Web comprising fine fiber and reactive, adsorptive or absorptive particulate
The assemblies of the invention can comprise a fine fiber layer having dispersed within the fine fiber layer an active particulate material. Fluid that flows through the assemblies of the invention can have any material dispersed or dissolved in the fluid react with, be absorbed by, or adsorbed onto, the active particulate within the nanofiber layer. The structures of the invention can act simply as reactive, absorptive, or adsorptive layers with no filtration properties, or the structures of the invention can be assembled into filters that can filter particulate from a mobile fluid while simultaneously reacting, absorbing, or adsorbing materials from the mobile fluid.
1. A filter element comprising a fused fiber web or porous membrane formed, on a non-woven filter substrate, by heat treating a substantially continuous fine fiber layer, the element having a thickness of about 0.1 to 20 microns and a pore size of about 0.01 to 2 microns, a dispersed active particulate comprising about 0.1 to 50 vol % of the web or membrane, the particulate comprising about 0.001 to 10 kg per square meter of the web or membrane and wherein the solidity of the web or membrane without the active particulate is greater than the web or membrane with the active particulate.
2. The element of claim 1 , wherein the element comprises a flow-by direction such that the fluid can flow in a path parallel to the web or membrane with no substantial filtration path through the web or membrane.
3. The element of claim 1 , wherein the web or membrane comprises a flow through path through the web or membrane.
4. The element of claim 1 , wherein the thickness of the web or membrane is about 1 to 100 times the original heat treated fiber diameter.
5. The element of claim 1 , wherein the element comprises about 5 to 95 wt % fine fiber layer mass and about 95 to 5 wt % particulate comprising an active particulate, inert particulate, and mixtures thereof, the layer comprising 1 to 100 g-m −2 of particulate.
6. The element of claim 1 , wherein the element comprises about 30 to 75 wt % of fine fiber layer mass and about 70 to 25 wt % of active particulate wherein the layer comprises 1 to 1,000 g-m −2 of active particulate.
7. The element of claim 1 , wherein the active particulate has a major dimension of less than 500 microns.
8. The element of claim 1 , wherein the particulate comprises an absorbent particulate, and adsorbent particulate, a reactive particulate or mixtures thereof.
9. The element of claim 1 , wherein the particulate, has a major dimension of less than about 200 microns.
10. The element of claim 1 , wherein the particulate has a major dimension of about 5 to 200 microns.
11. The element of claim 1 , wherein the particulate is an amorphous or non-spherical particulate.
12. The element of claim 1 , including a second layer comprising a filter substrate.
13. The element of claim 1 , wherein the particulate is mono-dispersed.
14. The element of claim 1 , wherein the particulate is poly-dispersed.
15. The element of claim 1 , wherein the permeability of the web or membrane without the active particulate is greater than the web or membrane with the active particulate.
16. The element of claim 1 , wherein the efficiency of the web or membrane without the active particulate is less than the web or membrane with the active particulate.