Laminate Glass-Ceramic Layers for Thin UV and NIR Shielding
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Solution Overview
Problem
Current technologies for UV and NIR shielding in glass applications, such as automotive and architectural glazing, face challenges including high costs, complexity, and inefficiencies in heat management due to radiation trapping, which limits the use of IR-absorbing glasses and requires costly modifications to manufacturing processes.
Innovation Solution
The development of laminate glass-ceramic articles with tungsten oxide-doped, mixed molybdenum-tungsten oxide-doped, and molybdenum oxide-doped alumino-borosilicate compositions that have lower thermal expansion coefficients than the core glass layer, allowing for thinner, lighter-weight configurations with enhanced UV and IR blocking capabilities without the need for additional coatings or films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional absorptive tinted glasses with IR-absorbing species (≥1.5 wt% Fe2+) are used to block UV and NIR wavelengths, then UV and NIR transmission is reduced, but radiation trapping during melting occurs causing cold zones in gas-fired melters or super-heating in Joule heated tanks, preventing the glass from reaching forming temperature
Solution Approach 1:
The patent changes the chemical composition parameters by using Fe2+ concentrations below 1.5 wt% and employing specific combinations of Fe2+, MoO3, and WO3 dopants. This parameter modification allows the glass to achieve UV and NIR absorption without excessive IR absorption that causes radiation trapping, enabling successful melting and forming in conventional furnaces
Solution Approach 2:
The patent creates a composite doping system combining Fe2+ with MoO3 and/or WO3. This composite approach allows the glass to achieve enhanced UV and NIR blocking characteristics while maintaining manufacturability, as the combined dopant system provides synergistic optical properties without the drawbacks of high Fe2+ content alone
2Weight of stationary object
If glass thickness is decreased for light-weighting in automotive and architectural glazing, then weight is reduced, but the amount of light transmittance increases reducing UV and NIR blocking effectiveness
Solution Approach 1:
The patent modifies the optical parameters of the glass by incorporating specific dopant combinations (Fe2+, MoO3, WO3) that increase the absorption coefficient for UV and NIR wavelengths. This allows thinner glass sections to achieve the same level of UV and NIR blocking as thicker conventional glass, enabling weight reduction without sacrificing protective performance
Solution Approach 2:
The patent enhances the local optical properties of the glass by strategically positioning dopant concentrations throughout the glass matrix. The Fe2+, MoO3, and WO3 dopants create localized regions of enhanced UV and NIR absorption that are distributed throughout the glass structure, allowing thin sections to provide effective radiation blocking
3Object-affected harmful factors
If solar-absorbing interlayers with NIR-absorbing particles (LaB6, ITO, ATO, organic dyes, pigments) are used to block NIR wavelengths, then NIR transmission is reduced, but cost increases significantly compared to conventional clear/un-tinted PVB
Solution Approach 1:
The patent merges the UV and NIR blocking functions into a single glass layer through compositional doping, eliminating the need for separate solar-absorbing interlayers. By incorporating Fe2+, MoO3, and WO3 directly into the glass matrix, the glass itself provides both UV and NIR absorption, consolidating multiple functions into one material and reducing overall system cost
Solution Approach 2:
The patent employs cost-effective dopants (Fe2+, MoO3, WO3) that can be incorporated during standard glass manufacturing processes, replacing expensive engineered interlayers containing rare earth particles or complex dye systems. This approach uses readily available materials and conventional manufacturing techniques to achieve the same optical performance
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
These laminate glass-ceramic articles achieve high visible transmittance and strong UV/IR attenuation at reduced path lengths, reducing manufacturing costs and avoiding the limitations of traditional coatings, while maintaining durability and compatibility with RF signals.
Implementation Method 1
Near infrared (NIR) shielding glasses are being employed to block wavelengths ranging from 700-3500 nm
Implementation Method 2
The key challenge in achieving greater UV and IR absorbance in conventional absorptive tinted glasses
Implementation Method 3
each having a CTE that is lower than or equal to the first CTE of the core glass layer
Data Source
AI summary
A laminate glass-ceramic article is provided that includes: a core glass layer having a first coefficient of thermal expansion (CTE); and a plurality of clad glass-ceramic layers, each having a CTE that is lower than or equal to the first CTE of the core glass layer. A first of the clad glass-ceramic layers is laminated to a first surface of core glass layer and a second of the clad glass-ceramic layers is laminated to a second surface of the core glass layer. Further, a total thickness of the plurality of clad glass-ceramic layers is from about 0.05 mm to about 0.5 mm. In addition, each of the glass-ceramic layers includes: an alumino-boro-silicate glass, 0 mol %≤MoO3≤15 mol %, and 0 mol %≤WO3≤15 mol %, the WO3 (mol %) plus the MoO3 (mol %) is from 0.7 mol % to 19 mol %.