| 摘要 |
The present invention provides a separation unit for separating a web material along preformed lines of weakness. The separation unit has a width direction and comprises at least a first roller having a rotational axis extending in the width direction and a web width extending in the width direction, and at least a second roller having a rotational axis extending parallel with the rotational axis of the first roller and a web width extending in the width direction. The second roller is positioned at a distance from the first roller, the distance extending in a direction perpendicular to the width direction. Each of the first and the second rollers is provided with at least one protrusion element extending perpendicularly from the axes. Each of the protrusion elements has a maximum width in the width direction, a maximum radial extension from the rotational axes, an inner portion adjacent to the rotational axes, and an outer portion remote from the rotational axes. The outer portions of the protrusion elements on the first roller are arranged in a staggered relationship with the outer portions of the protrusion elements on the second roller such that the outer portions of the protrusion elements on the first roller are partially overlapping with the outer portions of the protrusion elements on the second roller with a radial overlap length, thus forming an undulating passage for a web material between the rollers. The radial overlap length is between 2-40 mm, preferably 2-20 mm, more preferably 3-12 mm, or most preferably between 4-10 mm. |
