Microwave-induced localized heating of cnt filled polymer composites for enhanced inter-bead diffusive bonding of fused filament fabricated part

Patent metadata

Field	Value
Publication number	US-2020009850-A1
Application number	US-201916517419-A
Country	US
Kind code	A1
Filing date	Jul 19, 2019
Priority date	Dec 26, 2013
Publication date	Jan 9, 2020
Grant date	—

Abstract

A microwave-induced heating of CNT filled (or coated) polymer composites for enhancing inter-bead diffusive bonding of fused filament fabricated parts. The technique incorporates microwave absorbing nanomaterials (carbon nanotubes (CNTs)) onto the surface or throughout the volume of 3D printer polymer filament to increase the inter-bead bond strength following a post microwave irradiation treatment and/or in-situ focused microwave beam during printing. The overall strength of the final 3D printed part will be dramatically increased and the isotropic mechanical properties of fused filament part will approach or exceed conventionally manufactured counterparts.

First claim

1 - 35 . (canceled)

36 . A polymer composite, comprising:
a polymer filament having an outer layer, wherein the outer layer comprises an electrically conductive percolated network of an electrically conductive nanomaterial.

37 . The polymer composite of claim 36 , wherein the polymer filament comprises at least one polymer selected from a group consisting of styrene (ABS), polycarbonate (PC), polylactic acid (PLA), polyethylene (PE), polycarbonate(PC)/styrene(ABS), polyphenylsulfone (PPSU), polyamide (nylon), polystyrene (PS), polyetherimide, polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE), and combinations thereof.

38 . The polymer composite of claim 36 , wherein the outer layer comprises a first polymer mixture of the electrically conductive nanomaterials and a polymer.

39 . The polymer composite of claim 36 , wherein the electrically conductive nanomaterial comprises carbon nanotubes.

40 . The polymer composite of claim 39 , wherein the carbon nanotubes are multi-walled carbon nanotubes.

41 . The polymer composite of claim 36 , wherein the outer layer has a thickness between 100 nm and 0.5 mm.

42 . The polymer composite of claim 36 , wherein the outer layer comprises between 1 wt % and 50 wt % of carbon nanotubes.

43 . The polymer composite of claim 36 , wherein the outer layer has a wt % of carbon nanotubes sufficient to form the electrically conductive percolated network of the electrically conductive material.

44 . The polymer composite of claim 36 , wherein the polymer filament has a volume and the electrically conductive nanomaterial is present throughout the volume.

45 . A polymer composite, comprising:
a polymer filament having an outer layer, wherein the outer layer comprises an electrically conductive nanomaterial provided at a concentration sufficient to provide a threshold dielectric loss tangent of the polymer filament that provides fusing at an interface of the outer layer of the polymer filament to an adjacent polymer filament upon the electrically conductive nanomaterial absorbing an electromagnetic wave selected to produce a predetermined temperature profile in the outer layer.

46 . The polymer composite of claim 45 , wherein the threshold dielectric loss tangent maximizes an electric current induced in the electrically conductive nanomaterial by the electromagnetic wave.

47 . The polymer composite of claim 45 , wherein the concentration of the electrically conductive nanomaterial is adjusted such that the outer layer exhibits a desired bond strength at the interface.

48 . The polymer composite of claim 45 , wherein the outer layer comprises polymer chains that inter-diffuse across the interface upon fusing.

49 . The polymer composite of claim 45 , wherein the polymer filament comprises at least one polymer selected from a group consisting of styrene (ABS), polycarbonate (PC), polylactic acid (PLA), polyethylene (PE), polycarbonate(PC)/styrene(ABS), polyphenylsulfone (PPSU), polyamide (nylon), polystyrene (PS), polyetherimide, polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE), and combinations thereof.

50 . The polymer composite of claim 45 , wherein the outer layer comprises a first polymer mixture of the electrically conductive nanomaterials and a polymer.

51 . The polymer composite of claim 45 , wherein the electrically conductive nanomaterial comprises carbon nanotubes.

52 . The polymer composite of claim 45 , wherein the outer layer has a wt % of carbon nanotubes sufficient to form an electrically conductive percolated network of the electrically conductive material.

53 . The polymer composite of claim 45 , wherein the polymer filament has a volume and the electrically conductive nanomaterial is present throughout the volume.

54 . A three-dimensional object, comprising:
a plurality of polymer filaments arranged in successive layers, wherein the polymer filaments comprise a coating comprising an electrically conductive percolated network of an electrically conductive material and wherein the coating of the polymer filaments are fused together.

55 . The three-dimensional object of claim 54 , wherein the polymer filaments comprise at least one polymer selected from a group consisting of styrene (ABS), polycarbonate (PC), polylactic acid (PLA), polyethylene (PE), polycarbonate(PC)/styrene(ABS), polyphenylsulfone (PPSU), polyamide (nylon), polystyrene (PS), polyetherimide, polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE), and combinations thereof.

56 . The three-dimensional object of claim 54 , wherein the coating comprises a first polymer mixture of the electrically conductive nanomaterials and a polymer.

57 . The three-dimensional object of claim 54 , wherein the electrically conductive nanomaterial comprises carbon nanotubes.

58 . The three-dimensional object of claim 54 , wherein the outer layer has a wt % of carbon nanotubes sufficient to form the electrically conductive percolated network of the electrically conductive material.

59 . The three-dimensional object of claim 54 , wherein the polymer filament has a volume and the electrically conductive nanomaterial is present throughout the volume.

Assignees

• Univ Texas Tech System

Inventors

• Sweeney Charles B
• Green Micah J
• Saed Mohammad

Classifications

• B29C64/118

  using filamentary material being melted, e.g. fused deposition modelling [FDM] · CPC title

• B29C70/38

  Automated lay-up, e.g. using robots, laying filaments according to predetermined patterns {(application heads for tyres B29D30/28)} · CPC title

• B29K2105/167

  Nanotubes · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B29B15/14

  of filaments or wires · CPC title