Magnetic platen assembly for additive manufacturing system

• US 9,744,730 B2
• Filed: 11/22/2013
• Issued: 08/29/2017
• Est. Priority Date: 11/22/2013
• Status: Active Grant

• Current Assignee: Evolve Additive Solutions, Inc.
• Original Assignee: Stratasys Incorporated
• Inventors: Comb, James W.
• Primary Examiner(s): Hauth, Galen
• Application Number:
  US14/087,590
• Publication Number:
  US 20150145174A1
• Time in Patent Office: 1,376 Days
• 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 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B29C 64/165 using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• CPC Class Codes: B29C 64/182 in parallel batches
• 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 64/205 Means for applying layers
• CPC Class Codes: B29C 64/245 Platforms or substrates support structures intended to be sacrificed after manufacture B29C64/40
• 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: G03G 15/1625 on a base other than paper
• CPC Class Codes: G03G 15/224 Machines for forming tactile or three dimensional images by electrographic means, e.g. braille, 3d printing
• CPC Class Codes: G03G 15/225 using contact-printing
• CPC Class Codes: G03G 15/24 whereby at least two steps are performed simultaneously
• CPC Class Codes: G03G 2215/1695 at the second or higher order transfer point

Abstract

A platen assembly for use in an additive manufacturing system, which includes a platen plate that is preferably secured to a gantry mechanism of the additive manufacturing system, and having a top surface, and one or more magnets secured to the platen plate and configured to generate one or more magnetic fields at the top surface of the platen plate. The platen gantry is configured to magnetically couple interchangeable and replaceable build sheets to the top surface of the platen plate due to the one or more generated magnetic fields, and where the magnetically-coupled build sheets are configured to receive the printed layers from the printing mechanism.

Claims

1. An electrophotography-based additive manufacturing system for printing a three-dimensional part, the additive manufacturing system comprising:

a printing mechanism configured to print imaged layers of charged powder material to a moving belt; and

a platen assembly comprising;

a platen plate having a top surface having a plurality of spaced apart members extending therefrom; and

one or more magnets secured to the platen plate and configured to generate one or more magnetic fields at the top surface of the platen plate;

wherein the platen assembly is configured to magnetically couple a build sheet to the top surface of the platen plate due to the one or more generated magnetic fields and the plurality of spaced apart members are configured to be accepted by a plurality of apertures in the build sheet, and wherein the build sheet is configured to receive the printed layers from the printing mechanism wherein the platen assembly moves in a synchronized rate of speed with the imaged layer to transfer the imaged layer from the moving belt to the platen or previously printed part layers over time using heat and pressure.

2. The additive manufacturing system of claim 1, and further comprising the build sheet, which comprises:

a base sheet comprising one or more ferromagnetic materials; and

a top film disposed on the base sheet and comprising one or more polymeric materials, wherein the top film defines a receiving surface for the build sheet to receive the printed layers and wherein the plurality of apertures extend through the base sheet and the top sheet.

3. The additive manufacturing system of claim 2, wherein the top film comprises an adhesive tape.

4. The platen assembly of claim 1, wherein the printing mechanism comprises one or more electrophotography engines and a transfer medium.

5. The additive manufacturing system of claim 1, and further comprising at least one heating element configured to heat the platen plate and the magnetically coupled build sheet.

6. The additive manufacturing system of claim 1, and further comprising a gantry mechanism operably secured to the platen plate.

7. The additive manufacturing system of claim 1, wherein the one or more magnets are permanent magnets.

8. The additive manufacturing system of claim 1, wherein the one or more magnets are electromagnets configured to receive electrical currents from the additive manufacturing system to generate and to disable the one or more magnetic fields.

9. A method for using a platen assembly in an electrophotography-based additive manufacturing system, the method comprising:

placing a first build sheet onto a top surface of a platen plate that is operably mounted to a gantry mechanism of the additive manufacturing system by positioning a plurality of holes in the first build sheet about a plurality of members extending from the platen plate;

magnetically coupling the placed first build sheet to the top surface of the platen plate;

printing imaged layers of a three dimensional part of charged powder material to a moving belt;

transferring the imaged layers of a three-dimensional part onto the magnetically-coupled first build sheet wherein the platen plate and build sheet moves in a synchronized rate of speed with the layer on the moving belt while heating and pressing the printed layers to previously printed layers over time;

removing the first build sheet with the printed three-dimensional part from the top surface of the platen plate;

flexing the first build sheet to delaminate the three-dimensional part from the first build sheet; and

placing a second build sheet onto the top surface of the platen plate;

magnetically coupling the placed second build sheet to the top surface of the platen plate; and

printing layers of a second three-dimensional part onto the magnetically-coupled second build sheet.

10. The method of claim 9, wherein the first build sheet comprises a ferromagnetic base sheet and a top film disposed on the ferromagnetic base sheet, and wherein printing layers of the three-dimensional part onto the magnetically-coupled first build sheet comprises printing layers of the three-dimensional part onto the top film of the first build sheet.

11. The method of claim 9, wherein printing the layers of the three-dimensional part and printing the layers of the second three-dimensional part are each performed with an electrophotography-based additive manufacturing technique.

12. The method of claim 9, wherein printing layers of the three-dimensional part onto the magnetically-coupled first build sheet comprises rolling a nip roller across the magnetically-coupled first build sheet.

13. The method of claim 9, and further comprising heating the platen plate and the build sheet.

14. The method of claim 13, and further comprising thermally insulating the platen plate from the gantry mechanism.