Fiber-Resin Composite Sheet With Dual-Phase Thermoplastics for Laser Welding

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Solution Overview

Problem

There is a need to improve the manufacturing efficiency of core structures made from paper or fabric substrates without compromising their mechanical properties, particularly in applications such as aircraft, trains, and boats, where existing methods are inefficient and do not fully utilize the potential of high-strength fibrous substrates.

Innovation Solution

A fiber-resin composite sheet is developed, comprising a reinforcing fibrous substrate coated with a blend of two thermoplastic polymers, where the first polymer forms a continuous or co-continuous phase and the second polymer is dispersed within, enhancing mechanical and thermal performance while allowing for easier processing through techniques like laser welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional single-polymer resin coating is used on fibrous substrates, then manufacturing process is simpler, but manufacturing efficiency is lower and bonding performance is insufficient

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidresin composition complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining two different thermoplastic polymers (first and second polymers) into a single resin coating system. This dual-polymer composition enables improved manufacturing efficiency through laser welding while maintaining structural integrity, resolving the contradiction between manufacturing efficiency and material complexity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes parameter changes by controlling the melting points of the two polymers differently - the first polymer has a melting point of 25-350°C while the second polymer has a melting point of 75-400°C. This differential melting behavior enables staged processing: the first polymer melts during laser welding for bonding, while the second polymer remains intact until later expansion processing, thus improving manufacturing efficiency without compromising structural integrity.

Inventive Principle:
Principle #35Parameter changes

2Strength

If high-strength fibrous substrates are used, then mechanical properties are improved, but manufacturing efficiency remains low due to difficult processing

Engineering Contradiction:
Improvemechanical strengthVSAvoidprocessing ease
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by utilizing the differential melting points of two polymers with specific ranges (first polymer: 25-350°C, second polymer: 75-400°C). This enables selective processing - the first polymer melts at lower temperatures during laser welding to facilitate bonding of high-strength substrates, while the second polymer maintains structural integrity during subsequent high-temperature expansion processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces traditional mechanical bonding methods with laser welding technology. The resin coating containing thermoplastic polymers enables direct laser welding of fibrous substrates, eliminating the need for mechanical fasteners or complex joining mechanisms, thereby improving manufacturing efficiency while maintaining the mechanical strength of high-strength substrates.

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

3Productivity

If laser welding is implemented for core structures, then manufacturing efficiency is improved, but resin composition must be specifically optimized

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidresin composition precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by precisely controlling the melting point ranges of two polymers (first polymer: 25-350°C, second polymer: 75-400°C) and their weight ratios (first polymer: 20-80 wt%, second polymer: 20-80 wt%). This optimized composition enables successful laser welding while maintaining structural integrity during subsequent expansion processes, resolving the contradiction between manufacturing efficiency and composition precision.

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 composite sheet exhibits improved bending performance, ease of expansion during manufacturing, and enhanced bond strength between substrates, enabling broader operating temperature ranges and improved shape retention, thus addressing the inefficiencies in existing methods while maintaining mechanical integrity.

Implementation Method 1

the first and second polymers form a two phase blend wherein the first polymer forms a continuous or co-continuous phase with the second polymer

Methodology Applied
Scientific EffectPhase separation:

Implementation Method 2

the second polymer is dispersed in the continuous or co-continuous phase of the first polymer

Methodology Applied
Scientific EffectDispersion:

Implementation Method 3

the first polymer has a melting point of from 75 to 400 degrees C... the second polymer has a melting point of from 25 to 350 degrees C

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP2817451B1A fiber-resin composite sheet and article comprising the same
Publication Date: 2016.01.13 EI DU PONT DE NEMOURS & CO
  • EP2817451B1 patent drawingFigure 1A~1B
  • EP2817451B1 patent drawingFigure 2~3
  • EP2817451B1 patent drawingFigure 4~5

AI summary

A fiber - resin composite sheet comprises a reinforcing substrate of high tenacity fibers and a resin coated onto or into the substrate, the resin comprising a first thermoplastic polymer and a second thermoplastic polymer wherein, (i) the first and second polymers form a two phase blend, (ii) the first polymer is thermoplastic has a melting point of from 75 to 400 degrees C and forms a continuous or co-continuous phase with the second polymer, (iii) the second polymer is particulate having an effective diameter of from 0.01 to 15 micrometers, has a melting point of from 25 to 350 degrees C. and is dispersed in the continuous or co-continuous phase of the first polymer and (iv) the first polymer comprises from 35 to 99 weight percent of the combined weight of first and second polymers in the blend,