Microcellular thermoplastic foamed with supercritical fluid
AssigneeMassachusetts Institute of Technology
InventorsSung W. Cha, Nam P. Suh, Daniel F. Baldwin, Chul B. Park
Life of this patent
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Abstract
A supermicrocellular foamed material and a method for producing such material, the material to be foamed such as a polymerplastic material, having a supercritical fluid, such as carbon dioxide in its supercritical state, introduced into the material to form a foamed fluid/material system having a plurality of cells distributed substantially throughout the material. Cell densities lying in a range from about 10.sup.9 to about 10.sup.15 per cubic centimeter of the material can be achieved with the average cell sizes being at least less than 2.0 microns and preferably in a range from about 0.1 micron to about 1.0 micron.
Claims11
A foamed material comprising
- a non-thermosetting, polymerized plastic material to be foamed;
- a supercritical fluid introduced into said polymerized plastic material to form a supercritical fluid/material system having a plurality of cells distributed substantially throughout said material.
A non-thermosetting polymer plastic foamed material having a plurality of closed cells substantially uniformly distributed therein, the cell density of said cells in said material lying in a range from about 10.sup.9 to about 10.sup.15 cells per cubic centimeter of said material, the average size of said cells being less than 2 microns, wherein the total volume of the cells formed in said foamed material comprise a fractional percentage of the total volume of said foamed material which lies within a range from about 20 to about 90 fraction percent.
A method of producing a foamed material comprising the steps of
- providing a non-thermosetting, polymerized plastic material to be foamed;
- introducing a supercritical fluid into said polymerized plastic material to be foamed at a first temperature and at a first pressure;
- externally changing the temperature and pressure from said first temperature and said first pressure to a different selected second temperature and a different selected second pressure to produce a supermicrocellular foamed material containing a plurality of voids or cells distributed substantially throughout said material.
Dependencies are inferred from the claim text.