Ribbon liquefier and method of use in extrusion-based digital manufacturing systems

• US 8,926,882 B2
• Filed: 04/22/2013
• Issued: 01/06/2015
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Batchelder, J. Samuel, Swanson, William J., Crump, S. Scott
• Primary Examiner(s): Gupta, Yogendra
• Assistant Examiner(s): Luk, Emmanuel S
• Application Number:
  US13/867,366
• Publication Number:
  US 20130234366A1
• Time in Patent Office: 624 Days
• Field of Search: 425/DIG.17, 425/113, 425/375, 425/144, 425/97, 425/145, 425/162, 264/75, 264/245, 264/255, 264/308, 700/119
• US Class Current: 264/308
• CPC Class Codes: B29C 41/46 Heating or cooling
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/07 Flat, e.g. panels
• CPC Class Codes: B29C 48/2888 in band or in strip form, e.g. rubber strips
• CPC Class Codes: B29C 64/106 using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• CPC Class Codes: B29C 64/118 using filamentary material being melted, e.g. fused deposition modelling [FDM]
• CPC Class Codes: B29C 64/386 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B29K 2025/00 Use of polymers of vinyl-aromatic compounds or derivatives thereof as moulding material
• CPC Class Codes: B29K 2055/02 ABS polymers, i.e. acrylonitrile-butadiene-styrene polymers
• CPC Class Codes: B29K 2069/00 Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2077/00 Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2079/085 Thermoplastic polyimides, e.g. polyesterimides, PEI, i.e. polyetherimides, or polyamideimides; Derivatives thereof
• CPC Class Codes: B29K 2081/06 PSU, i.e. polysulfones; PES, i.e. polyethersulfones or derivatives thereof
• CPC Class Codes: B29K 2105/0032 Pigments, colouring agents or opacifiyng agents
• CPC Class Codes: B29K 2105/0044 Stabilisers, e.g. against oxydation, light or heat
• CPC Class Codes: B29K 2105/0067 Melt
• CPC Class Codes: B29K 2105/16 Fillers
• CPC Class Codes: B29L 2009/00 Layered products
• 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: B33Y 50/02 : for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 70/00 : Materials specially adapted for additive manufacturing

Abstract

A ribbon liquefier comprising an outer liquefier portion configured to receive thermal energy from a heat transfer component, and a channel at least partially defined by the outer liquefier portion, where the channel has dimensions that are configured to receive the ribbon filament, and where the ribbon liquefier is configured to melt the ribbon filament received in the channel to at least an extrudable state with the received thermal energy to provide a melt flow. The dimensions of the channel are further configured to conform the melt flow from an axially-asymmetric flow to a substantially axially-symmetric flow in an extrusion tip connected to the ribbon liquefier.

Claims

1. A method for building a three-dimensional model in an extrusion-based digital manufacturing system, the method comprising:

heating a ribbon liquefier retained by the extrusion-based digital manufacturing system, the ribbon liquefier having a static channel with an inlet end and an outlet end;

feeding a ribbon filament into the inlet end of the static channel of the heated ribbon liquefier;

melting the ribbon filament in the static channel to at least an extrudable state with the heat to provide a molten material, wherein the molten material conforms to an axially-asymmetric flow in the channel;

moving the molten material having the axially-asymmetric flow from the static channel to an extrusion tip disposed at the outlet end of the channel with a viscosity-pump action of the fed ribbon filament;

conforming the molten material to a substantially axially-symmetric flow;

extruding the molten material having the substantially axially-symmetric flow from the extrusion tip; and

depositing the extruded material as a road to form at least a portion of a layer of the three-dimensional model.

2. The method of claim 1, wherein the static channel extends along a longitudinal axis and has a substantially-rectangular cross section perpendicular to the longitudinal axis, wherein the substantially-rectangular cross section has a width and a thickness, wherein an aspect ratio of the width to the thickness is about 2:

1 or greater.

3. The method of claim 2, wherein aspect ratio of the width to the thickness ranges from 2.5:

1 to about 20;

1.

4. The method of claim 2, wherein the width ranges from about 1.0 millimeter to about 12.7 millimeters, and the thickness ranges from about 0.25 millimeters to about 2.5 millimeters.

5. The method of claim 1, wherein the static channel extends along a longitudinal axis and has an arcuate cross section perpendicular to the longitudinal axis.

6. The method of claim 1, wherein feeding the ribbon filament into the inlet end of the static channel comprises driving the ribbon filament into the inlet end of the static channel with a filament drive mechanism.

7. The method of claim 1, wherein the ribbon filament comprises topographical surface patterns.

8. The method of claim 1, wherein melting the ribbon filament in the static channel comprises transferring the heat as thermal energy to the ribbon filament in the static channel in a manner such that at least about 60% of the transferred thermal energy diffuses through the ribbon filament in one cross-sectional dimension of the ribbon filament.

9. A method for building a three-dimensional model in an extrusion-based digital manufacturing system, the method comprising:

providing a ribbon filament to an extrusion head retained by the extrusion-based digital manufacturing system, wherein the extrusion head comprises a ribbon liquefier, a heat transfer component coupled to the ribbon liquefier, and an extrusion tip, and wherein the ribbon liquefier has a static channel with a substantially-rectangular cross section;

transferring thermal energy from the heat transfer component to at least a portion of the ribbon liquefier;

feeding the ribbon filament into an inlet end of the static channel of the ribbon liquefier;

melting the ribbon filament in the static channel to at least an extrudable state with the transferred thermal energy to provide a molten material;

conforming the molten material to dimensions of the static channel;

moving the molten material to an extrusion tip of the extrusion head with a viscosity-pump action of the fed ribbon filament;

conforming the melt flow from the dimensions of the static channel to a substantially axially-symmetric flow;

extruding the melt flow from the extrusion tip; and

depositing the extruded material as a road to form at least a portion of a layer of the three-dimensional model.

10. The method of claim 9, wherein an aspect ratio of the ribbon filament corresponds to an aspect ratio of the inlet end of the static channel.

11. The method of claim 9, wherein the extrusion head further comprises a filament drive mechanism, and wherein feeding the ribbon filament into the inlet end of the static channel comprises driving the ribbon filament into the inlet end of the static channel with the filament drive mechanism.

12. The method of claim 9, wherein the substantially-rectangular cross section of the static channel has a width and a thickness, wherein an aspect ratio of the width to the thickness is about 2:

1 or greater.

13. The method of claim 9, wherein the width ranges from about 1.0 millimeter to about 12.7 millimeters, and the thickness ranges from about 0.25 millimeters to about 2.5 millimeters.

14. The method of claim 9, wherein at least a portion of the ribbon liquefier has a layer comprising a fluorinated polymer.

15. A method for building a three-dimensional model in an extrusion-based digital manufacturing system, the method comprising:

providing thermal energy to a ribbon liquefier retained by the extrusion-based digital manufacturing system, wherein the ribbon liquefier comprises a static channel having an inlet end and an outlet end;

feeding successive segments of a ribbon filament from a supply source to the inlet end of the static channel of the ribbon liquefier, wherein the supply source is offset from the ribbon liquefier;

transferring the provided thermal energy to the successive segments of the ribbon filament in the static channel in a manner such that at least about 60% of the transferred thermal energy diffuses through the ribbon filament in one cross-sectional dimension of the ribbon filament to melt the successive segments of the ribbon filament to produce a molten material;

moving the molten material from the static channel to an extrusion tip disposed at the outlet end of the static channel with a viscosity-pump action of unmelted segments of the fed ribbon filament;

extruding the molten material from the extrusion tip; and

depositing the extruded material as a road to form at least a portion of a layer of the three-dimensional model.

16. The method of claim 15, wherein an aspect ratio of the ribbon filament corresponds to an aspect ratio of the inlet end of the static channel.

17. The method of claim 15, wherein at least about 65% of the transferred thermal energy diffuses through the ribbon filament in the one cross-sectional dimension of the ribbon filament.

18. The method of claim 17, wherein at least about 70% of the transferred thermal energy diffuses through the ribbon filament in the one cross-sectional dimension of the ribbon filament.

19. The method of claim 15, wherein feeding the successive segments of the ribbon filament into the inlet end of the static channel comprises driving the successive segments of the ribbon filament into the inlet end of the static channel with a filament drive mechanism.

20. The method of claim 15, wherein the static channel extends along a longitudinal axis and has a substantially-rectangular cross section perpendicular to the longitudinal axis, wherein the substantially-rectangular cross section has a width and a thickness, wherein an aspect ratio of the width to the thickness is about 2:

1 or greater.