WO2021113452A1

WO2021113452A1 - High-speed three-dimensional printing device

Info

Publication number: WO2021113452A1
Application number: PCT/US2020/063025
Authority: WO
Inventors: Cheng Luo
Original assignee: Board Of Regents, The University Of Texas System
Priority date: 2019-12-03
Filing date: 2020-12-03
Publication date: 2021-06-10

Abstract

Various implementations include a three-dimensional printing device including a reservoir, extruder, pump, and at least one heating device. The reservoir receives a melted printing material. The extruder has a hollow extruder body, including a first end and a second end. The second end of the extruder body defines an extruder opening for extruding the melted printing material. The pump is configured to create a pressure differential for causing the melted printing material to flow from the reservoir to the extruder and out of the extruder opening. The at least one heating device is configured to maintain the melted printing material in a liquid state. Various other implementations include a melting system and an extruder, pump, and heating device similar to the above device. The melting system includes a hopper for receiving solid printing material and a melter for melting the solid printing material.

Description

HIGH-SPEED THREE-DIMENSIONAL PRINTING DEVICE

BACKGROUND

[0001] Fused-filament fabrication (“FFF”), also known as fused deposition modeling and material extrusion based additive manufacturing (AM), is one of the most widely used processes in AM to fabricate three-dimensional (“3D”) polymer parts. The prior art FFF printer 100 shown in FIG. 1A includes a reel of solid filaments 198 which is loaded into the printer 100. The solid filament 198 is then fed into an extruder 170 using two pinch wheels 150, 152. The extruder 170 shown in FIG. IB includes three main components: a long cylindrical tube 184 for liquefying a solid filament 198; a print nozzle 180 for extruding the molten filament 199; and a short conical tube 182 for connecting the cylindrical tube 184 and print nozzle 180. The cylindrical tube 184 is pre-heated by a surrounding heater 188 to a high temperature for melting the filament 198. This temperature is normally much higher than glass-transition temperature. The solid filament 198 is first molten inside the long cylindrical tube 184 of the extruder 170, and then extruded through the nozzle 180, followed by deposition on a build plate 190. The extruded filaments 199 function as “printing ink.” They are stacked together to form a 3D polymer part, as shown in FIG. 1 A.

[0002] The print speed of the printer is limited by the associated feed rate, which refers to the moving speed of the filament inside the extruder. The maximum feed rate allowed is typically in the order of 1 mm/s. At a higher rate, the filament would not be sufficiently molten, causing nozzle clogging, as shown in FIG. IB. To increase the allowed feed rate, prior art printers pre-heated a solid filament using a laser. However, since the solid filament is still solid before it gets into the extruder, jamming remains as a concern when the feed rate is further increased.

[0003] Thus, there is a desire for a 3D printer capable of higher feed rates without jamming.

SUMMARY

[0004] Various implementations include a three-dimensional printing device. The device includes a reservoir, an extruder, a pump, and at least one heating device. The reservoir is for receiving a melted printing material. The extruder has a hollow extruder body. The extruder body includes a first end and a second end opposite and spaced apart from the first end. The second end of the extruder body defines an extruder opening for extruding the melted printing material. The pump is configured to create a pressure differential for causing the melted printing material to flow from the reservoir to the extruder and out of the extruder opening. The at least one heating device is configured to maintain the melted printing material in a liquid state.

[0005] In some implementations, the at least one heating device includes a reservoir heating device for keeping the melted printing material disposed within the reservoir in a liquid state.

[0006] In some implementations, the at least one heating device includes a pump heating device for keeping the melted printing material disposed within the pump in a liquid state.

[0007] In some implementations, the at least one heating device includes an extruder heating device for keeping the melted printing material disposed within the extruder in a liquid state.

[0008] In some implementations, the pump is configured to provide a continuous pressure differential such that the melted printing material continuously flows from the reservoir to the extruder and out of the extruder opening when the pump is activated. In some implementations, the pump includes a gear pump.

[0009] In some implementations, the device further includes a build plate and a computer numerical control (CNC) machine for moving the build plate and the extruder relative to each other.

[0010] In some implementations, the melted printing material is a polymer melt.

[0011] In some implementations, the device further includes a composite filament feeding system including a feeding device for introducing a composite filament into the extruder such that the composite filament exits the extruder opening with the melted printing material. In some implementations, the composite filament feeding system further includes a filament heater for melting a portion of the composite filament before introducing the composite filament into the extruder. In some implementations, the composite filament feeding system further includes a cutting device for cutting the composite filament.

[0012] Various other implementations include a three-dimensional printing device. The device includes a melting system, an extruder, a pump, and at least one heating device. The melting system includes a hopper for receiving solid printing material and a melter for melting the solid printing material into a melted printing material. The extruder has a hollow extruder body. The extruder body includes a first end and a second end opposite and spaced apart from the first end. The second end of the extruder body defines an extruder opening for extruding the melted printing material. The pump is configured to create a pressure differential for causing the melted printing material to flow from the melting system to the extruder and out of the extruder opening. The at least one heating device is configured to maintain the melted printing material in a liquid state.

[0013] In some implementations, the melter includes a melting heater for melting the solid printing material into a melted printing material and a screw pump for causing the solid printing material to flow through the melter as the solid printing material is melted.

[0014] In some implementations, the at least one heating device includes a pump heating device for keeping the melted printing material disposed within the pump in a liquid state.

[0015] In some implementations, the at least one heating device includes an extruder heating device for keeping the melted printing material disposed within the extruder in a liquid state.

[0016] In some implementations, the pump is configured to provide a continuous pressure differential such that the melted printing material continuously flows from the melting system to the extruder and out of the extruder opening when the pump is activated. In some implementations, the pump includes a gear pump.

[0017] In some implementations, the device further includes a build plate and a computer numerical control (CNC) machine for moving the build plate and the extruder relative to each other.

[0018] In some implementations, the melted printing material is a polymer melt.

[0019] In some implementations, the device further includes a composite filament feeding system including a feeding device for introducing a composite filament into the extruder such that the composite filament exits the extruder opening with the melted printing material. In some implementations, the composite filament feeding system further includes a filament heater for melting a portion of the composite filament before introducing the composite filament into the extruder. In some implementations, the composite filament feeding system further includes a cutting device for cutting the composite filament. BRIEF DESCRIPTION OF DRAWINGS

[0020] Example features and implementations are disclosed in the accompanying drawings. However, the present disclosure is not limited to the precise arrangements and instrumentalities shown. Similar elements in different implementations are designated using the same reference numerals.

[0021] FIG. 1 A is a side view of a 3D printer of the prior art.

[0022] FIG. IB is a side view of the extruder of the 3D printer of FIG. 1 A.

[0023] FIG. 2 is a side view of a 3D printing device, according to one implementation.

[0024] FIG. 3 is a side view of a 3D printing device, according to another implementation.

[0025] FIG. 4 is a side view of a 3D printing device, according to another implementation.

DETAILED DESCRIPTION

[0026] The devices, systems, and methods disclosed herein provide for a three- dimensional printing device that uses melted printing material. In some implementations, the device includes a reservoir for accepting melted printing material and maintaining the printing material in a melted state. In other implementations, the device includes a melting system for accepting solid printing material and converting the solid printing material into a melted state. Because the devices, systems, and methods disclosed herein accept melted printing material instead of melting the solid printing material as the device feeds the solid printing material through the extruder, the device is less likely to malfunction due to the melting speed being slower than the feed rate.

[0027] Various implementations include a three-dimensional printing device. The device includes a reservoir, an extruder, a pump, and at least one heating device. The reservoir is for receiving a melted printing material. The extruder has a hollow extruder body. The extruder body includes a first end and a second end opposite and spaced apart from the first end. The second end of the extruder body defines an extruder opening for extruding the melted printing material. The pump is configured to create a pressure differential for causing the melted printing material to flow from the reservoir to the extruder and out of the extruder opening. The at least one heating device is configured to maintain the melted printing material in a liquid state. [0028] Various other implementations include a three-dimensional printing device. The device includes a melting system, an extruder, a pump, and at least one heating device. The melting system includes a hopper for receiving solid printing material and a melter for melting the solid printing material into a melted printing material. The extruder has a hollow extruder body. The extruder body includes a first end and a second end opposite and spaced apart from the first end. The second end of the extruder body defines an extruder opening for extruding the melted printing material. The pump is configured to create a pressure differential for causing the melted printing material to flow from the melting system to the extruder and out of the extruder opening. The at least one heating device is configured to maintain the melted printing material in a liquid state.

[0029] FIG. 2 shows a three-dimensional printing device 200. The device 200 includes a reservoir 210, a pump 240, an extruder 270, a build plate 290, and a computer numerical control (CNC) machine 292.

[0030] The reservoir 210 includes a hollow reservoir body 212 having a first end 214 and a second end 216 opposite and spaced apart from the first end 214. Melted printing material 299 is received by the reservoir 210 by pouring the melted printing material 299 through the first end 214 of the reservoir 210. The melted printing material 299 shown in FIG. 2 is a polymer melt such as acrylonitrile butadiene styrene (ABS), polylactide (PLA), or polycaprolactone (PCL), but in other implementations, the melted printing material is any material capable of being melted, extruded through the device and onto the build plate, and then being solidified.

[0031] The reservoir 210 includes a reservoir heating device 230 surrounding the reservoir body 212. The reservoir heating device 230 is configured to provide enough heat to melted printing material 299 within the reservoir 210 to maintain the melted printing material 299 in a liquid state. The reservoir heating device 230 shown in FIG. 2 is an electric resistance heating device, but in other implementations, the reservoir heating device is any other device capable of creating enough heat to maintain the melted printing material within the reservoir in a liquid state.

[0032] The pump 240 shown in FIG. 2 is a gear pump having a first end 244 and a second end 246 opposite and spaced apart from the first end 244. The first end 244 of the pump 240 is coupled to, and in fluid communication with, the second end 216 of the reservoir 210 such that the melted printing material 299 within the reservoir 210 can flow into the pump 240. The pump 240 is configured to create a pressure differential to cause the melted printing material 299 to flow through the device 200. The pump 240 includes two gears 250, 252 with interlocking teeth. As the gears 250, 252 turn, the teeth of each gear 250, 252 entrap a portion of the melted printing material 299 disposed near the first end 244 of the pump 240 and transfer the melted printing material 299 toward the second end 246 of the pump 240. As the pump 240 transfers the melted printing material 299 from the first end 244 of the pump 240 to the second end 246 of the pump 240, a pressure differential is created between the first end 244 of the pump 240 and the second end 246 of the pump 240. Because the gears 250, 252 turn in a single direction and at a constant rate, the pressure differential created is also constant such that the melted printing material 299 flows through the device 200 at a constant rate. The pump 240 shown in FIG. 2 is a gear pump, but in other implementations, the pump is any device capable of creating a constant pressure differential, such as a screw pump.

[0033] The pump 240 includes a pump heating device 260 surrounding the pump 240. The pump heating device 260 is configured to provide enough heat to melted printing material 299 within the pump 240 to maintain the melted printing material 299 in a liquid state. The pump heating device 260 shown in FIG. 2 is an electric resistance heating device, but in other implementations, the pump heating device is any other device capable of creating enough heat to maintain the melted printing material within the pump in a liquid state.

[0034] The extruder 270 has a hollow extruder body 272 having a first end 274 and a second end 276 opposite and spaced apart from the first end 274. The extruder 270 includes a print nozzle 280 proximal to the second end 276 of the extruder 270, a cylindrical portion 284 proximal to the first end 274 of the extruder 270, and a short conical portion 282 for coupling the print nozzle 280 to the cylindrical portion 284. The first end 274 of the extruder 270 is coupled to, and in fluid communication with, the second end 246 of the pump 240 such that the melted printing material 299 within the pump 240 can flow into the extruder 270. The printing nozzle 280 of the extruder 270 has a cross sectional shape in a plane perpendicular to a central axis of the extruder 270. The cross-sectional shape of the printing nozzle 280 is selected to produce a predetermined size and shape extrusion of melted printing material 299 as the melted printing material 299 flows through the second end 276 of the extruder 270.

[0035] The extruder 270 includes an extruder heating device 288 surrounding the extruder 270. The extruder heating device 288 is configured to provide enough heat to melted printing material 299 within the extruder 270 to maintain the melted printing material 299 in a liquid state. The extruder heating device 288 shown in FIG. 2 is an electric resistance heating device, but in other implementations, the extruder heating device is any other device capable of creating enough heat to maintain the melted printing material within the extruder in a liquid state.

[0036] The build plate 290 is disposed adjacent the second end 276 of the extruder 270. The build plate 290 includes a flat surface onto which the melted printing material 299 is deposited as it flows from the second end 276 of the extruder 270.

[0037] The CNC machine 292 is coupled to the reservoir 210, pump 240, and extruder 270. The CNC machine 292 is able to move the reservoir 210, pump 240, and extruder 270 relative to the build plate 290 such that the melted printing material 299 flowing from the second end 276 of the extruder 270 can be deposited on the build plate 290 in lines. The melted printing material 299 can then solidify to form the desired manufactured part.

[0038] Prior art FFF printers, such as the one shown in FIGS. 1 A and IB, typically have a feed rate of 1 mm/s. The devices disclosed herein has been shown to have a feed rate of at least 100 mm/s and can be as high as 500 mm/s, depending on the forces applied by the pump. Thus, the devices and methods disclosed herein provide for three-dimensional printing at a speed of at least 100 times the speed of the prior art FFF printer shown in FIGS. 1 A and IB.

[0039] FIG. 3 shows another implementation of a three-dimensional printing device 300. The device 300 includes a pump 340, an extruder 370, a build plate 390, and a CNC machine 392 like the device 200 shown in FIG. 2. The pump 340, extruder 370, build plate 390, and CNC machine 392 of device 300 are similar to the pump 240, extruder 270, build plate 290, and CNC machine 292 of device 200 shown in FIG. 2, and thus, features of the pump 340, extruder 370, build plate 390, and CNC machine 392 of device 300 are indicated using similar reference numbers. However, rather than including a reservoir 210 like the device 200 shown in FIG. 2, the device 300 shown in FIG. 3 includes a melting system 310.

[0040] The melting system 310 includes a hopper 312 and a melter 320. The hopper 312 has a first end 314 and a second end 316 opposite and spaced apart from the first end 314. The hopper 312 receives solid printing material 398 deposited through the first end 314 of the hopper 312. [0041] The melter 320 includes a tube 322 and a screw pump 328 disposed within the tube 322. The tube 322 has a first end 324 and a second end 326 opposite and spaced apart from the first end 324. The second end 316 of the hopper 312 is coupled to, and in fluid communication with, the first end 324 of the tube 322. The screw pump 328 is coupled to a motor 329 for rotating the screw pump 328 within the tube 322. As the screw pump 328 rotates, the solid printing material 398 within the hopper 312 enters the tube 322 and is moved from the first end 324 of the tube 322 to the second end 326 of the tube 322 by the screw pump 328. The second end 326 of the melter tube 322 is coupled, and in fluid communication with, the first end 344 of the pump 340.

[0042] The melter 320 includes a melting heater 330 surrounding the melter tube 322. The melting heater 330 is configured to provide enough heat to melt the solid printing material 398 within the melter tube 322 and to maintain the melted printing material 399 in a liquid state as it passes through the tube 322. The melting heater 330 shown in FIG. 3 is an electric resistance heating device, but in other implementations, the melting heater is any other device capable of creating enough heat to melt the solid printing material and to maintain the melted printing material within the melter tube in a liquid state.

[0043] FIG. 4 shows another implementation of a three-dimensional printing device 400 similar to the device 200 shown in FIG. 2, but the device 400 shown in FIG. 4 includes a composite filament feeding system 493. The composite filament feeding system 493 includes a feeding device 494, a filament heater 495, and a cutting device 496.

[0044] The feeding device 494 includes two gears 497, 497’ for feeding a solid composite filament 498 into the extruder 470 such that the composite filament 498 exits the extruder second opening 476 with the melted printing material 499. The filament heater

495 surrounds the composite filament 498 before the composite filament 498 enters the extruder 470 so that the composite filament 498 can be partially melted before being introduced into the extruder 470. By partially melting the composite filament 498 before introducing the composite filament 498 into the melted printing material 499 within the extruder 470, the composite filament 498 and melted printing material 499 are able to better bond with each other. When the device 400 ends the printing process, the cutting device

496 cuts the composite filament 498. Although the filament feeding system 493 shown in FIG. 4 is included in a device 400 including a reservoir 410, in other implementations, the filament feeding system is included in the same way in a device with a melting system, such as the device shown in FIG. 3. [0045] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the claims. Accordingly, other implementations are within the scope of the following claims.

[0046] Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present claims. In the drawings, the same reference numbers are employed for designating the same elements throughout the several figures. A number of examples are provided, nevertheless, it will be understood that various modifications can be made without departing from the spirit and scope of the disclosure herein. As used in the specification, and in the appended claims, the singular forms “a,” “an,” “the” include plural referents unless the context clearly dictates otherwise. The term “comprising” and variations thereof as used herein is used synonymously with the term “including” and variations thereof and are open, non-limiting terms. Although the terms “comprising” and “including” have been used herein to describe various implementations, the terms “consisting essentially of’ and “consisting of’ can be used in place of “comprising” and “including” to provide for more specific implementations and are also disclosed.

Claims

WHAT IS CLAIMED IS:

1. A three-dimensional printing device, the device comprising: a reservoir for receiving a melted printing material; an extruder having a hollow extruder body, the extruder body including a first end and a second end opposite and spaced apart from the first end, wherein the second end of the extruder body defines an extruder opening for extruding the melted printing material; a pump configured to create a pressure differential for causing the melted printing material to flow from the reservoir to the extruder and out of the extruder opening; and at least one heating device configured to maintain the melted printing material in a liquid state.

2. The device of claim 1, wherein the at least one heating device includes a reservoir heating device for keeping the melted printing material disposed within the reservoir in a liquid state.

3. The device of claim 1, wherein the at least one heating device includes a pump heating device for keeping the melted printing material disposed within the pump in a liquid state.

4. The device of claim 1, wherein the at least one heating device includes an extruder heating device for keeping the melted printing material disposed within the extruder in a liquid state.

5. The device of claim 1, wherein the pump is configured to provide a continuous pressure differential such that the melted printing material continuously flows from the reservoir to the extruder and out of the extruder opening when the pump is activated.

6. The device of claim 5, wherein the pump comprises a gear pump.

7. The device of claim 1, further comprising a build plate and a computer numerical control (CNC) machine for moving the build plate and the extruder relative to each other.

8. The device of claim 1, wherein the melted printing material is a polymer melt.

9. The device of claim 1, further comprising a composite filament feeding system including a feeding device for introducing a composite filament into the extruder such that the composite filament exits the extruder opening with the melted printing material.

10. The device of claim 9, wherein the composite filament feeding system further includes a filament heater for melting a portion of the composite filament before introducing the composite filament into the extruder.

11. The device of claim 9, wherein the composite filament feeding system further includes a cutting device for cutting the composite filament.

12. A three-dimensional printing device, the device comprising: a melting system including a hopper for receiving solid printing material and a melter for melting the solid printing material into a melted printing material; an extruder having a hollow extruder body, the extruder body including a first end and a second end opposite and spaced apart from the first end, wherein the second end of the extruder body defines an extruder opening for extruding the melted printing material; a pump configured to create a pressure differential for causing the melted printing material to flow from the melting system to the extruder and out of the extruder opening; and at least one heating device configured to maintain the melted printing material in a liquid state.

13. The device of claim 12, wherein the melter includes a melting heater for melting the solid printing material into a melted printing material and a screw pump for causing the solid printing material to flow through the melter as the solid printing material is melted.

14. The device of claim 12, wherein the at least one heating device includes a pump heating device for keeping the melted printing material disposed within the pump in a liquid state.

15. The device of claim 12, wherein the at least one heating device includes an extruder heating device for keeping the melted printing material disposed within the extruder in a liquid state.

16. The device of claim 12, wherein the pump is configured to provide a continuous pressure differential such that the melted printing material continuously flows from the melting system to the extruder and out of the extruder opening when the pump is activated.

17. The device of claim 16, wherein the pump comprises a gear pump.

18. The device of claim 12, further comprising a build plate and a computer numerical control (CNC) machine for moving the build plate and the extruder relative to each other.

19. The device of claim 12, wherein the melted printing material is a polymer melt.

20. The device of claim 12, further comprising a composite filament feeding system including a feeding device for introducing a composite filament into the extruder such that the composite filament exits the extruder opening with the melted printing material.

21. The device of claim 20, wherein the composite filament feeding system further includes a filament heater for melting a portion of the composite filament before introducing the composite filament into the extruder.

22. The device of claim 19, wherein the composite filament feeding system further includes a cutting device for cutting the composite filament.