US 12,409,401 B2
Pleated filtration assembly comprising spunbonded prefilter
Himanshu Jasuja, Woodbury, MN (US); Nathan E. Schultz, Woodbury, MN (US); Seth M. Kirk, Minneapolis, MN (US); Bryan L. Gerhardt, Woodbury, MN (US); Daniel C. Duan, St. Paul, MN (US); and Michael R. Berrigan, Oakdale, MN (US)
Assigned to 3M Innovative Properties Company, St. Paul, MN (US)
Appl. No. 18/011,959
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
PCT Filed Jun. 30, 2021, PCT No. PCT/IB2021/055876
§ 371(c)(1), (2) Date Dec. 21, 2022,
PCT Pub. No. WO2022/009028, PCT Pub. Date Jan. 13, 2022.
Claims priority of provisional application 63/049,506, filed on Jul. 8, 2020.
Prior Publication US 2023/0233968 A1, Jul. 27, 2023
Int. Cl. B01D 39/00 (2006.01); B01D 39/16 (2006.01); B01D 46/00 (2022.01); B01D 46/52 (2006.01)
CPC B01D 39/163 (2013.01) [B01D 46/0001 (2013.01); B01D 46/522 (2013.01); B01D 2239/0407 (2013.01); B01D 2239/0435 (2013.01); B01D 2239/0622 (2013.01); B01D 2239/0627 (2013.01); B01D 2239/0636 (2013.01); B01D 2239/0668 (2013.01); B01D 2239/1233 (2013.01); B01D 2239/1291 (2013.01); B01D 2275/10 (2013.01); B01D 2279/50 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A pleated multilayer air filter assembly comprising a primary filtration layer and a prefilter layer that are bonded to each other and are co-pleated with each other,
wherein the primary filtration layer comprises meltblown electret fibers,
wherein the prefilter layer comprises meltspun, spunbonded electret fibers that comprise a radially outer surface comprising polymethylpentene with at least 95% of the meltspun, spunbonded electret fibers of the prefilter layer being bicomponent sheath-core fibers with a sheath of polymethylpentene and with a core of polypropylene,
and,
wherein a ratio of an Effective Fiber Diameter of the meltspun, spunbonded electret fibers of the prefilter layer to an Effective Fiber Diameter of the meltblown electret fibers of the primary filtration layer is at least 1.5.