TAPPI TIP 0404-60: High Vacuum Sheet Dewatering outlines a practical method for evaluating water removal performance in the flat box section of sheet formers. It explains how vacuum, furnish, basis weight, dwell time, and incoming sheet solids affect dewatering performance.
The document includes empirical dewatering curves, regression equations, application steps, and guidance for estimating outgoing sheet solids under different operating conditions. It also addresses wire drag load, cover friction coefficients, vacuum optimization, temperature effects, and the application of results to kraft, old corrugated container, and repulped newsprint grades.
This technical reference is useful for designing new installations, optimizing existing forming sections, evaluating vacuum box performance, and balancing sheet dryness against frictional drag, fabric wear, airflow, and equipment requirements.
Application Scope: Paper machine forming sections, flat box and vacuum box design, high-vacuum dewatering analysis, forming fabric performance, and pulp and paper process optimization.
