ADDITIVE MANUFACTURING

Abstract

The present invention relates to a system (100) for automatically processing an additively manufactured part. The system comprises an inspection module (120) for determining at least one part parameter associated with a surface finish quality of the part, a processing module (118) for processing a surface of the part responsive to the at least one part parameter and controller (102) configured to modify a processing parameter of a surface finishing process, performed by the processing module, based on the at least one part parameter determined by the inspection module.

Claims

1. A system for automatically processing an additively manufactured part, comprising: a support removal module for removing support material from the additively manufactured part; an inspection module for determining at least one part parameter associated with a surface finish quality of the additively manufactured part; a processing module for processing a surface of the additively manufactured part responsive to the at least one part parameter; at least one conveyor for locating the additively manufactured part in the support removal module and moving the additively manufactured part between the modules; and a controller configured to modify a processing parameter of a surface finishing process, performed by the processing module, based on the at least one part parameter determined by the inspection module.

2. The system according to claim 1, wherein the support removal module comprises a cooling chamber, and a sensor configured to monitor a temperature of the cooling chamber, and wherein the controller is configured to receive feedback from the sensor and produce an output for adjusting a print procedure of an additive manufacturing apparatus based on the feedback received from the sensor.

3. The system according to claim 1, wherein the controller is further configured to modify a support removal process parameter of a support removal process, performed by the support removal module, based on the at least one part parameter determined by the inspection module.

4. The system according to claim 1, wherein the inspection module is further configured to analyse the at least one part parameter after the surface of the additively manufactured part has been processed by the processing module, and wherein the controller is configured to further modify the or a processing parameter of the surface finishing process, performed by the processing module, based on the at least one part parameter determined by the inspection module after the surface of the additively manufactured part has been processed by the processing module.

5. The system according to claim 1, wherein the controller is configured to modify a processing parameter of a surface finishing process for processing a new part, based on the at least one part parameter determined by the inspection module.

6. The system according to claim 1, wherein the inspection module is an optical inspection module, and optionally wherein the inspection module is a non-contact optical inspection module.

7. The system according to claim 1, wherein the support removal apparatus comprises at least one de-powdering module to remove unprocessed support powder surrounding the additively manufactured part, and optionally wherein the at least one de-powdering module comprises a plurality of de-powdering modules each configured to remove a different grade of powder from the additively manufactured part.

8. The system according to claim 7, wherein the de-powdering module comprises a fluidising bed reactor and/or wherein the de-powdering module is configured to impart ultrasonic waves in a water-surfactant solution.

9. The system according to claim 1, wherein the inspection module is configured to optically determine a surface texture and/or roughness of the additively manufactured part.

10. The system according to claim 1, wherein the inspection module is configured to determine the at least one part parameter associated with a surface finish of the additively manufactured part whilst the additively manufactured part is being transported on the at least one conveyor.

11. The system according to claim 1, wherein the processing module is configured to smooth a surface of the additively manufactured part responsive to the at least one part parameter associated with a surface finish of the additively manufactured part.

12. The system according to claim 1, wherein the at least one conveyor comprises at least one conveyor belt for transporting the additively manufactured part from the support removal module to the processing module, and/or comprises at least one robotic arm.

13. A system for automatically processing an additively manufactured part, comprising: an inspection module for determining at least one part parameter associated with a surface finish quality of the additively manufactured part; a processing module for processing a surface of the additively manufactured part responsive to the at least one part parameter; and a controller configured to modify a processing parameter of a surface finishing process, performed by the processing module, based on the at least one part parameter determined by the inspection module.

14. A method of automatically processing an additively manufactured part, comprising: providing the additively manufactured part; by an inspection module, determining at least one part parameter associated with a surface finish of the additively manufactured part; by a controller, modifying a processing parameter of a surface finishing process, performed by a processing module, based on the at least one part parameter determined by the inspection module; and by the processing module, processing a surface of the additively manufactured part responsive to the at least one part parameter.

15. The method according to claim 14, further comprising the step of: by the controller, modifying a support removal process parameter of a support removal process, performed by a support removal module, based on the at least one part parameter determined by the inspection module; and by the support removal module, removing support material from the additively manufactured part.

16. The method according to claim 14, further comprising the steps of: by the inspection module, determining at least one part parameter associated with a surface finish of the additively manufactured part after the surface of the additively manufactured part has been processed by the processing module; and by the controller, modifying the or a processing parameter of the surface finishing process, performed by the processing module, based on the at least one part parameter determined by the inspection module after the surface of the additively manufactured part has been processed by the processing module.

17. The method according to claim 14, further comprising the steps of: by a cooling chamber, cooling the manufactured part; by a sensor, monitoring a temperature of the cooling chamber; and by the controller, receiving feedback from the sensor and producing an output for adjusting a print procedure of an additive manufacturing apparatus based on the feedback received from the sensor.

18. The method according to claim 14, comprising, by the inspection module, optically determining a surface texture and/or roughness of the additively manufactured part.

19. The method according to claim 14, comprising, by the processing module, smoothing a surface of the additively manufactured part responsive to the at least one part parameter associated with a surface finish of the additively manufactured part.

20. The method according to claim 14, comprising, by a controller, modifying a processing parameter of a surface finishing process for processing a new part, based on the at least one part parameter determined by the inspection module.

Description

DESCRIPTION OF THE DRAWINGS

[0195] Certain embodiments of the present invention will now be described with reference to the accompanying drawings in which:

[0196] FIG. 1 illustrates a digital manufacturing system according to certain embodiments of the present invention; and

[0197] FIG. 2 illustrates a digital manufacturing method according to certain embodiments of the present invention.

DETAILED DESCRIPTION

[0198] As illustrated in FIG. 1, a digital manufacturing system 100 includes a controller 102, e.g. a computer, connected by wire or wirelessly to one or more 3D printers 104 for additively manufacturing at least one AM part. The controller 102 is configured to receive data, for example CAD data, relating to the 3D part/s to be printed. The data, e.g. an STL file including part requirements (e.g. dimensional tolerances, geometrical tolerances, surface texture, surface roughness, and colour), is sent to the 3D printer/s via suitable 3D printer software. The 3D printer/s 104 may be the same or a combination of different AM printers from the same or different manufacturers each suitable for printing a 3D part using an AM technique, including Selective Laser Sintering (SLS), Multi Jet Fusion (MJF), High Speed Sintering (HSS), Fused Filament Fabrication or Fused Deposition Modelling (FFF/FDM) or Stereolithography (SLA), or the like.

[0199] A robotic system 106 is configured to retrieve one or more 3D printed powder blocks, including one or more AM parts therein, from at least one of the printers 104 and transport them to a support removal module 108.

[0200] The support removal module 108 includes a cooling chamber to cool down an as-printed powder cake of AM parts to a temperature suitable for de-powdering. The cooling chamber is aptly configured to control the temperature of the cooling chamber surfaces and interior, and aptly includes at least one thermocouple to monitor the ambient temperature within the cooling chamber.

[0201] A pump may be provided to flood the cooling chamber with an inert gas and a vacuum pump may be provided to remove the inert gas from the cooling chamber.

[0202] At least one heat exchanger may be provided to control the temperature of the cooling chamber.

[0203] The as-printed cake including one or more AM parts may be located in the cooling chamber by a robotic actuator of the robotic system 106, e.g. transported automatically and in a controlled manner from a printing/processing chamber of one of the 3D printers 104 to the cooling chamber.

[0204] The support removal module 108 is configured to remove unprocessed powder surrounding the AM part. The module may include a de-powdering chamber which is separate to the cooling chamber or the cooling chamber may be configured to be a de-powdering chamber. The de-powdering chamber may aptly include a fluidising bed reactor to remove the powder from the AM part by fluidising loose powder and separating it from the solid AM part. The fluidising bed reactor comprises a gas inlet, distributor, and gas outlet.

[0205] Alternatively, the de-powdering chamber may comprise a sieve shaker with an ultrasonic vibrating device to vigorously agitate the AM part/s and remove the bulk of un-sintered powder therefrom. The sieve may comprise a stainless-steel mesh with a pore size larger than the diameter of the polymer powder particles, and the vibrating device may comprise an array of ultrasonic transducers. The removed un-sintered powder may be collected beneath the fluidisation chamber or sieve shaker in a powder collection chamber of a powder recovery module 110.

[0206] Optionally, the AM part/s may be automatically transferred by the or a further robotic system to one or more additional de-powdering chambers 112a,112b for further de-powdering, e.g. medium and fine grade de-powdering and/or half-sintered powder which is unsuitable for recycling. The additional de-powdering chamber/s 112 may also include a sieve shaker and ultrasonic vibrating device or may include other suitable de-powdering means such as a de-powdering module configured to impart ultrasonic waves in a water-surfactant solution, such as described in GB1808639.7 by Additive Manufacturing Technologies Limited. The recovered powder can be disposed via the same powder recovery module 110 or a different powder recovery module/s 114.

[0207] The system 100 includes at least one first conveyor 116, e.g. belt, for transporting ‘unprocessed’ AM parts from the de-powdering modules 108,112a, 112b towards a surface finishing module/apparatus 118.

[0208] An optical inspection module 120 is also provided to identify a surface texture of each AM part on the first conveyor 116, corresponding to a surface finish quality of the part before post-processing. The inspection module 120 is also configured to provide data relating to the surface finish quality of the part to the controller 102. The controller 102 is configured to then operate the surface finishing module/apparatus 118 accordingly to achieve a desired surface texture. A suitable inspection module 120 is described in GB1806168.9 by Additive Manufacturing Technologies Limited.

[0209] In other embodiments, the controller 102 may be configured to modify parameters of the de-powdering process, performed by the de-powdering module 108, based on the surface texture identified by the optical inspection module 120. This helps to remove the supports of the part in a more efficient way to ensure as much of the support as possible is removed. Also it helps to reduce the amount of surface processing that is required by the surface finishing module 118, thereby helping to further improve product throughput.

[0210] The system 100 includes at least one first robotic arm 122 with object recognition/vision capability for automatically identifying an AM part/s on the first conveyor 116 and locating/retrieving the same onto/from a rack/hanger of the surface finishing module/apparatus 118. At least one further robotic arm 124 may be provided with object recognition/vision capability for automatically locating/retrieving each rack/hanger into/from the surface finishing module/apparatus 118. Aptly, the first and further robotic arms 122,124 may be provided by the same unit.

[0211] The surface finishing module/apparatus 118 is aptly configured to automatically smooth an AM polymer part to a desired surface roughness by using a solvent-based method, such as described in GB1721485.9 by Additive Manufacturing Technologies Limited. The surface finishing module/apparatus 118 is also aptly configured to automatically colour an AM polymer part using a suitable colouring method, such as described in GB1812476.8 by Additive Manufacturing Technologies Limited.

[0212] Once the AM part/s has been processed as desired, it is removed from the surface finishing module/apparatus 118 by the robotic arm/s 122,124 and placed on a second conveyor 126, e.g. belt.

[0213] The optical inspection module 120 is configured to re-identify the surface texture of the AM part, after it has been processed by the surface finishing module 118, to determine the surface finish quality of the processed AM part/s. If the AM part fails to meet a desired surface finish quality, the part is reprocessed or discarded as required. The empty racks are retrieved from the second conveyor. Post-processed AM parts which meet the desired surface finish quality (i.e. a desired smoothness and/or colour) are removed from the second conveyor by the robotic arm/s for packaging and shipping.

[0214] The optical inspection module 120 is configured to feed back the surface finish quality of the identified post-processed part to the controller 102. In turn, the controller 102 is configured to adjust parameters of the surface finishing process, performed by the surface finishing module 118, accordingly to help ensure that any further parts being manufactured and post-processed by the system achieve the desired surface finish quality.

[0215] The individual processes and modules of the system 100 are linked and selectively controlled by a software application executed by the controller 102 which automatically manages the AM process and links the system 100 to the 3D printers and the initial CAD stage.

[0216] A digital manufacturing method 200 according to certain embodiments of the present invention will now be described with reference to FIG. 2.

[0217] At step 202, a powder cake/block containing one or more AM parts has been manufactured using one of the 3D printers 104.

[0218] At step 204, the AM block is transferred by the robotic system 106, e.g. a robotic arm, to the cooling and de-powdering module 106 and cooled to a desired temperature for de-powdering. Once the AM block is cooled to around 100° C. or less, it is transferred to the de-powdering module 108 by the robotic system 106.

[0219] To decrease the cooling time, the controller 102 is configured to the adjust the print procedures of the 3D printers 104 based on the temperature of the cooling chamber to allow for more rapid cooling of the chamber and hence improved processing times.

[0220] At step 206, the AM block is broken down and the AM parts within the block are de-powdered by the de-powdering module/s. In case of non-powder-based parts like FDM/SLA, a support removing module may be provided for respective support removal of FDM or SLA parts, and optionally curing of SLA parts. The support removing module may in addition to or as an alternative to the de-powdering module.

[0221] At step 208, the powder from the AM parts is recovered using the powder recovery module/s 110,114. The recovered powder is aptly sorted into un-sintered re-usable powder and non-reusable waste powder. In the meantime, the de-powdered AM parts are transferred onto the first conveyor 116.

[0222] At step 210, while on the first conveyor 116, the surface of the de-powdered AM part/s is analysed using the non-contact optical inspection module 120. The inspection module 120 analyses the surface texture, colour, and part geometry and sends the information to the controller 102 which in turn sends appropriate parameters to the surface finishing module 118.

[0223] In other embodiments, the controller 102 may further modify parameters of the de-powdering process, performed by the de-powdering module 108, based on the analysis of the non-contact optical inspection module 120. This helps to improve the quality of support removing and reduce the amount of post-processing that is required at the surface finishing module 118.

[0224] The AM parts are then transferred further along the first conveyor 116 towards the first robotic arm 122 which identifies the parts and hangs them onto a rack/hanger/frame support for loading into the surface finishing module 118.

[0225] At step 212, the AM parts undergo the desired surface processing, including smoothing and/or colouring before being removed from the surface finishing module 118 by the second robotic arm 124 and placed on the second conveyor 126. The processed AM parts are removed from the rack/hanger by the first robotic arm 122.

[0226] At step 214, the surface of the processed AM parts is re-analysed by the non-contact optical inspection module 120. The inspection module 120 feeds back the determined surface quality to the controller 102. Any AM parts that do not meet a predetermined quality criteria and which can no longer be improved via re-processing are discarded for recycling. The controller 102 then adjusts parameters of the surface finishing process, performed by the surface finishing module 118, based upon the inspection module 120 feedback so that any future parts processed by the system are able to meet the desired surface quality criteria.

[0227] This helps to ensure that any further parts processed using the system meet the predetermined quality criteria, which helps to reduce the amount of “dud” parts processed via the system.

[0228] At step 218, the finished and acceptable AM parts are manually or robotically removed from the second conveyor to be packaged/shipped.

[0229] The afore-described system and method are therefore able to digitally post-process and handling unique 3D printed components, without requiring burdensome operator input for the processing of each part, thereby removing the operator from the process.

[0230] Furthermore, by using an iterative feedback approach, the system can generate special sets of parameters for each unique 3D printed part for each post-processing step, without any need of human supervision, to help efficiently ensure that any future parts manufactured using the system meet desired surface quality criteria.

[0231] Certain embodiments of the present invention therefore provide a system and method for fully automating the AM process from initial part design to inspection of a post-processed AM part. The present invention provides a flexible and customisable modular end-to-end automated post-processing manufacturing system and method for fully automating the AM process which can be used for many different consumer and industrial applications.

[0232] In exemplary embodiments, the support removal process and processing step may be performed as a single step e.g. by the system including a single processing module for processing a surface of the part responsive to the at least one part parameter and a controller configured to modify a processing parameter of a surface finishing process, performed by the processing module, based on the at least one part parameter determined by the inspection module.