Method and system for removing powder from additively manufactured parts

Abstract

Systems and methods are disclosed for removing unwanted material from additively manufactured parts through the application of vibration and / or acoustic energy. The systems and methods include a vibration platform disposed within a chamber. An additively manufactured part having unwanted material attached thereto is placed on the vibration platform. The platform is vibrated, thereby detaching the unwanted material from the part. The systems and methods can also include applying acoustic energy to detach the unwanted material from the part. Advantageously, the unwanted material removed from the additively manufactured part is recyclable.

Description

[Technical Field]

[0001] (Reference Application) This application claims priority to U.S. Provisional Patent Application No. 63 / 010464, filed April 15, 2020.

[0002] The present disclosure relates generally to additive manufacturing, and more particularly to systems and methods for removing unwanted material from parts formed by a 3D printer during the printing stage of the overall additive manufacturing process. [Background technology]

[0003] Some additive manufacturing methods (also known as 3D printing), such as selective laser sintering (SLS), electron beam melting (e-beam), multi-jet fusion (MJF), and powder bed fusion (PBF), use a computer-controlled beam or printer head to fabricate solid objects, fusing or solidifying portions of the object (e.g., walls) one layer at a time until the entire three-dimensional object is formed. After the three-dimensional solid object is formed, unwanted material, such as powder from which the object is made, may adhere to or encase the solid object. This unwanted material must be removed from the printed solid object before proceeding to the next step, such as painting, curing, passivation, coating, or assembly. The removal of unwanted powder material from an additively manufactured part is sometimes called decaking or depowdering. Depending on the additive manufacturing method, printed objects may still have unwanted support material on their surface after the printing step. Some additively manufactured objects may have surface roughness or build lines after being formed by the printer. Finishing processes are required to remove unwanted materials such as powder and support material, or to smooth out rough surfaces of the AM object.

[0004] Further disclosure regarding techniques and methods relating to additive manufacturing and the removal of unwanted material from objects formed by additive manufacturing can be found in co-pending patent applications US20190176403, US20190202126, US20190270248, US20190275745, US20190315065, US20170348910, and PCT / US2020 / 041396, which are assigned to the owner of the present application and are incorporated by reference in their entirety. Summary of the Invention

[0005] Systems and methods are disclosed for removing unwanted material from additively manufactured parts using vibration and / or acoustic energy. The systems and methods include a vibration platform disposed in a chamber. The additively manufactured part having the unwanted material attached thereto is placed on the vibration platform. The platform is vibrated, thereby separating the unwanted material from the part. The systems and methods can also use acoustic energy to separate the unwanted material from the part. The unwanted material removed from the additively manufactured part can be recovered and recycled. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view of an embodiment of a system for removing unwanted material from an additively manufactured part. [Figure 2] FIG. 2 is a cross-sectional side view of the embodiment shown in FIG. [Figure 3] FIG. 3 is a flow chart illustrating an embodiment of a process for removing unwanted material from an additively manufactured part that is performed by the system of FIGS. 1 and 2. [Figure 4] FIG. 4 shows the embodiment of FIG. 2 at one stage in the process of FIG. [Figure 5] FIG. 5 is a cross-sectional side view of another embodiment of a system for removing unwanted material from an additively manufactured part. [Figure 6]FIG. 6 is a flow chart illustrating the steps performed by the system of FIG. [Figure 7A] FIG. 10 is a perspective view of a portion of another embodiment of a system for removing unwanted material from an additively manufactured part. [Figure 7B] FIG. 10 is a perspective view of a portion of another embodiment of a system for removing unwanted material from an additively manufactured part. [Figure 8A] 1 illustrates various types of vibrations that can be utilized in the disclosed embodiments. [Figure 8B] 1 illustrates various types of vibrations that can be utilized in the disclosed embodiments. [Figure 8C] 1 illustrates various types of vibrations that can be utilized in the disclosed embodiments. [Figure 9] FIG. 9 is a cross-sectional side view of another embodiment of a system for removing unwanted material from an additively manufactured part. [Figure 10] FIG. 10 shows an external side view of the system shown in FIG. [Figure 11] FIG. 11 shows a perspective view of the processing platform of the system shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0007] While the present invention is described below with reference to specific examples, other examples, including those that do not possess all of the advantages and features disclosed herein, are also within the scope of the present invention. Various modifications can be made to the present system and method without departing from the scope of the present invention.

[0008] An embodiment of a system 200 for removing unwanted material from an additively manufactured part (also referred to as an "object") is shown in FIG. 1. The system 200 includes a chamber 202 and an adjacent housing 204. The chamber 202 has an openable door 208. The door 208 provides access to a chamber interior 210 (shown in FIG. 2). The door 208 includes a seal around its perimeter to prevent or reduce air, powder, or sound leakage from the chamber 202. The chamber 202 is sized to accommodate the additively manufactured part (also referred to as an "object"), including any unwanted material formed during that portion of the additive manufacturing process performed by the 3D printer. The chamber 202 and door 208 can be fabricated from a suitable durable material, such as plastic, metal (e.g., stainless steel, polycarbonate), or a combination thereof. The chamber 202 also includes a viewing window 209. The viewing window 209 is made of a transparent material, such as glass or plastic. The sight glass 209 allows an operator to view the chamber interior 210. The sight glass 209 is located in a wall of the chamber. For example, the sight glass 209 is located in the chamber door 208.

[0009] FIG. 2 shows a cross-sectional view of the chamber 202. A platform 212 is positioned within the interior 210 of the chamber 202. The platform 212 is made of a durable material. Suitable materials include metals such as stainless steel and aluminum, plastic, cardboard, paper, and the like. The platform 212 is sized and configured to accommodate one or more parts 214 formed by an additive manufacturing process such as SLS. For example, the platform 212 is circular and approximately 25 centimeters (10 inches) in diameter, although other sizes are possible. In this embodiment, the parts 214 weigh approximately 2.4 to 4 grams. The amount of parts 214 that can be placed on the platform 212 and subjected to finishing processes at one time can vary. In this embodiment, approximately 6 to 110 parts can be placed on the platform 212 and subjected to finishing processes at one time. Other amounts are also possible. When formed by this additive manufacturing process, waste material 216 remains on the surface of the parts 214. In this example, the waste material 216 is nylon powder. Additionally, when formed by this additive manufacturing process, the part 214 may be encased in unwanted powder material 216.

[0010] As shown in FIG. 2 , the chamber 202 has an inner wall 218 spaced apart from an outer wall 219. In this embodiment, the inner wall 218 extends around the entire perimeter of the interior 210 of the chamber 202 and is spaced inward from the outer wall 219. The inner wall 218 defines an interior portion of the interior 210. In this embodiment, the inner wall 218 is open at the top. The platform 212 is mounted within the chamber 202 spaced apart from the inner wall 218, forming a gap 220 between the edge of the platform 212 and the inner wall 218. The gap 220 need not extend around the entire perimeter of the platform 202. The gap 220 is narrow enough to prevent an object 214 placed on the platform 212 from falling through the gap 220, but wide enough to allow unwanted material 216 that separates from the object 214 during finishing processing to pass through the gap 220. For example, gap 220 is approximately 1.27 centimeters (1 / 2 inch), but may be other sizes depending on the size of the part to be placed on platform 212 .

[0011] The platform 212 is mounted so that it can move (i.e. vibrate) within the chamber 202. This can be achieved in a variety of different ways. One preferred way is to have a flexible connection between the platform 212 and the chamber 202. Another way is to have a hinged or loose connection. Another way is to have a rigid fixed rim 224 that is fixed to the outer wall 219 of the chamber and has a flexible connection to the center of the platform 212, similar to a speaker diaphragm.

[0012] Connected to the underside of platform 212 is transducer 222. Transducer 222 is operatively connected to platform 212 to provide vibrations. For example, the transducer may be an electromagnetic coil. Transducer 222 is connected to a power source 228 by wire or cable 230. Power source 228 is located outside of chamber 202 within housing 204, which is located adjacent to chamber 202. Cable 230 passes through the walls of chamber 202 and housing 204 and connects transducer 222 to power source 228. For example, power source 228 may be an amplifier.

[0013] Within housing 204 is a control unit 236. Alternatively, control unit 236 may be located at a remote location. Control unit 236 is operably connected to the hardware of system 200, including power supply 228. For example, control unit 236 may be a personal computer (PC) running a suitable operating system, such as Windows® operating system. Alternatively, control unit 236 may be another computing platform, including a smartphone running Android® or iOS®. For example, control unit 236 and power supply 228 may be combined into a single unit.

[0014] The control unit 236 contains suitable programs 240 that enable the system 200 to operate as described below.

[0015] Connected to control unit 236 is user interface 242. User interface 242 may include a touch screen or other hardware for receiving input from and outputting information to a (human) user operator. In the embodiment shown in Figure 2, user interface 242 is shown as being located on housing 204. Alternatively, user interface 242 may be located elsewhere, including a remote location.

[0016] The floor of the chamber 202 is provided with a discharge chute 244. The discharge chute 244 is connected to a discharge line 246 for removing the waste material 216 that has been removed from the part 214. The discharge line 246 is connected to a vacuum or suction device to pull the waste material 216 from the chamber 202. A filter system (not shown) may be included in-line with the discharge line 246 to capture small particles.

[0017] (operation) Figure 3 shows a flowchart of a process 250 performed by / in conjunction with the system 202 of Figures 1 and 2. In step 254, an object 214 produced by additive manufacturing and encased in unwanted material (e.g., powder) is placed within the system 200, specifically, on the platform 212 within the chamber 202.

[0018] Next, solid polishing media 256 is placed on the platform 212 (step 258). This step is optional and may be omitted in some embodiments. The solid polishing media 256 can be mixed or sprinkled on the part 214. For example, the solid polishing media 256 is UPM. Alternatively, irregularly shaped plastic acrylic media particles are used. Other types of solid polishing media, such as M-CAT, are also available. The amount of solid polishing media 256 placed on the platform depends on the amount and size of the part 214. For example, approximately one-half cup of solid polishing media 256 is used. After the part 214 and solid polishing media 256, encased in unwanted material 216, are placed on the platform 212 in the chamber 202, the door 208 is closed.

[0019] Control unit 236 is operated (e.g., via user interface 242), causing power supply 228 to power transducer 222, thereby vibrating platform 212 (step 260). There are various types of vibrations available for vibrating platform 212. FIGS. 8A, 8B, and 8C depict various types of vibrations available for platform 212. (The depictions in FIGS. 8A, 8B, and 8C are not necessarily to scale; these types of vibrations are not the only types available, and others are also available.) FIG. 8A depicts a uniform up-and-down vibrational motion. In this type of vibration, the platform surface moves uniformly up and down across its entire width, similar to an audio speaker. FIG. 8B depicts platform 212 vibrating in a sinusoidal motion, where portions of the platform move upward while other portions simultaneously move downward. This type of vibration is typical of Chladni plates, where locations of motion are separated by locations of relatively little motion, corresponding to nodes of relative stability. FIG. 8C shows another type of vibratory motion, where the platform 212 operates in a trampoline-type motion, with a higher amplitude in the center and decreasing amplitude towards the edges.

[0020] The purpose of vibration type selection (as well as vibration waveform, frequency, and amplitude selection) is to separate the AM part from the adhering unwanted material. One way to achieve this separation is to impart completely different motions to the AM part and the unwanted material, causing the unwanted material to separate from the AM part. In some cases, the vibration type is selected to resonate either the AM part or the unwanted material (but not both). For example, vibration can be selected to cause the unwanted material to resonate at a specific frequency but not the AM part at all. Alternatively, the vibration type can be selected to cause the AM part to resonate at one frequency and the unwanted material to resonate at a second, different frequency. In this way, separation of the unwanted material from the AM part can be achieved by subjecting either the AM part or the unwanted material to different vibrations. Furthermore, appropriate vibration selection can also separate the unwanted material from the AM part, causing it to fall off the platform in a manner similar to how powder accumulates at the nodes of a Chladni plate.

[0021] Refers to the use in cymatics to describe wave phenomena. The selection of the type of vibration, the type of waveform, the frequency and amplitude of the vibration, the duration of the vibration, and whether different types of waveforms, frequencies, or amplitudes are used depends on several factors. These factors include the material composition of the AM part, the size and shape of the AM part, the amount of unwanted material deposited on the AM part, and other factors.

[0022] Referring again to FIG. 3 , in this embodiment, the power supply 228 provides a sine wave to the transducer 222. Alternatively, other types of waveforms may be used. In this embodiment, the platform 212 is vibrated at a frequency between 75 and 135 hertz, although other frequencies may be used. The platform 212 may be vibrated for any duration. In this embodiment, the platform 212 is vibrated for 30 minutes. Other durations may also be used. While the platform 212 is vibrating, the vibrations of the platform 212 are transferred to the components 214 and unwanted material 216 placed on the platform 212. Movement occurs between the components 214 and the unwanted material 216. The vibration of the vibrating platform 212 separates the unwanted material 216 from the components 214. Solid polishing media 254, which vibrates between the components 214, aids in this process. If the components 214 are relatively small, the amplitude is large, or the vibration frequency is low, the components 214 may bounce on the platform 212. If the part 214 is relatively large, if the amplitude is small, or if the vibration frequency is high, the part 214 may move relatively little on the platform 212. As the vibrational motion continues, some or all of the unwanted material 216 that separates from the part 214 will eventually move or bounce toward the edge of the platform 212 and fall through the gap 220 to the bottom of the chamber 202, as shown in FIG. 4. Some or all of the abrasive substance 254 may also fall to the bottom of the chamber 202. The part 214 is too large to fall through the gap 220 and remains on the platform 212. The unwanted material 216 collects at the bottom of the chamber 202 where it can be removed by suction or other means through the chute 244 and discharge tube 246 (step 262 in FIG. 3).

[0023] 3, the part 214 is inspected to determine if sufficient unwanted material has been removed (step 264). This step can be performed manually (e.g., by an operator) by stopping the vibration and inspecting the part 214. Alternatively, this step can be performed using machine vision or other automated processes. If it is determined that the part 214 requires further finishing, the part 214 is placed back on the platform 212 and the platform 212 is vibrated again (steps 266 and 260). The part 214 may be rotated or moved on the platform 212 to facilitate powder removal. The step of vibrating the part 214 on the platform 212 and then inspecting the part can be performed as many times as necessary.

[0024] If inspection determines that part 214 is sufficiently finished (e.g., that the unwanted material 216 has been sufficiently removed), part 214 is removed from chamber 202 (steps 266 and 268). The unwanted material 216 removed from part 214 is recycled or disposed of (step 270). This completes process 250. Part 214 is now ready for the next step, such as further de-powdering, curing, cleaning, painting, passivation, assembly, etc.

[0025] Alternative Embodiments (First Alternative Embodiment) Figure 5 illustrates another embodiment of a system for removing unwanted material from an additively manufactured part. System 300 of Figure 5 has similar components to those described in connection with the embodiment of system 200 shown in Figures 1, 2, and 4. System 300 includes a chamber 302 with a door (not shown but similar to door 208 of Figure 1) and an adjacent housing 304. Disposed within chamber 302 is a platform 312 sized and configured to receive an additively manufactured part 314, with unwanted material (e.g., nylon powder) 316 remaining on and enveloping the surface of part 314.

[0026] Platform 312 is separated from the inner wall 318 of chamber 302 by a gap 320. A transducer (or actuator) 322 is operably connected to the underside of platform 312 to provide vibrations. Transducer 322 is connected by cable 330 to a power supply 328 located within housing 304. A control unit 336 is operably connected to the hardware of system 300, including power supply 328 and a user interface 342. Control unit 336 contains an appropriate program 340. A discharge chute 344 is located in the floor of chamber 302 and connects to a discharge pipe 346.

[0027] System 300 also includes one or more cameras 350. Cameras 350 are positioned within chamber 302, adjacent to and / or above platform 312. Cameras 350 are connected to control unit 336 by suitable means, such as a cable. Cameras 350 are configured to be pointed in a particular direction and to capture images (including video) of the interior of chamber 302, including objects placed on platform 312, such as part 314, unwanted material 316, and solid polishing media 356, if any.

[0028] The system 300 also includes one or more additional sensors 352. The additional sensors 352 are located within the chamber 302, adjacent to and / or above the platform 312. The additional sensors 352 are connected to the control unit 336 by suitable means, such as cables. The additional sensors 352 may include one or more microphones, thermometers, accelerometers, scanners, radar, lidar, etc. The additional sensors 352 are configured to measure properties of objects on the platform 312 or within the chamber 302.

[0029] System 300 also includes a weigh scale 354. Scale 354 is disposed within chamber 302 and is connected to control unit 336 by suitable means, such as a cable (not shown). Scale 354 is configured to measure the weight of an object on platform 312 and provide data indicative thereof to control unit 336.

[0030] The system 300 also includes a cyclone generator 360. The cyclone generator 360 is connected to the interior of the chamber 302 by one or more suction ducts or tubes 362. The cyclone generator 360 is connected to an air source, such as ambient air. The cyclone generator 360 generates an airflow within the chamber 302. The cyclone generator 360 may include an electric impeller or a blower for generating the airflow. The suction duct 362 is positioned and arranged to generate a cyclonic airflow that circulates within the chamber 302. The cyclone generator 360 is operably connected to and operates under the control of the control unit 336. For example, the cyclone generator 360 exerts a vertical suction force (negative pressure) to remove the freed unwanted powder 316. The cyclone generator 360 may drive the unwanted powder 316 toward the top or bottom of the chamber 302.

[0031] One or more acoustic transducers 366 are mounted in the chamber 302. The acoustic transducers 366 may be horns, speakers, diaphragms, diaphragms or membranes, or other devices capable of generating audio waves (i.e., sound waves, acoustic waves). The acoustic transducers 366 are configured to generate audio waves in the air within the chamber 302. The acoustic transducers 366 are configured to generate audio waves at different frequencies and amplitudes based on an input signal. In this embodiment, the acoustic transducers 366 are mounted and oriented to project audio waves toward the parts 314 and unwanted material 316 on the platform 312. The acoustic transducers 366 are operably connected to amplifiers 368, which are further connected to the control unit 336.

[0032] System 300 also includes a profile database 370. Profile database 370 is a data storage configured to store a variety of different operational profiles, or recipes. An operational profile consists of stored data including operational parameters of various parts to be placed in system 300 for removal of unwanted material. Profile database 370 is operably connected to control unit 336. Profile database 370 may be located within housing 304 with control unit 336 or may be located at a remote location. Profile database 370 is configured to exchange data with control unit 336.

[0033] (operation) Figure 6 shows a flowchart of a process 400 performed by / in conjunction with the system 300 of Figure 5. In step 402, an object 314 manufactured by additive manufacturing and encased in unwanted material (e.g., powder) 316 is placed on a platform 312 within a chamber 302.

[0034] Solid abrasive media 356 is then placed on platform 312 and mixed or interspersed with parts 314 (step 404). At this point, door 308 to chamber 302 is closed.

[0035] If the system 300 is operating in an automatic mode, a profile can be selected (step 406). This step is optional. The profile can be selected using the user interface 342. The profiles are stored in the profile database 370. An appropriate profile can be selected based on matching parameters such as the type of material from which the parts are made, the quantity of parts in the chamber 302, the part dimensions, the part geometry, and the desired finishing characteristics. New profiles can also be generated from the characteristics and history of the finishing operation. Alternatively, the system 300 can be operated in a manual mode, with operating characteristics such as airflow, vibration frequency, amplitude, temperature, acoustic energy, duration, etc. selected by the operator via the user interface 342.

[0036] Based on the selected operating characteristics, one or more of the following steps are performed: A vibrating motion is applied to the platform 312 (step 408); a cyclone generator 360 is activated to create a cyclonic airflow within the chamber (step 410); and acoustic transducer(s) 366 are activated to create sound waves that impact the part 314 and the waste material 316 (step 414). The waste material 316 falls to the bottom of the chamber 302 and is discharged through a chute 344 and a discharge tube 346 (step 416). The part 324 is evaluated to determine the progress of the removal of the waste material 316 (step 418). This evaluation step can be performed periodically, intermittently, or continuously after any period of time. This evaluation step can be performed using input from a weigh scale 354, a camera 350, other sensors 352, direct visual observation, or other means. This evaluation step can be performed with the aid of software tools such as image recognition or machine vision programs that evaluate the progress of the removal of the waste material. These steps (steps 408, 410, 414, 416, 418) may be performed all at once, one or more at a time, in overlapping or non-overlapping stages, cyclically, on-off, intermittently, or according to any other scheme or routine.

[0037] Once sufficient waste material 316 has been removed, part 314 is removed from chamber 302 (step 420). Waste material 316 is discharged through discharge tube 346 and recycled or disposed of (step 422).

[0038] (Second Alternative Embodiment) 7A and 7B illustrate another alternative embodiment of a system 500 for removing unwanted material from additively manufactured parts. Referring to FIGS. 7A and 7B, a chamber 502 includes a vibratory platform 512. A part (not shown) to be cleaned (decake) can be placed on the vibratory platform 512. The vibratory platform 512 is attached to a slidable tray 513 that allows the vibratory platform 512 to slide from a position outside the chamber 502 (shown in FIG. 7A ) to a position inside the chamber 502 (shown in FIG. 7B ). The slidable tray 513 allows the vibratory platform 512 to slide to a position outside the chamber 502, facilitating the placement of parts on the vibratory platform 512 and inspection of the parts to assess progress in removing unwanted material. This allows an operator to remove finished parts, leaving other parts that require further processing on the platform 512, and adding more parts if space is available on the platform 512. In Figures 7A and 7B, unwanted material removed from the additively manufactured part falls from the vibrating platform 512 into a lower chamber portion 508. The lower chamber portion 508 is mounted on a slidable tray 509 that allows the lower chamber portion 508 to slide from a position outside the chamber 502 (shown in Figure 7A) to a position inside the chamber 502 (shown in Figure 7B). The embodiment 500 shown in Figures 7A and 7B also includes a glove port 511 for use with gloves (not shown). The gloves allow an operator to inspect and trim the part on the platform 512 (via a sight glass, not shown) without opening the chamber 502. The embodiment of system 500 in Figures 7A and 7B can operate in a manner similar to system 200 shown in Figures 1, 2, and 4 or system 300 shown in Figure 5.

[0039] (Third Alternative Embodiment) 9 and 10 illustrate another alternative embodiment. Figures 9 and 10 show a system 600 for removing powder from an additively manufactured object. System 600 removes powder from a 3D printed object using a method similar to other embodiments disclosed herein. System 600 includes additional components and features, such as features that facilitate handling of the powder-encased object and removal of the object from the 3D printer that produced it.

[0040] System 600 includes a housing 602 having multiple compartments and chambers, as described below. System 600 includes a control panel 601. Control panel 601 is located on one side of housing 602 in enclosure 603, or control panel 601 can be located in some other convenient location on or within housing 602. Control panel 601 includes a user interface. The user interface allows an operator to input instructions, commands, parameters, and other information into system 600, as well as receive information and other output from system 600. Control panel 601 is connected to a controller for system 600.

[0041] Figure 9 shows the housing 602 with the front panel removed. Within the housing 602 is a receiving area 604. The receiving area 604 has a size and dimensions that allow an interchangeable print frame 606 to be received therein. The interchangeable print frame 606 is a component used in 3D printers that use powder bed technology to manufacture objects. The interchangeable print frame 606 is a box-like structure consisting of an outer sidewall 607, an open top, and a movable platform 605 whose floor can move up and down vertically within the outer wall 607.

[0042] In a powder bed 3D printer, an object is printed one layer at a time within a print frame. In the 3D printer, a layer of powder is spread on the platform 605, with the platform 605 in an upright position relative to the outer sidewall 607. An energy beam (e.g., laser, ultraviolet light, electrons, etc.) is applied to the layer of powder, fusing the powder and forming a layer of the object. The movable platform 605 is then lowered slightly relative to the outer sidewall 607, and a new layer of powder is spread on the movable platform 605. The beam is applied to the new layer of powder, forming a new layer of the object. This process is repeated to form the entire object. Depending on the size of the object being printed, multiple objects can be printed simultaneously within the interchangeable print frame 606. At the end of printing, the movable platform 605 is in a bottom position within the interchangeable print frame 606, and the entire solid object formed is encased in unfused powder within the interchangeable print frame 606.

[0043] In the system 600 of FIG. 9 , an interchangeable print frame 606 of a powder bed 3D printer is mounted in a receiving area 604. In this embodiment, the receiving area 604 includes a tray that can be pulled outward from the receiving area 604 to receive the interchangeable print frame 606. After the interchangeable print frame 606 is seated in the tray, the tray is pushed back into the receiving area 604. The interchangeable print frame 606 contains an object printed by the 3D printer as well as unfused powder that surrounds and encases the object. In this embodiment, the receiving area 604 has specific dimensions to accommodate the interchangeable print frame of a particular 3D printer. Alternatively, the receiving area 604 may have various dimensions to accommodate frame sizes for different printers. Alternatively, the receiving area 604 may have adjustable dimensions and be adjustable to accommodate various frame sizes for different printers. For example, a sealant (not shown) engages the interchangeable print frame 606 and provides an airtight seal around it.

[0044] Below the receiving area 604 is a cooling device 610. The cooling device 610 may be, for example, a radiator, and may receive a circulating fluid, such as chilled water or water from a facility water supply. The cooling device 610 serves to reduce the temperature of the powder and objects within the interchangeable print frame 606, if necessary. For example, the powder and objects within the interchangeable print frame 606 are preferably kept at about 100 degrees Celsius or less. One or more temperature sensors (not shown) located in the receiving area 602 may be used to measure the temperature of the powder and objects within the interchangeable print frame 606 in the receiving area 602.

[0045] Adjacent to the receiving area 604 is a processing chamber 620 (or parts bin). Above the receiving area 604 and the processing chamber 620 is a transfer chamber 618. The transfer chamber 618 extends horizontally above the receiving area 602 and the processing chamber 620. The bottom of the transfer chamber 618 has a first opening that leads to the receiving area 602 and a second opening that leads to the processing chamber 620.

[0046] A lift mechanism 624 is disposed below the receiving area 604. The lift mechanism 624 includes two components: an outer partial component 625 and an inner partial component 626. When the replaceable print frame 606 is within the receiving area 602, an upper end 627 of the outer partial component 625 engages with the outer wall 607 of the replaceable print frame 606. When the replaceable print frame 606 is within the receiving area 602, an upper end 628 of the inner partial component 626 engages with the movable platform 605 of the replaceable print frame 606. The lift mechanism 624 is operable to lift the replaceable print frame 606 toward the opening leading to the transfer chamber 618. Once the top of the interchangeable print frame 606 is flush with and sealed to the bottom of the transfer chamber 620, the outer partial component 625 stops raising the outer wall 607 of the interchangeable print frame 606, but the inner partial component 626 continues to raise the movable platform 605 of the interchangeable print frame 606, forcing all of the powder in the interchangeable print frame 606, as well as any print objects encased in powder, through the bottom opening and into the transfer chamber 618. The transfer chamber 618 and the receiving area 604 are connected by an airtight seal to prevent or minimize powder leakage when the lift mechanism 624 pushes the powder and objects up from the interchangeable print frame 606 into the transfer chamber 618.

[0047] Within transfer chamber 618 is a movable decoating wall panel 632. The movable decoating wall panel 632 is positioned at the end of transfer chamber 618 opposite processing chamber 620 until lift mechanism 624 forces the powder and objects into transfer chamber 618. The movable decoating wall panel 632 is operable to move horizontally through transfer chamber 618, forcing the powder and encased objects received from receiving area 604 horizontally through transfer chamber 618 toward an opening in the bottom of transfer chamber 618 that leads to processing chamber 620, causing the powder and encased objects to fall into processing chamber 620. For example, a seal (not shown) engages with decoating wall panel 632 and provides an airtight seal around its periphery.

[0048] An upper bellows 634 connects the transfer chamber 618 to the processing chamber 620. The upper bellows 634 allows relative motion between the transfer chamber 618 and the processing chamber 620 while forming an airtight seal between the two chambers.

[0049] The processing chamber 620 includes a processing platform 636. The processing platform 636 is located approximately midway between the top and bottom of the processing chamber 620. The processing platform 636 is configured to allow powder to pass through but not objects. Referring to FIG. 11 , the processing platform 636 in this embodiment is formed from multiple rods 640 that extend across the processing chamber 620. Each rod 640 has a diameter of approximately 6.35 millimeters (1 / 4 inch). The rods 640 are spaced apart to create a gap of approximately 3.17 millimeters (1 / 8 inch) between adjacent rods. The rods 640 are made of a durable material such as stainless steel. The rods 640 are fixed to the sides of the processing chamber 620. The movable wall panel 632 pushes the powder and any entrapped objects into the processing chamber 620, where they fall onto the processing platform 636.

[0050] 9, the floor 648 of the processing chamber 620 is provided with a discharge chute 652. The floor 648 of the processing chamber 620 slopes downward toward the discharge chute 652.

[0051] A powder collection box 656 is located below the discharge chute 652. A lower bellows 660 connects the discharge chute 652 to the powder collection box 656. The lower bellows 660 allows relative movement between the processing chamber 620 and the powder collection box 656 while forming an airtight seal between the processing chamber 620 and the powder collection box 656.

[0052] The processing chamber 620 rests on and is supported from the bottom by a number of springs 664 (only one of which is shown). The springs 664 allow movement or vibration of the processing chamber 620. For example, the springs 664 allow the processing chamber 620 to move up and down vertically.

[0053] A driver (or shaker) 670 is connected to the bottom of the processing chamber 620. The driver 670 is a device having an output shaft that moves up and down at a selectable speed, frequency, and amplitude. The connection of the driver 670 to the processing chamber 620 is fixed such that the driver 670 can move the processing chamber 620 up and down at a selectable speed, frequency, and amplitude. A cooling device (not shown), such as a fan, is associated with the driver 670 to reduce or prevent overheating.

[0054] System 600 is operable to accept an entire interchangeable printer frame containing a 3D printed object still encased in powder and automatically deposit the powder and encased object from the interchangeable printer frame into a processing chamber, thereby removing the powder from the object. Embodiments of system 600 allow for recovery of much or all of the unfused powder with minimal or no operator intervention.

[0055] Once the powder and the object encased in the powder (and possibly the abrasive material) are placed on the processing platform 636 in the processing chamber 620, the driver 670 is actuated to move (i.e., reciprocate or vibrate) the entire processing chamber 620. As described in connection with other embodiments, the operating parameters, i.e., the frequency, amplitude, and duration of the vibration, are selectable. Selection of appropriate operating parameters, including the frequency, amplitude, and duration of the vibration, is based on factors including efficient removal of the powder, reduced damage to the object, and the amount of powder to be removed. Selection of appropriate frequency, amplitude, and duration of the vibration takes into account information and parameters about the powder and the object encased in the powder, including the size of the object, the thickness of the object, the material composition of the object, the inner and outer surfaces, internal passages, and other factors. For example, the information and parameters about the object are obtained from a design file used by the 3D printer to manufacture the object. In this embodiment, the information and parameters about the object in the design file are used to select appropriate operating parameters (including the frequency, amplitude, and duration of the vibration) for powder removal from the object in the processing chamber 620. One or more cycles, each having a different combination of operating parameters, can be determined. The use of the design file information to select appropriate operating parameters with respect to frequency, amplitude, and duration of vibration in the processing chamber 620 may be performed automatically by a software program in the system 600, or the use of the design file information to select appropriate operating parameters with respect to frequency, amplitude, and duration of vibration in the processing chamber 620 may be performed manually, by an operator, or by reference to a pre-stored recipe or profile.

[0056] For example, the process chamber 620 may be vibrated at an infrasonic frequency. Other higher or lower frequencies may be used, including audio or ultrasonic frequencies. For example, the process chamber 620 may be vibrated at a frequency between 10 and 500 hertz. The magnitude of the displacement of the process chamber 620 during vibration is related to the frequency and acceleration. For example, the displacement may be approximately 0.75 inches (2 centimeters).

[0057] The operating parameters, including, for example, frequency, amplitude, and duration, are selected to impart an acceleration of greater than 1 g to the processing chamber 620. For example, the operating parameters are selected to impart an acceleration of greater than 2 g to the processing chamber 620 in a sinusoidal motion. When the processing chamber 620 is vibrated at an acceleration greater than 1 g, objects and powder (falling at 1 g) within the processing chamber 620 are lifted above the processing platform 636 while the processing chamber 620 accelerates downward. When the processing chamber 620 reverses direction and begins to accelerate upward, collisions occur between the upwardly moving processing platform 636 and powder or objects falling downward toward the processing platform 636. These collisions help to shake the powder off the objects. Similarly, if there are de-powdered objects on the upwardly moving processing platform 636, collisions occur between these de-powdered objects and powder or objects falling from above the de-powdered objects on the processing platform 636. These collisions also help to shake the powder off the objects.

[0058] For example, the operating parameters selected and applied to the processing chamber 620 (i.e., frequency, amplitude, and duration of vibration) are chosen to resonate objects encased in powder. The objects encased in powder may have a different resonant frequency than the powder encasing the objects. When the processing chamber 620 is vibrated at a frequency that causes the objects to resonate, the objects vibrate (i.e., move) relative to the powder encasing them. This process facilitates powder removal from the objects. This process also facilitates powder removal from internal passages provided within the objects.

[0059] The time required to depowder an object in the print frame varies depending on the size of the object, the shape of the object, the temperature, and various other factors, for example, run times ranging from about 1 minute to about 1 hour.

[0060] As the processing chamber 620 is vibrated, the powder removed from the object falls through the gaps between the rods 640 of the processing platform 636 and into the discharge chute 652 at the bottom of the processing chamber 620, where it collects in a powder collection bin 656. The powder collection bin 656 is removable, so that the full powder collection bin 656 can be removed at the end of the powder removal operation. If necessary, a forklift or other suitable lifting mechanism can be used. The powder collected in the powder collection bin 656 can be recycled or disposed of appropriately.

[0061] The system 600 includes a ventilation system (e.g., air circulation). The ventilation system is designed to reduce or prevent air or powder from escaping from within the housing 602. The ventilation system maintains a lower pressure within the housing than the atmospheric pressure outside the housing 602. Within the housing 602, an air intake 680 is located immediately adjacent to the location of the cooling device 610, as shown in FIG. 10 . An air filter (not shown) is located immediately behind the air intake 680. The system 600 includes first and second exhaust stacks 684, 688 connected to and extending from the top of the housing 602. One or more air filters (not shown) are located in line with each exhaust stack 684, 688. The ventilation system includes one or more fans 682 (shown in FIG. 9 ) associated with the exhaust stacks 684, 688. The fan 682 draws air into the housing 602 through the air intake 680 and expels air from the housing 602 through the first and second exhaust stacks 684, 688. The doors and panels of the housing 602 are airtight and have airtight seals that restrict or prevent air from entering or leaving the housing except through the air intake 680 and exhaust stacks 684, 688.

[0062] 10, housing 602 includes a sight glass 690. Sight glass 690 is located adjacent to transfer chamber 618. Sight glass 690 allows an operator to view the contents of transfer chamber 618 as well as look into processing chamber 620. A light fixture 692 (shown in FIG. 9) is located within transfer chamber 618 to aid in viewing the interior of transfer chamber 618 and processing chamber 620 through sight glass 690.

[0063] System 600 includes one or more cameras 700, 702 disposed within housing 602. More specifically, cameras 700, 702 are disposed within transfer chamber 618. One of the cameras 700 faces toward the receiving area of ​​transfer chamber 618. The other camera 702 faces downward toward processing chamber 620. The outputs of cameras 700, 702 are provided to control panel 601, allowing video from the cameras to be viewed. The outputs of cameras 700, 702 can also be stored as data files for later review and analysis.

[0064] An embodiment of the system 600 includes sound-insulating material. The processing chamber 620 is capable of operating at audible frequencies. Sound-insulating material can be attached to line the interior surfaces of the panels that make up the housing 602 to reduce the noise level outside the system 600 during operation.

[0065] The housing 602 and the interior compartments and chambers (including the receiving area 604, transfer chamber 618, processing chamber 620, and powder collection box 656) are made from a durable, hard, non-reactive material such as steel, powder-coated steel, stainless steel, aluminum, or high-strength plastic.

[0066] System 600 includes various sensors used to monitor system operation and ensure proper operation of the system and its components. One accelerometer is associated with driver 670, and another with processing chamber 620 to measure and detect movement of these components. One or more temperature sensors (e.g., thermocouples, infrared sensors, etc.) are associated with transfer chamber 618, cooling device 610, driver 670, and powder collection box 656. Sound sensors are located inside and / or outside of housing 602 to detect noise levels. Differential pressure sensors are located upstream and downstream of the filter to detect blockages, for example. Motion or displacement sensors are associated with door panels to detect occlusions. One or more particle sensors can be located inside housing 602 to detect possible powder leakage from processing chamber 620. System 600 can include other sensors in addition to those listed above. The sensors send their outputs to a controller for system 600.

[0067] The system 600 has several advantages. One advantage of system 600 is provided by the processing platform 636. As described above and shown in FIG. 11 , processing platform 636 is formed from multiple rods 640 that extend across processing chamber 620. Processing platform 636 allows powder shaken off objects to pass through gaps between rods 640 and fall to the bottom of processing chamber 620, while preventing the de-powdered objects from passing through. Rods 640 have relatively low friction in the horizontal direction, allowing objects to move horizontally along the rods 640 across processing platform 636. Gaps that allow objects to move horizontally along processing platform 636 are preferable to grids with small holes, because objects can get trapped in the holes and clog them, potentially damaging the object. However, rods with gaps between them allow objects to slide horizontally, which prevents the gaps from clogging and reduces the chance of damage to the object.

[0068] Another advantage of the embodiment of system 600 of Figures 9 and 10 is its ability to handle large output volumes from powder bed 3D printers. System 600 can simultaneously remove powder from all objects in an interchangeable print frame in one run. Such frames can weigh up to approximately 90 kilograms (200 pounds).

[0069] Another advantage of the system 600 of Figures 9 and 10 is that it reduces the handling of objects coming out of the 3D printer. In system 600, the entire print frame containing the object and unfused powder is mounted in the receiving area, eliminating the need for an operator to remove the powder and object from the print frame. Powder and object removal occurs inside the housing of system 600, which reduces the amount of powder that leaks and increases the amount of powder that can be recovered or recycled.

[0070] (Other alternatives) In one of the above embodiments, a solid abrasive media is described as being placed on the vibration platform along with the part to be cleaned or finished. In another embodiment, the part can be cleaned or finished without the addition of a solid abrasive media. In this alternative, the part to be cleaned or finished is placed on the vibration platform, and the vibration platform is vibrated for a predetermined period of time. This alternative may be suitable for certain parts, such as particularly delicate parts.

[0071] In the embodiments described above, the system operates without utilizing other material removal techniques. In other embodiments, systems that utilize a vibratory platform to remove unwanted material may utilize other techniques to supplement, enhance, or complement the removal of unwanted material. These other techniques may include the use of acoustic energy, pressurized sprays (liquid, solid, or gas), or chemicals such as cleaning agents. These other techniques may be incorporated into the same system or chamber that contains the vibratory platform, or may be located in a separate chamber adjacent to or in-line with the chamber that contains the vibratory platform.

[0072] In the embodiments of Figures 2, 5, 7A, and 7B, the vibrating platform is solid. In other embodiments, the vibrating platform has holes through which unwanted material that separates from the part falls to the bottom of the chamber. The holes can be of any suitable size and type, including, but not limited to, a mesh structure. Instead of holes, the platform can be made of other structures that allow material that separates from the part to fall to the bottom of the chamber.

[0073] In the above-described embodiments, removal of unwanted material from the AM object can be performed at room temperature. In other embodiments, heat is applied in combination with a vibration platform to facilitate removal of unwanted material from the AM part. A heating element can be provided in the chamber of the system to apply heat to facilitate removal of unwanted material from the AM part. The heating element can be operated under the control of a control unit. Alternatively, the heating element can be operated based on input provided by a user via a user interface. In yet another embodiment, the system can include a cooling element that cools or chills the air in the chamber during the material removal process. The cooling element can be operated under the control of a control unit based on information stored in a profile or based on input provided by a user via a user interface. In a further alternative, the system can include both a heating element and a cooling element.

[0074] In various different embodiments, different types of vibrations, different types of waveforms, different wave frequencies, and different wave amplitudes can be applied to the vibrating platform. Different types of waveforms can include sine waves, square waves, sawtooth waves, etc. Alternatively, multiple different vibrations, multiple different waveforms, multiple different amplitudes, multiple different wave frequencies, or combinations thereof can be applied simultaneously to the components in the chamber. When different vibrations, waveforms, amplitudes, or frequencies are applied, the different vibrations, waveforms, amplitudes, or frequencies can be applied from the same vibrating platform. The frequencies applied to the vibrating platform can be in the audio range, ultrasonic range, or other ranges.

[0075] In some of the above-described embodiments, the interior of the chamber is maintained at atmospheric pressure. Alternatively, the chamber can be maintained at a pressure above or below atmospheric pressure, including near vacuum pressure. Alternatively, the pressure within the chamber can be varied during the material removal process. The pressure changes and the timing of the changes can be defined by a profile.

[0076] In the above-described embodiments, the motion profile was selected by the user. Alternatively, the user may manually define some or all of the motion parameters. Alternatively, the motion parameters may be specified by an entity performing the 3D printing portion of the additive manufacturing process.

[0077] In another alternative, the system automatically measures the progress of material removal during removal of unwanted material and automatically adjusts operating parameters to improve or complete the removal process. This alternative can employ AUTOMAT3D® technology developed by Post Process Technologies, Inc. An embodiment of this technology is disclosed in co-pending patent application US20190315065, the disclosure of which is incorporated by reference in its entirety. Sensors within the chamber measure the progress of the material removal process and feed this information back into the digital file used to modify or adjust operating parameters.

[0078] In yet another alternative, the waste material removal system is part of an overall additive manufacturing system, including both the object formation and waste material removal components. According to this alternative, the design file (e.g., a CAD file) for object formation and the motion profile for material removal are part of an overall design file that forms the object and removes waste material. In this alternative, object formation and waste material removal are planned together for overall optimization and efficiency of object manufacturing. One alternative is the CONNECT3D® technology developed by Post Process Technologies, Inc. An embodiment of this technology is disclosed in co-pending patent application US20190275745, the entire disclosure of which is incorporated by reference. In an automated embodiment, the material removal process can be performed without user input, i.e., in a closed loop. Furthermore, in an embodiment of the overall additive manufacturing system, the object can be placed on a conveyor and moved by a robotic arm or other means from where the object is formed to another location where vibrational energy is applied to remove the waste material. In yet another embodiment, vibrational energy is applied to remove the waste material from the additively manufactured object in the same location (e.g., chamber) where the object is formed.

[0079] In some embodiments, the inner walls of the chamber are anechoic or otherwise configured to enhance / not impair the delivery of energy to the object(s) and materials on the platform.

[0080] The vibration platform can be vibrated at a variety of frequencies, such as 75 to 135 Hz, 35 to 135 Hz, or 10 to 500 Hz. Other frequencies are also possible. The platform can vibrate continuously or intermittently, for example, to facilitate powder removal. The platform movement can be defined by a motion profile.

[0081] In the above-described embodiment, the medium in the chamber is air, but other gaseous or liquid fluid media may be used in the chamber.

[0082] In another alternative embodiment, the platform rotates, i.e., is a rotating turntable.

[0083] <Advantages> The disclosed embodiments have several advantages. One advantage is that unwanted material can be easily recycled. Compared to material removal systems that use liquid sprays, the disclosed embodiments allow for relatively easy recovery of removed material for recycling. Compared to material removal systems that use liquid sprays, the disclosed embodiments do not require filtering of the liquid after spraying for reuse, recovery or recycling of the liquid, and / or recycling of the removed material. Compared to material removal systems that use the action of chemicals, the disclosed embodiments have the advantage that unwanted material is removed from the additively manufactured object without contacting the object with chemicals. Compared to material removal systems that use the action of chemicals, the disclosed embodiments also avoid the costs (including disposal costs) of such chemicals.

[0084] In accordance with 37 CFR § 1.72(b), an Abstract has been prepared and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Moreover, in the foregoing Detailed Description, various features have been grouped together or described in a single embodiment for the purpose of brevity of the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter is directed to some of the features of any disclosed embodiment. Thus, the following claims are incorporated into the Detailed Description, with each claim standing on its own merits, defining separately claimed subject matter.

[0085] The foregoing detailed description should be understood as illustrative rather than restrictive, and the following claims, including all equivalents, are intended to define the scope of this disclosure. The claims should not be construed as limited to the order or elements described unless expressly stated. Accordingly, all embodiments that come within the scope and spirit of the following claims, and equivalents thereof, are intended to be disclosed.

Claims

1. A system for removing unwanted material from an additively manufactured part, comprising: a processing chamber; a platform mounted within the processing chamber and having a vibration region configured to operably place the additively manufactured part from which the unwanted material is to be removed; and an actuator connected to a vibration portion, the vibration portion operable to vibrate the vibration area to bounce the additively manufactured part placed on the vibration area, thereby removing unwanted material around the additively manufactured part; A system in which at least a portion of the platform is separated from an inner wall defining an interior portion of the processing chamber by a gap, allowing the unwanted material to fall through the gap to the bottom of the processing chamber, and the gap is narrow enough to prevent the additively manufactured part placed on the platform from passing through.

2. A system for removing unwanted material from an additively manufactured part, comprising: a processing chamber; a platform mounted within the processing chamber and having a vibration region configured to operably place the additively manufactured part from which the unwanted material is to be removed; and an actuator connected to a vibration portion, the vibration portion operable to vibrate the vibration area to bounce the additively manufactured part placed on the vibration area; A system in which different motions are imparted to the additively manufactured part and the unwanted material on the vibration region, such that unwanted material around the additively manufactured part is separated from the additively manufactured part.

3. A system for removing unwanted material from an additively manufactured part, comprising: a processing chamber; a platform mounted within the processing chamber and having a vibration region configured to operably place the additively manufactured part from which the unwanted material is to be removed; and an actuator connected to a vibration portion, the vibration portion operable to vibrate the vibration area to bounce the additively manufactured part placed on the vibration area, thereby removing unwanted material around the additively manufactured part; The platform is comprised of a plurality of rods, each rod spaced apart from adjacent rods, the spacing between adjacent rods being small enough to prevent the additively manufactured part from passing through.

4. 3. The system of claim 2, further comprising a ventilation system that circulates air past the additively manufactured part above the vibration region to facilitate removal of unwanted material.

5. The system of claim 2 , further comprising a discharge for removing the unwanted material from the processing chamber after the unwanted material has been removed from the additively manufactured part.

6. 3. The system of claim 2, further comprising an acoustic transducer disposed within the processing chamber and operatively configured to direct acoustic energy waves at the additively manufactured part to facilitate removal of the unwanted material.

7. 3. The system of claim 2, further comprising at least one camera positioned and operatively configured to capture images of the additively manufactured part and the unwanted material within the processing chamber.

8. 3. The system of claim 2, further comprising a sight glass disposed in a wall of the processing chamber.

9. The system of claim 2 further comprising a glove port disposed in a wall of the processing chamber.

10. 1. A system for removing unwanted material from an additively manufactured part, comprising: a receiving area sized to receive an interchangeable print frame therein that contains the additively manufactured part encased in the waste material, the print frame being used in an additive manufacturing printer to print the additively manufactured part; a transfer chamber in receiving relationship with the receiving area for receiving the additive manufactured part and the waste material therefrom, the transfer chamber conveying the additive manufactured part and the waste material to a processing chamber; the processing chamber receiving the additively manufactured part and the waste material from the transfer chamber; a platform mounted within the processing chamber and having a vibration region configured to operably place the additively manufactured part from which the unwanted material is to be removed; and an actuator that applies vibration to the vibration region, The system includes an actuator that vibrates the vibration region, thereby removing unwanted material around the additively manufactured part.

11. 11. The system of claim 10, further comprising a powder collection bin positioned below the processing chamber into which unwanted material falls after being removed from the additively manufactured part.

12. 11. The system of claim 10, wherein the additive manufacturing printer uses selective laser sintering, electron beam melting, multi-jet fusion, or powder bed fusion to manufacture parts.

13. A method for removing unwanted material from an additively manufactured part, receiving an exchangeable print frame containing the additively manufactured part encased in the unwanted material into a receiving area in a housing, wherein the print frame is used in an additive manufacturing printer to print the additively manufactured part; ejecting the additively manufactured part encased in the unwanted material from within the print frame into a transfer chamber within the housing; pushing the additively manufactured part encased in the unwanted material within the transfer chamber onto a platform within a processing chamber within a housing; vibrating at least a region of the platform to separate unwanted material from the additively manufactured part.

14. The method of claim 13 , further comprising applying a solid abrasive medium to the additively manufactured part on the platform.

15. 14. The method of claim 13, wherein the platform is vibrated at a frequency of 10 to 500 hertz.

16. The method of claim 13 , further comprising creating a cyclonic airflow within the processing chamber to facilitate removal of the unwanted material from the additively manufactured part.

17. The method of claim 13 further comprising removing the unwanted material from the processing chamber.

18. The method of claim 13 , wherein the region of the platform is vibrated at a frequency at which either the additively manufactured part or the unwanted material resonates.

19. 14. The method of claim 13, wherein the additively manufactured part is manufactured by selective laser sintering, electron beam melting, multi-jet fusion, or powder bed fusion.

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