摘要 |
<p>The perforated web and a carrier web are passed through a heated zone while moving through a curved path in which the perforated web is tensioned. Upon heating of the perforated web, the thermoplastic material of the web shrinks so that a net structure with opened perforations is formed. Inward shrinking of the peripheral zones of the perforated web is prevented by the tensioning of the perforated web in the curved path.</p> |