WO2022203669A1 - Removing particulate material from an object - Google Patents

Removing particulate material from an object Download PDF

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Publication number
WO2022203669A1
WO2022203669A1 PCT/US2021/023933 US2021023933W WO2022203669A1 WO 2022203669 A1 WO2022203669 A1 WO 2022203669A1 US 2021023933 W US2021023933 W US 2021023933W WO 2022203669 A1 WO2022203669 A1 WO 2022203669A1
Authority
WO
WIPO (PCT)
Prior art keywords
cleaning
particulate material
green part
platform
controller
Prior art date
Application number
PCT/US2021/023933
Other languages
French (fr)
Inventor
Jorge DIOSDADO BORREGO
David CHANCLON FERNANDEZ
Fernando VICIANO MARTIN
Original Assignee
Hewlett-Packard Development Company, L.P.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hewlett-Packard Development Company, L.P. filed Critical Hewlett-Packard Development Company, L.P.
Priority to PCT/US2021/023933 priority Critical patent/WO2022203669A1/en
Publication of WO2022203669A1 publication Critical patent/WO2022203669A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
    • B33Y40/20—Post-treatment, e.g. curing, coating or polishing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B5/00—Cleaning by methods involving the use of air flow or gas flow
    • B08B5/02—Cleaning by the force of jets, e.g. blowing-out cavities
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/10—Formation of a green body
    • B22F10/14—Formation of a green body by jetting of binder onto a bed of metal powder
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/60—Treatment of workpieces or articles after build-up
    • B22F10/68—Cleaning or washing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F12/00—Apparatus or devices specially adapted for additive manufacturing; Auxiliary means for additive manufacturing; Combinations of additive manufacturing apparatus or devices with other processing apparatus or devices
    • B22F12/80—Plants, production lines or modules
    • B22F12/88—Handling of additively manufactured products, e.g. by robots
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • B22F2998/10—Processes characterised by the sequence of their steps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2999/00—Aspects linked to processes or compositions used in powder metallurgy
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y10/00—Processes of additive manufacturing
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C2202/00—Physical properties
    • C22C2202/02—Magnetic

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Robotics (AREA)

Abstract

According to one aspect, there is provided a method of removing non-bound particulate material from a 3D printed object formed from a magnetically attractable particulate material. The method comprises magnetically securing the object to a cleaning platform using an electromagnet, and removing non-bound particulate build material from the object.

Description

REMOVING PARTICULATE MATERIAL FROM AN OBJECT
BACKGROUND
[0001] Powder-based three-dimensional (3D) printing systems generate 3D objects through the selective solidification of successively formed layers of a particulate build material in a build chamber. The collection of formed layers within the build chamber is referred to as the build bed.
[0002] Binder jet systems are a type of 3D printing systems that form 3D objects by printing a liquid binder agent on each formed layer of build material in a pattern corresponding to the cross-section of the object to be generated. In some such systems a metal particulate build material is used and the binder agent is cured after printing to generate a relatively weakly bound object commonly referred to as a green part. After the printing and curing process, the green part is effectively buried within the build bed, surrounded by non-solidified build material.
[0003] After generation, a green part has to be removed or separated from the build bed and be thoroughly cleaned, such that it is consists of only build material that is intended to form part of the object. After cleaning the green part is sintered in a furnace to generate a highly dense final object.
BRIEF DESCRIPTION
[0004] Examples will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
[0005] Figure 1 is a schematic diagram of a cleaning module according to an example;
[0006] Figure 2 is a flow diagram outlining a method of operating a cleaning module according to an example; and
[0007] Figure 3 is a flow diagram outlining a method of operating a cleaning module according to an example.
DETAILED DESCRIPTION
[0008] When a green part is removed or is separated from a build bed it will, inevitably, have some amount of non-solidified build material stuck to the surface. Depending on the geometry and orientation of the green part, larger volumes of non-solidified build material may additionally accumulate in some areas. Furthermore, binder agent components, such as solvents, may leech or migrate from where binder agent is printed and cause some generally weak consolidation of build material which may adhere to the green part. Such consolidated build material will, however, be more weakly bound together than the build material forming the green part. However, green parts have to be well cleaned prior to being sintered to ensure that the final object geometry closely matches the intended geometry of the final sintered object.
[0009] Cleaning of green parts is, however, a relatively complex process due to the generally relatively weak bonding of the build material that is provided by the binder agent. Cleaning of green parts may be performed, for example, by placing green parts within a cleaning chamber and using a fluid cleaning process, such as use of air streams, to remove non-solidified build material. If a cleaning process is too powerful the green part may be damaged by the air stream. Furthermore, objects may move under the force of an air stream and may be damaged, for example through collision with the surfaces of the cleaning chamber, or through collision with other objects within the cleaning chamber.
[0010] Referring now to Figure 1 there is provided a cleaning module 100 according to an example to provide effective and safe cleaning of green parts that are formed from particulate build materials that are magnetically attractable, or that include magnetically attractable material, that further aims to reduce damage caused through movement of green parts during a cleaning operation. Examples of such materials include particulate stainless steel 17-4, copper, and tungsten materials.
[0011] The cleaning module 100 comprises a cleaning chamber 102. The cleaning chamber 102 is formed from a set of walls 104 that in one example form a closed, or a substantially closed, cuboidal-shaped chamber. The set of walls may include a top wall, or ceiling, and a base. The cleaning module 100 further comprises a cleaning platform 106 on which green parts, such as green part 108, may be positioned prior to a cleaning process starting. In one example, the cleaning platform 106 is an apertured plate to allow air to flow through the apertures in the plate although in other examples the cleaning platform 106 may be formed from a solid plate. [0012] The cleaning module 100 further comprises an electromagnet 110 that may be controlled to magnetically secure the object 108 to the cleaning platform 106. In one example, the electromagnet 110 is separate from and positioned below the cleaning platform 106, although in other examples it may be positioned in any other suitable position. In another example, the electromagnet 110 may be integrated within the cleaning platform 106. The magnetic force generated by the electromagnet 110 may be dimensioned in such a way as to securely attach green parts to the cleaning platform 106 such that they do not unduly move during a cleaning operation. The electromagnet 110 may be powered by a controllable power supply (not shown) that enables the magnetic force exerted thereby to be varied.
[0013] The cleaning module 100 further comprises a cleaning member 112. In one example the cleaning member 112 comprises, or may be coupled to, an air (or gas) stream generator. The air stream exits the cleaning member 112 through a suitable output port which may take the form of a nozzle, an air-knife, or the like. In other examples the cleaning member 112 may comprise or may include other cleaning elements such as brushing or wiping elements. In the example shown, the cleaning member 112 generates a cleaning air stream 114 that is directable to the green part 108 to clean the green part 108. In one example, the cleaning member 112 and/or the cleaning air stream 114 may be movable relative to the green part 108.
[0014] Although not shown in Figure 1 , the cleaning module 100 may comprise a suitable build material removal airflow, or other suitable mechanism, through which build material removed during cleaning of the green part 108 is removed from the cleaning chamber 102.
[0015] The cleaning module 100 further comprises a controller 120, such as a microprocessor or micro-controller, that is coupled to a memory 122. On the memory 122 are stored controlled understandable instructions 124 that, when executed, cause the controller 120 to control elements of the cleaning module 100 to magnetically secure a green part to the cleaning platform 106 during a cleaning process. [0016] Example operation of the cleaning module 100 will now be described in detail with additional reference to the flow diagram of Figure 2.
[0017] The cleaning process starts when a green part is positioned on the cleaning platform 106. Depending on the particular system, this may be performed manually or by a robotic or other suitable automated system.
[0018] At block 202, the controller 120 controls the electromagnet 110 to exert a magnetic force. This may be achieved, for example, by controlling a power supply to supply a predetermined current to the electromagnet 110. In one example the controller 120 may vary the magnetic force exerted by the electromagnet, for example based on characteristics, such the nature of the build material, the size, etc. of the green part 108.
[0019] The exerted magnetic force attracts the green part 108 towards the electromagnet 110, and thereby exerts a holding force on the cleaning platform 106 to securely hold the green part in place. This helps prevent the green part from moving, and thus becoming damaged, during a subsequent cleaning process. It will be understood, however, that the system described herein is only suitable for use with green parts that are magnetically attracted to a magnetic force. The force exerted by the electromagnet 110 should be set to be a force suitable to substantially prevent the green part 108 from moving, whilst at the same time not being so strong as to cause damage to the green part. A suitable force can be easily determined through appropriate testing, and will depend at least in part of the type of build material used to generate the green part and on the strength of particulate bonding due to the binder agent.
[0020] At block 204, the controller 120 controls the cleaning member 112 to clean the green part 108, for example by controlling it to apply a cleaning air flow 114. The cleaning air flow 114 removes non-solidified powder not forming part of the green part. In one example the orientation and the force of the cleaning air flow 114 may be controlled by the controller 120. In one example the relative position between the cleaning member 112 and the green part 108 may be controlled by the controller 120, for example, by controlling the position of the cleaning member 112, the position of the cleaning platform 106, the orientation of the air flow 114, or any combination thereof. [0021] At block 206, the controller 120 determines whether the cleaning process has completed. In one example this is determined when the cleaning process has been performed for a predetermined time period, or for a predetermined number of cleaning cycles. A cleaning cycle may, for example, comprise a set of predetermined cleaning steps. In another example, a vision system (not shown) may be used to determine when the green part has been suitable cleaned. In another example, a build material extraction system (not shown) may be used to extract build material removed from the green part 108 by cleaning member 112 and may determine when the rate of removal of build material is below a predetermined threshold. When the controller 120 determines that the cleaning process is complete stops the cleaning process.
[0022] At block 208, the controller 120 disactivates the electromagnet 110 to release the holding force exerted thereby on the green part 108. The cleaned green part 108 may then be removed from the cleaning chamber 102 and be sintered in a sintering furnace to form a final object. Depending on the geometry of the green part the orientation of the green part on the cleaning platform 106 may be changed and a further cleaning cycle performed to remove build material from portions of the green part that were not adequately cleaned in the first cleaning cycle.
[0023] A further example of operation of the cleaning module 100 will now be described in detail with additional reference to the flow diagram of Figure 3. [0024] As before, the cleaning process starts when a green part is position on the cleaning platform 106. Depending on the particular system, this may be performed manually or by a robotic or other suitable automated system.
[0025] At block 302, the controller 120 controls the electromagnet 110, as described above, to exert a magnetic force and to secure the green part 108 to the cleaning platform 106.
[0026] At block 304, the controller 120 controls the cleaning member 112 to perform a cleaning process on the green part, for example as described above. However, in this example the controller 120 stops the cleaning process after a predetermined time, such as after 10 seconds, after 30 seconds, after 1 minute, after 5 minutes, or after 10 minutes. This is because it has been observed during testing that at least a portion of the build material removed from the green part 108 during cleaning may become attracted to the magnetic force generated by the electromagnet 110 and may accumulate around the base of the green part 108 and on the cleaning platform 106. This accumulation of build material prevents effective cleaning of the green part.
[0027] Once the cleaning process has been stopped, at block 306 the controller 120 deactivates electromagnet 110 which unsecures the green part from the cleaning platform 106, and further releases any accumulated build material that was magnetically attracted to the base of the green part or the cleaning platform 106. If the cleaning platform 106 is an apertured plate some of the accumulated build material may fall through the apertures.
[0028] At block 308, the controller 120 may control elements of the cleaning system 100, such as the cleaning member 112 and a build material extraction system (not shown) remove at least a portion of the accumulate build material. Since the green part 108 is no longer magnetically secured to the cleaning platform 106 the controller controls the cleaning member 112 to operate with a relatively gentle cleaning action, such as a relatively low-powered air flow (compared to the power of the air flow used to remove non-bound particulate material from the green part) that may be not directly oriented toward the green part 108, to remove the accumulated build material without moving or damaging the green part 108. In one example the accumulated build material removal process may be performed for a predetermined period of time, such as 5 seconds, 10 seconds, 30 seconds, or 60 seconds. In one example, the cleaning platform 106 may be coupled to a vibrator element (not shown) to cause gentle vibrations to assist in removal and/or fluidization of accumulated build material.
[0029] At block 310, the controller 120 determines whether the cleaning process has completed, for example as described above. If the controller 120 determines that the cleaning process has not completed, the process of blocks 302 to 310 may be repeated until it is determined that the cleaning process has completed. In this way the controller 120 causes the cleaning module to perform a number of cleaning cycles, each cleaning cycle comprising a period during which the air stream removes non-bound particulate material from a green part magnetically secured to the cleaning platform, and a period during which the air stream removes accumulated particulate material from around the base of the green part whilst the green part is not magnetically secured to the cleaning platform.
[0030] In a further example, the determination of the completion of the cleaning process 310 may be performed during the cleaning process of block 304.
[0031] It will be appreciated that example described herein can be realized in the form of hardware, software or a combination of hardware and software. Accordingly, some examples provide a program comprising code for implementing a system or method as described herein and a machine-readable storage storing such a program.
[0032] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
[0033] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

Claims

1. Apparatus for cleaning green parts generated by 3D printing using a particulate material, the apparatus comprising: a cleaning chamber; a cleaning platform; a cleaning element; an electromagnet; a controller to: control the electromagnet to magnetically secure a green part in the cleaning chamber to the cleaning platform; and control the cleaning element to remove non-bound particulate material from the green part whilst it is magnetically secured to the cleaning platform.
2. The apparatus of claim 1 , wherein the cleaning element comprises an airstream generator to generate a cleaning airstream, and wherein the controller is to control the cleaning element to direct the airstream to a green part secured on the cleaning platform to remove non-bound particulate material from the green part.
3. The apparatus of claim 2, wherein the controller is to, after a predetermined period of time: control the cleaning element to stop directing an airstream to the green part; control the electromagnet to stop securing the green part to the cleaning platform; and control the cleaning element to direct the airstream to particulate material accumulated around the base of the green part and/or on the cleaning platform to remove the accumulated particulate material therefrom.
4. The apparatus of claim 3, wherein the controller is to control the airstream to remove particulate material accumulated around the base of the green part and/or the cleaning platform such that the airstream is less powerful than the airstream generated to remove non-bound particulate material from the green part.
5. The apparatus of claim 3, wherein after the predetermined period of time the controller is to control the electromagnet to magnetically secure the green part to the cleaning chamber; and control the cleaning element to continue removing non-bound particulate material from the secured green part whilst the green part is magnetically secured to the cleaning platform
6. The apparatus of claim 5, wherein the controller is to cause the cleaning module to perform a predetermined number of cycles, each cycle comprising a period during which the air stream removes non-bound particulate material from a green part magnetically secured to the cleaning platform, and a period during which the air stream removes accumulated particulate material from around the base of the green part whilst the green part is not magnetically secured to the cleaning platform.
7. The apparatus of claim 1 , further comprising a particulate material extraction system to remove particulate material removed by the cleaning element, and wherein the controller is to determine when to end the cleaning process by determining when the rate of removal of particulate material falls below a predetermined threshold.
8. The apparatus of claim 1 , wherein the electromagnet is integrated in the cleaning platform.
9. A method of removing non-bound particulate material from a 3D printed object formed from a magnetically attractable particulate material, comprising: magnetically securing the object to a cleaning platform using an electromagnet; and removing non-bound particulate build material from the object.
10. The method of claim 9, wherein removing non-bound particulate build material from the object comprises removing the non-bound particulate build material using an air stream.
11. The method of claim 9, further comprising: stopping removing non-bound particulate material from the object; removing the magnetic force generated by the electromagnet; and removing non-particulate material accumulated around the base of the green part and/or on the cleaning platform.
12. The method of claim 11, further comprising, repeating the steps of claim 11 to perform a predetermined number of cleaning cycles.
13. The method of claim 12, further comprising, determining when the cleaning process has completed by determining when a rate of removal of particulate material is below a threshold.
14. The method of claim 9, further comprising performing the removal of non bound particulate material within a substantially enclosed cleaning chamber.
PCT/US2021/023933 2021-03-24 2021-03-24 Removing particulate material from an object WO2022203669A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US2021/023933 WO2022203669A1 (en) 2021-03-24 2021-03-24 Removing particulate material from an object

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2021/023933 WO2022203669A1 (en) 2021-03-24 2021-03-24 Removing particulate material from an object

Publications (1)

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WO2022203669A1 true WO2022203669A1 (en) 2022-09-29

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Application Number Title Priority Date Filing Date
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5387380A (en) * 1989-12-08 1995-02-07 Massachusetts Institute Of Technology Three-dimensional printing techniques
US20080241404A1 (en) * 2005-09-20 2008-10-02 Sandrine Allaman Apparatus for Building a Three-Dimensional Article and a Method for Building a Three-Dimensional Article
CN107791360A (en) * 2017-10-20 2018-03-13 龙泉市金宏瓷业有限公司 A kind of composite ceramic 3D printer discharging controlling device
US10807162B2 (en) * 2016-09-15 2020-10-20 Mantle Inc. System and method for additive metal manufacturing

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5387380A (en) * 1989-12-08 1995-02-07 Massachusetts Institute Of Technology Three-dimensional printing techniques
US20080241404A1 (en) * 2005-09-20 2008-10-02 Sandrine Allaman Apparatus for Building a Three-Dimensional Article and a Method for Building a Three-Dimensional Article
US10807162B2 (en) * 2016-09-15 2020-10-20 Mantle Inc. System and method for additive metal manufacturing
CN107791360A (en) * 2017-10-20 2018-03-13 龙泉市金宏瓷业有限公司 A kind of composite ceramic 3D printer discharging controlling device

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