| 摘要 |
<p>A bag forming/filling system includes a delivery mechanism to feed a predetermined length of web material from a web roll to a bag forming cylinder, in which the web is sealed by a sealing machine to form a bag. A predelivery mechanism unwinds and loosens a portion of the web from the web roll by a length substantially corresponding to the predetermined length before operation of the delivery mechanism. The predelivery mechanism may include a pivotally movable tension lever, which moves in an unwinding direction substantially during the closing motion of the sealing machine. In a second embodiment, the predelivery mechanism includes a drive element for rotating the web roll and a detector for detecting a slackened length of a portion of the web.</p> |
