Abstract: The present disclosure relates to a method for preparing a foamed structure, comprising: providing a preform prepared from one or more of thermoplastic materials, in which the preform has corresponding shape of the foamed structure; subjecting the preform to a first treatment with a first supercritical fluid at a first temperature and a first pressure; optionally, subjecting the preform treated with the first supercritical fluid to a second treatment with a second supercritical fluid at a second temperature and a second pressure; and foaming the resulting preform into a structure having predetermined shape and size.

Abstract: The present disclosure relates to a non-corrugated foamed structure having an average resilience coefficient of greater than 45% as measured by the ASTM D-2632 method and an average pore size of 99 ?m or less.