Filler Elements for Void-Free Bonded Components

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Solution Overview

Problem

The production of large-format, complex-shaped fibre-reinforced plastic components with integral reinforcement elements often results in undesirable voids due to thermal expansion of moulding tools and misalignment, leading to reduced material thickness and increased costs for further treatment.

Innovation Solution

The use of filler elements and sealing elements positioned gap-free between the moulding tools and base laminate, which support the moulding tools and prevent matrix material penetration into voids, reducing the occurrence of voids caused by thermal expansion and misalignment, and ensuring the use of cost-effective aluminium alloy moulding tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If aluminium alloy moulding tools are used to reduce cost, then manufacturing cost decreases, but thermal expansion during curing causes voids and reduces manufacturing precision

Engineering Contradiction:
Improvemanufacturing costVSAvoiddimensional stability
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent introduces filler elements as intermediary components between the moulding tools and the laminate. These filler elements compensate for the thermal expansion of aluminium alloy moulding tools during curing, preventing void formation while allowing the use of cost-effective aluminium tools instead of expensive stainless steel tools.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical state and positioning of filler elements during the curing process. The filler elements are inserted in a relaxed state at room temperature and then compressed as the laminate cures and expands thermally, allowing them to adapt to dimensional changes and maintain void-free bonding.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If moulding tools are heated during curing, then curing process is enabled, but thermal expansion creates gaps and voids

Engineering Contradiction:
Improvecuring temperatureVSAvoiddimensional stability
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The patent applies filler elements as a preventive measure before thermal expansion occurs. These elements are positioned and secured to the moulding tools in advance, creating a cushioning effect that compensates for the upcoming thermal expansion during the curing heating process.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent explicitly accounts for and utilizes thermal expansion principles by incorporating filler elements that compensate for the expected expansion of aluminium alloy moulding tools when heated from room temperature to curing temperatures (up to 120°C or higher).

Inventive Principle:
Principle #37Thermal expansion

3Reliability

If vacuum pressure is applied during curing, then void removal is improved, but matrix material penetrates into existing voids reducing material thickness

Engineering Contradiction:
Improvevoid removalVSAvoidmaterial thickness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies filler elements as a preliminary protective measure before vacuum curing begins. These elements prevent the formation of voids in the first place by maintaining consistent spacing and pressure distribution, thereby preventing matrix material from penetrating into voids that would otherwise form during the vacuum curing process.

Inventive Principle:
Principle #9Preliminary anti-action

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 solution significantly reduces the formation of voids during the curing process, maintaining the desired material thickness and reducing the need for complex rework, while allowing the use of cost-effective aluminium alloy moulding tools, thus lowering production costs and ensuring consistent component quality.

Implementation Method 1

the moulding tool is covered with an aeration material and with a vacuum envelope

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

the thermal expansion of the moulding tools during the curing process

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

placed in an autoclave for purposes of full curing at high pressure and temperatures of up to 220°C

Methodology Applied
Scientific EffectCuring:

Data Source

PatentEP2736706B1A device for the manufacture of a bonded component and also a method
Publication Date: 2016.12.28 AIRBUS OPERATIONS GMBH
  • EP2736706B1 patent drawingFigure 1~2
  • EP2736706B1 patent drawingFigure 3~4

AI summary

A device (50) and a method for the manufacture of a bonded component (58) with fibre-reinforced plastics with at least one base moulding tool (52) and at least one moulding tool (60), wherein the bonded component (58) is arranged between the base moulding tool (52) and the moulding tool (60) and the bonded component (58) has at least one base laminate (54) and at least one reinforcement laminate (56), and the moulding tool (60) is covered with an aeration material and with a vacuum envelope, wherein the vacuum envelope is sealed with respect to the base moulding tool (52). At least one filler element (70, 72) is fitted to each of the two end faces (62, 64) of the base laminate (54) in an essentially gap-free manner. As a consequence of the filler elements (70, 72) as well as optionally provided sealing elements (66, 68) undesirable cavities within the device (50), in particular as a result of thermal expansion effects of the upper moulding tool (60) as well as any deviations of location and/or size (84, 86) of the base laminate (54), the reinforcement laminate (56), and also the moulding tool (60), are reduced to a significant extent.