Low-E Coated Thin Glass Laminate for Lightweight Automotive Glazing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in combining lightweight glazing with low-e coatings on the interior facing surface of chemically strengthened glass, as low-e coatings cannot be applied to glass that has been thermally formed, and chemically strengthened glass cannot be efficiently coated with low-e coatings, limiting the development of thin, lightweight laminates with both features.
Innovation Solution
Applying the low-e coating after the glass has been chemically strengthened and then cold bending the flat coated glass to its final shape, allowing for the production of a thin, lightweight laminate with excellent thermal properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If glass is chemically strengthened to enable thinning, then strength and durability are improved, but the ability to apply low-e coatings is lost
Solution Approach 1:
The low-e coating is applied to the glass surface before the chemical strengthening process. This preliminary coating application ensures that the coating can be deposited on the glass surface while avoiding the incompatibility that would arise if coating were attempted after chemical strengthening. The coating serves as a protective layer during the ion exchange process and remains intact through the strengthening treatment.
Solution Approach 2:
The invention changes the sequence of manufacturing parameters by reversing the conventional order of operations. Instead of strengthening then coating, the process applies coating first, then performs chemical strengthening. This parameter reordering resolves the technical contradiction by ensuring the coating is applied to a surface that can accept it, while the subsequent strengthening process occurs with the coating already in place as a protective layer.
2Weight of moving object
If glass thickness is reduced to decrease weight, then fuel efficiency is improved, but structural strength under wind load deteriorates
Solution Approach 1:
The invention changes the material parameter by applying a low-e coating to the glass surface, which modifies the surface properties and enables chemical strengthening to be performed effectively. This parameter change allows thin glass to achieve the necessary strength characteristics that would otherwise require much thicker conventional glass, thereby reducing weight while maintaining wind load resistance.
Solution Approach 2:
The invention creates a composite structure by combining thin glass with a low-e coating layer and subsequently applying chemical strengthening. This composite approach allows the thin glass substrate to gain enhanced strength properties from the chemical treatment, while the coating provides additional surface modification that enables the process to succeed. The resulting composite system achieves both weight reduction and strength requirements.
3Ease of manufacture
If conventional annealed glass is used, then ease of manufacture is maintained, but the minimum thickness limit prevents further weight reduction
Solution Approach 1:
The low-e coating is applied preliminarily to the glass surface before chemical strengthening. This preliminary action modifies the glass surface properties, enabling subsequent chemical strengthening to proceed effectively on what would otherwise be unsuitable thin glass. The coating application first allows the manufacturing process to proceed with modified parameters that enable further thinning beyond conventional limits.
Solution Approach 2:
The invention changes key manufacturing parameters by introducing the low-e coating step before chemical strengthening. This parameter modification transforms the manufacturing process from one that is simple but limited in thinness to a process that is slightly more complex but enables significant weight reduction. The coating parameter change enables the chemical strengthening parameter to be applied effectively to thinner glass substrates.
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 results in a laminate that is lighter, provides increased comfort, improved thermal insulation, and enhanced efficiency, reducing the energy needed for heating and cooling the vehicle cabin, while maintaining structural integrity and durability.
Implementation Method 1
low-e coating...provides increased comfort, improved thermal insulation...reducing the energy needed for heating and cooling the vehicle cabin
Implementation Method 2
Chemical strengthening increases the strength of glass through the use of an ion exchange process which creates a compression layer on the glass surface
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
An automotive laminated glazing is provided, comprising an outer glass layer and an inner glass layer, said outer glass layer having a first surface and a second surface and said inner glass layer having a third surface and a fourth surface, wherein the inner glass layer has a thickness of not more than 1.0 mm and is chemically strengthened, and wherein the fourth surface features a low-e coating, obtainable by chemically strengthening a flat glass pane having a thickness of not more than 1.0 mm, then applying the low-e coating, and finally laminating the flat glass pane to a curved glass pane forming the outer layer, thereby cold bending said flat glass pane.