Conductive Composite Fiber with Segmented Surface Layers

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Solution Overview

Problem

Conductive composite fibers face challenges in maintaining stable static elimination performance due to variations in conductive layer area and crimping issues, which affect their practical application in woven and knitted fabrics.

Innovation Solution

A conductive composite fiber is developed with a polyamide resin containing conductive carbon black and a thermoplastic resin, where the conductive layers are exposed at three or more locations on the fiber surface, using a composite spinneret to ensure equal disposition and controlled oxygen concentration, resulting in suppressed variation in surface specific resistance and crimping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conductive layers are exposed on the fiber surface to improve static elimination performance, then conductivity is improved, but variation in conductive layer area and surface specific resistance increases

Engineering Contradiction:
Improvestatic elimination performanceVSAvoidvariation in conductive layer area
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The fiber is structured with multiple discrete conductive layers (at least three) distributed along the fiber surface, rather than a single continuous conductive layer. This segmentation allows each conductive layer to be precisely controlled in position and area, reducing overall variation while maintaining effective conductivity for static elimination.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each conductive layer is positioned at specific locations along the fiber surface with controlled local properties. The nonconductive layers between them provide isolation and control over the electrical properties at each location, enabling precise management of surface specific resistance variation while maintaining overall conductive performance.

Inventive Principle:
Principle #3Local quality

2Reliability

If conductive carbon black is uniformly dispersed in polymer to create conductive fiber, then conductivity is achieved, but manufacturing difficulty and cost increase significantly

Engineering Contradiction:
Improveconductive performanceVSAvoidmanufacturing difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention uses a composite structure combining conductive polymer layers containing conductive carbon black with nonconductive polymer layers. This composite approach allows the conductive components to be concentrated in specific layers rather than uniformly dispersed throughout the entire fiber, simplifying manufacturing while maintaining conductive performance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The conductive material is segmented into discrete conductive layers rather than being uniformly distributed. This segmentation reduces the total amount of conductive carbon black needed and simplifies the manufacturing process by allowing separate processing of conductive and nonconductive layers before final fiber formation.

Inventive Principle:
Principle #1Segmentation

3Reliability

If conductive layers are exposed at multiple locations to reduce variation, then static elimination performance improves, but crimping of original yarn occurs due to unequal disposition

Engineering Contradiction:
Improvestatic elimination performanceVSAvoidyarn crimping
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The conductive layers are disposed equally along the fiber surface at regular intervals, creating a uniform electrical distribution pattern. This equal disposition prevents localized stress concentrations that would cause crimping, while still providing multiple exposure points for effective static elimination across the yarn surface.

Inventive Principle:
Principle #12Equipotentiality

4Reliability

If metal fibers are used for excellent static elimination performance, then conductivity is improved, but compatibility with organic materials and processing performance deteriorate

Engineering Contradiction:
Improvestatic elimination performanceVSAvoidcompatibility with organic materials
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention uses composite polymer layers (conductive and nonconductive) instead of metal fibers, maintaining compatibility with organic textile materials while achieving the desired conductive performance. This allows the fiber to be processed using standard textile manufacturing techniques for weaving and knitting.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the material parameter from metal to polymer-based conductive layers, fundamentally altering the chemical and physical properties to achieve compatibility with organic materials while maintaining electrical conductivity through conductive carbon black dispersion in the polymer matrix.

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

This configuration achieves stable and improved antistatic performance for woven and knitted fabrics by maintaining low variation in conductive layer area and surface specific resistance, enhancing the fiber's static elimination effectiveness and durability.

Implementation Method 1

a polyamide resin containing conductive carbon black as a conductive layer

Methodology Applied
Scientific EffectElectrical Conduction: Conduction (electrical)

Data Source

PatentEP3690088B1Conductive composite fiber
Publication Date: 2024.08.28 TORAY INDUSTRIES INC
  • EP3690088B1 patent drawingFigure 1
  • EP3690088B1 patent drawingFigure 2~2(c)
  • EP3690088B1 patent drawing

AI summary

Provided is a conductive composite fiber formed from a polymer containing conductive carbon black in a polyamide resin as a conductive layer and thermoplastic resin as a nonconductive layer, wherein the conductive layer is exposed in three or more locations on the outside surface of the fiber in a cross section, the coefficient of variation (CV %) in the surface area of each conductive layer in a fiber cross section is 10% or less, and the average value of the area specific resistance is 4 log (Ω·cm). It is possible to provide a conductive composite fiber wherein the variation in the fiber surface specific resistance is suppressed and the variation in the exposed surface area of each conductive layer polymer in a fiber cross section is suppressed by exposure of the conductive layer in three or more locations on the fiber surface, crimping of the original yarn is suppressed by equal disposition, and antistatic performance for woven and knitted fabrics and carpets is improved.