Method for manufacturing carbon fiber

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Solution Overview

Problem

Existing carbon fibers lack sufficient surface activity and interface bonding performance with resin, limiting their mechanical performance in composite materials.

Innovation Solution

An electrochemical oxidation method is employed to introduce oxygen-containing functional groups on the carbon fiber surface by anodic electrolysis in specific electrolytes, controlling parameters such as conductivity, voltage, electricity amount, and treatment time to enhance surface reactivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional surface treatment methods are used, then production process is simple, but surface activity and interface bonding performance are insufficient

Engineering Contradiction:
Improveinterface bonding performanceVSAvoidsurface treatment process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention changes the chemical composition parameters of the electrolyte (using specific ratios of H2SO4, H3PO4, and CH3COOH) and electrical parameters (voltage, current density, treatment time) to optimize surface oxidation effectiveness. This resolves the contradiction by achieving high interface bonding performance through controlled parameter adjustments rather than complex multi-step processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces conventional mechanical or chemical surface treatment methods with an electrochemical oxidation system. By using electrical current to generate active oxygen species in the electrolyte, the process achieves superior surface activation and bonding performance while maintaining operational simplicity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If electrolyte conductivity is increased to improve treatment efficiency, then surface oxidation effectiveness improves, but energy consumption increases

Engineering Contradiction:
Improvesurface treatment efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The invention optimizes electrolyte composition to achieve balanced conductivity (not excessively high) while maintaining effective surface oxidation. The specific electrolyte formulation (containing H2SO4, H3PO4, and CH3COOH in controlled ratios) provides sufficient ionic conductivity for efficient treatment without requiring excessive energy input, thus resolving the productivity-energy consumption contradiction

Inventive Principle:
Principle #35Parameter changes

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

The treated carbon fibers exhibit improved mechanical properties and enhanced bonding with resin, resulting in high tensile strength and durability in composite bottles.

Implementation Method 1

performing a surface treatment, wherein a surface of the carbon fiber is oxidized by active oxygen generated by anodic electrolysis

Methodology Applied
Scientific EffectAnodic electrolysis: Electrolysis

Implementation Method 2

a surface of the carbon fiber is oxidized by active oxygen generated by anodic electrolysis, and thereby oxygen-containing functional groups are introduced to the surface

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP4123067B1Method for manufacturing carbon fiber
Publication Date: 2025.09.10 TAIWAN SOKOU INDS KOFUN YUUGENKOUSHI
  • EP4123067B1 patent drawingFigure 1
  • EP4123067B1 patent drawingFigure 2
  • EP4123067B1 patent drawingFigure 3

AI summary

A method for manufacturing carbon fiber, the method includes: placing a carbon fiber as an anode in an electrolyte, wherein the electrolyte is nitric acid, sulfuric acid, phosphoric acid, acetic acid, ammonium bicarbonate, sodium hydroxide, or potassium nitrate; and performing a surface treatment, wherein a surface of the carbon fiber is oxidized by active oxygen generated by anodic electrolysis, and thereby oxygen-containing functional groups are introduced to the surface. The disclosure also provides a carbon fiber composite bottle, which includes a bottle body and a carbon fiber. The bottle body is a type III bottle or a type IV bottle. The carbon fiber surrounds the bottle body, the surface oxygen concentration of the carbon fiber is 5-35%, and the surface roughness of the carbon fiber is 5-25 nm.