Air filter medium, filter pack, and air filter unit
US-2021260516-A1 · Aug 26, 2021 · US
Air filter medium, filter pleat pack, and air filter unit
US12440794B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-12440794-B2 |
| Application number | US-202118027455-A |
| Country | US |
| Kind code | B2 |
| Filing date | Sep 28, 2021 |
| Priority date | Sep 28, 2020 |
| Publication date | Oct 14, 2025 |
| Grant date | Oct 14, 2025 |
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Abstract
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A provided air filter medium is an air filter medium including a porous fluorine resin membrane, the air filter medium further including: a glass filter medium layer. The glass filter medium layer and the porous fluorine resin membrane are placed in this order from upstream to downstream of the air filter medium configured to allow an air flow to pass through the air filter medium. At a surface of the glass filter medium layer on an upstream side in a direction of the air flow, a carbon-to-silicon ratio (C/Si) evaluated by X-ray fluorescent analysis is 0.020 or more. This air filter medium is suitable for reducing a pressure drop increase even in an environment including liquid particles such as oil mist.
First claim
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The invention claimed is: 1. An air filter medium comprising a porous fluorine resin membrane, the air filter medium further comprising: a glass filter medium layer, wherein the glass filter medium layer and the porous fluorine resin membrane are placed in this order from upstream to downstream of the air filter medium configured to allow an air flow to pass through the air filter medium, and at a surface of the glass filter medium layer on an upstream side in a direction of the air flow, a carbon-to-silicon ratio (C/Si) evaluated by X-ray fluorescent analysis is 0.020 or more. 2. The air filter medium according to claim 1 , wherein the carbon-to-silicon ratio at the surface on the upstream side is 0.025 or more. 3. The air filter medium according to claim 1 , wherein the carbon-to-silicon ratio at the surface on the upstream side is 0.030 or less. 4. The air filter medium according to claim 1 , wherein a reduction in mass of the air filter medium is 70 mg or less, the reduction being evaluated for an evaluation surface after 10 rubs according to Method C (Taber method) of an abrasion resistance test defined in JIS L 1096, the evaluation surface being the surface on the upstream side. 5. The air filter medium according to claim 1 , wherein the surface on the upstream side forms one of exposed surfaces of the air filter medium. 6. The air filter medium according to claim 1 , further comprising a first air-permeable supporting layer placed between the glass filter medium layer and the porous fluorine resin membrane. 7. The air filter medium according to claim 1 , further comprising a second air-permeable supporting layer placed on a downstream side in the direction of the air flow with respect to the porous fluorine resin membrane. 8. The air filter medium according to claim 1 , wherein the porous fluorine resin membrane is a porous polytetrafluoroethylene membrane. 9. The air filter medium according to claim 1 , wherein there is only one of the porous fluorine resin membrane in the air filter medium. 10. A filter pleat pack comprising an air filter medium folded into pleats, wherein the air filter medium is the air filter medium according to claim 1 . 11. An air filter unit comprising an air filter medium, wherein the air filter medium is the air filter medium according to claim 1 . 12. An air filter unit comprising a filter pleat pack, wherein the filter pleat pack is the filter pleat pack according to claim 10 .
Assignees
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Classifications
Wound layers · CPC title
Support layers · CPC title
Polytetrafluoroethylene · CPC title
using folded, pleated material · CPC title
Glass or glassy material · CPC title
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- What does patent US12440794B2 cover?
- A provided air filter medium is an air filter medium including a porous fluorine resin membrane, the air filter medium further including: a glass filter medium layer. The glass filter medium layer and the porous fluorine resin membrane are placed in this order from upstream to downstream of the air filter medium configured to allow an air flow to pass through the air filter medium. At a surface…
- Who is the assignee on this patent?
- Nitto Denko Corp
- What technology area does this patent fall under?
- Primary CPC classification B01D39/1692. Mapped technology areas include Operations & Transport.
- When was this patent published?
- Publication date Tue Oct 14 2025 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 3 related publications on this page (citations in our corpus or others sharing the same primary CPC).