QUANTITATIVE-EVALUATION OF THE FORMING JET DELIVERED FROM 4 DIFFERENTHYDRAULIC HEADBOXES USING HIGH-SPEED DIGITAL IMAGING

Hydraulic headboxes have many different forms and shapes with some sim ilar design features and some significant different parts. The tubes i n the tube bank have different geometries and arrangements. Some headb oxes have sheets inside that extend from the tube bank to several inch es from the slice. The author uses earlier outlined methods to examine the forming jet delivered by four different headboxes. The combinatio n of these covers most features available in hydraulic headboxes. The paper examines the hydrodynamic characteristics of the forming jet for each machine and discusses the relation between observed features in the forming jet and the headbox structure.