Multi-segment expandable polymer compositions which expand in a controllable direction
AssigneeDow Global Technologies LLC
InventorsFrank V. Billotto, Mark P. Allen, Frank J. Flavin
Life of this patent
Estimating the term…
Abstract
Expandable polymer compositions are used to reinforce or provide various types of insulation to cavities in structural elements. The polymer compositions include at least two different segments, which may or may not be joined. At least one of the segments will expand before another segment when heated. The first-to-expand segment forms a physical barrier to the expansion of later-expanding segments, thereby restricting the expansion of the later-expanding segment in at least one direction. In this manner, the location of the expanded polymer within the cavity can be easily and inexpensively controlled.
Claims28
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.
A method comprising
- 1) inserting at least two segments of a solid, thermally expandable polymer composition into a cavity,
- 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 polymer composition expands before at least one second segment to form a support or barrier which constrains expansion of the second segment in at least one direction within the cavity,
- wherein said cavity is vertically oriented, and an expanded first segment constrains the downward expansion of the at least one second segment such that a portion of the cavity below the expanded composition remains unfilled after full expansion of the at least one second segment.
A method comprising
- 1) inserting at least two segments of a solid, thermally expandable polymer composition into a cavity,
- 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 polymer composition expands before at least one second segment to form a support or barrier which constrains expansion of the second segment in at least one direction within the cavity,
- wherein said cavity is vertically oriented, and an expanded first segment constrains the upward expansion of the at least one second segment such that a portion of the cavity above the expanded composition remains unfilled after full expansion of the at least one second segment.
Dependencies are inferred from the claim text.