| 摘要 |
<p>Method and apparatuses for measuring and regulating the strain of a material web (W) is disclosed. A material web (W) is passed through a first and second non-slip roller pair (6, 11). The first and second roller pair (6, 11) form a predefined span. In some embodiments, the angular positions of the first and second roller pair (6, 11) are monitored, and the phase angle (¦ ab ) between the roller pairs (6,11) is calculated. The phase angle (¦ ab ) is directly related to the level of strain in the web (W), and the velocity of the web is controlled to maintain a phase angle (¦ ab ) which corresponds with the desired strain level. This maintains a constant strain level in the predefined span. In one embodiment, the strain entering a non-slip roll pair is controlled to be zero. The roll pair then introduces a predefined strain to the span entering subsequent processes.</p> |
