| 摘要 |
There is provided a heat sealing bar (19) having a heating ribbon (35) which endures repeated sealing operations. The heat sealing bar comprises a slender block-like bar body (31), an insulating layer (33) formed on the surface of the bar body (31), and a heating ribbon (35) fixed on the insulating layer (33). A heat pipe (41) is embedded in the bar body (31) along the heating ribbon (35). The heat pipe (41) transfers heat in the longitudinal direction of the heat sealing bar (19) from a portion of a small thermal load to a portion of a larger thermal load, thereby holding the entirety of the heat sealing bar uniform in temperature. Accordingly, the opposite ends and central portion of the heating ribbon (35) fall in a stationary state in the same temperature range as that for the rest of the heating ribbon. As a result, the heating ribbon (35) expands uniformly over the entirety thereof, and there never occurs the phenomenon of an inconsistency in expansion between the heating ribbons (35) and the insulating layer (33). |
