Drying the wet web is one of the most energy intensive unit processes in the production of paper and board products. To help reduce the demand on the the dryer section, the web is first pressed under high load to remove excess water mechanically. Efficient water removal in the press section is therefore essential to decreasing energy consumption during production. A common rule of thumb is that a 1 % increase in the dry content after pressing can result in a 4-6% reduction of the dryer demand. However, an overly aggressive pressing strategy can destroy desirable paper properties such as bulk, deteriorate surface properties and printability, can create moisture variability that persists after drying and in extreme cases leads to web crushing. Water removal strategies aimed at simultaneously optimizing dryness, bulk, surface properties and total energy consumption for water removal are therefore needed.
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