| 摘要 |
A headbox for delivering a multilayer stock jet to a forming surface (9) in a twin-wire former comprises slice chamber (15) with slice opening (17), and separator vanes (33', 33'') arranged in the slice chamber extending from headbox side wall to headbox side wall and at least up to slice opening (17). The vanes are provided with thickened upstream ends which are anchored by screws (63) in grooves in wall member (65). Each vane has a bending rigidity that is sufficient to permit the stock flow on both sides of the vane to take place at such different pressures and such different flow velocities in relation to one another that the headbox is capable of delivering a smooth and stable multilayer stock jet with a velocity difference of at least about 15 m/min between at least two adjacent layers in the stock jet. <IMAGE> |
