Cellulosic/polyamide composite
AssigneesCornell Research Foundation, Inc., CLARCOR Inc.
InventorsMargaret W. Frey, Lei Li, Thomas B. Green
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Abstract
Composite of polyamide layer solvent bonded to cellulosic substrate is formed by solution electrospinning deposit of polyamide on cellulosic substrate with the solution subjected to electrospinning containing as solvent for polyamide one that swells cellulosic fibers on contact therewith and/or by depositing very long polyamide fibers of low average diameter.
Claims12
A composite comprising a cellulosic substrate comprising cellulosic fibers with a polyamide layer comprising polyamide fibers adhered thereto by an interrelation of fibers of the cellulosic substrate and fibers of the polyamide layer so that the cellulosic substrate and polyamide layer cannot be separated from each other by manually applied peeling force(s).
Filter medium composite comprising a cellulosic substrate comprising cellulosic fibers and having a caliper ranging from 0.010 inch to 0.020 inch and polyamide layer comprising polyamide fibers having average diameter ranging from 100 to 150 nm with a coverage level being less than 0.1 gm/m2, said medium providing a ratio of increase in percent fractional efficiency compared to that for the cellulosic substrate to percent increase in pressure drop across medium compared to that for cellulosic substrate ranging from 3 to 15.
A method for preparing a filter medium comprising the steps of:
- (a) dissolving polyamide in a solvent which swells cellulosic fibers during contact therewith, to form a polyamide solution,
- (b) moving the solution to a droplet forming zone,
- (c) forming droplets of the solution in the droplet forming zone,
- (d) providing an electric charge on the droplets to form jets of polyamide solution and provide unstable flow involving a plurality of electrically induced bending instabilities/whipping motions and flashing off of solvent and production of and elongation of polyamide fibers,
- (e) collecting the polyamide fibers on a surface of a moving substrate layer comprising cellulosic fibers to adhere a layer of polyamide fibers to substrate layer so as to prevent peeling apart of polyamide fiber layer and substrate layer.
Dependencies are inferred from the claim text.