Method for Manufacturing SMC

Patent metadata

Field	Value
Publication number	US-2023021189-A1
Application number	US-202217946395-A
Country	US
Kind code	A1
Filing date	Sep 16, 2022
Priority date	Mar 26, 2020
Publication date	Jan 19, 2023
Grant date	—

Abstract

A manufacturing method of an SMC of the present invention comprises (i) forming chopped carbon fiber bundles by chopping a continuous carbon fiber bundle having a filament number of NK with a rotary cutter, (ii) fragmentation-processing the chopped carbon fiber bundles by using a fragmentation-processing apparatus comprising a rotating body, (iii) forming a carbon fiber mat by depositing the fragmentation-processed chopped carbon fiber bundles on a carrier film traveling below the rotary cutter, and (iv) impregnating the carbon fiber mat with a thermosetting resin composition, wherein N is 20 or more, and the fragmentation-processing apparatus comprises a first pin roller and a second pin roller which are disposed side by side, each having a rotation axis parallel to a rotation axis direction of the rotary cutter.

First claim

1 . A manufacturing method of an SMC, comprising:
(i) forming chopped carbon fiber bundles by chopping a continuous carbon fiber bundle having a filament number of NK with a rotary cutter; (ii) fragmentation-processing the chopped carbon fiber bundles by using a fragmentation-processing apparatus comprising a rotating body; (iii) forming a carbon fiber mat by depositing the fragmentation-processed chopped carbon fiber bundles on a carrier film traveling below the rotary cutter; and (iv) impregnating the carbon fiber mat with a thermosetting resin composition, wherein N is 20 or more, and the fragmentation-processing apparatus comprises a first pin roller and a second pin roller which are disposed side by side, each having a rotation axis parallel to a rotation axis direction of the rotary cutter.

2 . The manufacturing method according to claim 1 ,
wherein the first pin roller is rotationally driven such that its pins move downward from above on its side facing the second pin roller, and the second pin roller is rotationally driven such that its pins move downward from above on its side facing the first pin roller.

3 . The manufacturing method according to claim 1 ,
wherein a sum of a maximum radius of the first pin roller and a maximum radius of the second pin roller is equal to or greater than a distance between rotation axes of the first pin roller and the second pin roller.

4 . The manufacturing method according to claim 3 ,
wherein the sum of the maximum radius of the first pin roller and the maximum radius of the second pin roller is greater than the distance between the rotation axes of the first pin roller and the second pin roller.

5 . The manufacturing method according to claim 1 ,
wherein a sum of a maximum radius of the first pin roller and a maximum radius of the second pin roller is smaller than a distance between rotation axes of the first pin roller and the second pin roller, and a difference therebetween is 10 mm or less.

6 . The manufacturing method according to claim 1 ,
wherein N is 40 or more.

7 . The manufacturing method according to claim 1 ,
wherein N is 100 or less.

8 . The manufacturing method according to claim 1 ,
wherein the continuous carbon fiber bundle is a continuous carbon fiber bundle partially split into n sub-bundles (where, n is an integer of 2 or more) such that N/n is 10 to 25.

9 . The manufacturing method according to claim 8 ,
wherein N/n is 10 to 20 or 10 to 15.

10 . The manufacturing method according to claim 1 ,
wherein a content of a chopped carbon fiber bundle having a filament number of 1K or less in the carbon fiber mat is less than 1% by weight.

11 . The manufacturing method according to claim 1 ,
wherein the carbon fiber mat is pressurized together with the thermosetting resin composition to impregnate the carbon fiber mat with the thermosetting resin composition.

12 . The manufacturing method according to claim 1 ,
wherein at least a part of the thermosetting resin composition is applied to an upper surface of the carrier film before the carbon fiber mat is formed on the carrier film.

13 . A manufacturing method of an SMC, comprising:
(i) forming chopped carbon fiber bundles by chopping a continuous carbon fiber bundle having a filament number of NK with a rotary cutter; (ii) fragmentation-processing the chopped carbon fiber bundles by using a fragmentation-processing apparatus comprising a rotating body; (iii) forming a carbon fiber mat by depositing the fragmentation-processed chopped carbon fiber bundles on a carrier film traveling below the rotary cutter; and (iv) impregnating the carbon fiber mat with a thermosetting resin composition, wherein N is 20 or more, and the fragmentation-processing apparatus comprises a first pin roller and a second pin roller which are disposed side by side, each having a rotation axis parallel to a rotation axis direction of the rotary cutter, wherein the first pin roller is rotationally driven such that its pins move downward from above on its side facing the second pin roller, and the second pin roller is rotationally driven such that its pins move downward from above on its side facing the first pin roller, and wherein a sum of a maximum radius of the first pin roller and a maximum radius of the second pin roller is smaller than, equal to or greater than a distance between rotation axes of the first pin roller and the second pin roller, provided that when the sum is smaller than the distance, the difference therebetween is 10 mm or less.

14 . A manufacturing method of an SMC, comprising:
(i) forming chopped carbon fiber bundles by chopping a continuous carbon fiber bundle having a filament number of NK with a rotary cutter; (ii) fragmentation-processing the chopped carbon fiber bundles by using a fragmentation-processing apparatus comprising a rotating body; (iii) forming a carbon fiber mat by depositing the fragmentation-processed chopped carbon fiber bundles on a carrier film traveling below the rotary cutter; and (iv) impregnating the carbon fiber mat with a thermosetting resin composition, wherein N is 20 or more, and the fragmentation-processing apparatus comprises a first pin roller and a second pin roller which are disposed side by side, each having a rotation axis parallel to a rotation axis direction of the rotary cutter, wherein the first pin roller is rotationally driven such that its pins move downward from above on its side facing the second pin roller, and the second pin roller is rotationally driven such that its pins move downward from above on its side facing the first pin roller, wherein a sum of a maximum radius of the first pin roller and a maximum radius of the second pin roller is smaller than, equal to or greater than a distance between rotation axes of the first pin roller and the second pin roller, provided that when the sum is smaller than the distance, the difference therebetween is 10 mm or less, and wherein the continuous carbon fiber bundle is a continuous carbon fiber bundle partially split into n sub-bundles (where, n is an integer of 2 or more) such that N/n is 10 to 25.

15 . The manufacturing method according to claim 13 ,
wherein the sum of the maximum radius of the first pin roller and the maximum radius of the second pin roller is greater than the distance between the rotation axes of the first pin roller and the second pin roller.

16 . The manufacturing method according to claim 13 ,
wherein N is 40 or more.

17 . The manufacturing method according to claim 13 ,
wherein a content of a chopped carbon fiber bundle having a filament number of 1K or less in the carbon fiber mat is less than 1% by weight.

18 . The manufacturing method according to claim 14 ,
wherein the sum of the maximum radius of the first pin roller and the maximum radius of the second pin roller is greater than the distance between the rotation axes of the first pin roller and the second pin roller.

19 . The manufacturing method according to claim 14 ,
wherein N is 40 or more.

20 . The manufacturing method according to claim 14 ,
wherein a content of a chopped carbon fiber bundle having a filament number of 1K or less in the carbon fiber mat is less than 1% by weight.

Assignees

• Mitsubishi Chem Corp

Inventors

• Nakao Hiroyuki
• Watanabe Yasushi
• Samejima Tadao
• Mizutori Yukihiro

Classifications

• B29K2021/006

  Thermosetting elastomers · CPC title

• B29L2007/002

  Panels; Plates; Sheets · CPC title

• B29C70/12

  using fibres of short length, e.g. in the form of a mat {(non-woven fabrics per se D04H1/00)} · CPC title

• B29C70/508 Primary

  and first forming a mat composed of short fibres · CPC title

• B29B15/122 Primary

  with a matrix in liquid form, e.g. as melt, solution or latex · CPC title