Method for producing upsized frp member

• US 20040130072A1
• Filed: 04/02/2003
• Published: 07/08/2004
• Est. Priority Date: 08/07/2001
• Status: Active Grant

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Sekido, Toshihide, Wadahara, Eisuke, Kitano, Akihiko, Noma, Fumiaki
• Granted Patent: US 7,081,218 B2
• Time in Patent Office: Days
• US Class Current: 264/408
• CPC Class Codes: B29C 70/443 and impregnating by vacuum or injection
• CPC Class Codes: B29C 70/48 and impregnating the reinforcements in the closed mould, e.g. resin transfer moulding [RTM] , e.g. by vacuum
• CPC Class Codes: B29C 70/547 using channels or porous distribution layers incorporated in or associated with the product
• CPC Class Codes: B29K 2105/0845 Woven fabrics
• CPC Class Codes: B29K 2707/04 Carbon
• CPC Class Codes: B29L 2031/3055 Cars
• CPC Class Codes: B29L 2031/3064 Trains
• CPC Class Codes: B29L 2031/3067 Ships
• CPC Class Codes: B29L 2031/3082 Fuselages
• CPC Class Codes: B29L 2031/3085 Wings

Abstract

The present invention relates to a method for manufacturing a large FRP member and has the following structure.

The method for manufacturing a large FRP member, comprising the following steps (A) to (F). They are:

setting step (A) of disposing a preform containing a reinforcing fiber base material on a surface of a molding die;

sealing step (B) of covering a molding portion with a bagging material or a mold and providing at least one suction port and at least one resin injection port for sealing;

evacuating step (C) of evacuating the molding portion through the suction port;

hot-air heating step (D) of heating the molding portion by hot air;

resin injection step (E) of injecting a thermosetting resin from the resin injection port for impregnating the reinforcing fiber base material with the resin while a temperature Tm of the molding die and a temperature Tv of the bagging material or the mold are both set to room temperature or more, and a difference ΔT in temperature between the Tm and the Tv is set to 10° C. or less; and

curing step (F) of curing the resin by maintaining the molding portion at a predetermined temperature Tpc which is equal to or more than room temperature.

Preferably, the preform described above includes the reinforcing fiber base material and a resin distribution medium. In addition, it is preferable that in the hot-air heating step (D), the molding die be placed in a sealed chamber which is heat insulated with a heat insulating material, the hot air be circulated and supplied, and timing of starting the injection of the resin from a plurality of the resin injection ports be controlled in accordance with signals supplied from resin detection sensors provided in the molding die.

The present invention provides a method for manufacturing a large FRP member having superior quality at an inexpensive cost and with high production yield, in which non-impregnated portions and voids are unlikely to be formed.

Claims

1. A method for manufacturing a large FRP member comprising the following steps (A) to (F),

the step (A) being a step of disposing a preform containing at least one reinforcing fiber base material on a surface of a molding die;

the step (B) being a step of covering a molding portion with a bagging material or a mold and providing at least one suction port and at least one resin injection port for sealing;

the step (C) being a step of evacuating the molding portion through the suction port;

the step (D) being a step of heating the molding portion by hot air or the mold;

the step (E) being a step of injecting a thermosetting resin from the resin injection port for impregnating the reinforcing fiber base material with the resin while a temperature Tm of the molding die and a temperature Tv of the bagging material or the mold are both set to room temperature or more, and a difference Δ

T in temperature therebetween is set to 10°

C. or less;

the step (F) being a step of curing the resin by maintaining the molding portion at a predetermined temperature Tpc which is equal to or more than room temperature.

2. A method for manufacturing a large FRP member, according to claim 1, wherein, in the heating step (D), the molding die is placed in a sealed chamber which is heat insulated with a heat insulating material, and the entire molding portion is heated by supplying hot air.

3. A method for manufacturing a large FRP member, according to claim 2, wherein, in the heating step (D), the hot air is supplied and circulated.

4. A method for manufacturing a large FRP member, according to claim 1, wherein the preform comprises the reinforcing fiber base material and a resin distribution medium.

5. A method for manufacturing a large FRP member, according to claim 4, wherein a sheet-shape resin distribution medium is used as the resin distribution medium.

6. A method for manufacturing a large FRP member, according to claim 4, wherein the resin distribution medium comprises a net-shape sheet, and the net-shape sheet is removed from a FRP after the curing step (F).

7. A method for manufacturing a large FRP member, according to claim 4, wherein the resin distribution medium comprises a core material provided with resin flow grooves, and the core material is allowed to remain in a FRP after the curing step (F).

8. A method for manufacturing a large FRP member, according to claim 1, wherein the temperature Tm of the molding die or the temperature Tv of the bagging material or the mold is in the range of from 50 to 160°

C., and the predetermined temperature Tpc of the molding portion is in the range of from 80 to 180°

C. in the curing step (F).

9. A method for manufacturing a large FRP member, according to claim 1, further comprising the following steps (G) and (H) after the curing step (F),

the step (G) being a step of recovering a FRP,

the step (H) being a step of fully curing the resin by maintaining the recovered FRP at a predetermined temperature Tac which is higher than the predetermined temperature Tpc of the molding portion and which is 100°

C. or more.

10. A method for manufacturing a large FRP member, according to claim 1, wherein a resin having a glass transition temperature of 120°

C. or more after curing is used as the thermosetting resin.

11. A method for manufacturing a large FRP member, according to claim 10, wherein a viscosity η

p at the temperature Tm of the molding die or the temperature Tv of the bagging material or the mold, whichever is lower, is 500 mPa.s or less, and a difference Δ

η

between the viscosity at the Tm and the viscosity at the Tv is 200 mPa.s or less.

12. A method for manufacturing a large FRP member, according to claim 1, wherein the molding portion is evacuated through a plurality of the suction ports, and the resin is injected from a plurality of the resin injection ports.

13. A method for manufacturing a large FRP member, according to claim 12, wherein timing of starting the injection of the resin from said plurality of the resin injection ports is staggered.

14. A method for manufacturing a large FRP member, according to claim 12, wherein timing of starting the injection of the resin from said plurality of the resin injection ports is controlled in accordance with signals supplied from a resin detection sensor provided in the molding die.

15. A method for manufacturing a large FRP member, according to claim 14, wherein the resin detection sensor is a detection sensor comprising a first optical fiber having an emitting surface at the vicinity of a front edge thereof for emitting light, and a second optical fiber having an incident surface at the vicinity of a front edge thereof for receiving the emitted light.

16. A method for manufacturing a large FRP member, according to claim 14, wherein the resin detection sensor is a detection sensor comprising a flexible dielectric circuit substrate which detects the change in dielectric constant.

17. A method for manufacturing a large FRP member, according to claim 1, wherein, in the resin injection step (E), a reinforcing fiber volume ratio Vpf of the reinforcing fiber base material in the preform is set to 45% to 62%, and the thermosetting resin is injected.

18. A method for manufacturing a large FRP member, according to claim 1, wherein a reinforcing fiber volume ratio Vf of the reinforcing fiber base material in the large FRP member is set to 45% to 65% in the curing step (F).

19. A method for manufacturing a large FRP member, according to claim 1, wherein the reinforcing fiber base material is a reinforcing fiber base material comprising carbon fibers.

20. A method for manufacturing a large FRP member, according to claim 1, wherein the reinforcing fiber base material is a reinforcing fiber base material comprising a carbon fiber woven fabric.

21. A method for manufacturing a large FRP member, according to claim 1, wherein a plurality of the reinforcing fiber base materials is laminated to each other and disposed.

22. A method for manufacturing a large FRP member, according to claim 19, wherein parts of the reinforcing fiber base materials are fixed to each other.

23. A method for manufacturing a large FRP member, according to claim 1, wherein a resin bath is disposed at a position higher than that of a molding surface in the resin injection step (E).

24. A method for manufacturing a large FRP member, according to claim 1, wherein the evacuation is continued from the suction port in the resin injection step (E) until the injected resin is gelled.

25. A method for manufacturing a large FRP member, according to claim 1, wherein a FRP having a maximum length of 3 m or more is molded.

26. A method for manufacturing a large FRP member, according to claim 1, wherein the large FRP member is a primary structural member, a secondary structural member, an exterior member, an internal member, or a component thereof for transport facilities of aircrafts, automobiles, railroad vehicles, or ships and vessels.

27. A method for manufacturing a large FRP member, according to claim 24, wherein the primary structural member is a fuselage, a main wing, or a component thereof of an aircraft.

28. A method for manufacturing a large FRP member, according to claim 25, wherein the primary structural member is a CFRP-made skin-stringer structural member for a fuselage or a main wing of an aircraft.