Meltblown filter medium
Filter media, as well as related assemblies, systems and methods. Filter media may contain one or more layers formed of a meltblown material.
1. A filter medium, comprising:
a first layer;
a second layer comprising a meltblown material; and
an adhesive material between the first and second layers,
wherein the adhesive layer is constructed and arranged to adhere the first layer to the second layer and to permit fluid to pass through the adhesive layer,
wherein the filter medium has:
an initial dust capture efficiency of at least 80% and a dust holding capacity of at least 50 g/m 2 , wherein the initial dust capture efficiency and the dust holding capacity are measured by taking a 100 cm 2 surface area of the filter medium and challenging the medium with a fine dust (0.1-80 μm) at a concentration of 200 mg/m 3 and a face velocity of 20 cm/s, wherein the initial dust capture efficiency is measured after one minute and the dust holding capacity is measured when the pressure reaches 1800 Pa; and
an initial cleanability test time and an aged cleanability test time, the aged cleanability test time being at least 70% of the initial cleanability test time,
wherein the initial cleanability test time is the amount of time it takes to complete 30 test cycles and the aged cleanability test time is the amount of time it takes to complete 30 test cycles after aging the filter medium,
wherein each test cycle comprises sending AC fine dust at 16 g/hr through the filter medium at a test area of 177 cm 2 , a face velocity of 5 cm/s, and when the filter medium reaches a pressure of 10 mBar subjecting the filter medium to a 150 millisecond pulse at 4 bar to remove AC fine dust from the filter medium,
wherein aging comprises continuously exposing the filter medium to AC fine dust at 12 g/hr for 10,000 aging cycles and subjecting the filter medium to a 150 millisecond pulse at 4 bar 14 times per minute, wherein the aging cycles are defined between consecutive pulses.
2. A filter medium according to claim 1 , wherein the article has a NaCl particle filtration efficiency of at least 30%.
3. A filter medium according to claim 1 , wherein the article has a periodic dust capture efficiency of at least 80%, and a dust holding capacity of at least 50 g/m 2 .
4. A filter medium according to claim 1 , wherein the article has an initial cleanability test time of at least four hours.
5. A filter medium according to claim 1 , wherein the article has a soot particle capture efficiency of at least 80%.
6. A filter medium according to claim 1 , wherein the article has a NaCl particle filtration of at least 30% and a NaCl particle capture test time of at least 40 minutes.
7. A filter medium according to claim 1 , wherein the article has a liquid filtration efficiency of at least 45%.
8. A filter medium according to claim 1 ,
wherein the first layer has first and second sides;
and
the adhesive material is between the first side of the first layer and the second layer,
wherein the filter medium is a corrugated filter medium having a retained corrugation of at least 25%.
9. The filter medium of claim 8 , wherein the filter medium has a corrugation depth of at least 14 mils on the first side of the first layer.
10. The filter medium of claim 8 , wherein the filter medium has a corrugation depth of at most 25 mils on the first side of the first layer.
11. The filter medium of claim 8 , wherein the filter medium has a corrugation depth of at least 14 mils on the second side of the first layer.
12. The filter medium of claim 8 , wherein the filter medium has a corrugation depth of at most 25 mils on the second side of the first layer.
13. The filter medium of claim 8 , wherein the filter medium has a retained corrugation of at least 30%.
14. The filter medium of claim 8 , wherein the filter medium has a retained corrugation of at least 50%.
15. The filter medium of claim 8 , wherein the filter medium has a retained corrugation of at least 70%.
16. The filter medium of claim 8 , wherein the first layer has a corrugation depth of at least 20 mils on the first and second sides.
17. The filter medium of claim 8 , wherein the first layer has a corrugation depth of at least 22 mils on the first and second sides.
18. The filter medium of claim 8 , wherein the first layer has a corrugation depth of at most 30 mils on the first and second sides.
19. The filter medium of claim 1 , wherein the meltblown material comprises a plurality of fibers having an average diameter of at most 1.5 microns.
20. The filter medium of claim 1 , wherein the meltblown material comprises a plurality of fibers having an average diameter of at least 0.2 micron.
21. The filter medium of claim 1 , wherein the meltblown material comprises a plurality of discrete fibers, at least 5% of the discrete fibers extending a distance of at least 0.3 micron in a direction perpendicular to a length of the second layer.
22. The filter medium of claim 1 , wherein the first layer comprises a material selected from the group consisting of short laid fibers, spunlace fibers, carded non-woven materials, woven cloths and open cell foam structures.
23. The filter medium of claim 1 , wherein a thickness of the first layer is at least 200 microns.
24. The filter medium of claim 1 , wherein a thickness of the first layer is at most 1500 microns.
25. The filter medium of claim 1 , wherein the first layer has a basis weight of at least 25 g/m 2 .
26. The filter medium of claim 1 , wherein the meltblown material comprises a polymer.
27. The filter medium of claim 1 , wherein a thickness of the second layer is at least 5 microns.
28. The filter medium of claim 1 , wherein a thickness of the second layer is at most 200 microns.
29. The filter medium of claim 1 , wherein the second layer has a basis weight of at least 0.5 g/m 2 .
30. The filter medium of claim 1 , wherein the second layer has an air permeability of at most 500 CFM.
31. The filter medium of claim 1 , wherein a thickness of the article is at least 200 microns.
32. The filter medium of claim 1 , wherein a thickness of the article is at most 1500 microns.
33. The filter medium of claim 1 , wherein the article has a basis weight of at most 500 g/m 2 .
34. The filter medium of claim 1 , wherein the article has an air permeability of at most 100 CFM.
35. The filter medium of claim 1 , wherein the article has an air permeability of at most 100 CFM.