Screen Printed Opacifying Agent for Automotive Glass Bending
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for forming opaque patterns on glass substrates for automotive and window applications face challenges such as volatile outgassing, sticking, and optical distortion during the double lite bending process, particularly when using ceramic frits, which require high-temperature pre-firing and result in unreliable results and increased energy consumption.
Innovation Solution
A method involving screen printing a water-inclusive opacifying agent with a high thread count mesh in a humid environment, followed by heating to a lower temperature for partial curing and then to a higher temperature for full curing, eliminating the need for pre-firing and reducing volatile emissions, while maintaining a low surface stress and avoiding sticking issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ceramic frits are used for screen printing opaque patterns, then the opaque pattern can be formed on glass substrates, but volatile outgassing occurs during heating causing sticking and optical distortion
Solution Approach 1:
The patent changes the chemical composition parameters of the opacifying agent from traditional ceramic frit to a water-inclusive composition containing specific metal oxides (Bi2O3, ZnO, B2O3, SiO2) in controlled ratios. This parameter change allows the material to cure at lower temperatures without excessive volatile outgassing, resolving the contradiction between forming reliable opaque patterns and avoiding harmful outgassing effects.
Solution Approach 2:
The patent uses a composite opacifying agent formulation combining multiple metal oxides (bismuth oxide, zinc oxide, boron oxide, silicon dioxide) with water as the vehicle. This composite material provides both the opacity function and the desired low-outgassing curing behavior, eliminating the sticking and optical distortion problems associated with traditional ceramic frits.
2Reliability
If high-temperature pre-firing is used to cure ceramic frits, then the opaque pattern can be fully cured, but energy consumption increases and process complexity increases
Solution Approach 1:
The patent changes the curing temperature parameter from traditional high-temperature pre-firing (above 600°C) to a lower temperature range (200-400°C) followed by a final cure during bending. This parameter change significantly reduces energy consumption while achieving complete curing through the water-inclusive composition's controlled evaporation and chemical reaction characteristics.
Solution Approach 2:
The patent performs preliminary curing of the opacifying agent at a lower temperature before the final bending process, rather than requiring high-temperature pre-firing. This preliminary action at reduced temperature removes volatiles and initiates curing, then the final cure is completed during the subsequent bending operation, reducing total energy input while maintaining curing completeness.
3Reliability
If high-temperature pre-firing is used to cure ceramic frits, then the opaque pattern can be fully cured, but the manufacturing process complexity increases
Solution Approach 1:
The patent merges the opacifying agent curing process with the subsequent bending and lamination process. Instead of requiring a separate high-temperature pre-firing step, the opacifying agent is cured in-situ during the bending operation when the glass substrates are already being heated to bending temperature. This consolidation eliminates a process step and reduces overall manufacturing complexity.
Solution Approach 2:
The patent applies the opacifying agent to the glass substrate before bending, performing the screen printing action preliminarily. The actual curing then occurs during the subsequent bending process, combining two operations (curing and bending) into one thermal cycle, thereby reducing process complexity compared to separate pre-firing and bending steps.
4Manufacturing precision
If traditional screen printing mesh is used, then the printing process is simple, but the opaque pattern quality and resolution are insufficient
Solution Approach 1:
The patent changes the screen mesh parameter from traditional coarser meshes to high thread count meshes (200-400 threads per inch). This parameter change enables the formation of high-resolution opaque patterns with fine detail while maintaining printability of the water-inclusive opacifying agent formulation through optimized screen printing parameters.
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 approach enables a reliable, energy-efficient, and high-quality opaque pattern formation on glass substrates with reduced residual stress and optical distortions, improving the manufacturing process and product durability.
Implementation Method 1
heating to a lower temperature for partial curing and then to a higher temperature for full curing
Implementation Method 2
applied in a high relative humidity environment, e.g., to help ensure process ability
Implementation Method 3
the two substrates are separated slightly, for example, by a powder layer and gradually heated to approximately 600 to 640 degrees C. and bent to form the desire shape
Data Source
AI summary
Certain example embodiments relate to a method of making a coated article and/or glazing (e.g., for automobile, window, and/or other applications). An opaque paint that is not technically a frit is used to form a desired opaque pattern. The paint is screen printed on a substrate. Screen printing parameters are selected, e.g., so that the mesh has a high threads per inch count; the paint is pushed through the screen using hydraulic forces that account for a sheer thinning property of the paint by balancing squeegee speed, squeegee angle relative to the screen, and hardness of the squeegee; and/or relative humidity above and/or near the screen is at least about 80%. Preferably, the paint is substantially fully curable at 400 degrees C. or less. The substrate with the pattern thereon may be bent using a high temperature process, optionally with another substrate to which it may be laminated.