Method and system for manufacturing a three-dimensional porous structure

Patent metadata

Field	Value
Publication number	US-12515409-B2
Application number	US-202017569933-A
Country	US
Kind code	B2
Filing date	Jul 17, 2020
Priority date	Jul 19, 2019
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

A method and system for manufacturing a three-dimensional porous structure. Filaments are deposited in a predetermined interconnected arrangement in a plurality of stacked layers for forming a porous structure with interconnected pores. A pressure value indicative of a pressure being applied on the build material in the build material reservoir of a nozzle used for deposition is monitored during deposition of the filaments. The processing unit is configured to adjust at least one extrusion parameter in order to compensate for the irregular rising and/or falling of the pressure value.

First claim

The invention claimed is:

1 . A method for manufacturing a three-dimensional porous structure, the method including the steps of:
providing an extrusion unit comprising a nozzle with a nozzle outlet and a build material reservoir, the build material reservoir being in fluid communication with said nozzle outlet, the build material comprising particles of inorganic material dispersed in a binder and at least one solvent; depositing, by means of the extrusion unit, filaments of the build material in a predetermined interconnected arrangement in a plurality of stacked layers for forming the three-dimensional porous structure with interconnected pores; monitoring, by means of a measuring unit, a pressure value indicative of a pressure being applied on the build material in the build material reservoir during extrusion of the build material through the nozzle to achieve deposition of the filaments; and processing, by means of a processing unit, the monitored pressure value during a continuous extrusion phase for detecting one or more deposition irregularities by identifying an irregular rising and/or falling of the pressure value with respect to a plateau level determined from the actual measured pressure reached during the continuous extrusion phase, wherein during the irregular rising the pressure value momentary spikes by at least 15% above the plateau level before returning to the plateau level, wherein during the irregular falling the pressure value momentary drops by at least 15% below the plateau level before returning to the plateau level, and wherein the processing unit is configured to adjust at least one extrusion parameter in order to compensate for the irregular rising and/or falling of the pressure value.

2 . The method according to claim 1 , wherein adjusting an extrusion parameter involves at least one of:
adjusting the pressure exerted to the build material in the build material reservoir and/or in the nozzle; adjusting the viscosity of the build material in the build material reservoir and/or in the nozzle; adjusting the build material flow rate; adjusting the nozzle opening; adjusting an actuation of an extrusion screw in the nozzle; or providing vibrations to the build material.

3 . The method according to claim 2 , wherein adjusting the viscosity of the build material in the build material reservoir is carried out by at least one of: adjusting a temperature of the build material, adjusting an amount of a solvent contained in the build material, or adding a release agent.

4 . The method according to claim 1 , wherein the measuring unit includes a load sensor positionable at a build material reservoir, between build material reservoir and nozzle, and/or at the nozzle.

5 . The method according to claim 1 , wherein the measuring unit is configured to monitor the pressure value indicative of the pressure being applied on the build material at a plurality of positions.

6 . The method according to claim 1 , wherein the processing unit is configured to link the one or more identified deposition irregularities to one or more deposition defects in the porous structure, wherein a severity of the deposition defect is determined based on an amplitude and/or shape of the irregular rising and/or falling of the pressure value with respect to the plateau level reached during deposition.

7 . The method according to claim 1 , wherein the processing unit is configured to determine a location of the identified deposition defect in the porous structure based on a position of the nozzle in a print path when the deposition irregularity is detected.

8 . The method according to claim 6 , wherein the processing unit is configured to determine one or more defect zones in the manufactured porous structure based on locations of identified one or more deposition defects in the porous structure.

9 . The method according to claim 8 , wherein the processing unit is configured to estimate an impact of the one or more defect zones on the structural integrity of the porous structure, based on at least one of a location and severity of the deposition defect at the defect zone, wherein the processing unit is configured to determine or estimate whether the printed porous structure complies with targeted properties, in particular one or more of strength and geometric effects, based on said estimate of the impact of the one or more weakened zones on the structural integrity of the porous structure.

10 . The method according to claim 9 , wherein the processing unit employs a computational model for determining or estimating the impact of the one or more defect zones on the structural integrity of the porous structure, wherein at locations of the one or more detected deposition defects the filament is modelled with a diameter based on the respective detected irregular rising or falling of the pressure value.

11 . The method according to claim 1 , wherein the manufacturing of the porous structure is cancelled prematurely if the one or more deposition irregularities are identified resulting in the one or more deposition defects in the porous structure.

12 . The method according to claim 9 , wherein the impact of the one or more weakened zones is estimated during deposition of the filaments for manufacturing the porous structure, wherein the manufacturing is prematurely cancelled based on said estimate of the impact.

13 . The method according to claim 4 , wherein the load cell includes a transducer arranged for creating an electrical signal whose magnitude is proportional to the force being measured, wherein the load cell is arranged to measure the force applied for discharging the build material out of the nozzle.

14 . The method according to claim 1 , wherein the measuring unit further includes a flow sensor configured to measure a flow value indicative of a flow of build material extruded through the nozzle outlet, wherein the processing unit is configured to process the flow data for determining one or more flow irregularities formed by an irregular rising and/or falling of the flow with respect to a plateau flow level during deposition.

15 . The method according to claim 1 , wherein the pressure value is determined by means of a first measuring unit and a second measuring unit, the first and second measuring units being placed at different locations, wherein the first measuring is configured to measure a first pressure value indicative of a pressure being applied on the build material in the build material reservoir, wherein the second measuring unit is configured to measure at least a second pressure value, wherein the method further comprises determining a difference between the first and at least one second pressure value and adjusting an extrusion parameter depending on the determined difference.

16 . The method according to claim 1 , wherein the plateau level has a baseline envelope forming a channel with an upper limit and a lower limit, wherein the irregular rising and/or falling of the pressure value with respect to the plateau level is identified when the pressure value breaks out of the baseline envelope of the plateau level.

17 . A non-transitory computer readable medium comprising a program of instructions that, when executed by a processor, perform the method according to claim 1 .

18 . An additive manufacturing system for manufacturing a three-dimensional porous structure, the system comprising:
an extrusion unit including a nozzle with a nozzle outlet and a build material reservoir, the build material reservoir being in fluid communicatio

Assignees

• Vito Nv

Inventors

• Michielsen Bart
• Lefevere Jasper
• Bouwen Wim
• Mullens Steven
• Gysen Marijn
• Van Hoof Erwin

Classifications

• B29K2105/04

  cellular or porous · CPC title

• B29C64/255

  Enclosures for the building material, e.g. powder containers · CPC title

• B29C64/118 Primary

  using filamentary material being melted, e.g. fused deposition modelling [FDM] · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title