Hollow porous fibers
AssigneeKimberly-Clark Worldwide, Inc.
InventorsVasily A. Topolkaraev, Mark M. Mleziva, Ryan J. McEneany, Neil T. Scholl, Antonio J. Carrillo
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Abstract
A hollow fiber that generally extends in a longitudinal direction is provided. The hollow fiber comprises a hollow cavity that extends along at least a portion of the fiber in the longitudinal direction. The cavity is defined by an interior wall that is formed front a thermoplastic composition containing a continuous phase that includes a polyolefin matrix polymer and a nanoinclusion additive dispersed within the continuous phase in the form of discrete domains. A porous network is defined in the composition that includes a plurality of nanopores.
Claims22
A hollow fiber that generally extends in a longitudinal direction, the hollow fiber comprising a hollow cavity that extends along at least a portion of the fiber in the longitudinal direction, wherein the cavity is defined by an interior wall that is formed from a thermoplastic composition containing a continuous phase that includes a polyolefin matrix polymer and a nanoinclusion additive dispersed within the continuous phase in the form of discrete domains,
- wherein the interior wall has an average wall thickness of from about 0.5 to about 50 micrometers,
- wherein a porous network is defined in the thermoplastic composition that includes a plurality of nanopores, wherein the hollow fiber comprises an average percent pore volume of from about 25% to about 80% per cubic centimeter.
A method for forming a hollow fiber, the method comprising:
- forming a thermoplastic composition that contains a continuous phase that includes a polyolefin matrix polymer and a nanoinclusion additive dispersed within the continuous phase in the form of discrete domains;
- extruding the composition through a capillary to form the fiber, wherein one or more shaped slots are positioned within the capillary;
- and
- drawing the fiber at a temperature that is lower than the melting temperature of the polyolefin matrix polymer, thereby forming a porous network that includes a plurality of nanopores,
- wherein the hollow fiber comprises a hollow cavity that extends along at least a portion of the fiber in the longitudinal direction, wherein the cavity is defined by an interior wall having an average wall thickness of from about 0.5 to about 50 micrometers, wherein the hollow fiber comprises an average percent volume of from about 25% to 80% per cubic centimeter.
Dependencies are inferred from the claim text.