摘要 |
<p>A continuous zigzag-shaped coupling element strip, for use in the production of slide fasteners, is produced on a rotating die wheel having an endless zigzag-shaped peripheral cavity receptive to heated thermoplastic material delivered from a fixed extrusion nozzle. The cavity has a plurality of bottlenecks to restrict or retard the flow of the delivered thermoplastic material in the cavity so as to retain much of the thermoplastic material in central and transverse cavity portions that correspond to head and leg portions of a coupling element.</p> |