Patent ID: 8133420

Claim:
A method comprising 1) inserting at least two segments of a solid, thermally expandable polymer composition into a cavity, wherein the segments are joined together to form a single piece or a number of pieces that contain at least a first segment and a second segment, 2) heating the thermally expandable polymer composition in the cavity to a temperature sufficient to expand the segments of the polymer composition and 3) permitting the segments of the polymer composition to expand to at least 500% of their initial volumes to form a foam that fills at least a portion of the cavity, wherein, under the conditions of heating, at least one first segment of the piece or pieces of the polymer composition expands before at least one second segment of the piece or pieces of the polymer composition to form a support or barrier which constrains expansion of the second segment of the piece or pieces of the polymer composition in at least one direction within the cavity, and wherein a portion of the cavity adjacent to an expanded first segment remains unfilled after full expansion of the at least one second segment.