparatus 100. The method may implement a CAD or other related three-dimensional drafting and rendering system, a slicing engine, and the like. The slicing engine may be configured to receive a model or drawing of the component 70 for processing and building the model or drawing into build instructions that define a number of motion control operations to be performed by the apparatus 100 to build the component 70, powder layer placement, deposition patterns for binders, and the like. The slicing engine may determine the number of layers of powder the build should include, as well as the locations within the layers of powder where the binder 50 should be dispensed. The deposition configuration of the binder 50 can also include defining the amount (volume) of binder 50 that is dispensed at a particular location within the layer of powder.

[0089] In some embodiments, network 16 is a personal area network that utilizes Bluetooth technology to communicatively couple control system 10. In other embodiments, network 16 is one or more computer networks (e.g., a personal area network, a local area network, or a wide area network). Area networks), cellular networks, satellite networks, and / or global positioning systems, and combinations thereof. Thus, the control system 10 and / or the device 100 may be communicatively coupled to the network 16 via wires, via a wide area network, via a local area network, via a personal area network, via a cellular network, via a satellite network, etc. Suitable local area networks may include wired Ethernet and / or wireless technologies, such as, for example, Wi-Fi. Suitable personal area networks may include wireless technologies, such as, for example, IrDA, Bluetooth, Wireless USB, Z-Wave, ZigBee, and / or other short-range communication protocols. Suitable personal area networks may also include wired computer buses, such as, for example, USB and FireWire. Suitable cellular networks include, but are not limited to, technologies such as LTE, WiMAX, UMTS, CDMA, and GSM.

[0090] The apparatus 100 further includes one or more fluid reservoirs 110, 112 fluidly coupled to the print assembly 150 via one or more conduits. In some embodiments, the print assembly 150 may also include one or more localized fluid manifolds 110A and 112A for locally storing fluids. In particular, the one or more fluid reservoirs may be fluidly coupled to the one or more localized fluid manifolds 110A and 112A of the print assembly 150. In this case, the multiple jet nozzles 158 of each of the multiple print heads 156 are in fluid communication with materials stored within the one or more localized fluid manifolds 110A and 112A. FIG. 1B illustrates the one or more fluid reservoirs as including a first fluid reservoir 110 including a first material 114 stored therein and a second fluid reservoir 112 including a second material 115 stored therein, the first material 114 being different from the second material 115. The first fluid reservoir 110 is in fluid communication with the multiple print heads 156 via a first conduit 111, and the second fluid reservoir 112 is in fluid communication with the multiple print heads 156 via a second conduit 113. In some embodiments, the first fluid reservoir 110 and the second fluid reservoir 112 can contain the same material. In some embodiments, the multiple print heads 156 may be coupled to a single fluid reservoir containing the same material such that the multiple print heads 156 are configured to deposit the same material.

[0091] As described in more detail herein, in some embodiments, the first fluid reservoir 110 is coupled to a different subset (i.e., first subset) of the plurality of print heads 156 than the second fluid reservoir 112 (i.e., second subset), and the plurality of print heads 156 collectively receive and dispense each of the first material 114 and the second material 115, but each of the plurality of print heads 156 of the print assembly 150 receives and dispenses one of the first material 114 or the second material 115. In other embodiments, the first conduit line 111 and the second conduit line 113 may be coupled to each other with a coupling mechanism, such as, for example, a manifold, a valve, or the like. In this example, the fluid reservoirs 110, 112 are in fluid communication with the coupling mechanism via the conduit lines 111, 113, and the coupling mechanism includes a third conduit line coupled thereto and extending to the printing head 154. The coupling mechanism may be configured to selectively transition fluid communication between the fluid reservoirs 110, 112 and the printing heads 154 such that the plurality of print heads 156 receives one of the first material 114 or the second material 115 in response to actuation of the coupling mechanism. It should be appreciated that the coupling mechanism may be further configured to facilitate simultaneous fluid communication between the first fluid reservoir 110 and the second fluid reservoir 112 and the print assembly 150 such that the plurality of print heads 156 receives both materials 114, 115 simultaneously. In some embodiments, one or more valves, one or more pumps, or both, are connected to the conduit lines 111, 113 to control the flow of binder 50 to the print heads 156. and may be fluidly coupled to the printhead 156. In some cases, pumps and valves may be operated to cause an increase in pressure on the flow of binder 50 dispensed in and / or from the nozzles 158 of the printhead 156. Such an operation is referred to as a purging operation and may be utilized to clean the nozzles 158 and improve the operation of the printhead 156.

[0092] 2, an exemplary embodiment of a manufacturing apparatus 100 is shown. As described herein, the manufacturing apparatus 100 includes a process chamber 101, a support 104, a cleaning station 108, a build plate 120, a supply platform 130, a recoat assembly 140, a print assembly 150, a lower build material hopper 172, an upper build material hopper 170 which in turn feeds the supply platform 130, and an environmental control system 180. The process chamber 101 includes a cleaning zone CZ, a build zone BZ, and a supply zone SZ sequentially arranged in separate portions along the length of the process chamber 101. The process chamber 101 includes an actuator assembly for dispensing the build material 40 and depositing the binder material 50 in the additive manufacturing apparatus 100. The actuator assembly can generally include a support 104 extending along the length of the process chamber 101 in a first vertical plane (e.g., along a + / -X axis). The actuator assembly may further include a recoat assembly 140 for dispensing the build material 40 and a print assembly 150 for depositing the binder material 50. The print assembly 150 is movably coupled to the support 104 via a first actuator 102 ( FIG. 1B ) configured to move in forward (F) (+X-axis) and reverse (R) (−X-axis) directions along the length of the support 104. The print assembly 150 is disposed in a second vertical plane parallel to the first vertical plane.

[0093] The recoat assembly 140 includes one or more powder spreading members, such as one or more doctor blades 141 (FIG. 1B) and / or one or more rollers 142 (FIG. 1B), to distribute the build material 40 onto the build plate 120 in the BZ. The one or more rollers 142 may be driven by a motor to rotate and distribute the build material 40, or may be passive rotating members. In either case, a current sensor 24 may be utilized to monitor the rotation of the one or more rollers 142 to determine, for example, whether the rotation of the rollers is resisted as the recoat assembly 140 traverses the SZ and BZ. In some embodiments, the recoat assembly 140 includes a roller brush 143 (FIG. 1B) that can rotate against the one or more powder spreading members to clean them.

[0094] The recoat assembly 140 is movably coupled to the support 104 via a second actuator 103 (FIG. 1B) configured to move forward (F) and backward (R) along the length of the support. The recoat assembly 140 can include a recoat actuation axis along which the recoat assembly 140 is bidirectionally actuable, thereby providing bidirectional movement of the recoat assembly 140. The recoat assembly 140 is disposed in a second vertical plane parallel to the first vertical plane. The recoat actuation axis and the print actuation axis may share the same axis or may be parallel to each other and vertically spaced apart from each other.

[0095] The build plate 120 may be disposed within a build receptacle 124 that is optionally sealed to the process chamber 101. The supply zone SZ includes a supply platform 130 and is configured to supply build material 40 to the recoat assembly 140 for distribution across the build zone BZ. The supply platform 130 may be coupled to a lower build material hopper 172 via one or more control and transport mechanisms that provide a continuous and steady supply of build material 40. The upper build material hopper 170 delivers the build material 40 to the lower build material hopper 172. 72 and transfer build material 40 onto the supply platform 130. The build material 40 on the supply platform 130 may be transferred therefrom to the build plate 120 as the recoat assembly 140 traverses over the build plate 120. The supply platform 130 may be actuated up and down (along the + / - Z axis) such that the lower build hopper 172 can transfer additional build material 40 onto the supply platform 130 (e.g., when in the down position) and the recoat assembly 140 can push build material 40 from the supply platform 130 to the build plate 120 (e.g., when the supply platform 130 is in the up position).

[0096] The cleaning zone CZ includes a cleaning station 108. The cleaning station 108 may include one or more cleaning sections to facilitate cleaning of the print assembly 150, and in particular the multiple printheads 156 of the print assembly 150, between binder deposition operations. The cleaning sections may include, for example, but are not limited to, a soaking station containing a cleaning fluid for dissolving excess binder material 50 from the multiple printheads 156, a wiping station for removing excess binder material 50 and / or cleaning fluid from the multiple printheads 156, a jetting station for purging binder material 50 (e.g., for re-establishing a meniscus in the jet nozzles 158) and / or a jetting station for purging cleaning fluid from the multiple printheads 156, a capping station for maintaining moisture in the multiple jet nozzles 158 of the multiple printheads 156, or various combinations thereof. The print assembly 150 may be transitioned between the cleaning sections by the first actuator assembly 102. In some embodiments, the apparatus 100 can include a jet test / purge area 109 (e.g., where the print assembly 150 can perform a purge process) located proximate the cleaning station 108 and / or one end of the actuation axis 116 proximate the home position 151 (FIG. 1B). The jet test / purge area 109 of the apparatus 100 can be configured to facilitate material deposition (e.g., purging blocks) by the print assembly 150 prior to deposition along the build plate 120. In some embodiments, the jet test / purge area 109 functions as a jet test area. In such an example, the print assembly 150 can dispense binder 50 material in a predetermined pattern, referred to herein as a spit / test pattern. For example, the spit / test pattern can include a spatial arrangement of dots and / or lines of binder 50 dispensed by corresponding jet nozzles and spatially arranged in a manner that allows for differentiation between individual jet nozzles.Thus, the dispensed pattern, when captured by the vision system 14 and analyzed by the electronic control unit 10, can provide information such as the health of the jet nozzles, including volumetric output, trajectory alignment (e.g., straightness), spatial arrangement between individual jet nozzles 158 of the multiple jets (e.g., yaw, offset, and / or overlap), etc. The dispensed pattern can then be captured by the vision system 14 and analyzed by the electronic control unit 10 to determine if there is an anomaly in the nozzles 158 or print head 156 of the print assembly 150. The electronic control unit 10 can compare the captured image of the dispensed pattern to historical image data or image data of an expected dispensed pattern to determine if there is an anomaly in the nozzles 158 or print head 156 of the print assembly 150.

[0097] The manufacturing apparatus 100 further includes an environmental control system 180. The environmental control system 180 is coupled to the process chamber 101 via one or more ports, valves, ventilation conduits, etc. The environmental control system 180 includes one or more subsystems for controlling the environmental conditions within the process chamber 101. The one or more subsystems include a heat exchanger, The subsystems may include a condenser 181, a dehumidifier and / or condenser 182, a process gas supply source 183, an air or process gas filtration system 184, etc. Each of the subsystems may include one or more controllable valves that the electronic control unit 10 may electronically or pneumatically activate or deactivate such that the valves may be closed or the subsystems are connected or disconnected from the process chamber 101. In some embodiments, the environmental control system 180 is adapted to maintain environmental conditions within the process chamber 101 that are favorable for a build. For example, the environmental control system 180 may regulate the environment within a predetermined set of environmental conditions, which may include operating ranges of pressure within the process chamber 101, process gas concentrations, relative humidity, solvent vapor concentrations, concentration of airborne build material 40, temperature of the process chamber 101, etc.

[0098] 3-6, flow charts are shown illustrating an exemplary method of operation of the manufacturing apparatus 100. More specifically, the exemplary method discloses a closed loop control method for improving the reliability and speed of building the component 70. For example, in general, the method includes steps of detecting, analyzing, and compensating for build operations to improve reliability and increase the speed of operation. FIG. 3 illustrates a flow chart associated with a printing method for improving reliability. FIG. 4 illustrates a flow chart associated with a recoating method for improving reliability. FIG. 5 illustrates a flow chart associated with a curing method for improving build speed. FIG. 6 illustrates a flow chart associated with a method of operating the environmental control system 180 for improving reliability. It should be understood that each of these methods may be implemented as control logic and executed by the electronic control unit 10. Additionally, although the methods are illustrated in separate flow charts, the methods may be integrated together.

[0099] Referring to FIG. 3, a flow chart 300 illustrates a printing method including closed-loop control operations to improve the reliability of the build operation. In an embodiment, the electronic control unit 10 loads build instructions to the print assembly 150 for building the component 70 (block 302). In some embodiments, the build instructions include compensation settings, such as image shift settings and / or jet nozzle mapping to address defective nozzles 158. A plurality of pixels and / or voxels defining the spatial portion of the build material 40 within the build plate 120 may be defined based on a digital build file (e.g., defining a deposition pattern and / or apparatus 100 control instructions stored and / or uploaded to the electronic control unit 10) of the component 70 to be built by the apparatus 100. The digital build file may be included in the build instructions. The pixels per layer of the build may be defined along a trajectory configured for the print assembly 150 to traverse the build zone BZ. Based on the build instructions, the electronic control unit 10 can map one or more jet nozzles 158 to the trajectory and / or pixels of the current layer of the build and the corresponding designed deposition pattern such that the jet nozzles 158 deposit a predetermined drop volume of binder 50 at a predetermined location on the build material 40 within the build zone BZ.

[0100] In some embodiments, before the print assembly 150 begins depositing the binder 50 onto the build material 40 in the build zone, the print assembly 150 traverses the cleaning zone CZ at block 304. It should be understood that some processes described herein may be performed in parallel to reduce turnover time. For example, loading build instructions, performing cleaning operations of the print assembly 150, etc. may be performed in parallel. In the cleaning zone CZ, the print assembly 150 may traverse wipers and / or other elements of the cleaning station 108 to clean the jet nozzles 158 and / or establish a meniscus at each of the jet nozzles 158. In some embodiments, the print assembly 150 may traverse the cleaning zone CZ to clean the jet nozzles 158, for example, as described above at blocks 306 and 308. In response to determining the condition of the defective nozzle 158, a cleaning operation may be performed. The print assembly 150 may also perform a spit / inspection pattern in the jet inspection / purge area 109 (block 304). In block 306, the vision system 14 may image the spit pattern and digitize the image data for analysis. The image data is analyzed to determine whether there is a defective nozzle 158 in the print assembly 150. If the electronic control unit 10 determines the presence of a defective nozzle 158, a corrective jet mapping may be determined in block 308. In some embodiments, the electronic control unit 10 may cause the print assembly 150 to perform a cleaning operation in response to determining the presence of a defective jet nozzle 158 to attempt to correct the defect, such as a clogged nozzle, or to implement a corrective jet mapping so that the defective jet nozzle 158 may be removed from use during a layer build or the effect of the defective jet nozzle 158 may be minimized. The modified jet mapping may include remapping the jet nozzle 158 from a planned trajectory for a next build pass (e.g., a binder deposition pass on the build zone BZ) to a modified trajectory on the next build zone BZ. A trajectory refers to a path that a jet nozzle traverses the build zone BZ as the print assembly 150 traverses the BZ. The modified jet mapping may be implemented to update the control operation of the print assembly 150 in block 310 in response to determining that a defective jet nozzle 158 is present. For example, an adjustment to the programmed deposition pattern for a subsequent traverse of the print assembly across the build zone may include updating the mapping of a selected nozzle of the plurality of nozzles to select pixels of a subsequent build layer such that a first nozzle mapped to dispense binder to a first selected set of pixels during a first traverse of the print assembly is mapped to dispense binder to a second selected set of pixels during a second traverse of the print assembly across the build zone.In some embodiments, a first nozzle that is mapped to dispense binder in a previous traverse of the print assembly for a selected nozzle of the plurality of nozzles may be remapped for a subsequent build layer such that the first nozzle is mapped to an area of ​​the build layer where no pixels are present.

[0101] In some embodiments, this operation may be performed "on the fly", for example, before the print assembly 150 traverses the build zone BZ and dispenses the binder 50 during a forward pass. "On the fly" refers to adjusting the operation of the print assembly 150 (or the recoat assembly 140) while passing over a layer of the build that is not a predetermined adjustment loaded into the machine before the build operation of the layer begins. In block 312, the electronic control unit 10 causes the print assembly 150 to traverse the build zone forward while dispensing the binder 50 according to the programmed deposition pattern defined by the build instructions and any modified settings, such as modified jet maps. It should be noted that the activity in block 312 may be synchronized with the activity in block 404 of the recoat process to ensure that the print assembly 150 and the recoat assembly 140 do not collide. It should also be noted that the activity in block 312 may be synchronized with the activity in block 502 of the curing process.

[0102] Once the print assembly 150 has completed a forward pass through the build zone BZ, in block 314A, the print heads 156 of the print assembly 150 may be indexed by an integer multiple of sub-pixel increments before performing a second pass (e.g., a reverse pass) over the build zone BZ to improve binder deposition uniformity. In some embodiments, once the print assembly 150 has completed a forward pass through the build zone BZ, the completion of the forward pass may trigger the recoat assembly 140 to lower the build plate 120 before performing a pass over the build zone BZ to dispense a new layer of build material 40 in block 314B. In some embodiments, blocks 314A and 314B may be used to perform a forward pass through the build zone BZ. 4B are performed. In some cases, neither of the processes at blocks 314A and 314B are performed. That is, the print assembly 150 completes a forward pass over the build zone BZ dispensing binder 50 in block 312 and then proceeds to block 316, where the print assembly 150 performs a reverse pass over the build zone BZ. Additionally, if the build plate 120 is not lowered after the forward pass of the print assembly 150 over the build zone BZ, the build plate 120 is lowered after the reverse pass of the print assembly 150 over the build zone BZ. During the reverse pass over the build zone BZ, the print assembly 150 can dispense binder 50 as described herein, or can traverse the build zone BZ without dispensing additional binder 50 on a layer of the build.

[0103] In some embodiments, once the print assembly 150 completes a forward and / or reverse pass through the build zone BZ, the vision system 14 can capture image data of the build zone BZ for analysis at block 318 and for analysis at block 317. In some embodiments, once the print assembly 150 completes a first forward pass through the build zone BZ, the electronic control unit 10 can determine, in response to analysis of feedback from one or more sensors, that a subsequent forward pass is necessary to deliver the correct amount of binder 50 in the event of a jetting failure. In such an example, the electronic control unit 10 can return the print assembly 150 to the home position 151 side of the build zone BZ and repeat the forward binder deposition through the build zone BZ, optionally with the jet nozzle mapping adjusted so that one or more defective jet nozzles 158 are not aligned to the same trajectory as in the first pass.

[0104] In block 316, the electronic control unit 10 causes the print assembly 150 to traverse the build zone in a reverse direction while dispensing the binder 50 according to the programmed deposition pattern defined by the build instructions. Note that the activity in block 316 may be synchronized with the activity in block 502 of the curing process and, optionally, with the activity in block 404 of the recoat process. In block 318, either before or after the print assembly 150 traverses the build zone BZ in a reverse direction, the electronic control unit 10 analyzes the image data captured in block 317 to determine whether there are jetting defects or anomalies in the dispensed binder pattern. In response to determining the presence of an anomaly in the dispensed binder pattern, the electronic control unit 10 may adjust the trajectory of the build deposition pattern and / or the programmed mapping of the jet nozzles 158 to pixels for subsequent traversals of the print assembly 150 over the build zone to address the anomaly in block 320. Any adjustments to the jet nozzle mapping may be implemented by the electronic control unit 10 and print assembly 150 in block 322, before returning to block 302. In block 322, a pre-planned, e.g., randomized, indexing of the jet nozzles between layers of the build or between layer passes of the build may be implemented in the build instructions. For example, the pre-planned indexing provides that the same jet nozzle does not traverse the same trajectory across the build zone BZ, either between layers or between layer passes, thereby implementing a planned randomization of the portion of the build object onto which the jet nozzle dispenses binder. This randomization provides a level of redundancy in case a jet nozzle fails during the build. The randomization shifts (e.g., indexes) or passes the jet nozzle to different trajectories at predetermined intervals so that a faulty jet nozzle does not continue to traverse the same trajectory, thus exacerbating any problems caused by a faulty jet nozzle.Some adjustments may include, for example, modified jet nozzle mapping, grayscale corrections such as oversaturating the next layer to address defective binder deposition during a previous layer or other jet nozzle cleaning operations, etc. Other jet nozzle cleaning operations are described in more detail, for example, with respect to block 324. In some examples, further corrective actions, such as cleaning or material purging operations, may be completed by the print assembly 150 in response to determining the presence of anomalies in the dispensed binder pattern in block 320, at blocks 324 and 326. In operations where the same jet nozzle or jet nozzles 158 are repeatedly identified as defective or in need of cleaning more frequently than others, the electronic control unit 10 may detect an increase in the frequency of problems with the jet nozzle and flag jet nozzles to an operator or quality monitoring system so that replacement or repairs can be scheduled and performed.

[0105] For example, in block 324, the electronic control unit 10 can cause the print assembly 150 to perform a cleaning operation. The cleaning operation can include causing the print assembly 150 to traverse the wipers and / or other cleaning elements of the cleaning station 108 in the cleaning zone CZ. For example, valves associated with the print heads for controlling the flow of binder 50 from the binder supply lines 111 and 113 can be closed and the nozzles 158 can be pressurized. This operation can optionally be performed while the print assembly 150 is traversing the wipers of the cleaning station 108. The traversal of the CZ can be completed at a faster or slower rate than the print assembly 150 is traversing the BZ. The valves can then be opened in block 326 so that a rapid purge of the binder 50 into the jet test / purge region 109 can be accomplished. Such processing can, for example, clean the jet nozzles 158 and the print head 156 in response to determining anomalies in the dispensed binder pattern. The purge and / or cleaning operations and their parameters can be adjusted based on machine learning based on an analysis of image data from a previous layer. For example, the amount of pressure used during the cleaning process or the amount of binder 50 flow through the nozzle 158 may be adjusted to proactively improve future cleaning processes.

[0106] The electronic control unit 10 is configured to repeat the operations of blocks 302-322 each time a new layer of binder 50 is prescribed to be deposited in the build zone BZ in accordance with the build command.

[0107] Additionally, in some embodiments, while the print assembly 150 is undergoing a cleaning operation, the binder 50 supply to the print assembly 150 (e.g., one or more localized fluid manifolds 110A and 112A) may be refilled at block 328, optionally immediately prior to or immediately prior to printing. Additionally, at block 330, prior to further print assembly 150 deposition activities, e.g., reduced pressure may be implemented to re-establish binder 50 circulation within the print head, followed by a pressurized purge operation, such as the purge operation described with respect to block 324. At block 332, the electronic control unit 10 may monitor the print head binder supply pressures and determine whether they are within acceptable ranges, depending on the processing at block 312 and / or block 330. If they are not, the electronic control unit 10 may implement corrective action to adjust the pressures such that binder circulation to the nozzles 158 is within a predetermined acceptable range.

[0108] 4, a flow chart 400 illustrates a recoating method including a closed loop control operation to improve the reliability of the recoating operation. In an embodiment, the electronic control unit 10 loads build instructions for the recoat assembly 140 to build the component 70 at block 402, which causes the recoat assembly 140 to configure the height and traverse speed of the roller and / or doctor blade for the next dispensing of build material 40. The build instructions include the thickness of the build material for a new layer of build material 40, and and optionally, predefined build material dosing parameters that can define an overage to ensure good coverage by the recoat block, a recoat assembly speed for traversing the build zone, a rotational speed of the rollers of the recoat assembly 140, a rotational direction of the rollers of the recoat assembly 140, etc. The electronic control unit 10 can also determine whether the powder supply process, dosing, is complete in block 402. Dosing, the powder supply block includes actuating the supply platform actuator 132 to move the supply platform 130 upward (e.g., in the +Z direction) to introduce the build material 40 to the recoat assembly 140 for dispensing into the build zone BZ. Dosing occurs when the recoat assembly 140 is in the home position 153, e.g., in block 402a. Additionally, dosing occurs every time a new layer of build material 40 is dispensed into the build zone BZ by the recoat assembly 140.

[0109] From time to time, additional powder supply processes may be performed. For example, when the powder supply sensor indicates that the level of the build material 40 on the supply platform 130 falls below a threshold, the electronic control unit 10 may initiate one or more processes to replenish the build material 40 on the supply platform. In some embodiments, in block 402b, the lower build material hopper 172 may supply build material to the supply platform 130. This may be accomplished by lowering the supply platform 130 to a certain level so that the build material 40 stored in the lower build material hopper 172 can flow onto the supply platform 130. The supply platform 130 may then be raised again to perform dosing. In some embodiments, for example, a material handling system including the upper build material hopper 170 is required to replenish the lower build material hopper in block 402c, so that additional build material is supplied by the lower build material hopper 172 to the supply platform 130 for build and dosing. The frequency of the refill process in block 402b may occur after every few layers (e.g., every 20-40 layers), but further depends on the thickness of the individual layers, the size of the hoppers, and the cross-sectional area of ​​the build box. Additionally, the frequency of the refill process in block 402c may occur after 100 or more layers have been built (e.g., 100-500 layers, but further depends on the thickness of the individual layers, the capacity of the lower and upper build material hoppers 172 and 170, which may be monitored with sensors to indicate to the electronic control unit 10 the current fill level of the hoppers 172 and 170, etc.). It should be understood that the supply operations in blocks 402b and 402c may occur at various times during the build operation and do not have to be performed while the recoat assembly 140 is in its home position 153.

[0110] Once dosing is complete or while dosing is occurring, the electronic control unit 10 can execute block 404. In block 404, the electronic control unit 10 determines that the print assembly 150 has started or completed passing through the build zone BZ, for example, in block 316, and then causes the recoat assembly 140 to traverse the supply zone SZ pushing the powder mounted on the supply platform 130 in block 406. For example, the recoat assembly 140 can wait for the print assembly 150 to complete a reverse pass, and optionally wait for an additional delay in block 404. In some embodiments, the vent valve can be fully or partially closed so that suction of the environmental control device (system) 180 can be generated at the recoat assembly 140. This suction facilitates the collection of stray build material 40 to be collected and removed from the process chamber 101. It should be noted that the activity in block 406 can be synchronized with the activity in block 506 of the curing process. In some embodiments, a roller brush 143 (FIG. 1B) in the recoat assembly 140 causes the recoat assembly 140 to rotate the build zone BZ at block 408. Before traversing, it may rotate to clean the roller 142. In some embodiments, the roller 142 may rotate relative to the roller brush 143. In some embodiments, the roller brush 143 may move into engagement with the roller 142 so that the roller brush 143 can clean the roller 142.

[0111] While in some embodiments the recoat assembly 140 can directly follow the print assembly 150 across the build zone BZ, in some instances the electronic control unit 10 can implement a delay before causing the recoat assembly 140 to cross the build zone BZ to dispense a new layer of build material 40. In block 410, the electronic control unit 10 causes the recoat assembly 140 to cross the build zone BZ to dispense (e.g., push) the build material 40 thereon (e.g., in the reverse direction R, −X axis direction). One or more rollers 142 and / or doctor blade 141 of the recoat assembly 140 push the build material across the build zone BZ during a first pass (e.g., in the reverse direction). The rollers 142 can rotate at a rotational speed and / or direction that may be the same or different for each roller in a multi-roller system. Note that the activity in block 410 can be synchronized with the activity in block 506 of the curing process. When the recoat assembly 140 reaches the opposite end of the build zone BZ (e.g., the opposite end of the SZ), in block 412, the rollers and / or doctor blade of the recoat assembly 140 can be lifted and moved over ("hopped over") any remaining mounds of build material 40 from the first pass.

[0112] The electronic control unit 10 at block 414 causes the recoat assembly 140 to build in the reverse direction, again traversing the build zone BZ (e.g., in the forward direction F) and pushing any remaining build material 40 across the build zone BZ to generate the build material 40 thickness defined for the new layer. Note that the activity at block 414 may be synchronized with a preheating process at block 510 of the curing process. At block 416, the electronic control unit 10 further causes the recoat assembly 140 to traverse the supply zone SZ and push any remaining build material 40 back onto the build material supply platform 130, or optionally into a build material return bin located proximate to the supply platform 130.

[0113] The electronic control unit 10 is configured to repeat the operations of blocks 402-416 each time a new layer of build material 40 is prescribed to be dispensed into the build zone BZ in accordance with the build instructions.

[0114] Although the above description describes a process for dispensing build material 40 in the build zone BZ using the recoat assembly 140, the electronic control unit 10 may also perform a recoat defect detection and correction process. In block 418, the electronic control unit 10 loads build instructions including predetermined build material dosing parameters. The electronic control system 10 may facilitate loading the build instructions to the recoat assembly 140 in block 402 or may update the build instructions based on any corrective actions determined based on the results of blocks 420-424 described herein. In block 420, the electronic control unit 10 captures and receives image data from the vision system 14 in the build zone BZ before or during a forward and / or reverse pass by the print assembly 150, as described with reference to blocks 312 and 316 of FIG. 3. The image data is analyzed by the electronic control unit 10 to determine the presence of anomalies in the recoat (e.g., in the new layer of material distributed in the build zone BZ). In addition, during the first pass of the recoat assembly 140 (e.g., in the reverse R direction), the electronic control unit 10 may detect the force sensors 26 associated with the roller 142, the doctor blade 141, and / or other sensors at 422. The electronic control unit 10 monitors one or more sensors associated with the recoat assembly 140, such as the current sensor 24 configured to monitor the current draw on the sensor. The electronic control unit 10 may also monitor one or more sensors associated with the recoat assembly 140, such as the current sensor 24 configured to monitor the current draw on the roller 142, the force sensor 26 associated with the doctor blade 141, and / or other sensors in the return path (e.g., forward path) of the recoat assembly 140.

[0115] In response to the sensor data and / or image data received by the electronic control unit 10, the electronic control unit 10 performs an analysis of the sensor data and / or image data to determine the presence of any anomalies in the new layer of dispensed build material 40 at block 422. In response to determining the presence of anomalies at block 424, the electronic control unit 10 implements corrective action. The corrective action can include adjusting predetermined build material input parameters, having the recoat assembly 140 redistribute build material 40 onto the new layer prior to the print assembly dispensing binder 50 onto the new layer of build material 40, stopping the build block, interfacing the recoat assembly 140 with one or more cleaning elements of the cleaning station 108, etc.

[0116] 5, a flow chart 500 illustrates a recoat method including closed loop control operation of a curing block to improve the speed of curing and / or preheating of the build material 40 and / or binder 50 during application of the binder 50 and / or dispensing of the build material 40. As described herein above, the manufacturing apparatus 100 includes one or more energy sources 160, such as IR lamps 160, to facilitate the curing process and / or evaporation of solvent from the build material 40. In some embodiments, the one or more energy sources 160 may be coupled to the print assembly 150 and / or the recoat assembly 140. The following procedure describes an embodiment in which a first IR lamp 160A is coupled to a forward facing surface of the print assembly 150 and a second IR lamp 160B is coupled to a reverse facing surface of the recoat assembly 140.

[0117] Moving to block 502, as the print assembly 150 traverses the build zone BZ in the reverse direction (e.g., at block 316), the first IR lamp 160A applies energy at a first height and / or flow gas 161A to the build material 40 and binder 50 in the build zone BZ to promote a curing reaction and / or phase change. In block 504, after the print assembly 150 traverses the build zone BZ in block 316, the electronic control unit 10 optionally activates the build plate heater 121 to provide heat to the build on the build plate 120 to promote solvent evaporation. In other embodiments, the build plate heater 121 provides heat to the build on the build plate 120 to promote solvent evaporation throughout the build process and is not intermittently activated and deactivated. The build plate heater 121 can be actively cycled on and off near a temperature setpoint to allow the build plate 120 to maintain a predetermined temperature during the build. In some examples, as the build grows layer by layer, the set point may be increased so that the surface temperature of the build material 40 on the build plate 120 remains at a predetermined temperature (e.g., within a predetermined range) as the surface of the build increases in distance from the surface of the build plate 120 as the build progresses.

[0118] In some embodiments, electronic control unit 10 may cause environmental control device 180 to flow gas 161B through or around IR lamps 160B to displace binder vapor with hot air and provide an additional energy source (e.g., heat source) to build material 40 and binder 50 on build plate 120 to accelerate the curing process in block 506. IR lamps 160B may also provide IR energy to build material 40 and binder 50 on build plate 120 to accelerate the curing process in block 506. It should be appreciated that the IR lamps 160A, 160B, and 160C and the flow gases 161A, 161B, and 161C introduce heat to cure or preheat the build material 40 and binder 50 at various times during the build. Additionally, the flow gas 161B through or around the IR lamp 160B can cool the lamps and extend lamp life. Additionally, in block 508, as the recoat assembly 140 traverses the build zone BZ in the reverse direction R (e.g., in block 410), the second infrared lamp 160B applies a first level of energy to the build material 40 and binder 50 in the build zone to promote a curing reaction and / or phase change. Similarly, as the recoat assembly 140 traverses the build zone BZ in the forward direction F (e.g., during a return pass to the supply zone SZ, at block 414), the second infrared lamp 160B applies a second level of energy to the build material 40, and the binder 50 in the build zone preheats the build material 40 at block 510. Although the flow gas 161B is discussed with respect to the operation of the IR lamp 160B, it is understood that each energy source (e.g., each IR lamp 160A, 160B, or 160C) can include a flow gas 161A, 161B, and 161C (FIG. 1B) flowing through or around the IR lamp 160A, 160B, or 160C (FIG. 1B).

[0119] The electronic control unit 10 is configured to repeat the operations of blocks 502-510 each time a new layer of build material 40 is prescribed to be dispensed into the build zone BZ in accordance with the build instructions.

[0120] While the above blocks describe a process for implementing curing mechanisms such as IR lamps 160, flow gas 161 (e.g., heated flow gas generated by heat from IR lamps 160), and build plate heater 121, electronic control unit 10 can also implement a closed-loop control system that ensures that one or more energy sources 160 are providing the necessary heating to facilitate the curing process, phase change, and / or solvent evaporation.

[0121] In some embodiments, the electronic control unit 10 loads build instructions for a build, including predetermined IR lamp 160 energy levels, flow gas 161 velocity, and / or process gas temperatures (e.g., average ambient temperature in the process chamber 101) and surface temperature ranges (e.g., surface temperature of build material 40 on the build plate 120, optionally monitored using a pyrometer), at block 512. During the jet / recoat delay (e.g., at block 404) or as continuous operation during the build, the electronic control unit 10 monitors sensor data from one or more sensors. For example, the electronic control unit 10 can receive the surface temperature of the build material 40 in the build zone BZ using a pyrometer and / or process gas temperatures in the process chamber 101. At block 516, during the first pass and return of the recoat assembly 140 through the build zone (e.g., at blocks 410 and 414), the electronic control unit 10 monitors the flow gas 161 temperature and / or surface temperature of the build material 40 on the build plate 120. The electronic control unit 10 analyzes the sensor data to determine whether the temperature (which may be a function of, for example, IR lamp intensity and flow gas 161 velocity) and surface temperature of the flow gas 161 are within a predetermined temperature range defined in block 518. In response to determining that the temperature values ​​are not within the predetermined ranges, the electronic control unit 10 may adjust the intensity of one or more IR lamps 160, the velocity of the flow gas 161, the on / off cycle time of the build plate heater 121, and / or the delivery time of heated process gas from the environmental system to increase or decrease the temperature.

[0122] Referring now to FIG. 6, a flow chart 600 illustrates an environmental control system that includes closed loop control operations to improve the reliability of the recoat operation (e.g., by controlling the humidity within the process chamber 101) and to provide better control of the curing process. 1 illustrates a method for controlling the environment within the process chamber 101. The environmental control system 180 described herein includes multiple subsystems for controlling the environment within the process chamber 101. Depending on the type of component 70 and the materials used within the process chamber 101, various environmental conditions must be met to deliver the component 70 reliably. The one or more subsystems may include a heat exchanger 181, a dehumidifier or condenser 182, or other means for removing vapors from the process gas, a process gas supply 183, an air filtration system 184, etc. Each of the subsystems may include one or more controllable valves that the electronic control unit 10 can electronically activate or deactivate, such that the valves can be opened or closed, or the subsystems can be connected or disconnected from the process chamber 101.

[0123] In block 602, the electronic control unit 10 loads from the build instructions a predetermined set of environmental conditions for environmental control within the process chamber 101. The predetermined set of environmental conditions can include a predetermined temperature, relative humidity level, solvent concentration level, allowable concentration of airborne build material 40, and gas concentration levels within the process chamber 101.

[0124] The electronic control unit 10 loads a predetermined set of environmental conditions in the environmental control system 180 in block 604. Once the set of predetermined environmental conditions is loaded into the environmental control system 180, the environmental control system 180 can condition the process chamber 101 according to the predetermined conditions. In some embodiments, during a build, the electronic control unit 10 partially or fully closes an exhaust valve to the process chamber 101 in block 606 to create suction in the process chamber 101 around the recoat assembly 140 to extract stray build material 40 while the recoat assembly 140 can dispense a new layer of build material 40. Note that the activity in block 606 can be synchronized with the activity in block 404 of the recoat process. In block 608, the electronic control unit 10 flows heated process gas into the process chamber 101. The heated (or cooled) process gas in the process chamber 101 can be further controlled to maintain a predetermined average temperature and / or humidity in the process chamber 101. In some embodiments, the environmental control processes disclosed herein may occur in parallel or sequentially with one another. Note that the activities at block 608 may be synchronized with the activities at block 506 of the recoating process.

[0125] In block 610, during the first pass of the recoat assembly 140, the electronic control unit 10 maintains the exhaust valve partially or fully closed to maintain suction in the process chamber 101 around the recoat assembly 140 so that airborne build material 40 is extracted and filtered using a filtration device. The activity in block 610 may be synchronized with the activity in block 406 of the recoat process. Once the recoat assembly 140 completes its return pass across the build zone BZ to the supply zone SZ, the suction level and heated flow gas may be adjusted in block 612. Once complete, in block 614, the heated flow gas valve may be shut off and the exhaust valve of the process chamber 101 may be opened by the electronic control unit 10. Additionally, once the print assembly 150 is completed, passing over the build zone BZ, the gas flow is adjusted via the controller 616. The activity in block 616 may be synchronized with the activity in blocks 312 and 316 of the print process.

[0126] As the build process runs, the electronic control unit 10 receives sensor data regarding the environment of the process chamber 101. In addition to providing control signals and / or environmental conditions to the environmental control system 180, the electronic control unit 10 also monitors the sensor data and issues commands to correct any environmental conditions that are not within predetermined ranges defined by the build instructions. For example, in block 618, the electronic control unit 10 may receive one or more data sets from one or more sensors. The data may include sensor data indicative of a temperature of the process chamber 101, a relative humidity within the process chamber 101, a concentration of process gas within the process chamber 101, a concentration of airborne build material 40, and / or other conditions within the process chamber 101.

[0127] In block 620, the electronic control unit 10 can implement one or more corrective actions to adjust the environmental conditions determined not to be within the predetermined set of environmental conditions. For example, the electronic control unit 10 can cause the environmental control system 180 to initiate flow from a heat exchanger of the environmental control system 180 if the sensor data indicates that the temperature of the process chamber 101 is below the set of predetermined environmental conditions, and can cause the environmental control system 180 to stop flow from a heat exchanger of the environmental control system 180 if the sensor data indicates that the temperature of the process chamber is above the set of predetermined environmental conditions. In some embodiments, the electronic control unit 10 can cause the environmental control system 180 to initiate a cooling flow through the process chamber 101 to remove excess heat therein.

[0128] In some embodiments, electronic control unit 10 causes environmental control system 180 to initiate flow from a dehumidifier of environmental control system 180 when the sensor data indicates the relative humidity exceeds a predefined set of environmental conditions, and causes environmental control system 180 to stop flow from a dehumidifier of environmental control system 180 when the sensor data indicates the relative humidity falls below a predefined set of environmental conditions. Electronic control unit 10 causes environmental control system 180 to initiate flow from a process gas supply of environmental control system 180 when the sensor data indicates the process gas concentration falls below a predefined set of environmental conditions, and causes environmental control system 180 to stop flow from a process gas supply of environmental control system 180 when the sensor data indicates the process gas concentration exceeds a predefined set of environmental conditions.

[0129] Similarly, electronic control unit 10 causes environmental control system 180 to initiate flow from its condenser 182 if the sensor data indicates the solvent concentration is outside the set of predetermined environmental conditions, and causes environmental control system 180 to stop flow from its condenser 182 if the sensor data indicates the solvent concentration is within the set of predetermined environmental conditions. In some embodiments, electronic control unit 10 causes environmental control system 180 to activate (start) its air filtration system if the sensor data indicates the concentration of the aerial build material 40 is above the set of predetermined environmental conditions, and causes environmental control system 180 to stop flow from its air filtration system if the sensor data indicates the concentration of the aerial build material 40 is below the set of predetermined environmental conditions.

[0130] In some further embodiments, the build instructions may require that the environment within the process chamber 101 be an inert environment or at least be maintained as an inert environment during the specified build process. Thus, the electronic control unit 10 may cause the environmental control system 180 to create and / or maintain an inert environment within the process chamber 101 in block 622. The electronic control unit 10 may monitor one or more O2 sensors configured to monitor oxygen levels within the process chamber 101 to create and / or maintain an inert atmosphere within the process chamber 101.

[0131] It should be understood that steps of the foregoing processes may be omitted or performed in various orders while still achieving the objectives of the present disclosure. The functional blocks and / or flowchart elements described herein may be converted into machine-readable instructions. As a non-limiting example, the machine-readable instructions may be descriptive text that is parsed (e.g., HyperText Markup Language, Extensible Markup Language, The machine-readable instructions may be written using any programming protocol, such as (i) a programming language (such as a functional markup language), (ii) an assembly language, (iii) object code generated from the source code by a compiler, (iv) source code written using a syntax from any suitable programming language for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. Alternatively, the machine-readable instructions may be written in a hardware description language (HDL), such as logic implemented via either a field programmable gate array (FPGA) configuration or an application specific integrated circuit (ASIC), or equivalents thereof. Thus, the functionality described herein may be implemented in any conventional computer programming language, as pre-programmed hardware elements, or as a combination of hardware and software components.

[0132] 7, an exemplary schematic diagram of the operation of the print assembly 150 and the recoat assembly 140 during a build process is shown. As described herein, the additive manufacturing apparatus 100 includes a process chamber 101 having a length defined by at least a cleaning zone CZ, a build zone BZ, and a supply zone SZ arranged consecutively at discrete sites along the length of the process chamber 101. In some embodiments, there may be additional zones, referred to herein as auxiliary zones (auxiliary zones or AZs). The AZs may include other elements, such as an overflow bin for the build material 40, or a binder deposition test area. However, the additive manufacturing apparatus 100 does not necessarily include an AZ. The additive manufacturing apparatus 100 also includes a support extending along the length of the process chamber 101 in a first vertical plane, the print assembly 150, the recoat assembly 140, the vision system 14, and the electronic control unit 10. The print assembly 150 includes a plurality of nozzles 158 for dispensing the binder 50 within the build zone. The print assembly 150 is configured to move back and forth along the length of the support and is movably coupled to the support via a first actuator disposed in a second vertical plane parallel to the first vertical plane. The recoat assembly 140 can include one or more doctor blades 141 or rollers 142 for distributing the build material 40 within the build zone. The recoat assembly 140 is configured to move back and forth along the length of the support and is movably coupled to the support via a second actuator disposed in a second vertical plane parallel to the first vertical plane. Additionally, the vision system 14 is configured to image the build zone.

[0133] The build process below is described with reference to time intervals T1, T2, T3, and T4. Time intervals indicated with a plus "+" sign are intended to indicate further movement in the build process during the defined time interval. The electronic control unit 10 is communicatively coupled to the print assembly 150, the recoat assembly 140, the first and second actuators, the one or more energy sources 160, and the vision system 14, as well as other elements of the additive manufacturing apparatus 100 described herein. The electronic control unit 10 is configured to cause the print assembly 150 to traverse the build zone in a forward direction F (e.g., toward the supply zone) during the first interval T1 while dispensing the binder 50 according to a programmed deposition pattern. In some examples, the electronic control unit 10 receives image data from the vision system 14 of the dispensed binder pattern either as the print assembly 150 traverses the build zone in the forward direction F during the first interval T1 or as the print assembly 150 completes traversing the build zone in the forward direction F. Image data and other sensor data may be recorded and stored in memory of the electronic control unit 10 or other storage device for post analysis or analysis during subsequent build processing steps to adjust and improve build speed and / or quality. During a second interval T2 following the first interval T1, the electronic control unit 10 instructs the print assembly 150 to deposit the binder 50 according to a programmed deposition pattern during the second interval T2. During a second interval T2 following the first interval T1, the electronic control unit 10 receives image data of the dispensed binder pattern from the vision system 14. In some embodiments, for example, in embodiments where the vision system 14 is configured to move with or coupled to the print assembly 150, image data of the dispensed binder pattern may be captured during the first interval T1 as the print assembly 150 traverses the build zone in the forward direction F. In other examples, the vision system 14 may capture image data of the dispensed binder pattern once the print assembly 150 has completed traversing the build zone. For example, image data may be captured once the print assembly 150 has cleared the field of view of the vision system 14 to the build zone.

[0134] During the second and third intervals T2 and T3, the electronic control unit 10 causes the recoat assembly 140 to traverse the build zone in a reverse direction (e.g., away from the supply zone) of dispensing the build material 40 provided in the supply zone and form a new layer of build material 40 in the build zone according to predetermined build material input parameters. The recoat assembly 140 follows the print assembly 150 across the build zone. The electronic control unit 10 can analyze the image data as the recoat assembly 140 traverses the build zone to determine if there are any anomalies in the dispensed binder pattern.

[0135] During the third interval T3, the electronic control unit 10 can cause the print assembly 150 to perform at least one of a purge operation or a wipe operation while traversing the cleaning zone in a forward and / or reverse direction. The print assembly 150 can perform one or more cleaning operations in the cleaning zone CZ when the recoat assembly 140 completes a reverse pass through the build zone BZ, for example, during the second half of the third interval T3+. In some embodiments, the maintenance of the print assembly 150 described above can be performed based on an analysis of image data of the applied binder pattern. For example, the maintenance of the print assembly 150, such as a cleaning operation, can be performed when it is determined that there is an anomaly in the dispensed binder pattern. In some embodiments, redundancy of print heads or lateral index jets in the print assembly 150 can be performed in response to a determination (e.g., through image data analysis) of the presence of an anomaly in the dispensed binder pattern. For example, the analysis of the image data can indicate that one or more jet nozzles 158 of one or more print heads failed to properly dispense the binder 50 during traversal and dispensing of the binder 50 on a previous layer of the build material 40.

[0136] During a fourth interval T4, the electronic control unit 10 causes the recoat assembly 140 to traverse the build zone in a forward direction (e.g., toward the supply zone) and causes the print assembly 150 to traverse the build zone in a forward direction (toward the supply zone) and follow the recoat assembly 140 across the build zone to dispense binder 50 according to the programmed deposition pattern onto the new layer of build material 40.

[0137] In some embodiments, the electronic control unit 10 is further configured to adjust jet nozzle mapping for a subsequent traverse of the print assembly 150 over the build zone in response to determining the presence of an anomaly in the dispensed binder pattern. The electronic control unit 10 is further configured to implement corrective action for a subsequent dispensing of the build material 40 by the recoat assembly 140 in response to determining the presence of an anomaly in a new layer of the dispensed build material 40. In some embodiments, the electronic control unit 10 causes the print assembly 150 to perform sub-pixel indexing of the plurality of nozzles 158 between the first interval T1 and the second interval T2. Additionally, in some embodiments, the electronic control unit 10 causes the print assembly 150 to perform sub-pixel indexing of the plurality of nozzles 158 between the third and fourth intervals T3, T4. Perform sub-pixel indexing of nozzles 158. In some embodiments, a delay may be implemented before recoat assembly 140 begins to traverse the build zone in the reverse direction following print assembly 150 traversing the build zone during second and third intervals T2 and T3. The delay may be implemented to allow binder 50 to soak into build material 40, build plate 120 to be reduced in the -Z direction, print assembly 150 to clear the build zone, and / or the like.

[0138] Referring to the movement of the print assembly 150, the print assembly 150 traverses back and forth through the build zone at a first speed, and in some embodiments the print assembly 150 traverses forwards and backwards through the cleaning zone at a second speed, the second speed being slower than the first speed.

[0139] Based on the above, it should be understood that an embodiment of an additive manufacturing device is described herein. The additive manufacturing device may include a process chamber 101 defining a volume having a height, a length, and a width. The length defines a plurality of processing zones. The process chamber includes a cleaning zone, a build zone, and a supply zone sequentially arranged in separate portions along the length of the process chamber 101. The process chamber 101 includes an actuator assembly for dispensing the build material and depositing the binder material within the additive manufacturing device. The actuator assembly may generally include a support extending along the length of the process chamber 101 in a first vertical plane. The actuator assembly may further include a recoat assembly 140 for dispensing the build material and a print assembly 150 for depositing the binder material. The print assembly 150 includes a plurality of nozzles 158 for dispensing the binder 50 within the build zone. The print assembly 150 is movably coupled to the support via a first actuator configured to move back and forth along the length of the support. The print head actuator can include a print actuation axis, where the print head actuator is bidirectionally actuable along the print actuation axis, thereby providing bidirectional motion of the print head. The print assembly 150 is disposed in a second vertical plane parallel to the first vertical plane.

[0140] Moreover, the embodiments described herein more specifically disclose systems and methods for operating the print assembly 150, recoat assembly 140, curing system, environmental control system 180, and their interactions to improve the reliability and speed of the build process. To improve the reliability and speed of the build process, the manufacturing apparatus disclosed herein further implements one or more sensors and control systems configured to operate in a closed control loop.

[0141] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Accordingly, this specification is intended to cover modifications and variations of the various embodiments described herein, provided that such modifications and variations come within the scope of the appended claims and their equivalents.

[0142] Further aspects of the invention are provided by the subject matter of the following appendices. (Appendix 1) a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone, the zones being sequentially disposed in distinct portions along the length of the process chamber; a support extending along a length of the process chamber in a first vertical plane; a print assembly including a plurality of nozzles for dispensing binder within the build zone, the print assembly being configured to move in a forward or reverse direction along the length of the support; a print assembly movably coupled to the support via a first actuator and disposed in a second vertical plane parallel to the first vertical plane; a vision system configured to image a dispensed binder pattern in the build zone; and an electronic control unit communicatively coupled to the print assembly, the first actuator, and the vision system; Including, The electronic control unit includes: causing the print assembly to traverse the build zone in a forward or reverse direction while dispensing binder according to a programmed deposition pattern; receiving image data from the vision system of the dispensed binder pattern resulting from the programmed deposition pattern; analyzing the image data to determine if the distributed binder pattern has anomalies; upon determining the presence of an anomaly in the dispensed binder pattern, adjusting the programmed deposition pattern for a subsequent traverse of the print assembly over the build zone to address the anomaly. It is configured as follows: Additive manufacturing equipment. (Appendix 2) capturing image data of the dispensed binder pattern as the print assembly traverses the build zone in a forward or reverse direction; 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 3) An additive manufacturing apparatus as described in any of the above appended claims, wherein the anomaly is an area of ​​a build layer of a build produced in the build zone in which less than a predetermined amount of binder is present based on a comparison of the image data to the programmed deposition pattern. (Appendix 4) An additive manufacturing apparatus as described in any of the above appended claims, wherein the anomaly is an area of ​​a build layer of a build produced in the build zone where a greater than predetermined amount of binder is present or where binder is detected in one or more locations where binder should not be deposited based on a comparison of the image data with the programmed deposition pattern. (Appendix 5) An additive manufacturing apparatus as described in any of the above appended claims, wherein the programmed deposition pattern map selects one of the plurality of nozzles to select a pixel of a build layer of a build to be produced in the build zone. (Appendix 6) The additive manufacturing apparatus of any of the preceding claims, wherein adjusting the programmed deposition pattern for a subsequent traverse of the print assembly over the build zone includes updating an amount of binder defined for dispensing by a selected nozzle of the plurality of nozzles. (Appendix 7) The additive manufacturing device of any of the above appended claims, wherein adjusting the programmed deposition pattern for a subsequent traverse of the print assembly over the build zone includes updating mapping of selected nozzles of the plurality of nozzles to select pixels of a subsequent build layer, and a first nozzle mapped to dispense binder to a first selected set of pixels during a first traverse of the print assembly is mapped to dispense binder to a second selected set of pixels during a second traverse of the print assembly over the build zone. (Appendix 8) The additive manufacturing apparatus of any of the preceding claims, wherein adjusting the programmed deposition pattern for a subsequent traverse of the print assembly over the build zone includes performing a sub-pixel shift in alignment of the pixels defined in the programmed deposition pattern with a plurality of jet nozzles. (Appendix 9) further comprising a cleaning station disposed in the cleaning zone; the cleaning station is configured to clean the nozzles of the print assembly; The electronic control unit includes: interfacing the print assembly with one or more cleaning elements of the cleaning station upon determining the presence of an anomaly in the dispensed binder pattern. 13. The additive manufacturing apparatus of any preceding claim, further configured as follows: (Appendix 10) The additive manufacturing apparatus of any of the above appended claims, wherein the electronic control unit is further configured to cause the print assembly to perform a purge operation in the cleaning zone if it determines the presence of an anomaly in the dispensed binder pattern. (Appendix 11) The additive manufacturing apparatus of any of the preceding claims, wherein the vision system includes at least one of an electromagnetic radiation source, a camera, an infrared camera, or an X-ray imaging device. (Appendix 12) a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone, the zones being sequentially disposed in distinct portions along the length of the process chamber; a support extending along a length of the process chamber in a first vertical plane; a recoat assembly including at least one of a doctor blade and a roller for distributing build material within the build zone, the recoat assembly being movably coupled to the support via a second actuator configured to move in a forward or reverse direction along a length of the support and disposed in a second vertical plane parallel to the first vertical plane; a vision system configured to image the dispensed layer of build material in the build zone; and an electronic control unit communicatively coupled to the recoat assembly, the second actuator, and the vision system; Including, The electronic control unit includes: causing the recoat assembly to traverse the build zone to dispense build material according to predetermined build material input parameters to form a new layer of build material within the build zone; receiving image data from the vision system of the dispensed build material in the build zone; analyzing the image data to determine whether the dispensed build material is abnormal; and upon determining the presence of an anomaly in the dispensed new layer of build material, implementing corrective action for subsequent dispensing of build material by the recoat assembly. It is configured as follows: Additive manufacturing equipment. (Appendix 13) An additive manufacturing apparatus as claimed in any preceding claim, wherein the corrective action comprises adjusting predetermined build material input parameters. (Appendix 14) An additive manufacturing apparatus as described in any of the above appended claims, wherein the predetermined build material input parameters are at least one of build material thickness, over-input amount, recoat assembly speed for traversing the build zone, rotational speed of the rollers of the recoat assembly, and rotational direction of the rollers of the recoat assembly. (Appendix 15) The additive manufacturing apparatus of any of the preceding clauses, wherein the corrective action includes causing the recoat assembly to redistribute build material onto the new layer before the print assembly dispenses binder onto the new layer of build material. (Appendix 16) 13. An additive manufacturing apparatus according to any preceding claim, wherein the corrective action includes stopping a build. (Appendix 17) further comprising a cleaning station disposed in the cleaning zone or the supply zone; the cleaning station is configured to clean at least one of the doctor blade and the roller of the recoat assembly; The electronic control unit includes: and interfacing the recoat assembly with one or more cleaning elements of the cleaning station upon determining the presence of an anomaly in the new layer of dispensed build material. 13. The additive manufacturing apparatus of any preceding claim, further configured as follows: (Appendix 18) The electronic control unit includes: receiving a current draw value for a motor driving the roller of the recoat assembly; determining whether the rollers are operating in accordance with predetermined build material input parameters; determining the presence of an anomaly in the roller of the recoat assembly when the roller is determined not to be operating in accordance with the predetermined build material input parameters; 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 19) The additive manufacturing apparatus of any of the preceding claims, wherein the vision system includes at least one of a camera, an infrared camera, and an X-ray imaging device. (Appendix 20) a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone, the zones being sequentially disposed in distinct portions along the length of the process chamber; a support extending along a length of the process chamber in a first vertical plane; a print assembly movably coupled to the support via a first actuator configured to move in a forward or reverse direction along a length of the support and disposed in a second vertical plane parallel to the first vertical plane; a recoat assembly movably coupled to the support via a second actuator configured to move in a forward or reverse direction along a length of the support and disposed in the second vertical plane parallel to the first vertical plane; one or more IR lamps coupled to at least one of the print assembly and the recoat assembly, the IR lamps configured to apply energy to the build material and binder in the build zone to stimulate a curing reaction; one or more temperature sensors configured to monitor at least one of a gas temperature and a build material surface temperature of the process chamber; the print assembly, the first actuator, the recoat assembly, an electronic control unit communicatively coupled to the actuator, the one or more IR lamps, and the one or more temperature sensors; Including, The electronic control unit includes: causing one or more of the IR lamps to emit energy when the print assembly or the recoat assembly traverses the build zone; receiving temperature values ​​from one or more of said temperature sensors; determining whether the temperature value is within a predetermined range; adjusting an intensity of one or more of said IR lamps or a flow gas rate of one or more of said IR lamps if said temperature value is not within said predetermined range. It is configured as follows: Additive manufacturing equipment. (Appendix 21) The additive manufacturing apparatus of any preceding claim, wherein if the temperature value is determined to be below the predetermined range, an intensity of one or more of the IR lamps is increased. (Appendix 22) The additive manufacturing apparatus of any preceding claim, wherein if the temperature value is determined to exceed the predetermined range, an intensity of one or more of the IR lamps is reduced. (Appendix 23) a first IR lamp of the one or more IR lamps is coupled to the print assembly; a second IR lamp of the one or more IR lamps is coupled to the recoat assembly; 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 24) The additive manufacturing apparatus of any of the previous clauses, wherein the electronic control unit controls a flow gas rate around the one or more IR lamps. (Appendix 25) the one or more temperature sensors are gas temperature sensors; The electronic control unit includes: adjusting a flow rate of gas around one or more of the IR lamps if it is determined that the build material surface temperature value is not within the predetermined range.

[0023] 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 26) An additive manufacturing apparatus as described in any of the previous clauses, wherein if the surface temperature value is determined to be below the predetermined range, the flow gas rate around the one or more IR lamps is increased. (Appendix 27) The additive manufacturing apparatus of any preceding claim, further comprising reducing the flow gas rate around one or more of the IR lamps if the surface temperature value is determined to exceed the predetermined range. (Appendix 28) an environmental control system fluidly coupled to the process chamber; if the process chamber temperature value is determined to be not within a predetermined process chamber range, the environmental control system delivers heated gas to the process chamber. 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 29) a build plate heater thermally coupled to a build platform of the build zone; when the temperature value of the surface temperature of the build material surface is determined to be below the predetermined range, the electronic control unit causes the build plate heater to increase the amount of energy delivered to the build material and the build plate in the build zone. 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 30) a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone, the zones being sequentially disposed in distinct portions along the length of the process chamber; an environmental control system coupled to the process chamber and including one or more subsystems for controlling environmental conditions within the process chamber; one or more sensors configured to monitor at least one of a temperature of the process chamber, a vapor content, and a process gas concentration within the process chamber; an electronic control unit communicatively connected to the environmental control system and to one or more of the sensors; Including, The electronic control unit includes: receiving sensor data from one or more of said sensors; determining whether the sensor data from one or more of the sensors corresponds to a predetermined set of environmental conditions for the process chamber during a build; automatically adjusting one or more environmental control settings of the environmental control system if the sensor data is determined to be not within the set of predetermined environmental conditions. It is configured as follows: Additive manufacturing equipment. (Appendix 31) The electronic control unit includes: causing the environmental control system to initiate a flow of heat to the process chamber through a heat exchanger of the environmental control system when the sensor data indicates that the temperature of the process chamber is below the set of predetermined environmental conditions; causing the environmental control system to stop flow through the heat exchanger of the environmental control system to the process chamber if the sensor data indicates that the temperature of the process chamber exceeds the set of predetermined environmental conditions.

[0023] 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 32) The electronic control unit includes: causing the environmental control system to initiate a flow through a heat exchanger, dehumidifier, or condenser of the environmental control system when the sensor data indicates that the vapor content exceeds the set of predetermined environmental conditions; causing the environmental control system to stop flow through a heat exchanger, a dehumidifier, or a condenser of the environmental control system if the sensor data indicates that the vapor content is below the set of predetermined environmental conditions.

[0023] 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 33) The electronic control unit includes: causing the environmental control system to initiate a flow from a process gas supply of the environmental control system when the sensor data indicates that the process gas concentration is below the set of predetermined environmental conditions; If the sensor data indicates that the process gas concentration exceeds the set of predetermined environmental conditions, the environmental control system is Stop the flow from the

[0023] 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 34) a particulate sensor configured to sense a concentration of airborne build material within the process chamber; The electronic control unit includes: causing an environmental control system to initiate an air filtration system of the environmental control system if the sensor data indicates that the concentration of airborne build material is above the set of predetermined environmental conditions; causing the environmental control system to stop flow from the air filtration system of the environmental control system if the sensor data indicates that the concentration of airborne build material falls below the set of predetermined environmental conditions.

[0023] 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 35) a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone, the zones being sequentially disposed in distinct portions along the length of the process chamber; a support extending along a length of the process chamber in a first vertical plane; a print assembly including a plurality of nozzles that dispense a binder within the build zone, the print assembly being movably coupled to the support via a first actuator configured to move in a forward or reverse direction along a length of the support and disposed in a second vertical plane parallel to the first vertical plane; a recoat assembly including at least one of a doctor blade and a roller for dispensing build material within the build zone, the recoat assembly being movably coupled to the support via a second actuator configured to move in a forward or reverse direction along a length of the support and disposed in the second vertical plane parallel to the first vertical plane; a vision system configured to image the build zone; and an electronic control unit communicatively coupled to the print assembly, the recoat assembly, the first actuator, the second actuator, and the vision system; Including, The electronic control unit includes: causing the print assembly to traverse the build zone in the forward direction during a first interval while dispensing binder according to a programmed deposition pattern; receiving image data from the vision system of a distributed binder pattern during a second interval after the first interval; analyzing the image data to determine whether the binder pattern distributed during the second interval has an anomaly; causing a print assembly to traverse the build zone in the reverse direction during the second interval while dispensing binder according to the programmed deposition pattern; causing the recoat assembly to traverse the build zone in the reverse direction dispensing build material supplied to the supply zone to form a new layer of build material in the build zone according to predetermined build material input parameters, the recoat assembly following the print assembly traversing the build zone during the second and third intervals; causing the print assembly to perform at least one of a purge process and a wipe process while traversing the cleaning zone in a forward and reverse direction during the third interval; It is configured as follows: Additive manufacturing equipment. (Appendix 36) The electronic control unit includes: during a fourth interval, causing the recoat assembly to traverse the build zone in the forward direction while dispensing binder according to a programmed deposition pattern on the new layer of build material, and causing the print assembly to traverse the build zone in the forward direction following the recoat assembly traversing the build zone; 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 37) The additive manufacturing apparatus of any of the above appended notes, wherein the electronic control unit is further configured to adjust the programmed deposition pattern for a subsequent traverse of the print assembly over the build zone to address the anomaly if it determines the presence of the anomaly in the dispensed binder pattern. (Appendix 38) The additive manufacturing apparatus of any of the above appended claims, wherein the electronic control unit is further configured to implement corrective action for subsequent dispensing of build material by the recoat assembly when it determines the presence of the anomaly in the new layer of dispensed build material. (Appendix 39) The additive manufacturing apparatus of any of the above addendums, wherein the electronic control unit is further configured to cause the print assembly to perform sub-pixel indexing of the plurality of nozzles between the first interval and the second interval. (Appendix 40) The additive manufacturing apparatus of any of the preceding clauses, wherein a delay is implemented before the recoat assembly begins to traverse the build zone in the reverse direction following the print assembly traversing the build zone during the second and third intervals. (Appendix 41) The additive manufacturing apparatus of any of the preceding claims, wherein the print assembly traverses the build zone in the forward and reverse directions at a first speed. (Appendix 42) the print assembly traverses forward and reverse through the cleaning zone at a second speed; The second speed is slower than the first speed. 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 43) further comprising one or more IR lamps configured to apply energy to the binder and build material in the build zone to stimulate a curing reaction; the one or more IR lamps are coupled to at least one of the print assembly and the recoat assembly; 13. An additive manufacturing apparatus according to any preceding claim. (Appendix 44) Two IR lamps are coupled to the recoat assembly; a first IR lamp coupled to a forward facing surface of the recoat assembly; a second IR lamp coupled to a rear-facing surface of the recoat assembly; 13. An additive manufacturing apparatus according to any preceding claim.

[0143] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 108,549, entitled "Additive Manufacturing Apparatus and Method of Operation Thereof," filed November 2, 2020, the entire contents of which are incorporated by reference herein.

Claims

1. a process chamber having a length defined by at least a cleaning zone, a build zone, and a supply zone, the zones being sequentially disposed in distinct portions along the length of the process chamber; a support extending along a length of the process chamber in a first vertical plane; a print assembly movably coupled to the support via a first actuator configured to move in a forward or reverse direction along a length of the support and disposed in a second vertical plane parallel to the first vertical plane; a recoat assembly movably coupled to the support via a second actuator configured to move in a forward or reverse direction along a length of the support and disposed in the second vertical plane parallel to the first vertical plane; one or more IR lamps coupled to at least one of the print assembly and the recoat assembly, the IR lamps configured to apply energy to the build material and binder in the build zone to stimulate a curing reaction; one or more temperature sensors configured to monitor at least one of a gas temperature of the process chamber and a build material surface temperature; an electronic control unit communicatively coupled to the print assembly, the first actuator, the recoat assembly, the second actuator, the one or more IR lamps, and the one or more temperature sensors; Including, The electronic control unit includes: causing one or more of the IR lamps to emit energy as the print assembly or the recoat assembly traverses the build zone; receiving temperature values ​​from one or more of said temperature sensors; determining whether the temperature value is within a predetermined range; adjusting an intensity of one or more of the IR lamps or a flow gas rate of one or more of the IR lamps if the temperature value is not within the predetermined range. It is configured as follows: Additive manufacturing equipment.

2. The additive manufacturing device of claim 1 , wherein if the temperature value is determined to be below the predetermined range, an intensity of one or more of the IR lamps is increased.

3. The additive manufacturing device of claim 1 , wherein if the temperature value is determined to be above the predetermined range, an intensity of one or more of the IR lamps is reduced.

4. a first IR lamp of the one or more IR lamps is coupled to the print assembly; a second IR lamp of the one or more IR lamps is coupled to the recoat assembly; 10. The additive manufacturing device of claim 1.

5. The additive manufacturing device of claim 1 , wherein the electronic control unit controls a flow gas rate around the IR lamp or lamps.

6. the one or more temperature sensors are gas temperature sensors; The electronic control unit includes: adjusting the flow gas rate around the one or more IR lamps if it is determined that the build material surface temperature value is not within the predetermined range. [0023] 6. The additive manufacturing device of claim 5.

7. The additive manufacturing device of claim 6 , wherein if the surface temperature value is determined to be below the predetermined range, then increasing the flow gas rate around the one or more IR lamps.

8. The additive manufacturing device of claim 6, wherein if the surface temperature value is determined to be above the predetermined range, then reducing the flow gas rate around one or more of the IR lamps.

9. an environmental control system fluidly coupled to the process chamber; if the process chamber temperature value is determined to be not within a predetermined process chamber range, the environmental control system delivers heated gas to the process chamber.

10. The additive manufacturing device of claim 1.

10. a build plate heater thermally coupled to a build platform of the build zone; when the temperature value of the build material surface temperature is determined to be below the predetermined range, the electronic control unit causes the build plate heater to increase the amount of energy delivered to the build material and build plate in the build zone.

10. The additive manufacturing device of claim 1.

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