Quality Control for Conductive Coatings in Architecture, Automotive, Smart and Solar Glass Applications Across the Value Chain
Excelling in today’s glass coating industry means providing cost-efficient high quality coatings at all times. More and more functions and requirements are integrated into glass resulting in complex layer stacks. As result the glass passes through many processes. Stacks become more advanced and also post structuring effects such bird-friendly or mobile-friendly functions or antenna printing add to the complexity of the process chain.
This talk presents challenges and benefits potentials by when using of inline electrical metrology solutions for quality assurance and process control across the value chain in architecture, automotive, smart and solar glass industry. It also shares insights on state-of-the-art achievements in process control. It elaborates in detail on non-contact eddy current measurement technology and suggests closed-loop control to consider the interdependencies of electrical properties for subsequent processes.
Insights to emissivity changes during tempering processes and its potentials for utilization
This talk addresses the impact of tempering processes on the emissivity of LowE glass.
It introduces how the online monitoring by eddy current sensors can be used to monitor the change in emissivity. It suggests four strategies how the online emissivity monitoring can be used for improving the tempering performance and homogeneity and also to maximize the emissivity improvement as value add for furnace operators.
This paper presents the current status of measurement series conducted at different tempering sites on various types of LowE glass. The measurements have been made on the glass before and after tempering. The obtained data shows the emissivity improvement up to factor 2 and effects on homogeneity depending on the tempering recipe. It also shows significant worsening of the emissivity by using of wrong tempering settings causing too low convection during the heating causing significant glass bending leading to the well-known white marks in the middle of the glass. The study depicts such negative effects on the coatings and its emissivity properties measured by eddy current systems, so called EddyCus, which is an inductive method for contact or non-contact real-time emissivity assessment. Comparison to thermographic images are shown and discussed. Finally, the status of measurement and analysis are summarized and the potentials of a commercial use of these phenomena is discussed.