Copolyester-Stabilized Fiber Composite for Stronger Matrix Adhesion

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Solution Overview

Problem

Existing fiber resin composites face challenges in achieving improved stability and adhesion between reinforcing fibers and the polymer matrix, which affects their strength and durability in applications such as aviation and sports equipment.

Innovation Solution

A fiber resin composite material using a statistical copolyester formed from terephthalic acid, isophthalic acid, butanediol, diethylene glycol, and triethylene glycol as a fixing and stabilizing agent, applied through methods like scatter coating or sewing, enhances the adhesion and stability of the fibers within the polymer matrix.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional fixing agents are used to stabilize fiber structures, then handling and bonding is simplified, but adhesion to the polymer matrix remains insufficient

Engineering Contradiction:
Improvehandling and bonding of fiber structuresVSAvoidadhesion to polymer matrix
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention changes the chemical composition parameters of the fixing agent by using a copolyester with specific diacid and diol components in defined molar ratios. This compositional parameter change enables the fixing agent to provide both adequate stability for handling and improved adhesion to the polymer matrix, resolving the contradiction between ease of operation and reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs a composite fixing agent system consisting of a copolyester with specifically selected components (terephthalic acid, isophthalic acid, butanediol, diethylene glycol, triethylene glycol) in optimized proportions. This composite material approach allows the fixing agent to simultaneously achieve fiber stabilization and enhanced matrix adhesion, overcoming the limitations of conventional single-function fixing agents.

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If fiber structures are stabilized for improved handling, then processing is facilitated, but interlaminar shear strength is reduced

Engineering Contradiction:
Improveprocessing of fiber structuresVSAvoidinterlaminar shear strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The invention optimizes the molar ratios of diacid and diol components in the copolyester fixing agent to achieve the right balance between stability and strength. By adjusting these compositional parameters, the fixing agent provides sufficient stabilization for processing while maintaining or enhancing interlaminar shear strength through improved chemical adhesion to the matrix.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The copolyester fixing agent acts as an intermediary substance between the fiber structure and the polymer matrix. Its specifically designed composition allows it to perform dual functions: stabilizing the fiber structure for easy processing and simultaneously bonding to the matrix to maintain interlaminar shear strength, thus resolving the contradiction through its mediating role.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If thermoplastic fibers are used for fixing, then fiber stability is achieved, but adhesion to thermoset matrix is insufficient

Engineering Contradiction:
Improvefiber structure stabilityVSAvoidadhesion to thermoset matrix
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The invention changes the chemical parameters of the fixing agent by selecting specific diacid and diol components with appropriate reactivity and compatibility for thermoset matrices. The copolyester composition (with controlled molar ratios of terephthalic acid, isophthalic acid, butanediol, diethylene glycol, and triethylene glycol) provides both structural stability and enhanced chemical adhesion to thermoset matrices, overcoming the limitations of conventional thermoplastic fibers.

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 use of this copolyester significantly improves the interlaminar shear strength and residual compressive strength of the composite material, making it suitable for demanding applications in sports, aerospace, and other industries.

Implementation Method 1

the fiber structure is then fixed by the action of temperature and/or pressure

Methodology Applied
Scientific EffectTemperature and pressure fixation:

Implementation Method 2

The adhesion between the reinforcing material and the polymer matrix is particularly important here

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2631337B1Fibre-resin composite material and method for producing the same
Publication Date: 2015.09.23 EMS PATENT AG

AI summary

The invention relates to a fixed and/or stabilized fiber structure made from a fiber-containing material and a means for fixing and stabilizing it. The agent for fixing and stabilizing is a random copolyester formed from the diacid components terephthalic acid and optionally isophthalic acid and the diol components butanediol, diethylene glycol and triethylene glycol. A method for producing this fibrous structure is also provided. The fiber structure is used as a reinforcement material for polymer matrices, in particular epoxy resins. According to the invention, a fiber composite material containing at least one duroplastic resin and the fiber structure according to the invention are also provided.