Float glass manufacturing is a highly controlled continuous process where temperature stability directly affects product quality. Precise thermal monitoring at every stage — from melting to annealing — is essential to ensure uniform thickness, optical clarity, and structural integrity of the glass.
Infrared (IR) cameras provide a non-contact solution for continuous temperature measurement in extreme environments where conventional sensors are not suitable.
Process Characteristics and Measurement Challenges
The float glass process involves molten glass being formed into a flat ribbon on a bath of molten tin at temperatures exceeding 1000 °C. Accurate temperature control is required throughout multiple zones, each with its own measurement difficulties.
Key challenges include:
• high process temperatures and thermal gradients
• reflective glass surfaces affecting emissivity
• changing material properties during cooling
• harsh industrial conditions with dust, fumes, and heat
These factors make reliable and repeatable temperature measurement difficult using traditional contact-based methods.
Infrared Measurement in Float Glass Production
Infrared cameras enable continuous, real-time monitoring of temperature across the entire glass ribbon. Unlike point sensors, IR systems provide full surface temperature distribution, allowing operators to detect variations immediately.
Typical measurement zones include:
• furnace and melting tank
• tin bath (float bath)
• cooling and annealing zones (lehr)
By visualizing temperature profiles, operators can maintain optimal process conditions and quickly identify deviations.
Benefits of Using Infrared Cameras
The implementation of infrared cameras in float glass manufacturing provides several operational advantages:
• non-contact measurement in extreme temperatures
• real-time thermal imaging of the entire glass surface
• improved product quality through uniform temperature control
• early detection of defects and process instability
• reduced downtime and increased production efficiency
These capabilities allow manufacturers to transition from reactive control to proactive process optimization.
Optris Infrared Solutions for Glass Industry
Infrared cameras from Optris are specifically designed for demanding industrial applications such as glass manufacturing. They combine high measurement accuracy with robust construction and flexible integration capabilities.
A key solution for float glass applications is the Optris PI 400i LT infrared camera, developed for precise temperature monitoring of low-temperature glass processes and cooling zones.
The PI 400i LT offers:
• spectral range optimized for glass surfaces, improving measurement accuracy
• temperature measurement range starting from low temperatures up to industrial levels
• high optical resolution (382 × 288 pixels) for detailed thermal imaging
• real-time imaging with high frame rates
• compact design suitable for integration into production lines
• compatibility with industrial interfaces and process control systems
The camera is particularly effective in annealing and cooling stages, where stable temperature gradients are critical to avoid internal stress and defects.
Application Value in Industrial Production
Accurate thermal monitoring enables better control over critical production parameters, directly impacting product consistency and yield.
With infrared technology, manufacturers can:
• maintain stable temperature profiles across the glass ribbon
• optimize heating and cooling cycles
• reduce defects such as stress fractures and thickness variations
• improve overall process transparency
This transforms temperature measurement from a control requirement into a strategic tool for quality assurance and process optimization.
