US Patent:
20020045041, Apr 18, 2002
Inventors:
Mark Dillon - Huntingdon Valley PA, US
Richard Brandimarte - Bensalem PA, US
Raymond Triglia - Levittown PA, US
International Classification:
B32B003/26
US Classification:
428/311510, 428/315500, 428/316600
Abstract:
A microporous membrane is described comprising at least two layers, wherein each layer is characterized by nodes interconnected by fibrils, the layers are bonded by means of plastic flow at temperatures below the melting point of either membrane material, and the pore architecture is formed in situ by an expansion process. A stratified microporous membrane is produced wherein the pore architecture of each layer may be discretely controlled. The article is useful for filtration and medical applications where a pore size gradient is required.