| 摘要 |
An improved method and apparatus for enabling unsupported packaging film (e.g., low density polyethylene, linear low density polyethylene, and high density polyethylene) to be sealed in a tube in the process of making a flexible package. A "following belt" is provided which allows for a sandwiching effect to be imported on the film as it passes through its welding zone. In the prior art, while in this welding zone the polyethylene film would move with a conventional band seal assembly. But the opposite side of the polyethylene film would have to move relative to a drag iron this causing potential friction, seam failure and poor tracking. The present invention's use of a following belt allows the elements on both sides of the unsupported film to move with the film.
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