Patent ID: 7131788

Claim:
A void-maintaining laminate comprising a) a sheet-like base layer, said base layer having a lower surface and an upper surface; b) a plurality of compression elements extending from said upper surface of said base layer, each of said compression elements comprising a base, a tip located distal to said base, a shaft extending between said base and said tip, a shaft axis having a length measured from said base to said tip, and a neck diameter measured substantially perpendicular to said shaft length at a narrowest portion of said shaft; and c) a top layer, said top layer having a permittivity to fluids, and wherein said top layer is attached to a plurality of said compression elements at their respective said tips wherein said base layer, top layer and compression elements are constructed and arranged such that said laminate has a transmissivity of at least 10 −3 M 2 sec −1 of aqueous liquid at a normal load of at least 100 PSF (pounds/ft 2 ) sustainable for at least 100 hours.