摘要 |
A thin sealing device which is resistant to damage caused by foreign material is disclosed. The thin sealing device has an internal heating element. The thin sealing device has a blunt edge, which has a radius smaller than that of the heating element. A thermocouple is placed in a cavity near this blunt edge to monitor the temperature at the point of sealing. In some embodiments, the thin sealing device is pivotably attached at its leading (upstream) edge. The trailing (downstream) edge of the thin sealing device is moved by means of a compressible force, such as an air cylinder. In this way, the air in the cylinder pushes the thin sealing device downward into the plane of the film. However, a foreign object located on the film can overcome the force of the air cylinder, thereby lifting the thin sealing device out of the path of the film.
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