Method for direct inkjet printing of 3D objects

Patent metadata

Field	Value
Publication number	US-10828824-B2
Application number	US-201815893880-A
Country	US
Kind code	B2
Filing date	Feb 12, 2018
Priority date	Nov 5, 2012
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

A direct inkjet printing system for fabricating a part by an additive manufacturing process includes an ink delivery system operative to circulate the ink, a printhead associated with the ink delivery system, the printhead operative to dispense ink from the ink delivery system through a plurality of nozzles and based on a defined pattern, a building table for receiving the dispensed ink one layer at a time based on the defined pattern, wherein the part is formed from a plurality of layers of the ink dispensed from the printhead and a drying station operative to perform a drying process on layers of the ink dispensed from the printhead on a per layer basis.

First claim

What is claimed is:

1. A method for direct inkjet printing by an additive manufacturing process to fabricate a part, the method comprising:
dispensing droplets of ink in a layerwise manner onto a building table according to a pattern defined for fabricating the part, wherein a layer is printed in a two step process and wherein the ink is formulated with at least one of ceramic powder, encapsulated metal micro-particles and soluble polymer;
advancing the building table to a drying station after each of first and second step of the two step process; and
drying the droplets of ink in at least one drying station after each of a first and second step of the two step process;
wherein the first step of the two step process includes scanning a first array of the droplets in a printing direction with one pixel gaps in a cross printing direction and wherein the second step of the two step process includes scanning a second array of the droplets in the printing direction with one pixel gaps in a cross printing direction, wherein the second array fills at least a portion of the one pixel gaps formed by the first array.

2. The method according to claim 1 , comprising dispensing droplets of support material in a layerwise manner according to a pattern defined for supporting the part during fabrication, wherein a layer of droplets of support material is dispensed subsequent to forming a corresponding layer of the droplets of ink for fabricating the part.

3. The method according to claim 1 , comprising rotating the layer by 90 degrees prior to printing a subsequent layer.

4. The method according to claim 1 , wherein the droplets of ink are dispensed with a printhead including an array of nozzles and wherein the printhead is displaced by a half a pixel distance in a crossing printing direction prior to printing a subsequent layer.

5. The method according to claim 1 , comprising sintering the part.

6. The method according to claim 1 , further comprising:
accelerating the building table in an opposite direction to exit the drying station after the drying process.

7. The method according to claim 1 comprising:
advancing a building tray to a first drying station after the first step of the two step process, wherein the building tray is configured for receiving the droplets of ink for fabricating the part; and
advancing the building tray to a second drying station after the second step of the two step process.

8. The method according to claim 1 , wherein the drying of the droplets of ink in a drying station comprises circulating hot air in the drying station.

9. The method according to claim 1 , wherein the drying of the droplets of ink in a drying station comprises impinging jets of hot air on the droplets of ink.

10. The method according to claim 1 , wherein the drying station is configured for drying ink that has a viscosity of 10-20 cps at a dispensing temperature.

11. The method according to claim 1 , wherein the drying station is configured for drying ink that is formulated with at least one of ceramic powder, encapsulated metal micro-particles and soluble polymer.

12. The method according to claim 1 comprising flattening layers of the droplets of ink once every plurality of layers.

13. The method according to claim 12 , wherein the layers are flattened with a roller and wherein the roller is lowered toward the layers for performing the flattening on demand.

14. The method of claim 1 further comprising circulating the ink with gravitation based circulation in an ink delivery system prior to dispensing.

Assignees

• Stratasys Ltd

Inventors

• Sheinman Yehoshua

Classifications

• B33Y30/00 Primary

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

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B29C64/364

  Conditioning of environment · CPC title

• B29C64/209

  Heads; Nozzles · CPC title

• B29C64/245

  Platforms or substrates (support structures intended to be sacrificed after manufacture B29C64/40) · CPC title