Filter medium, filter element and use thereof and filter arrangement

Patent metadata

Field	Value
Publication number	US-11795593-B2
Application number	US-201916585812-A
Country	US
Kind code	B2
Filing date	Sep 27, 2019
Priority date	Mar 28, 2017
Publication date	Oct 24, 2023
Grant date	Oct 24, 2023

Abstract

A filter medium (10) for filtering a fluid, in particular for use in an interior air filter (32), comprises a spun-bonded nonwoven formed at least in part of multi-component segmented pie fibers (1) having at least a first plastic component (2) and a second plastic component (3). The multi-component fibers (1) are largely non-split, and in order to manufacture same, segmented pie filaments are spun in a spun-bonding process (S4) to form a spun-bonded nonwoven (10). The segmented pie filaments then form the multi-component fibers (4), the first plastic component (2) and/or the second plastic component (3) being made in particular of a polypropylene.

First claim

What is claimed is:

1. A filter medium for filtering a fluid, the filter medium comprising:
multi-component segmented pie fibers ( 1 );
a spun-bonded nonwoven which is formed at least partially of the multi-component segmented pie fibers ( 1 ), each fiber having:
a sheath surface ( 7 ) comprising a radially outer circumferential surface,
a length extension (Z),
a first plastic component ( 2 ) forming first pie segments, and
a second plastic component ( 3 ) forming second pie segments,
adjoining pie segments which are joined together side by side at inner segment boundaries ( 4 ) of the adjoining pie segments, the joining of these segments being present along at least 50% of the length extension of the fiber,
wherein each adjoining pie segment comprises a first pie segment joined to a second pie segment,
wherein for each adjoining pie segment, the pie segments therein are adjoined along the sheath surface,
wherein the sheath surface ( 7 ) includes longitudinal grooves ( 6 ′) formed along outer segment boundaries ( 6 ), the outer segment boundaries located between the adjoining pie segments ( 2 , 3 ),
wherein the first and second plastic components ( 2 , 3 ) adjoin one another along the sheath surface ( 7 ).

2. The filter medium according to claim 1 , wherein each sheath surface ( 7 ) has an average roughness depth (Rz) of less than 2 μm along its circumference.

3. The filter medium according to claim 1 , wherein one or more of the multi-component segmented pie fibers ( 1 ) have at least four of the pie segments ( 2 , 3 ).

4. The filter medium according to claim 1 , wherein one or more of the multi-component segmented pie fibers ( 1 ) do not split apart under the influence of a water jet treatment.

5. The filter medium according to claim 1 , wherein at least 70% of the of multi-component segmented pie fibers ( 1 ) have adjoining pie segments ( 2 , 3 ) joined together over at least 70% of their respective fiber's length extension (Z).

6. The filter medium according to claim 1 , wherein the spun-bonded nonwoven ( 1 ) has a machine direction (M), and the multi-component segmented pie fibers ( 1 ) are oriented along the machine direction (M).

7. The filter medium according to claim 6 , wherein
the spun-bonded nonwoven ( 10 ) has a flexural rigidity in the machine direction (M) of more than 170 mN.

8. The filter medium according to claim 1 , wherein
the adjoining pie segments ( 2 , 3 ) are partially fused together in areas of the inner segment boundaries ( 4 ).

9. The filter medium according to claim 1 , wherein
the multi-component segmented pie fibers ( 1 ) are interconnected exclusively by hot air bonding.

10. The filter medium according to claim 1 , wherein
the spun-bonded nonwoven ( 10 ) has a thickness (D) of between 1.0 mm and 2.0 mm.

11. The filter medium according to claim 1 , wherein
the multi-component segmented pie fibers ( 1 ) are thermally interconnected or thermally bonded together to form the spun-bonded nonwoven.

12. The filter medium according to claim 1 , wherein
the spun-bonded nonwoven ( 10 ) has a thickness of between 0.5 mm and 1.5 mm.

13. The filter medium according to claim 1 , wherein
the plastic components ( 2 , 3 ) of the multi-component segmented pie fibers ( 1 ) are charged as electrets.

14. The filter medium according to claim 1 , wherein
the spun-bonded nonwoven ( 10 ) has a grammage of between 80 g/m 2 and 160 g/m 2 .

15. The filter medium according to claim 1 , wherein
the filter medium ( 11 ) further comprises a meltblown material ( 9 ).

16. The filter medium according to claim 1 , wherein
the first plastic component ( 2 ) and/or the second plastic component ( 3 ) consist of a polypropylene.

17. The filter medium according to claim 1 , wherein
the first plastic component ( 2 ) has a first melting point (T 2 ); and
the second plastic component ( 3 ) has a second melting point (T 3 );
wherein the first melting point (T 2 ) is higher than the second melting point (T 3 ) by at least 8 degrees K.

18. The filter medium according to claim 1 , wherein
a mass fraction of the first plastic component is between 20% and 80%.

19. The filter medium according to claim 1 , wherein
the first plastic component ( 2 ) and/or the second plastic component ( 3 ) has/have a first portion of a first thermoplastic material (MA) having a first melting point (TA) and a second portion of a second thermoplastic material (MB) having a second melting point (TB);
wherein the first melting point (TA) is higher than the second melting point (TB).

20. The filter medium according to claim 19 , wherein
the second thermoplastic material (MB) of different adjacent multi-component segmented pie fibers ( 1 ) is partially fused together to solidify the multi-component segmented pie fibers ( 1 ) into the spun-bonded nonwoven ( 10 ).

21. The filter medium according to claim 20 , wherein
the first thermoplastic material (MA) is a polypropylene homopolymer and/or the second thermoplastic material (MB) is a metallocene polypropylene.

22. The filter medium according to claim 20 , wherein
the spun-bonded nonwoven ( 10 ) is thermally solidified in a respective area of 10 cm 2 in such a way that the spun-bonded nonwoven ( 10 ) is self-supporting.

23. The filter medium according to claim 19 , wherein
a mass fraction of the first thermoplastic material (MA) is between 70% and 95%.

24. The filter medium according to claim 19 , wherein
the first thermoplastic material (MA) and/or the second thermoplastic material (MB) has/have a melt flow index (MFI) of between 20 g/10 min and 30 g/10 min.

25. The filter medium according to claim 1 , wherein
the spun-bonded nonwoven ( 10 ) has an air permeability of between 1,300 l/m 2 s and 1,700 l/m 2 s.

26. The filter medium according to claim 1 , wherein
the spun-bonded nonwoven ( 10 ) has a NaCl retention capacity at 0.3 μm of greater than 20%.

27. The filter medium according to claim 1 , wherein the
spun-bonded nonwoven ( 10 ) has a dust storage capacity at 50 Pa of more than 20 g/m 2 .

28. The filter medium according to claim 1 , wherein
the spun-bonded nonwoven ( 10 ) comprises pleats ( 21 ) with a plurality of pleat sections ( 23 ) arranged between pleat edges ( 22 ).

29. The filter medium of claim 28 , wherein
the pleats ( 21 ) extend transversely to a machine direction (M).

Assignees

• Mann & Hummel Gmbh

Inventors

• Orendt Stefan
• Pemsel Thomas

Classifications

• D04H3/147 Primary

  Composite yarns or filaments · CPC title

• B01D39/163

  sintered or bonded · CPC title

• D04H3/018

  characterised by the shape · CPC title

• B01D2239/0216

  Bicomponent or multicomponent fibres · CPC title

• B01D2239/0627

  Spun-bonded · CPC title