METHOD FOR PRODUCING FIBER COMPOSITE

• US 20090242104A1
• Filed: 01/22/2009
• Published: 10/01/2009
• Est. Priority Date: 01/29/2008
• Status: Active Grant

• Current Assignee: Toyota Boshoku Kabushiki Kaisha
• Original Assignee: Toyota Boshoku Kabushiki Kaisha
• Inventors: WATANABE, Shigeki
• Granted Patent: US 8,123,990 B2
• Time in Patent Office: Days
• US Class Current: 156/181
• CPC Class Codes: B29B 15/105 of reinforcement of definite length with a matrix in solid form, e.g. powder, fibre or sheet form calendering B29C70/506
• CPC Class Codes: B29B 15/12 of reinforcements of indefinite length
• CPC Class Codes: B29C 70/506 and impregnating by melting a solid material, e.g. sheet, powder, fibres B29C70/508 takes precedence
• CPC Class Codes: B29K 2105/0076 Microcapsules

Abstract

The object of the present invention is to provide a method for producing a fiber composite excellent in lightweight and rigidity. The present method is one for producing fiber composite having a structure in which reinforcing fibers are bonded with a thermoplastic resin, is characterized in that said reinforcing fiber is at least one of a plant fiber and an inorganic fiber, and comprises a feeding process in which a thermally expandable capsule (20) having a shell wall composed of a thermoplastic resin is fed to one of either front side or back side of a mat (10a) comprising the reinforcing fiber and a thermoplastic resin fiber, a dispersing process in which one side of the mat is subjected to vibration from another side of the mat while pressing the one surface side of the mat (10a) to disperse the capsule (20) towards another side of the mat, a melting process in which the thermoplastic resin fiber constituting the mat is molten, and an expanding process in which the capsule (20) dispersed in the mat is heated to expand.

Claims

1. A method for producing a fiber composite having a structure in which reinforcing fibers are bonded with a thermoplastic resin, characterized in that said reinforcing fiber is at least one of a plant fiber and an inorganic fiber, and said method comprises:

a feeding process in which a thermally expandable capsule having a shell wall composed of a thermoplastic resin is fed to one of either front surface or back surface of a mat comprising said reinforcing fiber and a thermoplastic resin fiber,

a dispersing process in which said mat is subjected to vibration from another side of said mat while pressing said one surface side of said mat to disperse said thermally expandable capsule fed to said one surface side of said mat towards said another side of said mat,

a melting process in which said thermoplastic resin fiber constituting said mat is molten, and

an expanding process in which said thermally expandable capsule dispersed in said mat is heated to expand.

2. The method for producing a fiber composite according to claim 1,

wherein said feeding process is carried out by applying said thermally expandable capsule electrostatically to a surface of said mat.

3. The method for producing a fiber composite according to claim 2,

wherein said dispersing process is carried out by moving said mat with a conveyor,

wherein said pressing in said dispersing process is carried out by pressing said one surface side of said mat with a roller revolving to advance said mat in a moving direction of said conveyor, and

wherein said vibration in said dispersing process is carried out from said another side of a pressed part in said mat.

4. The method for producing a fiber composite according to claim 3,

wherein said vibration in said dispersing process is applied at an amplitude of 6 mm or less.

5. The method for producing a fiber composite according to claim 4,

wherein said vibration in said dispersing process is applied in a direction with an angle in the range from 30 to 90 degrees relative to the moving direction of said mat.

6. The method for producing a fiber composite according to claim 5,

wherein said melting process and said expanding process are carried out simultaneously.

7. The method for producing a fiber composite according to claim 5,

wherein a melting point of a first thermoplastic resin constituting said thermoplastic resin fiber is lower than a melting point of a second thermoplastic resin constituting said shell wall of said thermally expandable capsule,

wherein said melting process is carried out by heating said thermally expandable capsule to a temperature of said melting point or higher of said first thermoplastic resin, but not exceeding said melting point of said second thermoplastic resin while applying pressure to control expansion of said thermally expandable capsule, and

wherein said expanding process is carried out after said melting process.

8. The method for producing a fiber composite according to claim 1,

wherein said dispersing process is carried out by moving said mat with a conveyor,

wherein said pressing in said dispersing process is carried out by pressing said one surface side of said mat with a roller revolving to advance said mat in a moving direction of said conveyor, and

wherein said vibration in said dispersing process is carried out from said another side of a pressed part in said mat.

9. The method for producing a fiber composite according to claim 8,

wherein said vibration in said dispersing process is applied at an amplitude of 6 mm or less.

10. The method for producing a fiber composite according to claim 9,

wherein said vibration in said dispersing process is applied in a direction with an angle in the range from 30 to 90 degrees relative to the moving direction of said mat.

11. The method for producing a fiber composite according to claim 10,

wherein said melting process and said expanding process are carried out simultaneously.

12. The method for producing a fiber composite according to claim 10,

wherein a melting point of a first thermoplastic resin constituting said thermoplastic resin fiber is lower than a melting point of a second thermoplastic resin constituting said shell wall of said thermally expandable capsule,

wherein said melting process is carried out by heating said thermally expandable capsule to a temperature of said melting point or higher of said first thermoplastic resin, but not exceeding said melting point of said second thermoplastic resin while applying pressure to control expansion of said thermally expandable capsule, and

wherein said expanding process is carried out after said melting process.

13. The method for producing a fiber composite according to claim 1,

wherein said melting process and said expanding process are carried out simultaneously.

14. The method for producing a fiber composite according to claim 1,

wherein a melting point of a first thermoplastic resin constituting said thermoplastic resin fiber is lower than a melting point of a second thermoplastic resin constituting said shell wall of said thermally expandable capsule,

wherein said melting process is carried out by heating said thermally expandable capsule to a temperature of said melting point or higher of said first thermoplastic resin, but not exceeding said melting point of said second thermoplastic resin while applying pressure to control expansion of said thermally expandable capsule, and

wherein said expanding process is carried out after said melting process.