Electrified thermal control in glass manufacturing

The glass industry is increasingly electrifying thermally intensive process stages to improve efficiency, reduce fossil fuel use, and cut emissions. In both flat and hollow glass manufacturing, precise electric control of heating and cooling steps is becoming central to quality, productivity, and sustainability.

Electrification as a process enabler
Across glass production, electrification is reshaping how thermal energy is applied and managed. In flat glass manufacturing, accurate regulation of cooling phases and thermal gradients is critical to controlling flatness and preventing internal stresses or surface defects. Downstream of forming, additional heat treatments such as tempering, lamination, and bending are also moving toward fully electrified systems to enable finer control and lower environmental impact.

Similar trends apply to hollow glass, where electrified heating supports consistent wall thickness, dimensional accuracy, and surface quality. In both segments, automation and integrated management of process parameters are becoming essential as producers seek higher efficiency and tighter tolerances.

Gefran and intelligent power control
Within this context, Gefran positions itself as a technology partner for electrified thermal processes, combining sensors, automation systems, and power electronics. A recent addition to its portfolio is the GRC series of intelligent, compact power controllers designed for scalable control of electric heaters in high-temperature applications.

The GRC series is modular and available in single-phase, two-phase, and three-phase configurations, covering current ratings from 25 A to 150 A. It is intended for both linear and non-linear resistive loads, which are common in glass furnaces and downstream heat-treatment equipment. Integrated fuses and a compact form factor allow reduced panel space and simpler electrical cabinet design.

Precision, energy management, and connectivity
A key technical feature of the GRC controllers is the integrated Smart Load Management function. This system actively manages power demand by limiting absorption peaks, supporting more stable energy use and helping to improve overall plant efficiency—an important consideration as electrification increases installed power levels.

Accurate current and voltage measurement is built into the controllers. Combined with internal feedback algorithms, this allows stable regulation of delivered power even in the presence of electrical disturbances. Such stability is particularly relevant in flat glass processing, where small thermal variations can translate into defects or residual stresses.

Connectivity is another core aspect. The GRC devices are native Ethernet products with two physical ports, enabling direct access to operational data without additional gateways or expansion cards. This supports integration into digital plant architectures and provides a basis for monitoring, diagnostics, and data-driven optimization. Further extensions to the range, announced for release in March, are expected to add additional functionality aligned with digitization and sustainability requirements.

Complementary solutions for glass production
Alongside the GRC series, Gefran’s portfolio for the glass industry includes other power control and sensing technologies. GPC series power controllers are used for precise regulation of resistive heaters in applications such as float glass annealing lehrs, where controlled heating and cooling profiles are critical to product quality.

For load switching, GRP-H single-phase solid-state relays support reliable control of linear resistors and infrared lamps, including in continuous rolling furnaces for laminated glass production. Measurement and feedback across the process are provided by position, pressure, and temperature transducers, including magnetostrictive position sensors designed to operate without mechanical wear.

Integrated with solid-state relays such as the GRZ-H series, these sensors support coordinated control of thermal and mechanical parameters, for example, in automated insulating glass assembly lines during cold processing stages.

Toward more efficient and digital glass plants
The electrification of thermal processes in glass manufacturing is closely linked to automation, data availability, and energy management. By combining compact power electronics, accurate measurement, and native connectivity, solutions such as Gefran’s GRC series address both immediate process control requirements and longer-term goals related to efficiency, emissions reduction, and digital plant operation.