Molding Precursor, Process for Producing Molded Fiber-Reinforced Resin, and Molded Fiber-Reinforced Resin

• US 20070292669A1
• Filed: 12/02/2005
• Published: 12/20/2007
• Est. Priority Date: 12/06/2004
• Status: Active Grant

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Takemoto, Hidehiro, Yamasaki, Masaaki, Sekido, Toshihide
• Granted Patent: US 8,257,823 B2
• Time in Patent Office: Days
• US Class Current: 428/213
• CPC Class Codes: B29C 37/02 Deburring or deflashing thermal deburring in general B23D79/005
• CPC Class Codes: B29C 70/086 and with one or more layers of pure plastics material, e.g. foam layers applying a non-preformed coating, e.g. a gel-coat, B29C37/0025; with foam blocks B29C70/86
• CPC Class Codes: B29C 70/302 Details of the edges of fibre composites, e.g. edge finishing or means to avoid delamination
• CPC Class Codes: B29C 70/345 using matched moulds
• 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 70/545 Perforating, cutting or machining during or after moulding
• CPC Class Codes: B29C 70/865 completely encapsulated
• CPC Class Codes: Y10T 428/24777 Edge feature
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/24992 Density or compression of components
• CPC Class Codes: Y10T 428/249939 Two or more layers
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 442/60 Nonwoven fabric [i.e., nonwoven strand or fiber material]

Abstract

A molding precursor which includes a main body part and a burr formation part protruding outward from the edge of the main body part and extending continuously along the edge, wherein the main body part includes a first base having many reinforcing fibers and a second base having many fibers and has been superposed on the first base in an outer peripheral part of the main body part, the burr formation part is constituted of that part of the second base which protrudes outward from the edge of the main body part, and spaces among the many fibers constitute passages for a molding resin.

Claims

1. A molding precursor comprising a main body portion and a burr forming portion continuously extending from an edge of the main body portion outwardly, wherein said main body portion is formed of a first base material comprising numerous reinforcing fibers and a second base material comprising numerous fibers laminated on said first base material at an outer edge portion of said main body portion, said burr forming portion is formed by said second base material extending from the edge of said main body portion outwardly, and clearances among said numerous fibers form passages of a molding resin.

2. The molding precursor according to claim 1, wherein said first base material is arranged to at least partially cover said second base material positioned at said outer edge portion.

3. The molding precursor according to claim 1, wherein said first base material is arranged to at least partially hold said second base material positioned at said outer edge portion.

4. The molding precursor according to claim 1, wherein a surface layer forming base material which forms a surface portion of said first base material is arranged to extend from the edge of said main body portion outwardly and cover said second base material positioned at said burr forming portion.

5. The molding precursor according to claim 1, wherein said main body portion has a third base material comprising numerous reinforcing fibers laminated on said first base material and said second base material, said second base material has a form almost identical to that of said main body portion and is arranged between said first base material and said third base material, and a three-layer structure comprising said first base material, said second base material and said third base material is formed.

6. The molding precursor according to claim 5, wherein at least either said first base material or said third base material is arranged to extend from the edge of said main body portion outwardly and partially cover said second base material positioned at said burr forming portion.

7. The molding precursor according to claim 5, wherein at least either a surface layer forming base material which forms a surface portion of said first base material or a surface layer forming base material which forms a surface portion of said third base material is arranged to extend from the edge of said main body portion and further to cover said second base material positioned at said burr forming portion.

8. The molding precursor according to claim 5, wherein a core base material comprising foam is arranged in contact with said second base material in said main body portion.

9. The molding precursor according to claim 1, wherein the compressive characteristic value of said second base material is about 35% to about 80%.

10. The molding precursor according to claim 1, wherein the unit weight of said first base material is about 100 to about 1000 g/m².

11. The molding precursor according to claim 5, wherein the unit weight of said third base material is about 100 to about 1000 g/m².

12. The molding precursor according to claim 1, wherein the strength of the fibers forming said second base material is lower than the strength of the reinforcing fibers forming said first base material.

13. The molding precursor according to claim 5, wherein the strength of the fibers forming said second base material is lower than the strength of the reinforcing fibers forming said third base material.

14. The molding precursor according to claim 1, wherein said second base material is a nonwoven fabric.

15. The molding precursor according to claim 1, wherein the unit weight of said second base material is about 10 to about 1500 g/m².

16. A process for producing a molded fiber-reinforced resin by an RTM method, which comprises the steps of:

disposing a molding precursor in a molding cavity of a mold;

closing said mold in which said molding precursor is disposed;

injecting a heated and pressurized resin into said molding cavity of said mold closed;

solidifying said resin injected into said molding cavity;

opening said mold after said resin has been solidified; and

taking out the molded fiber-reinforced resin from the mold opened, wherein

(a) a molding precursor as set forth in claim 1 is said molding precursor;

(b) a film gate through which said resin injected flows is provided at least partially in an outer circumference of said molding cavity;

(c) in said step of disposing said molding precursor in said molding cavity of said mold, said molding precursor is disposed in said molding cavity of said mold in such a manner that said second base material is positioned at least partially in said film gate; and

(d) said second base material exists at least partially in a burr portion of said resin formed by said film gate.

17. The process according to claim 16, wherein a runner communicating with said film gate is provided outside said film gate, and said second base material of said molding precursor is disposed to reach the position of said runner.

18. The process according to claim 16, wherein a gate clearance of said film gate is about 0.1 to about 2.0 mm.

19. A molded fiber-reinforced resin composed of a matrix resin and a reinforcing fiber base material comprising numerous reinforcing fibers, wherein clearances among said numerous reinforcing fibers are impregnated with said matrix resin, and wherein the reinforcing fiber base material is a first base material;

a second base material comprising numerous fibers is laminated on said first base material at an outer edge portion of said first base material;

the strength of the fibers forming said second base material is lower than the strength of the reinforcing fibers forming said first base material; and

clearances among said numerous fibers forming said second base material are also impregnated with said matrix resin.

20. The molded fiber-reinforced resin according to claim 19, wherein said first base material is disposed to at least partially cover said second base material positioned at said outer edge portion.

21. The molded fiber-reinforced resin according to claim 19, wherein said first base material is disposed to at least partially hold said second base material positioned at said outer edge portion.

22. The molded fiber-reinforced resin according to claim 19, wherein a core base material comprising foam covered with said first base material is disposed at a central portion of said first base material.

23. The molded fiber-reinforced resin according to claim 19, wherein a third base material comprising numerous reinforcing fibers is laminated on said first base material and said second base material, said second base material has a form almost identical with that of said first base material and is disposed between said first base material and said third base material, and a three-layer structure comprising said first base material, said second base material and said third base material is formed.

24. The molded fiber-reinforced resin according to claim 23, wherein a core base material comprising foam is disposed in contact with said second base material.

25. The molded fiber-reinforced resin according to claim 19, wherein the unit weight of said first base material is about 100 to about 1000 g/m².

26. The molded fiber-reinforced resin according to claim 23, wherein the unit weight of said third base material is about 100 to about 1000 g/m².

27. The molded fiber-reinforced resin according to claim 19, wherein said second base material is a nonwoven fabric.

28. The molded fiber-reinforced resin according to claim 19, wherein the unit weight of said second base material is about 10 to about 1500 g/m².

29. The molded fiber-reinforced resin according to claim 19, wherein the thickness of the outer edge portion is about 1.5 to about 5 times the thickness of the central portion.