US 12,011,686 B2
Filter media comprising a pre-filter layer
Sudhakar Jaganathan, Northborough, MA (US); Nagendra Anantharamaiah, Acton, MA (US); and Maxim Silin, Hudson, MA (US)
Assigned to Hollingsworth & Vose Company, East Walpole, MA (US)
Filed by Hollingsworth & Vose Company, East Walpole, MA (US)
Filed on May 12, 2023, as Appl. No. 18/316,721.
Application 18/316,721 is a continuation of application No. 17/475,458, filed on Sep. 15, 2021, granted, now 11,684,885.
Application 17/475,458 is a continuation of application No. 16/504,835, filed on Jul. 8, 2019, granted, now 11,167,232.
Application 16/504,835 is a continuation of application No. 14/577,247, filed on Dec. 19, 2014, granted, now 10,343,095.
Prior Publication US 2024/0042367 A1, Feb. 8, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. B01D 53/22 (2006.01); A41D 13/11 (2006.01); B01D 39/16 (2006.01); B01D 46/52 (2006.01); B01D 46/54 (2006.01); B01D 46/62 (2022.01); A62B 23/02 (2006.01)
CPC B01D 46/62 (2022.01) [A41D 13/11 (2013.01); B01D 39/1623 (2013.01); B01D 39/1692 (2013.01); B01D 46/521 (2013.01); B01D 46/543 (2013.01); A62B 23/02 (2013.01); A62B 23/025 (2013.01); B01D 2239/0622 (2013.01); B01D 2239/0631 (2013.01); B01D 2239/065 (2013.01); B01D 2239/1233 (2013.01); B01D 2275/10 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A filter media, comprising:
a pre-filter layer comprising first fibers having a median diameter of less than or equal to about 2 microns, the pre-filter layer having a thickness greater than or equal to about 20 microns, wherein the pre-filter layer has a basis weight of less than about 30 g/m2 and an initial DOP efficiency of less than or equal to about 90%; and
a second layer comprising second fibers having a median diameter of less than or equal to about 1 micron, wherein the second layer has an initial DOP efficiency of greater than or equal to about 60% and wherein the initial DOP efficiency of the second layer is greater than the pre-filter layer.