Aircraft Transparency Solar Control Coating Stack

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Solution Overview

Problem

Conventional aircraft transparencies, such as cockpit and cabin windows, face challenges in managing solar energy transmission, which leads to increased cabin temperature and heat load on the aircraft's air conditioning system, while existing shading devices compromise passenger views or damage components.

Innovation Solution

A method involving a coating stack on stretched acrylic plies, comprising a primer layer with epoxy amino siloxane, a solar control coating with metallic silver layers, a protective coating of silica and alumina, a polysiloxane topcoat, and a diamond-like carbon overcoat, to control solar radiation while maintaining visibility and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional cabin windows are used to allow sunlight to enter the cabin, then passengers can see out and natural light is provided, but the temperature inside the cabin increases and the load on the air conditioning system increases

Engineering Contradiction:
Improvenatural light transmissionVSAvoidcabin temperature
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The window is divided into multiple layers including polymer substrates and multiple coating layers (primer, solar control, protective, topcoat, overcoat), with each layer serving a specific function to manage light and heat separately

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The window uses composite structure combining polymer substrates with multiple functional coatings (epoxy amino siloxane primer, metallic silver solar control layers, silica-alumina protective coating, polysiloxane topcoat, diamond-like carbon overcoat) to achieve both light transmission and heat rejection

Inventive Principle:
Principle #40Composite materials

2Temperature

If shading devices are used to decrease heat load, then the temperature inside the cabin is reduced, but the passenger can no longer enjoy the view out of the window

Engineering Contradiction:
Improvecabin temperatureVSAvoidview visibility
Core Design Contradiction:
TemperatureVSIllumination intensity

Solution Approach 1:

The solar control coating is applied selectively to the exterior surface of the window, providing heat rejection only where needed while maintaining visibility through the transparent window structure

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The solar control coating acts as an intermediary layer that blocks infrared radiation while allowing visible light to pass through, mediating between the solar energy and the cabin interior

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If electrochromic devices are used to darken the window, then heat transfer into the cabin is reduced, but the components of the electrochromic device are heated up or damaged

Engineering Contradiction:
Improveheat transfer reductionVSAvoidelectrochromic device durability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The solar control coating converts harmful solar radiation into reflected energy before it reaches the window components, using the reflective property of metallic silver layers to bounce back infrared radiation

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The solar control coating is applied in advance to the window surface to prevent solar heat from reaching and damaging the electrochromic device components

Inventive Principle:
Principle #10Preliminary 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

The solution effectively reduces solar heat load on aircraft cabins without obstructing passenger views, enhancing the durability and performance of aircraft transparencies by managing solar radiation transmission efficiently.

Implementation Method 1

a solar control coating with metallic silver layers

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

a solar control coating with metallic silver layers

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 3

an overcoat formed over at least a portion of the topcoat and comprising a diamond-like carbon type coating

Methodology Applied
Scientific EffectDiamond-like Carbon: Diamond-like Carbon

Data Source

PatentEP2440403B1Aircraft transparency with solar control properties
Publication Date: 2020.03.11 PPG INDUSTRIES OHIO INC
  • EP2440403B1 patent drawingFigure 1~2
  • EP2440403B1 patent drawingFigure 3
  • EP2440403B1 patent drawingFigure 4~5

AI summary

An aircraft transparency includes a first stretched acrylic ply and a second stretched acrylic ply. A coating stack having solar control properties is applied over at least a portion of one or more of the major surfaces. The coating stack includes a first primer layer comprising an epoxy amino siloxane-containing material. A solar coating having at least three metallic silver layers is formed over at least a portion of the first primer layer. A protective coating including silica and alumina is formed over at least a portion of the solar control coating. A topcoat including a polysiloxane material is formed over at least a portion of the protective coating. An overcoat is formed over at least a portion of the topcoat and includes a diamond-like carbon type coating.