In the beginning, the main objective for the switch to ceramic surfaces was increased run time of the rolls, thus lowering maintenance costs. Soon after startup, further benefits of the new coatings were observed with forming fabric life being extended by more than 50% in nearly all positions. Additionally, the roll surfaces have maintained their shape and integrity perfectly, especially at the ends, where previous cover fracturing through invasive corrosion has always been present and contributory to fabric damage, according to Voith.
Since CeraGuide B has been installed, forming fabric edge damage is now "a thing of the past," Voith continues, thanks to a unique roll end and edge radius treatment process, Also, wire drive stability has been excellent throughout without a single instance of slippage. The longest serving CeraGuide B cover has now been running in the machine for five years without interruption on the drive position of the bottom wire, where previous rolls with rubber covers had to be changed after 150 to 400 days of operation.
An additional potential for cost reduction, Voith notes, is offered through doctoring in those roll positions. Whereas former rubber covers needed a high amount of lubrication water to avoid wear or damage from the doctor blade, CeraGuide B can be doctored without any lubrication water. For example, on PM 1, 550 l/m/min of doctor lubrication water can be saved per doctoring position. Walther Böhm, technical director at Aschaffenburg, emphasizes that in addition to the water savings, equipment costs for providing that amount of water, like pumps, etc., disappear.
DS Smith is a producer of containerboard in Europe, and PM 1 at Aschaffenburg produces more than 280.000 metric tons of testliner and corrugated board annually in a basis weight range of 80-120 gsm.
More information http://voith.com/en/press/press-releases-99_42552.html about CeraGuide B ceramic coating is available online.
TAPPI
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