The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 15, 2003
Filed:
Jul. 31, 2002
Leroy Whinnery, Jr., Danville, CA (US);
Sandia Corporation, Livermore, CA (US);
Abstract
A method for providing a uniformly dense polymer foam body having a density between about 0.013 g/cm to about 0.5 g/cm is disclosed. The method utilizes a thermally expandable polymer microsphere material wherein some of the microspheres are unexpanded and some are only partially expanded. It is shown that by mixing the two types of materials in appropriate ratios to achieve the desired bulk final density, filling a mold with this mixture so as to displace all or essentially all of the internal volume of the mold, heating the mold for a predetermined interval at a temperature above about 130° C., and then cooling the mold to a temperature below 80° C. the molded part achieves a bulk density which varies by less then about ±6% everywhere throughout the part volume.