| 摘要 |
<p>Multi-ply laminate of sandwich construction esp. Al-sheet/polyurethane foam/Al-sheet is made in situ in that the foam coare is formed between the outer plies in such a way that there are spaced strips of comparatively harder polyurethane foam between which there are softer polyurethane foam strips i.e. harder and softer strips alternate. Mfr. comprises applying partition-like delimiters onto the lower Al-sheet within which a harder-setting, non-flowing, pre-expanded foam is introduced. The spaces between the resulting foam strips is filled with softer-setting liq. foam. Both foams expand at the same foaming pressure so that expansion occurs only in upward direction. The prod. is used in aircraft and motor lorry body construction.</p> |
