	US 12,330,100 B2
	Highly efficient filter medium
Jürgen Umminger, Lauda-Königshofen (DE)
Assigned to Johns Manville, Denver, CO (US)
Appl. No. 16/462,164
Filed by JOHNS MANVILLE, Denver, CO (US)
PCT Filed Dec. 18, 2017, PCT No. PCT/EP2017/083256 § 371(c)(1), (2) Date May 17, 2019, PCT Pub. No. WO2018/114764, PCT Pub. Date Jun. 28, 2018.
Claims priority of application No. 10 2016 015 248.6 (DE), filed on Dec. 21, 2016.
Prior Publication US 2019/0329169 A1, Oct. 31, 2019
Int. Cl. B01D 39/00 (2006.01); B01D 39/16 (2006.01); B01D 39/20 (2006.01)

CPC B01D 39/163 (2013.01) [B01D 39/2024 (2013.01); B01D 2239/064 (2013.01); B01D 2239/0668 (2013.01); B01D 2239/086 (2013.01); B01D 2239/1233 (2013.01)]

20 Claims

1. A filter formed from a multilayer filter medium, comprising:

a) a textile supporting layer formed from synthetic polymer fibers, glass fibres or mixtures thereof, wherein

a1) the textile supporting layer has a basis weight of 10 to 300 g/m²,

a2) the fibres of the textile supporting layer have a diameter in the range 2 to 25 dtex for polymer fibres or a diameter of 0.5-15 μm for glass fibres,

a3) the textile supporting layer is consolidated by chemical binders or by thermoplastic binders,

a4) the textile supporting layer has an air permeability of at least 750 L/m²sec,

b) a filter layer formed from a nonwoven, the fibres of the fiber nonwoven consisting of glass fibres, wherein the filter layer is applied to at least one side of the textile supporting layer, wherein

b1) the filter nonwoven has a basis weight of between 25 and 300 g/m²,

b2) the fibre nonwoven is consolidated by chemical binders,

b3) the quantity of chemical binder which is applied is 5 to 30% by weight with respect to the basis weight of the fibre nonwoven,

c) a textile covering nonwoven which is applied to the filter layer opposite the textile supporting layer in accordance with b), wherein the textile covering nonwoven is formed from synthetic polymer fibres, and

c1) the textile covering nonwoven has a basis weight of 20 to 100 g/m²,

c2) the fibres of the textile covering nonwoven have a diameter in the range 2 to 25 dtex,

c3) the textile covering nonwoven is consolidated by chemical binders or by thermoplastic binders,

c4) the quantity of chemical binder or of thermoplastic binder which is applied is 5 to 25% by weight with respect to the basis weight of the covering nonwoven,

c5) the textile covering nonwoven has an air permeability of at least 8500 L/m²sec,

c6) the textile covering nonwoven is formed from two to six nonwoven layers that are coupled together, and at least two of the two to six nonwoven layers are different, characterized in that the fibres forming the fibre nonwoven

b4) comprise a mixture of at least two types of glass fibres,

b5) wherein the first glass fibre type of the mixture in accordance with b4) has a diameter, determined as the mean value of a normal Gaussian distribution, of 0.6 μm±0.3 μm, and

b6) wherein the second glass fibre type of the mixture in accordance with b4) has a diameter, determined as the mean value of a normal Gaussian distribution, of 1.0 μm±0.3 μm, and

b7) wherein the first and second glass fibre types of the mixture in accordance with b4) are present in a ratio of 1 to 1.1 to 1 to 2 (by weight).