摘要 |
<p>A structural honeycomb core (10,10 min ) made of crystalline thermoplastic to provide corrosion-resistant, heat-resistant, high-impact structure is fabricated by use of welding heads (40) to inter-welding strips (20-27; 20 min -27 min ) at spaced locations along their lengths, release substrates (30,50) being interposed between the strips to prevent any one weld from joining more than two of the strips. In a first embodiment, the strips are welded while the crystalline thermoplastic is in its flexible state; and the welded web is expanded and heat-treated to convert the material to its rigid state. In a second embodiment, the strips are corrugated and rigidified prior to welding.</p> |