Abstract
The rebuild of a fourdrinier with a vintage blade style top forming configuration is examined for papermachines producing board grades. Limitations of the pre-rebuild design are discussed from a fundamental standpoint. The fluid mechanics of the vintage and rebuilt twin wire forming sections are examined. Design challenges and solutions to mitigate the limitations of the pre-rebuild former are discussed.
The rebuild is engineered for the specific furnish and application based upon end product needs. A majority of the existing forming section remains intact minimizing installed cost and papermachine down time for installation.
Three rebuilds are reported on, two on linerboard grades and one on a woodfree uncoated grade. Performance is characterized before and after each rebuild with regards to operating capacity and a variety of sheet properties, depending on the grade of paper being produced. Significant improvements in capacity, formation, smoothness, and mechanical strength properties were realized after the rebuilds.
This report is prepared focusing on the linerboard rebuild at this time.
