| 摘要 |
A sheet of plastics material is continuously extruded onto the upper run of an endless conveyor which carries aluminum vacuum mold plates each defining a cavity with a shingle pattern. The sheet is progressively vacuum-formed into the mold plate cavities, and opposite longitudinal upper and lower portions of the sheet are progressively vacuum-formed, with traveling plug assist in one embodiment, to define shingle panels with hook-shaped lower portions and upper portions defining grooves for receiving the lower portions. The upper portion of the sheet is punched with longitudinally spaced slots to form a nailing flange, and the sheet is then cut laterally at longitudinally spaced intervals to produce elongated siding panels each having integrally connected shingle panels. The shingle panels may have different bottom configurations or profiles and are interchangeable.
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