| 摘要 |
<p>A sandwich wall for pipes, tanks, and the like fluid confining uses, wherein concentric inner and outer glass fiber reinforced plastic skins or shells are separated from one another by essentially radial ribs integrated into the shells to form a monolithic construction. The ribs are of limited axial extent and are separated from one another by rib forms of substantially greater axial extent, the rib forms functioning essentially as spacers without otherwise materially contributing to the strength or rigidity of the structure. The ribs are composed of essentially the same resinous material as the shells plus a filler, which typically can be chopped glass fiber strands, sand, or other particulate material, glass fiber mat or woven fabric, glass flakes, or mixtures of such materials. The ribs may be either helical and continuous throughout the axial extent of the wall or annular and independent of one another. Various methods of making such sandwich wall structures are also disclosed.</p> |
