Method for manufacturing fiber reinforced plastic molded body

Patent metadata

Field	Value
Publication number	US-11325325-B2
Application number	US-201916392122-A
Country	US
Kind code	B2
Filing date	Apr 23, 2019
Priority date	Oct 31, 2016
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

Provided is a method for manufacturing a fiber reinforced plastic molded body, the method including: performing thermocompression molding, by using a molding die, on a molding precursor which is obtained by arranging a prepreg including a thermosetting resin and a fiber around a thermoplastic solid body.

First claim

The invention claimed is:

1. A method for manufacturing a fiber reinforced plastic molded body, the method comprising:
performing thermocompression molding, by using a molding die, on a molding precursor,
wherein the molding precursor is obtained by arranging a prepreg comprising a thermosetting resin and a fiber around a wax and forming a barrier layer between the prepreg and the wax, and
wherein, in the thermocompression molding, at least a part of the wax is melted and expands, and the molten wax is suppressed by the barrier layer from leaking outside the prepreg, such that internal pressure of a core, comprising the barrier layer and the wax, increases.

2. The method of claim 1 , wherein a density of the wax is 2 g/cm 3 or less.

3. The method of claim 2 , wherein a density of the wax is in a range of from 0.6 to 2 g/cm 3 .

4. The method of claim 1 , wherein a filler having a lower density than that of the wax is further accommodated in the wax.

5. The method of claim 1 , wherein the barrier layer is formed using a flexible bag.

6. The method of claim 1 , wherein the barrier layer comprises a fiber reinforcing material.

7. The method of claim 1 , wherein the thermocompression molding is performed under conditions wherein a relation between a melting point Tm (° C.) of the wax and an average molding temperature Tf (° C.) satisfies Tf−60≤Tm≤Tf.

8. The method of claim 1 , wherein a material forming the barrier layer has a melting point Tb (° C.), and
wherein the thermocompression molding is performed under conditions wherein a relation between a melting point Tm (° C.) of the wax and an average molding temperature Tf (° C.) and a melting point Tb (° C.) of the material forming the barrier layer satisfies Tm≤Tf<Tb.

9. The method of claim 1 , wherein, in the thermocompression molding, at least a part of a surface layer portion of the wax is melted.

10. The method of claim 1 , wherein the wax is pressed in the molding die at the time of the thermocompression molding.

11. The method of claim 1 , wherein the wax is removed from the obtained fiber reinforced plastic molded body after the thermocompression molding.

12. The method of claim 11 , wherein the wax is discharged outside the fiber reinforced plastic molded body at a temperature that is equal to or lower than a heat distortion temperature of the fiber reinforced plastic molded body and equal to or higher than a melting point Tm (° C.) of the wax.

13. The method of claim 1 , wherein the barrier layer is formed using a coating material.

14. The method of claim 1 , wherein the barrier layer is formed from a liquid rubber.

15. The method of claim 1 , wherein the fiber is a carbon fiber.

16. The method of claim 1 , wherein an average molding temperature in the thermocompression molding is 110 to 160° C.

17. The method of claim 1 , wherein an average molding temperature in the thermocompression molding is 120 to 150° C.

18. The method of claim 1 , wherein the wax has a melting point Tm in a range of from 80 to 140° C.

19. The method of claim 1 , wherein only a part of the wax is melted.

20. The method of claim 1 , wherein a substantially entire surface of the wax in the molding precursor is directly coated with the barrier layer.

Assignees

• Mitsubishi Chem Corp

Inventors

• Takano Tsuneo
• Honma Takashi
• Kaji Satoshi

Classifications

• B29C70/46 Primary

  using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs · CPC title

• B29K2995/0063

  Density · CPC title

• B29C33/52

  soluble or fusible {(in particular used in injection moulding B29C45/4457)} · CPC title

• B29K2105/06

  containing reinforcements, fillers or inserts · CPC title

• B29C43/32

  Component parts, details or accessories; Auxiliary operations · CPC title