Flow restraining elements in the headbox of a paper machine

摘要

A headbox for a paper machine comprising a top plate and a bottom plate defining a chamber therebetween and a plurality of flow restraining elements disposed one above another in the chamber to define a plurality of paths spaced one above another therein. The top and bottom plates are connected to one end to a perforated plate defining an inlet for the chamber and approach each other as they approach an outlet for the chamber. Each element is removably connected at one end to the perforated plate, and the paths extend from the inlet to the outlet. Each element has a mildly corrugated upper surface and a mildly corrugated lower surface which approach each other until they terminate in a free end remote from the perforated plate. Those surfaces are substantially symmetrical to each other with respect to a center line of said element. Each element has a free end portion formed from an easily deformable material, such as rubber or plastics. The surfaces of each element define an angle of 1 DEG to 15 DEG therebetween.