Composite Laminate Surface Tension Match for Foam Adhesion

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Solution Overview

Problem

Current methods for structural reinforcement of vehicle cavities using polymeric carriers and expandable foam are costly and time-consuming, and without a carrier, the strength of the reinforcement is reduced, making it difficult to control foam expansion and achieve adequate customization.

Innovation Solution

A composite laminate structure is formed with a reinforcement layer and epoxy-based expandable structural foam, where the surface tensions of both components are matched to enhance adhesion and load transfer, resulting in increased tensile and lap shear strength, and allowing for customization and controlled expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a polymeric carrier is used with expandable foam for structural reinforcement, then the strength and control of foam expansion is improved, but the manufacturing cost and time increase due to customization requirements and multiple molds

Engineering Contradiction:
Improvereinforcement strengthVSAvoidmanufacturing efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent combines the reinforcement layer and structural foam into a single integrated composite laminate structure through co-extrusion, eliminating the need for separate carrier manufacturing and foam application steps. This merging of components resolves the contradiction by achieving both structural strength and manufacturing efficiency in one process.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a composite laminate structure consisting of a reinforcement layer and an expandable foam layer bonded together. This composite approach provides the strength benefits of the reinforcement layer while maintaining the customizable shape and controlled expansion properties of the foam, without requiring complex multi-step manufacturing processes.

Inventive Principle:
Principle #40Composite materials

2Productivity

If structural foam is used without a carrier for reinforcement, then the manufacturing cost and time are reduced, but the strength and control of foam expansion are insufficient

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidreinforcement strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent merges the reinforcement function and foam expansion control into a single co-extruded composite laminate, where the reinforcement layer is integrally bonded to the foam layer. This provides both manufacturing efficiency and structural strength simultaneously.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The composite laminate structure combines a reinforcement layer with specific surface tension properties and an epoxy-based expandable structural foam layer. The reinforcement layer provides structural strength while the foam provides expansion capability, achieving both goals without separate manufacturing steps.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If the surface tension difference between structural foam and reinforcement layer is large, then the manufacturing process is simpler, but the adhesion and load transfer capability are reduced

Engineering Contradiction:
Improvebonding process simplicityVSAvoidlap shear strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent specifies that the reinforcement layer should have a surface tension of at least 35 dynes/cm and that the surface tensions of the structural foam and reinforcement layer should be within 15 dynes/cm of one another. By controlling these surface tension parameters, the patent optimizes wetting and adhesion between layers, ensuring strong load transfer while maintaining manufacturing feasibility.

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 laminate exhibits improved physical properties such as increased vertical rise, lap shear strength, and flexural properties, with enhanced storage and transport stability, and the ability to customize size, shape, and foam expansion direction, while maintaining strength and reducing weight and cost.

Implementation Method 1

The surface tensions of the structural foam and reinforcement layer are within 15 dynes/cm of one another so that adhesion between the structural foam and reinforcement layer is improved

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

an epoxy-based expandable structural foam material is located onto the reinforcement layer

Methodology Applied
Scientific EffectFoam expansion: Foam

Implementation Method 3

The epoxy resin may form a covalent bond with the reinforcement, such as with the carboxylic acid or amine of the reinforcement layer, upon exposure to temperatures greater than 150°C

Methodology Applied
Scientific EffectCovalent bonding: Chemical Bonding

Implementation Method 4

The reinforcement layer includes a carboxylic acid or amine chemical functional group. The epoxy resin may form a covalent bond with the reinforcement, such as with the carboxylic acid or amine of the reinforcement layer, upon exposure to temperatures greater than 150°C

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentEP2542403B2Structural composite laminate
Publication Date: 2023.08.16 ZEPHYROS INC
  • EP2542403B2 patent drawingFigure 1~2
  • EP2542403B2 patent drawingFigure 3~4
  • EP2542403B2 patent drawingFigure 5~6

AI summary

A composite laminate is formed from a structural foam and a reinforcement layer. The matched surface tensions of the structural foam and reinforcement layer result in increased bond strength between the structural foam and the reinforcement layer, thus providing for improved physical characteristics including improved lap shear and flexural strength.