Partially separated fiber bundle, production method for partially separated fiber bundle, fiber-reinforced resin molding material using partially separated fiber bundle, and production method for fiber-reinforced resin molding material using partially separated fiber bundle

Patent metadata

Field	Value
Publication number	US-10569986-B2
Application number	US-201716307678-A
Country	US
Kind code	B2
Filing date	Jun 1, 2017
Priority date	Jun 21, 2016
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

A partially separated fiber bundle includes separation-processed sections, each divided into a plurality of bundles of at least three bundles, and not-separation-processed sections, that are alternately formed along the lengthwise direction of a fiber bundle that comprises a plurality of single fibers. The partially separated fiber bundle is characterized in that, at any width-direction cross-section taken along the lengthwise direction thereof, a rate of single fibers contained in a region at which adjacent divided fiber bundles are joined by a not-separation-processed part is 67% or less relative to the total single fibers in the width-direction cross-section.

First claim

The invention claimed is:

1. A partially separated fiber bundle comprising separation-processed sections, each divided into a plurality of bundles of at least three bundles, and not-separation-processed sections, alternately formed along the lengthwise direction of a fiber bundle comprising a plurality of single fibers, characterized in that, at any width-direction cross-section taken along a lengthwise direction of the partially separated fiber bundle, a rate of single fibers contained in a region at which adjacent divided fiber bundles are joined by a not-separation-processed part is 67% or less relative to the total single fibers in the width-direction cross-section.

2. The partially separated fiber bundle according to claim 1 , wherein the length of each of the separation-processed sections is 30 mm or more and 1,500 mm or less.

3. The partially separated fiber bundle according to claim 1 , wherein the length of each of the not-separation-processed sections is 1 mm or more and 150 mm or less.

4. The partially separated fiber bundle according to claim 1 , wherein the content of the not-separated-processed sections contained in the partially separated fiber bundle is 3% or more and 50% or less.

5. A method of producing a partially separated fiber bundle comprising separation-processed sections, each divided into a plurality of bundles of at least three bundles, and not-separation-processed sections, alternately formed, wherein, while a fiber bundle comprising a plurality of single fibers travels along the lengthwise direction of the fiber bundle, a separation means provided with a plurality of projected parts is penetrated into the fiber bundle to create a separation-processed part, and entangled parts, where the single fibers are interlaced, are formed at contact parts with the projected parts in at least one separation-processed part, thereafter the separation means is removed from the fiber bundle, and after passing through an entanglement accumulation part including the entangled parts, the separation means is penetrated again into the fiber bundle, characterized in that the shapes of the projected parts of the separation means and the timings of the penetration and the removal of the separation means are controlled so that, at any width-direction cross-section taken along the lengthwise direction of the partially separated fiber bundle, a rate of single fibers contained in a region at which adjacent divided fiber bundles are joined by a not-separation-processed part becomes 67% or less relative to the total single fibers in the width-direction cross-section.

6. A method of producing a partially separated fiber bundle comprising separation-processed sections, each divided into a plurality of bundles of at least three bundles, and not-separation-processed sections, that are alternately formed, wherein a separation means provided with a plurality of projected parts is penetrated into a fiber bundle comprising a plurality of single fibers, while the separation means travels along the lengthwise direction of the fiber bundle, a separation-processed part is created, and entangled parts, where the single fibers are interlaced, are formed at contact parts with the projected parts in at least one separation-processed part, thereafter the separation means is removed from the fiber bundle, and after the separation means travels up to a position passing through an entanglement accumulation part including the entangled parts, the separation means is penetrated again into the fiber bundle, characterized in that the shapes of the projected parts of the separation means and timings of the penetration and removal of the separation means are controlled so that, at any width-direction cross-section taken along the lengthwise direction of the partially separated fiber bundle, a rate of single fibers contained in a region at which adjacent divided fiber bundles are joined by a not-separation-processed part becomes 67% or less relative to the total single fibers in the width-direction cross-section.

7. The method according to claim 5 , wherein a pressing force acting on the projected parts per a width of the fiber bundle at the contact parts is detected, and the separation means is removed from the fiber bundle accompanying an increase of the pressing force.

8. The method according to claim 5 , wherein the presence of a twist of the fiber bundle of 10 to 1,000 mm from the separation means having been penetrated into the fiber bundle in at least one of the front and rear of the fiber bundle along the lengthwise direction of the fiber bundle is detected by an imaging means.

9. The method according to claim 8 , wherein a pressing force acting on the projected parts per a width of the fiber bundle at the contact parts is detected, a twist is detected by the imaging means, and the separation means is controlled so that the pressing force is reduced until the projected parts are passed through the twist from immediately before being contacted with the twist.

10. The method according to claim 5 , wherein a plurality of the projected parts are independently controllable.

11. The method according to claim 5 , wherein the separation means has a rotational shaft orthogonal to the lengthwise direction of the fiber bundle, and the projected parts are provided on a surface of the rotational shaft.

12. A fiber-reinforced resin molding material comprising a reinforcing fiber mat obtained by cutting/spraying the partially separated fiber bundle according to claim 1 and a matrix resin.

13. The fiber-reinforced resin molding material according to claim 12 , wherein the matrix resin is a thermosetting resin.

14. The fiber-reinforced resin molding material according to claim 12 , wherein the fiber-reinforced resin molding material is a sheet molding compound.

15. A method of producing the fiber-reinforced resin molding material according to claim 12 , comprising at least steps [A] to [C]:
[A] a partial separation step of obtaining a partially separated fiber bundle comprising separation-processed sections, each divided into a plurality of bundles of at least three bundles, and not-separation-processed sections, alternately formed along the lengthwise direction of a reinforcing fiber bundle comprising a plurality of single fibers, wherein a separation processing is performed so that, at any width-direction cross-section taken along the lengthwise direction of the partially separated fiber bundle, a rate of single fibers contained in a region at which adjacent divided fiber bundles are joined by a not-separation-processed part becomes 67% or less relative to the total single fibers in the width-direction cross-section;
[B] a matting step of cutting the partially separated fiber bundle and spraying the cut bundles to obtain a reinforcing fiber mat; and
[C] a resin impregnation step of impregnating a matrix resin into the reinforcing fiber mat.

16. The method according to claim 15 , wherein at least the steps [A] to [C] are carried out continuously in a single process.

17. The method according to claim 15 , wherein in the step [B], the partially separated fiber bundle is cut at an angle θ (0<θ<90°) with respect to the lengthwise direction thereof.

Assignees

• Toray Industries

Inventors

• Motohashi Tetsuya
• Hashimoto Takafumi
• Noguchi Yasumoto
• Kawahara Yoshihiro
• Suzuki Tamotsu
• SATO Chiasa

Classifications

• B29B15/122 Primary

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

• D06H3/02

  visually (D06H3/12, D06H3/14, D06H3/16 take precedence) · CPC title

• D02J1/18 Primary

  Separating or spreading · CPC title

• B29B15/105

  of reinforcement of definite length with a matrix in solid form, e.g. powder, fibre or sheet form (calendering B29C70/506) · CPC title

• D10B2505/02

  Reinforcing materials; Prepregs · CPC title