E.i. Dupont De Nemours and Company

Henricus Jacobus Cornelis Gommeren

Lawrence Mark Knorr

Guanghui Chen

Hageun Suh

Jennifer Marie Galvin

W Douglas Bates, Iii

Rachel Elizabeth Montejo

Tina Amick Waller

Douglas W Iii Bates

A liquid filter with a composite medium that has a nanoweb adjacent to and optionally bonded to a microporous membrane. The membrane is characterized by an LRV value of 3.7 at a rated particle size, and the nanoweb has a fractional filtration efficiency of greater than 0.1 at the rated particle size of the membrane. The nanoweb also has a thickness efficiency ratio of greater than 0.0002 at that efficiency. The nanoweb acts to provide depth filtration to the membrane, prefilters particles and extends the lifetime of the membrane.

Liquid filtration media

Filtration media including at least one layer of nanofibers having average diameters less than 1000 nanometers with optional scrim layer(s) are disclosed for filtering particulate matter in liquid. The media achieve flow rates of at least 0.055 L/min/cmat relatively high levels of solidity. The media have also advantageously been found to have non-diminishing flow rates as differential pressures increase between 2 psi (14 kPa) and 15 psi (100 kPa).

Filtration media for liquid filtration

A liquid filter with a composite medium that has a nanoweb adjacent to and optionally bonded to a microporous membrane. The membrane is characterized by an LRV value of 3.7 at a rated particle size, and the nanoweb has a fractional filtration efficiency of greater than 0.95 at the rated particle size of the membrane. The nanoweb also has a thickness efficiency ratio of greater than 0.01 at that efficiency. The nanoweb acts to provide depth filtration to the membrane, prefilters particles and extends the lifetime of the membrane.

An improved casting substrate is provided for use in a composite membrane for use as a fluid filtration medium. The composite membrane has good adhesion between the casting substrate and the microporous membrane while maintaining high permeability. The casting substrate comprises a single spunbond layer or a multiple spunbond layers formed of thermoplastic fibers, optionally comprising at least one meltblown layer. The casting substrate allows the membrane casting solution to penetrate the casting substrate uniformly to a controlled depth without penetrating through the entire thickness of the substrate. The casting substrate has good uniformity of mean pore size, basis weight, thickness and surface roughness.

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Hockessin, DE, United States of America

Henricus Jacobus Cornelis Gommeren