Fluorescent binders for use in monitoring additive manufacturing processes

Patent metadata

Field	Value
Publication number	US-2021370588-A1
Application number	US-202117326707-A
Country	US
Kind code	A1
Filing date	May 21, 2021
Priority date	May 26, 2020
Publication date	Dec 2, 2021
Grant date	—

Abstract

A method of manufacturing a green body part comprises depositing a layer of a powder on a working surface; and selectively depositing a binder solution comprising a thermoplastic binder, a fluorescent material, and a binder medium into the layer of powder in a pattern representative of a structure of a layer of the green body part. The thermoplastic binder comprises one or more polymer strands dissolved in a solvent medium having an average molecular weight from greater than or equal to 7,000 g/mol to less than or equal to 100,000 g/mol. Binder solutions comprising fluorescent material and green body parts adhered together using the same are also disclosed.

First claim

What is claimed is:

1 . A method of manufacturing a green body part, comprising:
depositing a layer of powder on a working surface; and selectively depositing a binder solution comprising a thermoplastic binder, a fluorescent material, and a binder medium into the layer of powder in a pattern representative of a structure of a layer of the green body part wherein:
the thermoplastic binder comprises one or more polymer strands dissolved in a solvent medium having an average molecular weight from greater than or equal to 7,000 g/mol to less than or equal to 100,000 g/mol.

2 . The method according to claim 1 , wherein the fluorescent material is encapsulated prior to incorporation into the binder solution.

3 . The method according to claim 1 , wherein the fluorescent material is encapsulated on mixing into the binder solution.

4 . The method according to claim 1 , wherein the one or more polymer strands comprise one or more polymer species selected from the group consisting of polyvinyl alcohol (PVA), polyamides, polyacryl amide (PAAm), polyvinyl pyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid (PmAA), polymethyl methacrylate (PMMA), polyvinyl methyl ether-maleic anhydride (PVME-MA), polystyrene (PS), polyethylene oxide, polyethylene glycol (PEG), derivatives thereof, and combinations thereof.

5 . The method according to claim 1 , wherein the one or more polymer strands of the thermoplastic binder comprise a first polymer strand and a second polymer strand, wherein the first polymer strand comprises a first functional group and the second polymer strand comprises a second functional group different from the first functional group, wherein the first and second functional groups are configured to non-covalently couple the first polymer strand with the second polymer strand, and wherein the second polymer strand has an average molecular weight greater than or equal to 100 g/mol and less than or equal to 10,000 g/mol.

6 . The method according to claim 1 , wherein the fluorescent material comprises an aromatic dye that is encapsulated.

7 . The method according to claim 6 , wherein the aromatic dye is selected from the group consisting of a stilbene dye, pyrene dye, a coumarin dye, an anthracene dye, a tetracene dye, and combinations thereof.

8 . The method according to claim 1 , wherein the fluorescent material comprises a chromophore having at least one sulfonate or triazine group.

9 . The method according to claim 8 , wherein the chromophore comprises two, three, or four sulfonate groups.

10 . The method according to claim 8 , wherein the chromophore is a stilbene-based chromophore.

11 . The method according to claim 1 , wherein the binder solution is an aqueous binder solution.

12 . The method according to claim 1 , wherein the fluorescent material is present in an amount of from 0.01 wt % to 5 wt % based on a total weight of the binder solution.

13 . The method according to claim 12 , wherein the fluorescent material is present in an amount of from 0.1 wt % to 1 wt % based on a total weight of the binder solution.

14 . The method according to claim 1 , the method further comprising:
exposing the layer of the green body part to electromagnetic radiation; curing the layer of the green body part; and monitoring an intensity of light emitted by the fluorescent material, wherein the curing is performed until the intensity of the light emitted by the fluorescent material is below a predetermined threshold intensity.

15 . The method according to claim 14 , wherein the electromagnetic radiation is ultraviolet (UV) radiation.

16 . The method according to claim 15 , wherein the UV radiation has a wavelength from greater than or equal to 340 nm to less than or equal to 600 nm.

17 . The method according to claim 15 , wherein the UV radiation has a wavelength from greater than or equal to 340 nm to less than or equal to 400 nm.

18 . The method according to claim 1 , wherein the powder comprises a metal powder.

19 . A green body part comprising a powdered material adhered together with at least one binder comprising a fluorescent material.

20 . A binder solution comprising:
a thermoplastic binder comprising a first polymer strand having an average molecular weight from greater than or equal to 7,000 g/mol to less than or equal to 100,000 g/mol; a fluorescent material; and a binder medium.

Assignees

• Gen Electric

Inventors

• Natarajan Arunkumar
• Mook Joshua Tyler
• Chan Kwok Pong
• Alberts William C
• Bromberg Vadim

Classifications

• B22F1/107

  containing organic material comprising solvents, e.g. for slip casting · CPC title

• Y02P10/25

  Process efficiency · CPC title

• G01N2021/6439

  with indicators, stains, dyes, tags, labels, marks · CPC title

• G01N21/6428 Primary

  Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" (in vivo A61B5/00; immunoassay G01N33/53) · CPC title

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title