Fused filament fabrication nozzle with controllable exit shape

Patent metadata

Field	Value
Publication number	US-2018304369-A1
Application number	US-201816023799-A
Country	US
Kind code	A1
Filing date	Jun 29, 2018
Priority date	Dec 16, 2015
Publication date	Oct 25, 2018
Grant date	—

Abstract

A printer fabricates an object from a computerized model using a fused filament fabrication process. The shape of an extrusion nozzle may be varied during extrusion to control, e.g., an amount of build material deposited, a shape of extrudate exiting the nozzle, a feature resolution, and the like.

First claim

What is claimed is:

1 . A method comprising:
heating a wire form of a build material from a first temperature to a second temperature as the wire form of the build material moves, in a direction toward a nozzle, along a feed path extending from a source of the wire form of the build material to the nozzle, the build material including a metal powder dispersed in a binder system; at a working temperature greater than the second temperature, liquefying at least a portion of the build material moving along the feed path; and at the working temperature, extruding the build material through the nozzle and in a direction toward a build plate, the build material extruded through the nozzle forming a three-dimensional object on the build plate.

2 . The method of claim 1 , wherein a concentration of the metal powder in the build material is greater than 50 percent by volume.

3 . The method of claim 1 , wherein the wire form of the build material is brittle at the first temperature and plastic at the second temperature.

4 . The method of claim 1 , extruding the build material through the nozzle and in the direction toward the build plate includes moving the nozzle along an extrusion path relative to the build plate.

5 . The method of claim 1 , wherein the build material extruded through the nozzle has an extrusion diameter of 300 microns.

6 . The method of claim 1 , wherein the source of the wire form of the build material includes a spool of the wire form of the build material and advancing the wire form of the build material includes unspooling the wire form of the build material from the spool.

7 . The method of claim 1 , wherein the working temperature is a glass transition temperature of the build material.

8 . The method of claim 1 , wherein the working temperature is greater than about 160 degrees Celsius and less than about 250 degrees Celsius.

9 . The method of claim 1 , wherein, at the working temperature, the build material has non-Newtonian fluid properties.

10 . The method of claim 1 , further comprising actuating a drive train engaged with the wire form of the build material, the actuation of the drive train moving the wire form of the build material along the feed path, in the direction toward the nozzle.

11 . The method of claim 10 , wherein heating the wire form of the build material from the first temperature to the second temperature includes directing heat into the wire form of the build material through a portion of the drive train engaged with the wire form of the build material.

12 . The method of claim 11 , wherein the portion of the drive train engaged with the wire form of the build material includes a gear shaped to mesh with corresponding features in the wire form of the build material.

13 . The method of claim 11 , wherein the portion of the drive train engaged with the wire form of the build material deforms at least a portion of the wire form of the build material.

14 . The method of claim 10 , wherein actuation of the drive train moves the wire form of the build material through a vacuum gasket along the feed path and into a substantially inert environment.

15 . The method of claim 10 , wherein the source of the wire form of the build material is a coil and actuation of the drive train uncoils the wire form of the build material from the coil.

16 . The method of claim 1 , wherein heating the wire form of the build material from the first temperature to the second temperature includes resistively heating the wire form of the build material through contact pads disposed along the feed path.

17 . The method of claim 1 , wherein heating the wire form of the build material from the first temperature to the second temperature includes inductively heating the wire form of the build material via one or more electromagnets disposed along the feed path.

18 . The method of claim 1 , wherein the binder system includes a bulk binder and a backbone binder and debinding the binder system from the three-dimensional object includes removing the bulk binder and the backbone binder separately from the three-dimensional object.

19 . The method of claim 1 , wherein the metal powder includes particles having an average diameter of greater than about 1 micron and less than about 22 microns.

20 . The method of claim 1 , further comprising heating the nozzle to maintain the working temperature of the build material during extrusion of the build material through the nozzle.

21 . The method of claim 1 , further comprising debinding the binder system from the three-dimensional object to form a brown part.

22 . The method of claim 21 , further comprising densifying the metal powder in the brown part to form a final part.

Assignees

• Desktop Metal Inc

Inventors

• Myerberg Jonah Samuel
• Fulop Ricardo
• Gibson Michael Andrew
• Hart Anastasios John
• Fontana Richard Remo
• Schuh Christopher Allan
• Chiang Yet-Ming
• Verminski Matthew David
• Schmitt Peter Alfons
• Sachs Emanuel Michael
• Chin Ricardo

Classifications

• B22F10/30

  Process control · CPC title

• B22F12/57

  Metering means · CPC title

• B22F12/55

  Two or more means for feeding material · CPC title

• B22F10/18

  by mixing binder with metal in filament form, e.g. fused filament fabrication [FFF] · CPC title

• B22F3/24 Primary

  After-treatment of workpieces or articles {(B22F3/1146 takes precedence)} · CPC title