Method of fabricating a loaded powder, and a product made of electrically conductive composite materials

Patent metadata

Field	Value
Publication number	US-10655021-B2
Application number	US-201815957185-A
Country	US
Kind code	B2
Filing date	Apr 19, 2018
Priority date	Apr 20, 2017
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

A method of fabricating an electrically conductive loaded powder of thermoplastic polymers. The method comprises the steps of making an original powder containing cores made of thermoplastic polymers and of making the loaded powder by using electrically conductive submicrometer filaments and wax, forming a plurality of particulate compounds each comprising one of the cores together with at least one of the filaments and a protective membrane of the wax.

First claim

What is claimed is:

1. A method of fabricating an electrically conductive powder of thermoplastic polymers, the electrically conductive powder of thermoplastic polymers being referred to as a loaded powder, wherein the method comprises the steps of:
making an original powder containing cores of thermoplastic polymers, each of the cores comprising a grain or a flake; and
making the loaded powder using the original powder together with electrically conductive submicrometer filaments and wax so as to form a plurality of particulate compounds, a smallest dimension of each submicrometer filament being less than one micrometer and greater than or equal to one hundred nanometers, each particulate compound comprising at least one of the cores together with at least one of the filaments and a protective membrane of the wax, each articulate compound having at least one of the filaments and one of the protective membranes arranged around one of the cores.

2. The method according to claim 1 , wherein each filament is inscribed in a rectangular parallelepiped having a length lying in the range 50 μm to 200 μm, a height lying in the range 100 nm to 400 nm, and a width lying in the range 100 nm to 400 nm.

3. The method according to claim 1 , wherein each of the cores is inscribed in a cube presenting sides each extending over a length lying in the range 20 μm to 100 μm.

4. The method according to claim 1 , wherein the cores of thermoplastic polymers belong to a family selected from: polyaryletherketone (PAEK); poly(phenylene sulfide) (PPS); polyetherimide (PEI); or polyimide (PI).

5. The method according to claim 1 , wherein the filaments are made of silver.

6. The method according to claim 1 , wherein the wax is ethyl cellulose.

7. The method according to claim 1 , wherein the particulate compounds have a mean percentage by weight of filaments relative to the weight of the cores lying in the range 10% to 30%.

8. The method according to claim 1 , wherein the particulate compounds are formed by performing the following steps:
fabricating an intermediate solution, the intermediate solution comprising a solution of a solvent and of the wax in which at least the filaments are dispersed; and
spraying the intermediate solution into a reactor.

9. The method according to claim 8 , wherein the reactor is an air-fluidized bed reactor, and the method includes a step of fluidizing the original powder in the air-fluidized bed reactor, the spraying being performed by spraying the intermediate solution onto the original powder in the air-fluidized bed reactor.

10. The method according to claim 9 , wherein the solvent comprises ethanol.

11. The method according to claim 8 , wherein the reactor is an atomizer, the intermediate solution includes the original powder, and the spraying is performed in the atomizer using a fluid presenting a predetermined temperature higher than an evaporation temperature of the solvent.

12. The method according to claim 11 , wherein the solvent is water.

13. The method according to claim 11 , wherein the predetermined temperature is higher than a glass transition temperature of the wax.

14. A fabrication method for fabricating a product made of composite materials, the product being electrically conductive, wherein the method comprises the steps of:
depositing a loaded powder on reinforcement using a dry technique or a wet technique, making use of the loaded powder obtained by applying the method according to claim 1 ; and
passing the reinforcement and the loaded powder through an oven, which oven applies a predetermined heating cycle.

15. The fabrication method according to claim 14 , wherein the heating cycle comprises:
a first stage of temperature rising at a gradient of 50° C./min up to a maximum temperature of 330° C.; and
a second stage of maintaining the maximum temperature for a duration lying in the range 15 min to 30 min.

16. A method of fabricating an electrically conductive powder of thermoplastic polymers, the electrically conductive powder of thermoplastic polymers being referred to as a loaded powder, wherein the method comprises:
making an original powder containing cores of thermoplastic polymers, each of the cores comprising a grain or a flake; and
combining the original powder with electrically conductive submicrometer filaments and wax to form a plurality of particulate compounds to form the loaded powder, a smallest dimension of each submicrometer filament being less than one micrometer and greater than or equal to one hundred nanometers, each particulate compound comprising at least one of the cores together with at least one of the filaments and a protective membrane of the wax, each particulate compound having at least one of the filaments and one of the protective membranes arranged around one of the cores.

17. The method according to claim 16 , wherein each filament is inscribed in a rectangular parallelepiped having a length lying in the range 50 μm to 200 μm, a height lying in the range 100 nm to 400 nm, and a width lying in the range 100 nm to 400 nm.

18. The method according to claim 16 , wherein each of the cores is inscribed in a cube presenting sides each extending over a length lying in the range 20 μm to 100 μm.

19. The method according to claim 16 , wherein the cores of thermoplastic polymers belong to a family selected from: polyaryletherketone (PAEK); poly(phenylene sulfide) (PPS); polyetherimide (PEI); or polyimide (PI), the filaments are made of silver, and the wax is ethyl cellulose.

20. The method according to claim 16 , wherein the particulate compounds have a mean percentage by weight of filaments relative to the weight of the cores lying in the range 10% to 30%.

Assignees

• Airbus Helicopters

Inventors

• Joedicke Philippe

Classifications

• C08J2361/04

  Condensation polymers of aldehydes or ketones with phenols only · CPC title

• C08J2381/02

  Polythioethers; Polythioether-ethers · CPC title

• C08J2381/04

  Polysulfides · CPC title

• C08J2401/02

  Cellulose; Modified cellulose · CPC title

• C08J2491/06

  Waxes · CPC title