FOERFARANDE FOER ATT PAOVERKA EN PAO EN VIRA AVVATNAD FIBERBANA SAMT ANORDNING FOER UTFOERANDE AV FOERFARANDET

摘要

A method and apparatus are disclosed for influencing the fibers in the uppermost layer of a fibrous web lying on a screen, for example, in applying a watermark or evening the surface of the web, wherein a surface compression is exerted on the web by a screen roller and a second screen guided around the screen roller. The surface compression is maintained over a variable time period and causes a water film to appear on the upper surface of the web, in which the fiber density is much less than in the web prior to the surface compression. This water layer is forcibly aspirated from the web and the fibers therein thus experience a reorientation and become set in desired positions.