Laminated Glass Opaque Interlayer for Burn Line Elimination

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Solution Overview

Problem

The existing methods for applying enamelled patterns on glass glazings, such as automotive and architectural glazings, face challenges in light transmission reduction, adherence issues during thermal treatments, and thermal behavior modifications, leading to irregularities in forming processes, especially in laminated glazings where enamel compositions can cause 'Burn Lines' and increase energy consumption.

Innovation Solution

A thermoplastic interlayer with an opaque zone that absorbs visible wavelengths is used to mask unsightly elements, replacing traditional enamel compositions, which allows for simpler forming processes and reduced thermal impact, eliminating the need for high-temperature cooking and minimizing optical defects like 'Burn Lines'.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If enamel compositions are applied to glass surfaces to mask unsightly elements, then masking effectiveness is improved, but manufacturing complexity increases due to high-temperature firing requirements

Engineering Contradiction:
Improvemasking process simplicityVSAvoidfiring process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent changes the temperature parameter from high-temperature firing (enamel) to low-temperature lamination (thermoplastic). The thermoplastic interlayer is applied at temperatures below the glass transition temperature of the glass, eliminating the need for high-temperature firing facilities while achieving effective masking of unsightly elements.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces expensive, durable enamel coatings that require complex firing infrastructure with simpler, thermoplastic interlayers that can be applied using standard lamination equipment. The thermoplastic material achieves masking functionality without requiring permanent high-temperature processing capabilities.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Strength

If enamel compositions are fired at high temperatures to fix to glass, then adhesion is improved, but energy consumption increases

Engineering Contradiction:
Improveadhesion strengthVSAvoidfiring energy consumption
Core Design Contradiction:
StrengthVSUse of energy by moving object

Solution Approach 1:

The patent dramatically reduces the temperature parameter from enamel firing temperatures (typically 700-900°C) to thermoplastic lamination temperatures (typically 60-100°C below glass transition temperature). This parameter change maintains adequate adhesion for masking purposes while reducing energy consumption by more than 90%.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If enamel coatings are applied to glass sheets, then masking of unsightly elements is improved, but thermal behavior uniformity deteriorates causing forming irregularities

Engineering Contradiction:
Improvemasking effectivenessVSAvoidthermal behavior uniformity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent changes the thermal parameter from high-temperature enamel firing to low-temperature thermoplastic lamination. This eliminates localized thermal absorption differences that cause forming irregularities, as the thermoplastic interlayer does not create significant thermal radiation absorption variations during the forming process.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If enamel compositions are used for masking, then optical quality is improved, but risk of burn lines increases

Engineering Contradiction:
Improveoptical qualityVSAvoidburn line formation
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent reduces the temperature parameter from high-temperature enamel processing to low-temperature thermoplastic lamination. This parameter change eliminates the thermal conditions that cause burn lines while maintaining adequate masking effectiveness through the thermoplastic interlayer's optical properties.

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 thermoplastic interlayer effectively hides unsightly elements, simplifies the forming process, reduces energy consumption, and enhances the optical quality of laminated glazings by maintaining uniform thermal behavior and eliminating 'Burn Lines', while providing adequate masking and UV protection.

Implementation Method 1

A thermoplastic interlayer with an opaque zone that absorbs visible wavelengths is used to mask unsightly elements

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

Implementation Method 2

The presence of the enamel results in a significant difference in the absorption of thermal radiation, leading to local variations in the forming kinetics

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3233479B1Laminated glass
Publication Date: 2021.06.02 AGC GLASS EUROPE SA
  • EP3233479B1 patent drawingFigure 1~2
  • EP3233479B1 patent drawingFigure 3~4

AI summary

The invention relates to laminated glass comprising first (11) and second (12) sheets of glass laminated using at least one thermoplastic interlayer (20). According to the invention, such glass comprises at least one thermoplastic interlayer (20) including a zone that is opaque at visible wavelengths (21).