摘要 |
In a machine for forming a layered fibrous web, at least two different fiber suspensions are led through a head box (10), the fiber suspensions are separated from each other by a blade device (18, 180), the fiber suspensions are supplied to a web forming device (24) and a water layer is formed having a transversely uniform flow at an outlet at the end of the blade device (18, 180), such that the water layer constitutes an extension of the blade device and thereby prevents mixing of the fiber suspensions. The blade device (18, 180) can be freely movable in a substantially vertical direction in order to permit an equalization of pressure between the fiber suspension layers separated by the blade device and thereby reducing wake effects downstream the edge of the blade device. |