Composite Fiber Structure to Suppress Resin-Rich Gaps

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Solution Overview

Problem

Existing fiber-reinforced composite materials face issues with the generation of resin-rich portions due to gaps between reinforcing fiber yarns, which compromise the material's strength and integrity.

Innovation Solution

A fiber structure comprising a combination of first reinforcing fiber yarns formed of bundled discontinuous fibers wrapped with a covering yarn and second reinforcing fiber yarns made of continuous fibers, arranged alongside and extending in the same direction, with the second yarns held between the first yarns, ensuring dispersion of continuous fibers in the matrix resin to minimize resin-rich areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If reinforcing fiber yarns are maintained in bundle form with covering yarn, then the fiber structure can be formed, but gaps occur between reinforcing fibers leading to resin-rich portions

Engineering Contradiction:
Improvefiber structure formationVSAvoidcomposite material strength
Core Design Contradiction:
ShapeVSStrength

Solution Approach 1:

The invention divides the fiber structure into two types of yarns: first reinforcing fiber yarns (discontinuous fibers with covering yarn) and second reinforcing fiber yarns (continuous fibers without covering yarn). The second yarns are held between the first yarns to fill gaps and suppress resin-rich portion formation, thereby resolving the contradiction between maintaining fiber bundle shape and preventing strength reduction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention creates a composite fiber structure by combining two different types of reinforcing fiber yarns with distinct characteristics. The first yarns provide structural framework while the second yarns fill interstices, creating a multi-component fiber assembly that eliminates resin-rich portions and enhances overall composite strength.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If discontinuous fibers are used in bundled form, then fiber yarns can be formed, but resin-rich portions occur between yarns

Engineering Contradiction:
Improvefiber yarn formationVSAvoidcomposite material strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The invention segments the fiber yarn system into two functional components: first yarns made of discontinuous fibers with covering yarn for easy handling and formation, and second yarns made of continuous fibers without covering yarn for gap filling. This segmentation allows discontinuous fibers to be easily manufactured into yarns while preventing resin-rich portion formation through the complementary second yarns.

Inventive Principle:
Principle #1Segmentation

3Stability of the object's composition

If covering yarn wraps around discontinuous fibers, then fiber bundles are maintained, but gaps remain between reinforcing fibers

Engineering Contradiction:
Improvefiber bundle maintenanceVSAvoidcomposite material strength
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The invention divides the fiber system into first yarns (with covering yarn for bundle stability) and second yarns (without covering yarn for gap filling). The second yarns are positioned between the first yarns to fill the gaps that would otherwise be occupied by resin, thereby maintaining bundle stability while eliminating weak points.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies different structural qualities to different parts of the fiber assembly: the first yarns have covering yarn for localized bundle stability, while the second yarns are placed in specific gap regions to provide localized filling. This local differentiation resolves the contradiction between bundle maintenance and gap elimination.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4435162B1Fiber structure and fiber-reinforced composite material
Publication Date: 2025.12.17 TOYOTA INDUSTRIES CORP
  • EP4435162B1 patent drawingFigure 1~2
  • EP4435162B1 patent drawingFigure 3~4
  • EP4435162B1 patent drawingFigure 5~7

AI summary

A fiber structure (20, 60) serves as a reinforcement of a fiber-reinforced composite material (10, 50) that includes matrix resin (12) as a matrix. The fiber structure (20, 60) includes a plurality of first reinforcing fiber yarns (31) and a second reinforcing fiber yarn (21). The first reinforcing fiber yarns (31) is each formed of a bundle of fibers including discontinuous fibers (32) made of reinforcing fibers. The bundle of fibers is wrapped with a covering yarn (33). The second reinforcing fiber yarn (21) is formed of a bunch of continuous fibers (22) made of reinforcing fibers. The fiber structure (20, 60) includes a fiber body formed of the first reinforcing fiber yarns (31) and the second reinforcing fiber yarn (21) arranged alongside and extending in the same direction. The fiber body has a portion in which the second reinforcing fiber yarn (21) is held between and by the first reinforcing fiber yarns (31).