Description
A higher bow amount increases the spreading effect. The determination of the correct bow amount for a certain application requires a lot of experience on similar applications, in order to achieve the correct spreading effect and to determine whether a roll is suitable for a certain purpose.

The special application, type of paper, quality and level of humidity and all other features which can influence the paper during the operation, must be considered.

With fixed bow rolls, the bow height must be calculated in advance in order to comply with the spreading requirements under consideration of certain conditions.

The bow height in the VARIBOW spreader roll is adjustable during operation which is advantageous should conditions or parameters change.

Bow direction = 90°
When the bow is set in its normal position, the web is spread evenly from the center to both outside edges of the roll. The distance the web travels at the edges is exactly the same as at the center, thus maximum even spreading from the center to each edge is achieved.

Bow direction < 90°
To correct loose centers, the bow is rotated into the web so that the center travels a slightly further distance than the edges.

Bow direction > 90°
To correct slack edges, the bow is rotated out of the web so that the edges travel a slightly further distance than the center.