Patent ID: 7886411
Filing Date: 2011-02-15
Classification: D04H

Abstract:
1. A former head of the kind used for dry forming fibrous non-woven webs, where a fiber material mixed with air is conducted through a round transport duct, having a diameter, and uniformly expanded in the cross-direction through a spreading section and then passes through a discharge section onto a forming zone, comprising: a) the fiber velocities at the entrance of said spreading section are dissipated to be less than those in said transport duct; b) the geometry of said spreading section provides constant or slightly accelerating air and fiber velocities in said spreading section to those found in said transport duct; c) the length of said spreading section is about ten times greater than said diameter of said transport duct; and d) a means for adjusting a gap in said discharge section which allows control of the cross-direction air and fiber flows to said forming zone by modifying the air and fiber velocities through variations of said gap by undulating a static plate.