Embedding 3D printed fiber reinforcement in molded articles

• US 10,682,844 B2
• Filed: 01/12/2017
• Issued: 06/16/2020
• Est. Priority Date: 03/22/2013
• Status: Active Grant

• Current Assignee: MarkForged, Inc
• Original Assignee: MarkForged, Inc
• Inventors: Mark, Gregory Thomas
• Primary Examiner(s): Zhao, Xiao S
• Assistant Examiner(s): Luk, Emmanuel S
• Application Number:
  US15/404,816
• Publication Number:
  US 20170120519A1
• Time in Patent Office: 1,251 Days
• CPC Class Codes: B29C 45/1418 the inserts being deformed or preformed, e.g. by the injection pressure
• 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: B29C 64/393 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• CPC Class Codes: B29C 70/16 using fibres of substantial or continuous length non-woven fabrics per se D04H3/00
• CPC Class Codes: B29K 2025/08 Copolymers of styrene, e.g. AS or SAN, i.e. acrylonitrile styrene B29K2055/02 takes precedence
• CPC Class Codes: B29K 2063/00 Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2071/00 Use of polyethers , e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone 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 2101/12 Thermoplastic materials
• CPC Class Codes: B29K 2105/08 of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns
• CPC Class Codes: B29L 2031/3091 Bicycles
• CPC Class Codes: B29L 2031/3425 Printed circuits
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• 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
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 2219/35134 : 3-D cad-cam
• CPC Class Codes: G05B 2219/49007 : Making, forming 3-D object, model, surface
• CPC Class Codes: G06F 30/00 : Computer-aided design [CAD]
• CPC Class Codes: Y02P 90/02 : Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A reinforced molding is formed having an internal continuous fiber reinforcement preform embedded therein. Continuous reinforcing fiber is deposited in a reinforcement volume to form a continuous fiber reinforcement preform, and the reinforcement preform is then located within a mold of a molding apparatus. The mold is loaded with flowable and substantially isotropic molding material, e.g., by injection with heated and/or pressurized resin. The molding material is hardened (by curing or cooling or the like) to overmold the continuous fiber reinforcement preform. The resulting reinforced molding surrounds the internal continuous fiber reinforcement preform with a hardened substantially isotropic molding material.

Claims

1. A method of fabricating a reinforced molding, comprising:

additively depositing continuous reinforcing fiber in a reinforcement volume to form a continuous fiber reinforcement preform;

locating the continuous fiber reinforcement preform within a mold of a molding apparatus;

loading the mold with molten molding material;

hardening the molten molding material into a hardened molding material to overmold the continuous fiber reinforcement preform, thereby forming a reinforced molding having the hardened molding material surrounding the continuous fiber reinforcement preform, wherein the reinforcement volume is smaller than a volume of the entire reinforced molding; and

forming a support material in a first shape as a support preform,

wherein the continuous reinforcing fiber is additively deposited in the reinforcement volume in a second shape following a contour of the support preform to form the continuous fiber reinforcement preform.

2. The method according to claim 1, wherein the reinforcement volume includes a combined volume of the continuous reinforcing fiber and a fiber reinforcement matrix material that may be heated to a liquid state within which the continuous reinforcing fiber is additively deposited, and the reinforcement volume is less than 20 percent of the entire reinforced molding.

3. The method according to claim 2, wherein the molding is performed at a molding material pressure which removes air voids within the fiber reinforcement matrix material.

4. The method according to claim 1, wherein the continuous fiber reinforcement preform is bent or deformed from its formation shape to a deformed shape within the mold.

5. The method according to claim 1, wherein two or more continuous fiber reinforcement preforms are bonded to one another prior to being located within the mold.

6. The method according to claim 1, wherein the mold is an injection mold, and pack pressure applied to the molten molding material during molding consolidates the continuous fiber reinforcement preform into a final shape and removes voids within the continuous fiber reinforcement preform.

7. The method according to claim 1, wherein the mold is an injection mold, and heat from injected molding material remelts the fiber reinforcement matrix material of the continuous fiber reinforcement preform.

8. The method according to claim 1, wherein the continuous reinforcing fiber deposition is an additively deposited thermoplastic continuous fiber reinforced prepreg tape having a width at least three times its height.

9. The method according to claim 1, further comprising applying a vacuum during at least one of formation of the continuous fiber reinforcement preform and the reinforced molding to remove voids.

10. The method according to claim 1, wherein at least one part of the support preform extends to be contiguous with a surface of the reinforced molding.

11. The method according to claim 1, wherein the support preform is formed in a non-looped shape for permitting additively depositing the continuous reinforcing fiber by winding about the support preform.

12. The method according to claim 1, wherein the support preform is injection molded.

13. The method according to claim 1, wherein the support preform is injection molded as a honeycombed structure, with a contiguous outer surface suitable as a winding substrate.

14. The method according to claim 1, wherein at least one of the support preform and continuous fiber reinforcement preform are formed in alternating successive additive and injection molded stages.

15. The method according to claim 1, wherein the support preform is formed in a substantially rotationally symmetric shape or mandrel for permitting additively depositing the continuous reinforcing fiber by winding about the support preform.

16. The method according to claim 1, wherein the support preform is relatively moved in at least one rotational degree of freedom with respect to a deposition head that additively deposits the continuous reinforcing fiber in the second shape following the contour of the support preform to form the continuous fiber reinforcement preform.

17. The method according to claim 1, wherein the continuous fiber reinforcement preform embeds at least one sandwich panel structure.

18. The method according to claim 17, wherein the sandwich panel structure is a foldable structure, having a linear gap formed therein opposite a fold line to form a hinge.

19. The method according to claim 1, wherein the support preform is formed including a soluble material, and further comprising dissolving the support preform.

20. The method according to claim 19, wherein the support preform is dissolved before locating the continuous fiber reinforcement preform within the mold.

21. The method according to claim 19, wherein the support preform is one of displaced, melted, and dissolved by the molten molding material loaded into the mold.

22. The method according to claim 19, wherein the support preform is dissolved after the mold material is hardened.

23. The method according to claim 19, wherein the support preform is dissolved at least in part before the support preform is located in the mold, and at least in part after the molten molding material is hardened.

24. The method according to claim 1, wherein the support preform is bent or deformed from its formation shape to a deformed shape for depositing the continuous reinforcing fiber to form the continuous fiber reinforcement preform.

25. The method according to claim 1, further comprising arranging a wide prepreg sheet against the support preform before additively depositing continuous reinforcing fiber tape prepreg.

26. The method of fabricating a continuous fiber reinforced injection molding according to claim 1, wherein the continuous fiber reinforcement preform is located in the reinforcement volume following a contour to form the continuous fiber reinforcement preform as a first reinforced panel, and further comprising locating a honeycombed panel of molding material alongside the first reinforced panel, wherein the molding material is hardened to overmold the honeycombed panel against the first reinforced panel, thereby forming a fiber reinforced molding including a molding material honeycomb and a continuous fiber reinforcement.

27. The method according to claim 26, wherein a second reinforced panel is additively deposited upon the honeycombed panel.

28. The method according to claim 27, wherein the second reinforced panel is formed having a joining surface mirroring a surface of the first reinforced panel.

29. The method according to claim 27, wherein a honeycomb structure is formed as a second support preform upon which the second reinforced panel is deposited.

30. The method according to claim 1, wherein the molding material is substantially isotropic in tensile strength, and the continuous reinforcing fiber is substantially anisotropic in tensile strength.