Additive manufacturing method for building three-dimensional objects with core-shell arrangements, and three-dimensional objects thereof

• US 10,493,695 B2
• Filed: 07/25/2017
• Issued: 12/03/2019
• Est. Priority Date: 09/17/2010
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Mikulak, James K., Deckard, Carl R., Zinniel, Robert L.
• Primary Examiner(s): O'Hern, Brent T
• Application Number:
  US15/659,190
• Publication Number:
  US 20170320266A1
• Time in Patent Office: 861 Days
• Field of Search: 428 98
• CPC Class Codes: B29C 2948/92704 Temperature
• CPC Class Codes: B29C 48/0021 combined with joining, lining or laminating
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/07 Flat, e.g. panels
• CPC Class Codes: B29C 48/154 Coating solid articles, i.e. non-hollow articles
• CPC Class Codes: B29C 48/16 Articles comprising two or more components, e.g. co-extruded layers
• CPC Class Codes: B29C 48/21 the layers being joined at their surfaces
• CPC Class Codes: B29C 48/92 Measuring, controlling or regulating
• CPC Class Codes: B29C 64/118 using filamentary material being melted, e.g. fused deposition modelling [FDM]
• CPC Class Codes: B29C 64/188 involving additional operations performed on the added layers, e.g. smoothing, grinding or thickness control surface shaping B29C59/00; after-treatment of articles without altering their shape B29C71/00
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• CPC Class Codes: B32B 3/26 characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids foam layer B32B5/18; layer of synthetic resin characterised by fillers that create voids or cavities B32B27/205; characterised by an apertured layer
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: D01F 8/04 from synthetic polymers
• CPC Class Codes: D01F 8/12 with at least one polyamide as constituent
• CPC Class Codes: Y10T 428/23 Sheet including cover or casing
• CPC Class Codes: Y10T 428/24612 Composite web or sheet
• CPC Class Codes: Y10T 428/2929 Bicomponent, conjugate, composite or collateral fibers or filaments [i.e., coextruded sheath-core or side-by-side type]

Abstract

A consumable filament for use in an extrusion-based additive manufacturing system, where the consumable filament comprises a core portion of a first thermoplastic material, and a shell portion of a second thermoplastic material that is compositionally different from the first thermoplastic material, where the consumable filament is configured to be melted and extruded to form roads of a plurality of solidified layers of a three-dimensional object, and where the roads at least partially retain cross-sectional profiles corresponding to the core portion and the shell portion of the consumable filament.

Claims

1. A three-dimensional object built with an extrusion-based additive manufacturing system, the three-dimensional object comprising:

a plurality of solidified layers each comprising roads formed from a flowable consumable material that exits an extrusion tip of the extrusion-based additive manufacturing system, wherein the flowable consumable material exiting the extrusion tip comprises a core material and a shell material that is compositionally different from the core material, and wherein the shell material encases the core material to provide an interface between the core material and the shell material; and

wherein at least a portion of the roads of the plurality of solidified layers comprise core regions of the core material and shell regions of the shell material, and wherein the core regions and the shell regions substantially retain cross-sectional profiles corresponding to the interface between the core material and the shell material of the flowable consumable material.

2. The three-dimensional object of claim 1, wherein the core material and the shell material at least partially interdiffuse at the interface between the core material and the shell material.

3. The three-dimensional object of claim 1, wherein the core material comprises a first thermoplastic polymer.

4. The three-dimensional object of claim 3, wherein the shell material comprises a colorant.

5. The three-dimensional object of claim 4, wherein the shell material further comprises a second thermoplastic polymer.

6. The three-dimensional object of claim 5, wherein the first thermoplastic polymer of the core material comprises a first semi-crystalline polymeric material having a first peak crystallization temperature, and wherein the second thermoplastic polymer of the shell material comprises a second semi-crystalline polymeric material having a second peak crystallization temperature that is different than the first peak crystallization temperature.

7. The three-dimensional object of claim 1, wherein substantially all of the roads of the plurality of solidified layers comprise the core regions and the shell regions that retain cross-sectional profiles corresponding to the interface between the core material and the shell material of the flowable consumable material.

8. A three-dimensional object built with an extrusion-based additive manufacturing system, the three-dimensional object comprising:

a plurality of solidified layers each comprising roads formed from a flowable consumable material that exits an extrusion tip of the extrusion-based additive manufacturing system, wherein the flowable consumable material exiting the extrusion tip comprises a core material and a shell material that is compositionally different from the core material, and wherein the shell material encases the core material to provide an interface between the core material and the shell material; and

wherein at least a portion of the roads of the plurality of solidified layers comprise core regions of the core material and shell regions of the shell material, and wherein the core regions and the shell regions are substantially maintained after extrusion into the plurality of solidified layers.

9. The object of claim 8, wherein the shell comprises a first semi-crystalline polymer and the core comprises the first semi-crystalline polymer and a crystallization inhibitor.

10. The object of claim 8, wherein the shell comprises a first semi-crystalline polymer and one or more nucleating agents and the core comprises the first semi-crystalline polymer.

11. The object of claim 8, wherein the core comprises a majority of a first semi-crystalline polymer and the shell comprises a majority of a second semi-crystalline polymer.

12. The object of claim 11, wherein a difference in melting points of the first semi-crystalline polymer and the second semi-crystalline polymer is about 8°

C. or less.

13. The object of claim 11, wherein a difference in melting points of the first semi-crystalline polymer and the second semi-crystalline polymer is about 3°

C. or less.

14. The object of claim 8, wherein the core and the shell each comprise polyamides, polyethylenes, polypropylenes, polyetheretherketones, polyetherarylketones, perfluoroalkoxys, polychlorotrifluoroethylenes, polyphenylene sulfides, fluorinated ethylene propylenes, polytetrafluoroethylenes, ethylene-tetrafluoroethylenes, polyvinylidene fluorides, and ethylene-chlorortifluoroethylenes, copolymers thereof, and combinations thereof.

15. The object of claim 14, wherein the polyamides comprise aliphatic nylon polyamides, such as nylon 6, nylon 6-6, nylon 6-10, nylon 6-12, nylon 10, nylon 10-10, nylon 11, nylon 12, and combinations thereof, wherein the polyethylenes include low-density polyethylene, medium-density polyethylene, high-density polyethylene, and combinations thereof, and wherein the polypropylenes include isotactic polypropylenes, syndiotactic polypropylenes, branched and linear variations thereof, and combinations thereof.

16. A three-dimensional object built with an extrusion-based additive manufacturing system, the three-dimensional object comprising:

a plurality of solidified layers each comprising roads formed from a flowable consumable material that exits an extrusion tip of the extrusion-based additive manufacturing system, wherein the flowable consumable material exiting the extrusion tip comprises a core material and a shell material that is different from the core material, and wherein the shell material encases the core material to provide an interface between the core material and the shell material wherein the core material and the shell material are semi-crystalline materials having peak crystallization temperatures that have at least a 2°

C. or greater difference; and

wherein at least a portion of the roads of the plurality of solidified layers comprise core regions of the core material and shell regions of the shell material, and wherein the core regions and the shell regions are substantially maintained after extrusion into the plurality of solidified layers.

17. The three-dimensional object of claim 16, wherein the peak crystallization temperatures of the semi-crystalline core material and the semi-crystalline shell material are at least a 10°

C. or greater in difference.

18. The three-dimensional object of claim 16, wherein the peak crystallization temperatures of the semi-crystalline core material and the semi-crystalline shell material are less than 25°

C. or less in difference.