Thermosetting Adhesive Barrier for Composite Molding Jigs

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Solution Overview

Problem

When composite materials are heated for curing, the matrix can penetrate into the carbon foam core, leading to reduced laminate thickness, exposed fibers, and void generation, which compromises the smoothness of the tool surface and prevents their use as molding jigs.

Innovation Solution

A method involving the use of an uncured thermosetting adhesive between the porous body and composite material, where the adhesive is cured before the matrix, preventing matrix penetration by setting specific curing conditions based on viscosity profiles and calorific data to ensure the adhesive forms a strong bond with the porous body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the composite material is heated at high temperature for curing, then the curing reaction of the matrix proceeds and bonding strength is improved, but the matrix penetrates into the carbon foam and voids are generated

Engineering Contradiction:
Improvebonding strengthVSAvoidsurface smoothness
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The adhesive layer is applied and cured on the carbon foam surface before the composite material is placed and cured. This preliminary action creates a barrier that prevents matrix penetration during subsequent composite material curing, while still allowing strong bonding to occur.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

An adhesive layer is introduced as an intermediary substance between the carbon foam and the composite material. This adhesive layer acts as a mediator that enables strong bonding while preventing the matrix from penetrating into the carbon foam during curing.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If an adhesive layer is inserted between the carbon foam and composite material to prevent penetration, then bonding is strengthened, but the composite material matrix can still penetrate if the adhesive liquefies before curing

Engineering Contradiction:
Improvebonding strengthVSAvoidpenetration prevention
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The curing temperature profile is carefully controlled and adjusted so that the adhesive layer cures at a lower temperature than the composite material matrix. By changing the temperature parameter sequentially, the adhesive forms a stable barrier before the matrix liquefies and attempts to penetrate.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The curing process exploits phase transitions at different temperature levels. The adhesive undergoes its phase transition (curing) at a lower temperature before the composite material matrix undergoes its phase transition (liquefaction). This sequential phase transition ensures the adhesive forms a solid barrier before the matrix becomes fluid.

Inventive Principle:
Principle #36Phase transitions

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 method maintains the thickness of the composite material, inhibits void formation, and ensures a smooth surface by preventing matrix penetration into the porous body, allowing for effective use as a molding jig.

Implementation Method 1

curing the uncured thermosetting adhesive

Methodology Applied
Scientific EffectCuring reaction: Chemical Bonding

Implementation Method 2

acquiring calorific data for when the uncured thermosetting adhesive cures

Methodology Applied
Scientific EffectThermal curing: Exothermic Reaction

Implementation Method 3

the matrix initially undergoes a decrease in viscosity and becomes fluid

Methodology Applied
Scientific EffectViscosity decrease and liquefaction: Melting

Implementation Method 4

when the curing temperature is reached, undergoes an increase in viscosity and loses its fluidity

Methodology Applied
Scientific EffectCuring reaction: Chemical Bonding

Implementation Method 5

the uncured thermosetting adhesive has cured, penetration of the matrix into the interior of the porous body can be prevented

Methodology Applied
Scientific EffectPhysical barrier formation: Physical Containment

Data Source

PatentEP2589484B1Method for producing molded body
Publication Date: 2020.05.20 MITSUBISHI HEAVY IND LTD
  • EP2589484B1 patent drawingFigure 1~2
  • EP2589484B1 patent drawingFigure 3~4
  • EP2589484B1 patent drawingFigure 5~6

AI summary

A method for producing a molded body in which the matrix of a composite material is prevented from penetrating into a carbon foam. Specifically, a method for producing a molded body (1) that comprises: disposing a thermosetting adhesive (3) on a porous body (2), disposing a composite material (4) containing a thermosetting resin as a matrix on the adhesive (3), curing the adhesive (3), and liquefying and curing the matrix of the composite material (4) after the adhesive has been cured. In this production method, because the cured adhesive (3) bonds strongly to the porous body (2) before the matrix of the composite material (4) is liquefied, the subsequently liquefied matrix of the composite material (4) can be prevented from penetrating into the interior of the porous body (2).