Method for manufacturing a composite fabric

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Solution Overview

Problem

The existing methods for manufacturing composite fabrics with carbon fiber bundles and CNT networks result in a large number of CNT aggregates on the surface, which decrease the strength of carbon fiber-reinforced molded articles and limit designability.

Innovation Solution

A method involving the use of a filter part with a clearance of 100 µm or less to separate the woven fabric from a dispersion containing ultrasonically applied CNTs, preventing aggregate CNTs from adhering to the fabric and forming a network structure with a direct connection between CNTs, reducing aggregation to 25% or less per unit area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the woven fabric is immersed in a dispersion containing CNTs and ultrasonic vibrations are applied, then a CNT network structure is formed on the surface of the woven fabric, but a large number of CNT aggregates adhere to the surface of the woven fabric

Engineering Contradiction:
ImproveCNT network structure formationVSAvoidCNT aggregates
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

A filter part made of porous glass is introduced as an intermediary between the CNT dispersion and the woven fabric. The filter part with controlled pore size (0.2-10 μm) allows isolated CNTs to pass through and form a network on the fabric surface while blocking larger CNT aggregates from adhering to the fabric, thus resolving the contradiction between forming a CNT network structure and preventing harmful aggregate formation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If CNT aggregates are present on the surface of the woven fabric, then the composite fabric can be manufactured, but the strength of the carbon fiber-reinforced molded article decreases

Engineering Contradiction:
Improvecomposite fabric manufacturingVSAvoidmolded article strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The filter part is positioned in advance during the CNT deposition process to preemptively block aggregates before they can reach and adhere to the woven fabric. This preliminary filtering action ensures that only isolated CNTs deposit on the fabric surface, maintaining both ease of manufacture and high strength of the final molded article by preventing aggregate formation at the source

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If CNT aggregates are present on the surface of the woven fabric, then the composite fabric can be manufactured, but designability is reduced

Engineering Contradiction:
Improvecomposite fabric manufacturingVSAvoiddesignability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The porous glass filter part serves as a mediating element that enables the manufacturing process to proceed easily while simultaneously ensuring a uniform, aggregate-free CNT network structure on the fabric surface. This uniform structure enhances designability by providing consistent surface properties and aesthetic quality, allowing for greater design flexibility in the final molded articles

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances the strength of carbon fiber-reinforced molded articles by minimizing CNT aggregates and improving the uniformity of the composite layer, thereby increasing the adhesion strength and designability of the composite fabric.

Implementation Method 1

holding a surface of a filter part, through which a dispersion solvent and carbon nanotubes dispersed in the dispersion solvent are allowed to pass

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

immersing the woven fabric on which the filter part is held in a dispersion that contains the dispersion solvent and the dispersed carbon nanotubes and applying ultrasonic vibrations to the dispersion

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 3

a structure which is formed on a surface of the woven fabric and includes a plurality of carbon nanotubes, the structure includes a network structure part in which the plurality of carbon nanotubes are connected directly to one another

Methodology Applied
Scientific EffectNetwork structure formation:

Data Source

PatentEP3434823B1Method for manufacturing a composite fabric
Publication Date: 2021.05.12 NITTA CORP
  • EP3434823B1 patent drawingFigure 1~2
  • EP3434823B1 patent drawingFigure 3A~3B
  • EP3434823B1 patent drawingFigure 4A~4B

AI summary

Provided are a method for manufacturing a composite fabric capable of further improving the strength of a carbon fiber-reinforced molded article, a composite fabric, and a carbon fiber-reinforced molded article. The method includes a step of holding a surface of a filter part (22A), through which a dispersion solvent and carbon nanotubes dispersed in the dispersion solvent are allowed to pass, in contact with at least one surface of a woven fabric (12A) including a carbon fiber bundle as weaving yarn, a step of immersing the woven fabric (12A) on which the filter part (22A) is held in a dispersion that comprises the dispersion solvent and the dispersed carbon nanotubes and applying ultrasonic vibrations to the dispersion, and a step of extracting the woven fabric (12A) on which the filter part (22A) is held from the dispersion and removing the filter part (22A) from the woven fabric (12A).