Filter media with irregular structure
Articles and methods relating to filter media are generally provided. In some embodiments, a filter media has an irregular surface structure. For instance, the filter media may comprise a plurality of peaks that are irregular in one or more ways. A ratio of a peak height standard deviation to an average peak height may be greater than or equal to 0.05, and/or a ratio of a peak spacing standard deviation to an average peak spacing may be greater than or equal to 0.08. In some embodiments, a filter media comprises a non-woven fiber web having a layer thickness of greater than 0.3 mm and/or a stiffness of less than or equal to 100 mg.
1. An article, comprising:
a layer, wherein:
the layer comprises a plurality of peaks having an average peak spacing and a peak spacing standard deviation;
a ratio of the peak spacing standard deviation to the average peak spacing is greater than or equal to 0.08;
the layer has an average surface height of greater than 0 3 mm;
the average surface height is an average of relative heights of each point in a relative surface topography with respect to a reference height; and
the reference height is a height of which 95% of the points making up a measured surface topography are above and 5% of the points making up the measured surface topography are below.
2. An article, comprising:
a layer, wherein:
the layer comprises a plurality of peaks having an average peak height and a peak height standard deviation;
a ratio of the peak height standard deviation to the average peak height is greater than or equal to 0.15 and less than or equal to 0.5;
the layer has an average surface height of greater than 0 3 mm;
the average surface height is an average of relative heights of each point in a relative surface topography with respect to a reference height; and
the reference height is a height of which 95% of the points making up a measured surface topography are above and 5% of the points making up the measured surface topography are below.
3. The article of claim 2 , wherein the layer is a meltblown fiber web.
4. The article of claim 2 , wherein the layer is charged.
5. The article of claim 2 , wherein the article has an air permeability of greater than or equal to 2 CFM.
6. The article of claim 2 , wherein the article has an air permeability of greater than or equal to 20 CFM.
7. The article of claim 2 , wherein the article further comprises a scrim.
8. The article of claim 7 , wherein the scrim is a mesh.
9. The article of claim 7 , wherein the scrim is a spunbond web.
10. The article of claim 7 , wherein the scrim is capable of undergoing a reversible stretch of at least 50% along at least one axis.
11. The article of claim 7 , wherein the layer is adhered to the scrim by an adhesive.
12. The article of claim 2 , wherein the article further comprises a second layer.
13. The article of claim 12 , wherein the second layer is an electrospun fiber web.
14. The article of claim 13 , wherein the layer is a meltblown fiber web, and wherein the electrospun fiber web and a scrim are positioned on opposite sides of the layer.
15. The article of claim 2 , wherein the article comprises a support layer.
16. The article of claim 15 , wherein the support layer holds the layer in a waved configuration and maintains separation of peaks and troughs of adjacent waves of the layer.
17. The article of claim 2 , wherein the layer comprises a plurality of undulations, and wherein the plurality of undulations comprises the plurality of peaks.