摘要 |
A method of manufacturing a foam having a negative Poisson's ratio comprising the steps: placing a pad 12 of open cell polyurethane foam on a moulding surface 4; placing a flexible membrane 18 over the exposed surface of the foam to create a sealed chamber 20 between the moulding surface 4 and the flexible membrane 18 in which the foam pad 12 is disposed; applying an isostatic pressure difference between the inside and the outside of the chamber 20 thereby collapsing the foam pad 12 between the flexible membrane 18 and the moulding surface 4; heating the foam pad 12 to a predetermined temperature, and subsequently cooling the foam pad 12 while collapsed.
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