USE AND PRODUCTION OF COATED FILAMENTS FOR EXTRUSION-BASED 3D PRINTING PROCESSES

• US 20140134335A1
• Filed: 11/06/2013
• Published: 05/15/2014
• Est. Priority Date: 11/09/2012
• Status: Active Grant

• Current Assignee: Evonik Operations GmbH (Rag-Stiftung)
• Original Assignee: Evonik Industries AG (Rag-Stiftung)
• Inventors: PRIDOEHL, Markus, Behrens, Ulrike, Bernhardt, Stefan, Klaar, Ann-Kristin, von Karsa-Wilberforce, Samuel
• Granted Patent: US 9,193,110 B2
• Time in Patent Office: Days
• US Class Current: 427/256
• CPC Class Codes: B05D 1/265 Extrusion coatings
• CPC Class Codes: B05D 2201/02 Polymeric substrate
• CPC Class Codes: B05D 2256/00 Wires or fibres
• CPC Class Codes: B05D 7/20 to wires for insulating electric cables H01B13/16
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/06 Rod-shaped
• 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 64/314 Preparation
• 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 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: D01D 11/06 Coating with spinning solutions or melts
• CPC Class Codes: Y10T 428/2933 Coated or with bond, impregnation or core

Abstract

The present invention relates to a novel process for the production of coated filaments for subsequent application as print in extrusion-based 3D printers, e.g. FDM printers (fused deposition modelling printers). The filaments are coated in a separate process outside of the printer, and can also be used in a conventional extrusion printer. The present invention further relates to the coating device for application of the coating to the filament and to a roll containing the coated filaments.

Claims

1. A process for extrusion-based 3D printing, the process comprising:

applying a coating composition to a filament to obtain a coated filament;

fixing the coating on the filament;

conveying the fixed coated filament to a printing head;

melting the filament in the printing head; and

extruding the melted coated filament onto a substrate to form a three dimensional object;

wherein the coating composition comprises at least one selected from the group consisting of an additive, a pigment and an ink.

2. The process according to claim 1, wherein

the coating is conducted in a coating unit in which the filament is coated with the coating composition,

components of the coating composition are supplied to the coating unit from feed containers equipped with metering devices, and

the coated filament is fixed in a fixing unit downstream of the coating unit before being conveyed to the printing head.

3. The process according to claim 1, further comprising:

producing the coating composition from individual components in a mixer to obtain a coating composition mixture; and

passing the mixture to the coating unit.

4. The process according to claim 1, further comprising:

tensioning the filament during the coating and fixing, wherein

the tension is formed by a guide system or a brake upstream of the coating unit and optionally a conveying unit after the fixing unit.

5. The process according to claim 1, wherein the filament comprises a thermoplastically processable material.

6. The process according to claim 5, wherein the thermoplastically processable material is at least one selected from the group consisting of an acrylonitrile-butadiene-styrene terpolymer (ABS), a polycarbonate (PC), a poly(meth)acrylate, a polyphenylene sulphone (PPSU), a high density polyethylene (HDPE), a polyetherimide (PEI), a polyether ether ketone (PEEK), a polylactic acid (PLA).

7. The process according to claim 1, wherein the filament comprises an acid-, base- or water-soluble polymer, and the filament comprising the acid-, base- or water-soluble polymer is a support material in the three dimensional object.

8. The process according to claim 1 wherein the process is controlled by a CAD program, which program comprises:

coordinates for the three dimensional object; and

color information for the manufacturing process and for the regulation of the formulation of materials and of inks;

wherein the respective color shade is thus established through regulation of the metering devices and controlled metering of respective primary colours and black from feed containers into the system.

9. The process according to claim 1, wherein the coating composition comprises an additive and the additive is activatable by microwaves, heat, plasma, UV light or magnetic fields.

10. The process according to claim 1, wherein the coating composition further comprises at least one of an adhesion promoter and adhesive and the coating composition is optionally colorless.

11. The process according to claim 2, wherein the fixing unit comprises at least one selected from the group consisting of a UV source, an IR source, a plasma source, a heating system, a nozzle for optionally heated gas or air, and an optionally heated clear-run section measuring at least 1 cm.

12. The process according to claim 1, wherein the coating unit is a unit comprising at least one of a nozzle, a microextruder, an annular gap and a sponge-like material saturated with the coating composition.

13. The process according to claim 1, wherein the coating unit is on-line directly downstream of an extrusion process for the production of the filament.

14. The process according to claim 1, further comprising downstream of the fixing process, winding the fixed coated filament onto a roll.

15. A coating device for the production of coated filaments according to claim 1, wherein the location of the coating unit is not within a 3D printer.

17. A roll with coated filament for an extrusion-based 3D printer, wherein the roll is obtained by the process according to claim 12.

16. A roll with coated filament, wherein the filament is coated with at least one selected from the group consisting of an additive, a pigment and an ink.