| 摘要 |
A helically wound and helically ribbed plastic tubing incorporating an electrically conductive heating wire and an apparatus and method for making the tubing are disclosed. A plastic ribbon is wound about an axis into a tube with one edge of each lap overlapping and heat-bonded to an edge of the preceding lap as the tubing is rotated; a conductive wire is embedded in the ribbon; and a bead is applied and heat-sealed onto the tubing, encapsulating the conductive wire during rotation of the tubing, providing a unitary structure including a conductive wire integral to a flexible tubing having a corrugated crevice-free outside and a smooth inside. Coolant is applied to the tubing for cooling the unitary ribbon, wire and bead tubing and to assist in advancing the tubing along the axis. |
