Abstract: A hardened cellular material formed by stretching a stretchable material is disclosed. Fluid is allowed to enter softened stretchable material through apertures in a stretching surface to define voids at locations in the stretchable material at locations defined by the apertures. The stretchable material is then hardened with voids at locations controlled/defined by the apertures.

Abstract: A hardened cellular material formed by stretching a stretchable material is disclosed. Fluid is allowed to enter softened stretchable material through apertures in a stretching surface to define voids at locations in the stretchable material at locations defined by the apertures. The stretchable material is then hardened with voids at locations controlled/defined by the apertures.

Abstract: A material with a cellular structure is formed from melt-stretched granules. Granules compressed between stretching surfaces are melted to form viscous molten layers attaching ends of the granules to the surfaces. Melted central portions of the granules are stretched by moving the surfaces away from one another. A cellular structure is thus formed between the molten layers, both of which are solidified to form a solid material. A cellular material may also be formed by melting a melt-stretchable material to form a sheet of viscous molten mass formed of opposite surface layers connected by a central portion, stretching the central portion by pulling the surface layers away from one another to generate air cells randomly distributed throughout the central portion, and solidifying the cellular core and the skins formed from the central portion and the surface layers.