Handling Lightweight Board Grades: Flexible Steam Control for Modern Corrugators
Corrugators Industry
INTRODUCTION
Ultra-light and coated papers are unforgiving—too little heat and you get poor bond, too much and you warp. Traditional valve-and-trap steam layouts react slowly and can’t hold tight temperature windows across fast grade changes.
Jetomat Steam Jet Ejectors give corrugators the Flexibility to dial in steam conditions per order, switch recipes quickly, and keep sheets flat—while Saving Energy.
THE CHALLENGE WITH LIGHTWEIGHT & COATED GRADES
Light grammages and coated liners demand Precise Heat on preheaters/hotplates to avoid over-drying and warp. Legacy control valves throttle pressure (wasting energy) and rely on many traps that cycle, causing temperature swings right when you change board composition or speed. You need Fast Reaction and stable surface temperatures to meet JIT schedules.
WHAT JETOMAT DOES DIFFERENTLY
A Jetomat is a compact Thermo Vapour Recompressor Using variable Nozzle Design and a Diffuser and Nozzle section, high-pressure motive steam entrains low-pressure Flash Steam and recompresses it to your setpoint. That’s the Steam Jet Ejector Working Principle: instead of throttling (wasting exergy), you recycle it—forming an in-line Flash Steam Recovery System for your Heating Systems. This raises internal steam velocity on hotplates, thins the Steam Condensate film & improves Heat Transfer Efficiency.
FAST REACTION & TEMPERATURE ADJUSTMENT-BUILD FOR FREQUENT GRADE CHANGES
Corrugators equipped with modern Baelz control (Jetomat + controls) report Flexible Process Control, Fast Reaction Time, and quick Temperature Adjustment, enabling switches between extreme board compositions without losing stability or speed. That’s exactly what lightweight and coated papers need.
RUN A BROADER PRODUCT MIX-LIGHWEIGHT, COATED, SPECIALTY-WITHOUT SLOWDOWN
With responsive mixed-steam control at each zone, operators recipe-set preheater and hotplate temps for each order, then move on. Plants running this approach can handle light/coated mixes that were previously “risky,” while maintaining throughput and quality. The DS Smith Ghent case highlights the ability to run complex papers (light-weight and coated) reliably after the upgrade.
UNIFORM HEATING REDUCES WRAP AND WASTE
Higher average steam velocity and a thinner condensate layer give more uniform heat distribution across hotplates—key to controlling warp on delicate boards. Users report better control of warp and reduction of waste after upgrading the line’s steam side.
ENERGY WINS WHILE YOU IMPROVE QUALITY
Because Jetomat reuses low-pressure vapor as useful steam, corrugators often cut boiler fuel. Documented corrugated/paper retrofits show ~32% Steam Savings in dryer sections and ~80% lower boiler feed-water and chemicals when traps and venting are eliminated; some lines report no need to use a steam trap on the section after the change. That’s quality and Saving Energy together.
STABLE CONTROL OPENS THE OPERATING WINDOW
Modernized corrugator steam systems deliver temperature control and setting in function of board composition, reduce boiler demand (often enabling lower boiler pressure), and improve responsiveness—so you can run closer to the limit without tripping quality alarms. Expected boiler fuel reduction for such upgrades is ~10–20%.
FEWER MOVING PARTS, SIMPLER LOOPS
Thermocompression forms a Condensate and Flash Steam Recovery System that continuously entrains vapor. That often means fewer steam traps, fewer leaks, and less survey time. Some corrugated sections eliminate traps entirely after ejectors are installed, simplifying steam equipment and reducing unplanned downtime.
DIGITAL SUPERVISION & RECOPE CONTROL FOR JIT MANUFACTURING
Pair Jetomat zones with industrial controllers/supervision (e.g., WinBas-type). Plants gain process control with minimum operational interference, online supervision, and standard protocols for easy tie-in with planning systems—ideal for frequent grade changeovers and JIT order sequencing.
IMPLEMENTATION NOTES FOR CORRUGATOR TEAMS
Thermocompressor Design: Map header pressure, suction source (return/flash), and target mixed pressure per zone; size ejectors for extremes to avoid venting.
Control Strategy: Hold mixed-steam pressure or surface temperature; each zone gets its own setpoint for quick changeovers.
Piping & Layout: Short suction lines, proper drainage; many installs can reduce or remove a dedicated Steam Separator because the Vapor Compressor action reuses flash.
Rollout Plan: Start on the most sensitive zone (e.g., double-backer hotplates), validate gains, then replicate across preheater/hotplate banks
Jetomat
CONCLUSION
For lightweight and coated grades, the steam side must be fast, stable, and efficient. Jetomat Steam Jet Thermocompressors give corrugators the flexible steam control to run a wider product mix—switching recipes quickly, reducing warp and waste, and Saving Energy—all while simplifying the Steam and Condensate loop. Use a pilot zone to prove responsiveness and quality, then scale across the line to standardize performance for JIT market demands.
NEXT STEPS
Identify zones with the most grade-change defects/warp.
Log pressures/temps; build a quick mass-energy balance.
Pilot a Jetomat zone; measure energy, temperatures, and defect rate.
Standardize recipes and scale to remaining zones.