| 摘要 |
<p>The invention is a rotatable cylindrical roll for heat sealing heat sealable materials (15) that includes a heating zone (17) for sealing the material and a cooling zone (19) for supporting the newly formed seal. The device (10) comprises a conductive zone (25) and a resistive zone (20) that are in electrical communication. The resistive zone (20) comprises a cylindrical member having a circumferential band (40) of resistive material disposed on its surface. The conductive zone (25) comprises a cylindrical member having a plurality of conductive strips (50) extending laterally across its surface that are in electrical communication with the resistive band (40). Current is applied via a brush to the conductive strips (50). Current flows from the conductive strips (50) into the resistive band (40) and exits through a conductive strip that is in contact (32) with a ground. Current path through the resistive band (40) defines the heating zone (17), and the cooling zone (19) is defined by area of the resistant band (40) outside the heating zone (17).</p> |
