An automated thermal drying system utilizing high-pressure steam is the heart of any corrugated cardboard blank production line, determining the structural rigidity and flatness of the corrugated paperboards.

1. The Thermal Principle Behind Flute Shaping

Within the corrugating machine, raw paper rolls (which contain natural moisture) pass through preheating cylinders before entering the single facer corrugating rolls:

• Softening Cellulose Fibers: Heat radiating from the preheater cylinders (ranging from 150 to 180 degrees Celsius) softens the hydrogen bonds in paper fibers, giving the paperboard the elasticity required to bend into flutes without tearing.

• Starch Glue Gelatinization: The shaped fluting is coated with starch adhesive and pressed against a flat liner. Sudden high heat from the steam cylinders cooks the starch (gelatinization process), securing a rapid and solid bond between flute tips and liners.

• Evaporating Excess Moisture: Dries out the water solvent introduced by the starch adhesive, stabilizing the physical properties of the cardboard blank.

2. Preventing Board Warping

Warped cardboard sheets (board warp) after corrugation is a typical defect caused by uneven moisture content between liners and fluting. The computerized thermal control system at Tien Thanh A&E addresses this challenge:

• Multi-Point Moisture Balancing: Sensors measure paper humidity in real-time, automatically adjusting wrap angles on the preheater cylinders to scale contact area and align the moisture content of all paper webs.

• Double Facer Hot Plates: The combined corrugated board passes through a long flatbed steam chest under pressure rolls. The hot plates dry out residual moisture evenly, ensuring flat sheets exit the slitter-scorer.

3. Energy-Efficient Boiler Technology at Tien Thanh A&E

At our smart factory adhering to ISO 9001:2015 and ISO 14001 guidelines, Tien Thanh A&E deploys green upgrades:

• Closed-Loop Steam Condensate Recovery: 100% of condensed steam from the corrugating rolls is recovered and pumped back to the boiler, saving over 15% in boiler fuel and fresh water usage.

• Smart Automation Controls: Automatically reduces steam pressure and cylinder temperatures when the corrugator slows down or stops, preventing paper scorching and saving energy.

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