Method and device for conveying particulate material during the layer-wise production of patterns

• US 8,727,672 B2
• Filed: 10/06/2008
• Issued: 05/20/2014
• Est. Priority Date: 10/21/2007
• Status: Active Grant

• Current Assignee: Voxeljet AG
• Original Assignee: Voxeljet AG
• Inventors: Ederer, Ingo, Hartman, Andreas
• Primary Examiner(s): DILLON JR, JOSEPH A
• Application Number:
  US12/681,961
• Publication Number:
  US 20100272519A1
• Time in Patent Office: 2,052 Days
• Field of Search: 406/54, 406/55, 406/106, 406/164, 406/197, 406/198, 700/98, 700/119
• US Class Current: 406/197
• CPC Class Codes: B05C 19/06 Storage, supply or control of the application of particulate material; Recovery of excess particulate material
• CPC Class Codes: B22F 10/10 Formation of a green body
• CPC Class Codes: B22F 10/73 of powder
• CPC Class Codes: B22F 12/60 Planarisation devices; Compression devices
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/003 Apparatus, e.g. furnaces in general F27B
• CPC Class Codes: B29C 64/141 using only solid materials
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B29C 64/165 using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• CPC Class Codes: B29C 64/35 Cleaning
• CPC Class Codes: B29C 64/357 Recycling
• CPC Class Codes: B29K 2105/251 Particles, powder or granules expandable particles B29K2105/046
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

The present invention relates to a method for conveying particulate material during the manufacture of patterns in layers, wherein powder is conveyed out of a reservoir into a spreader unit and, if applicable, excess powder fed to the spreader unit is again conveyed back into the reservoir and wherein this conveying takes place in a closed conveying circuit.

Claims

1. A method comprising:

forming three dimension objects comprising the steps of;

1) providing a device for conveying particulate material comprising;

a) a reservoir;

b) a spreader unit; and

c) a plurality of particulate material conveying systems including a first particulate material conveying system having a screw conveyor and a second particulate material conveying system having a screw conveyor;

2) forming a first layer of the three dimension object by a layer forming step comprising;

a) conveying the particulate material out of the reservoir into the spreader unit with at least the first particulate material conveying system;

b) spreading the particulate material unit unto a build platform with the spreader; and

c) conveying excess particulate material that was fed to the spreader unit back into the reservoir after the step of spreading; and

3) forming a second layer of the three dimensional object by a layer forming step by repeating steps 2a, 2b and 2c;

wherein the steps 2a and 2c of conveying takes place in a closed conveying circuit that includes the plurality of particulate material conveying systems.

2. The method of claim 1, wherein the step of conveying the excess particulate material back into the reservoir takes place using a bypass opening in the particulate material conveying system.

4. The method according to claim 1, wherein the closed conveying circuit conveys the excess particulate material back into the reservoir after a coating process.

5. The method of claim 1, wherein the device for conveying particulate material includes an ejection system.

6. The method of claim 1, wherein the reservoir is arranged below the spreader unit in a vertical direction, when viewed in a direction at a right angle to a coating direction, at least during a filling process.

7. The method of claim 1, wherein at least one of the plurality of particulate material conveying systems comprises at least one conveyor belt, and

wherein the device for conveying particulate material includes a junction for introducing anew powder material into the reservoir.

8. The method of claim 1, wherein the step 2a of conveying the particulate material out of the reservoir into the spreader further employs the second particulate material conveying system, and

wherein the device for conveying particulate material includes a junction for introducing a new powder material into the reservoir.

9. The method of claim 1, wherein at least one of the particulate material conveying systems comprises a suction device for low pressure conveying, and

wherein the device for conveying particulate material includes a junction for introducing anew powder material into the reservoir.

10. The method of claim 5, wherein the ejection system comprises two covers comprising slits, and

wherein the device for conveying particulate material includes a junction for introducing anew powder material into the reservoir.

3. The method according to claim, wherein the step 2a of conveying the particulate material takes place via low pressure.