US 12,478,904 B2
Air filter medium and air filter product
Satoshi Hara, Osaka (JP); Hiroaki Shintani, Tokyo (JP); and Yoshitaka Ito, Tokyo (JP)
Assigned to DAIKIN INDUSTRIES, LTD., Osaka (JP)
Filed by DAIKIN INDUSTRIES, LTD., Osaka (JP)
Filed on Jan. 12, 2024, as Appl. No. 18/411,875.
Application 18/411,875 is a division of application No. 17/680,948, filed on Feb. 25, 2022, abandoned.
Application 17/680,948 is a continuation of application No. PCT/JP2020/032655, filed on Aug. 28, 2020.
Claims priority of application No. 2019-158603 (JP), filed on Aug. 30, 2019.
Prior Publication US 2024/0149196 A1, May 9, 2024
Int. Cl. B01D 39/00 (2006.01); B01D 39/16 (2006.01); D04H 3/016 (2012.01); B01D 46/02 (2006.01)
CPC B01D 39/1623 (2013.01) [D04H 3/016 (2013.01); B01D 46/023 (2013.01); B01D 2239/0618 (2013.01); B01D 2239/0636 (2013.01); B01D 2239/10 (2013.01); B01D 2239/1233 (2013.01); B01D 2239/1258 (2013.01); D10B 2505/04 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of producing an air filter medium, the method comprising:
a first step of preparing a tow band obtained by crimping a tow formed by combining a plurality of filaments, a particulate resin being adhered to the tow band and
a second step of obtaining a filter medium layer that includes
first fibers obtained by applying tension to the tow band to spread the tow band and the first fibers having an average fiber diameter of 5 μm or more and 50 μm or less, and
second fibers disposed in gaps between the first fibers and having an average fiber diameter of 30 nm or more and 1 μm or less,
wherein
the second fibers are drawn out from the particulate resin by drawing the particulate resin, and
the particulate resin is drawn by separating the first fibers from each other so that a gap is formed between the first fibers during the spreading of the tow band.