A paper mill producing packaging-grade paper ranging from 80 to 180gsm at a speed of 300 m/min faced challenges of sheet breaks, mechanical issues, fluctuating steam consumption, and the inability to utilize the full design load of the presses.
The forming section in this mill consists of a Fourdrinier machine, while the press section comprises two presses with diameters of 800 and 1250 mm [both double-felted]. The operating loads are 100 Kg/cm for the first press and 250 Kg/cm for the second press.
Previously, the mill purchased rolls based on a fixed square centimeter price basis, a common practice in the industry as the mill owners were concerned about controlling costs charged by roll suppliers.
Using a proprietary tool to predict press behavior, our team recommended modifications to the second press rolls and we changed their rubber covering. We chose a superior rubber covering developed in collaboration with ANDRITZ Fabrics and Rolls [Stowe Woodward Division]
This allowed the mill to operate the second press at its full design load, resulting in smooth press operation. These improvements enhanced sheet quality and paper properties.
Based on the successful results with the second press, the mill recovered the first press rolls and installed new covers that we recommended. This enabled the mill to operate at the full design load of 100 to 120 Kg/cm.
The mill has benefited from ANDRITZ Fabrics and Rolls [Stowe Woodward Division] and Lathia’s technology by achieving full design loads in the press section, smooth machine operation, reduced or eliminated sheet breaks, lower fuel consumption [savings of around 10 to 15%], and improved paper runnability.
Roll covers play a crucial role in the economical operation of paper machines and can significantly impact profitability along with paper quality.