| 摘要 |
<p>A flat sheet having two edge closure strips integrally fused to it can be made continuously by an appts. comprising a flat die (slit) for extruding the sheet and two adjacent nozzles for simultaneously extruding the closure strips, the sheet and strips are immediately fused together and cooled. The strip extruders are divided into two gps. which are adjustable relative to the slit and parallel to it. Pref. adjusters also enable the width of the sheet to be varied.</p> |
