Method for manufacturing a fibrous material impregnated with thermoplastic polymer

Patent metadata

Field	Value
Publication number	US-11938656-B2
Application number	US-201816623946-A
Country	US
Kind code	B2
Filing date	Jun 21, 2018
Priority date	Jun 22, 2017
Publication date	Mar 26, 2024
Grant date	Mar 26, 2024

Abstract

A method of manufacturing an impregnated fibrous material including a fibrous material made of continuous fibers and at least one thermoplastic polymer matrix, the method including pre-impregnating the fibrous material while it is in the form of a roving or several parallel rovings with the thermoplastic material and heating the thermoplastic matrix for melting, or maintaining in the molten state, the thermoplastic polymer after pre-impregnation, the at least one heating step being carried out by means of at least one heat-conducting spreading part (E) and at least one heating system, with the exception of a heated calendar, the roving or the rovings being in contact with part or all of the surface of the at least one spreading part (E) and partially or wholly passing over the surface of the at least one spreading part (E) at the level of the heating system.

First claim

The invention claimed is:

1. A method of manufacturing an impregnated fibrous material comprising a fibrous material made of continuous fibers and at least one thermoplastic polymer matrix, wherein said impregnated fibrous material is produced as a single unidirectional ribbon or a plurality of unidirectional parallel ribbons and wherein said method comprises:
a step of pre-impregnating said fibrous material while it is in the form of a roving or several parallel rovings with a thermoplastic polymer powder, the pre-impregnating being done with a pre-impregnation system chosen from among a fluidized bed or a spray gun; and
at least one step of heating the thermoplastic polymer powder after the thermoplastic polymer powder has pre-impregnated the fibrous material, the at least one step of heating including melting the thermoplastic polymer powder to impregnate the fibrous material and form the at least one thermoplastic polymer matrix,
the at least one heating step being carried out by means of at least one heat-conducting supporting part (E) and at least one heating system, with the exception of a heated calender, wherein said at least one heating system is chosen from an infrared bulb, a UV bulb or an equipment employing convection heating,
the roving or rovings being partially or wholly in contact with a surface of the at least one supporting part (E) and partially or wholly passing over the surface of the at least one supporting part (E) at a level of the at least one heating system,
wherein the method excludes any electrostatic impregnation method where the continuous fibers gain a deliberate charge, and
wherein the impregnated fibrous material possesses a porosity of less than 10%.

2. The method according to claim 1 , wherein said impregnated fibrous material is not flexible.

3. The method according to claim 1 , wherein one or more supports are present upstream from the pre-impregnation system.

4. The method according to claim 1 , wherein said at least one heating step immediately follows the pre-impregnation step.

5. The method according to claim 1 , wherein said at least one supporting part (E) is a first compression roller with either a convex, concave or cylindrical shape.

6. The method according to claim 5 , wherein said roving or rovings of fibrous material form an angle α′ 1 of 0.1 to 89° with the first compression roller and a horizontal tangent to said first compression roller, said roving or rovings expanding in contact with said first compression roller.

7. The method according to claim 5 , wherein a second compression roller is present after said first compression roller, said roving or rovings of fibrous material forming an angle α′ 2 of 0 to 180° with said second compression roller and a horizontal tangent to said second compression roller, said roving or rovings of fibrous material expanding in contact with said second compression roller.

8. The method according to claim 7 , wherein at least one third compression roller is present after said second compression roller, said roving or rovings of fibrous material forming an angle α′ 3 of 0 to 180° with said third compression roller and a horizontal tangent to said third compression roller, said roving or rovings of fibrous material expanding in contact with said third compression roller.

9. The method according to claim 1 , wherein said at least one supporting part is made up of 1 to 15 cylindrical compression rollers.

10. The method according to claim 9 , wherein said at least one supporting part is made up of six to ten cylindrical compression rollers, all at the same level.

11. The method according to claim 1 , wherein during the at least one heating step the roving or rovings of fibrous material possess a spreading percentage at an outlet of a last compression roller of about 0 to 300% relative to that of said roving or rovings of fibrous material at an inlet of a first compression roller.

12. The method according to claim 1 , wherein said thermoplastic polymer powder contains a nonreactive thermoplastic polymer.

13. The method according to claim 1 , wherein said thermoplastic polymer powder contains a reactive pre-polymer capable of reacting with itself or with a second pre-polymer, based on chain ends of said second pre-polymer, or with another chain extender, said reactive pre-polymer optionally being polymerized during the at least one heating step.

14. The method according to claim 1 , wherein said at least one thermoplastic polymer powder contains a polymer or copolymer selected from a group consisting of polyaryl ether ketones (PAEK); polyaryl ether ketone ketone (PAEKK); aromatic polyether imides (PEI); polyaryl sulfones; polyarylsulfides; polyamides (PA); PEBAs; polyolefins; and mixtures thereof.

15. The method according to claim 1 , wherein said at least one thermoplastic polymer matrix contains a polymer whose glass transition temperature is such that Tg≥80° C., or a semi-crystalline polymer whose melting temperature Tm≥150° C.

16. The method according to claim 1 , wherein said at least one thermoplastic polymer matrix contains polyamides.

17. The method according to claim 1 , wherein the impregnated fibrous material possesses a fiber level between 45 to 65% by volume.

18. The method according to claim 1 , wherein the porosity of said impregnated fibrous material is less than 5%.

19. The method according to claim 1 , wherein the method further comprises a step for shaping the impregnated roving or impregnated parallel rovings of fibrous material into a single unidirectional ribbon or a plurality of parallel unidirectional ribbons by calendering using at least one heating calender, said at least one heating calender including a plurality of calendering grooves in accordance with the number of said ribbons, wherein the shaping occurs with a pressure and/or separation between rollers of said calender.

20. The method according to claim 19 , wherein the shaping step is done using a plurality of heating calenders, mounted in parallel and/or in series relative to a passage direction of the fiber roving or rovings.

21. The method according to claim 19 , wherein said at least one heating calender comprises an integrated induction or microwave heating system, coupled with the presence of carbon fillers in said thermoplastic polymer matrix.

22. The method according to claim 19 , wherein a belt press is present between the at least one heating system and the at least one heating calender.

23. The method according to claim 19 , wherein a heating nozzle is present between the at least one heating system and the at least one heating calender.

24. The method according to claim 23 , wherein said heating nozzle covers said single roving or said plurality of parallel rovings after impregnation with a polymer powder, wherein the polymer powder is either identical to or different from said thermoplastic polymer powder.

25. The method according to claim 19 , wherein a belt press is present between the at least one heating system and the at least one heating calender and a heating nozzle is present between the belt press and the at least one heating calender.

26. The method according to claim 1 , wherein said thermoplastic polymer matrix further comprises carbonaceous fillers.

27. The method according to claim 1 , wherein said fibrous material comprises continuous fibers selected from carbon, glass, silicon carbide, basalt, s

Assignees

• Arkema France

Inventors

• Hochstetter Gilles
• Capelot Mathieu
• Savart Thibaut
• Babeau Arthur Pierre
• Huze Denis
• Tanguy François
• Gaillard Patrice

Classifications

• B29B15/125 Primary

  by dipping · CPC title

• B29C35/0805

  using electromagnetic radiation · CPC title

• B29C70/506

  and impregnating by melting a solid material, e.g. sheet, powder, fibres (B29C70/508 takes precedence) · CPC title

• B29C2035/0822

  using IR radiation · CPC title

• B29K2077/00

  Use of {PA, i.e.} polyamides, e.g. polyesteramides {or derivatives thereof}, as moulding material · CPC title