| 摘要 |
<p>The invention relates to a headbox (1) for a paper or board machine (4) having at least one first supply means (20) for supplying fibrous suspension (5) into a guide device (11) which is connected to a nozzle (28) out of which the fibrous suspension (5) emerges via a gap, and having a dosing device (40) for dosing at least one additive such as a filler material or a chemical of any type, in particular a paper chemical such as a retention agent. The headbox (1) according to the invention is characterized in that the headbox is a multi-layer headbox (1) with at least one first layer (12) and one second layer (8), wherein at least the first layer (12) of the headbox (1) comprises a fibrous suspension (5) and a second layer (8) of the headbox (1) comprises substantially white water, and wherein the first and second layers (8, 12) are guided separately at least in the guide device (11) and the dosing device (40) is arranged and designed in such a way that the additive is supplied substantially to the second layer (8) comprising substantially white water, wherein the white water is supplied to the guide device (11) via a second supply means (16), and wherein the dosing takes place at a location downstream of which no significant pressure drop and/or no significant turbulence occur in the second layer (8).</p> |
