EP0246917A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
High performance gas filter
Assignee: W.L. Gore and Associates Inc
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Filing: 1987-05-22
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Granted: —
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Expires: 2007-05-22
Abstract
Abstract A gas filter for providing a substantially dust-free atmosphere comprises a high performance filter paper (1) made of glass or chemical fibres, and a thin porous film (2) of expanded PTFE covering the downstream surface (3) of the filter paper (1) to prevent the escape of fine particles of the filter paper material from the filter without substantially increasing the pressure loss across the filter during operation.
Inventors
- 👤 Yoshimi Oshitari
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 04:06
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/08; B01D39/083; B01D39/086; B01D39/14; B01D39/16; B01D39/1692; B01D39/20; B01D39/2003; B01D39/2017; B01D2239/00; B01D2239/04; B01D2239/0457; B01D2239/06; B01D2239/065; B01D2239/0654; B01D2239/0668; B01D2239/12; B01D2239/1208; B01D2239/1216
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
77 words
A gas filter comprising a filter paper (1) made of a fibrous material and having inlet and outlet surfaces, characterised by a fine particle checking member provided on the outlet surface (3) of the filter paper (1) so that they overlie each other, the fine particle checking member comprising a thin porous film (2;12;22) having a multiplicity of pores of submicron size so as to substantially prevent the passing of fine particles from the high-performance filter paper.
Claim 2
Dependent Claim
77 words
A gas filter comprising a filter paper (1) made of a fibrous material and having inlet and outlet surfaces, characterised by a fine particle checking member provided on the outlet surface (3) of the filter paper (1) so that they overlie each other, the fine particle checking member comprising a thin porous film (2;12;22) having a multiplicity of pores of submicron size so as to substantially prevent the passing of fine particles from the high-performance filter paper.
Claim 3
Dependent Claim
17 words
A gas filter according to claim 1, wherein the filter paper (1) is comprised of glass fibres.
Claim 4
Dependent Claim
17 words
A gas filter according to claim 1, wherein the filter paper (1) is comprised of chemical fibres.
Claim 5
Dependent Claim
56 words
A gas filter according to any one of claims 1 to 3, wherein said thin porous film (2;12;22) is a continuous porous film of expanded porous polytetrafluoroethylene (PTFE) which includes a multiplicity of minute nodes, a multiplicity of minute fibrils connecting said nodes, and a multiplicity of minute void spaces surrounded by said nodes and fibrils.
Claim 6
Dependent Claim
21 words
A gas filter according to claim 4, wherein the maximum dimensions of the void spaces are not more than 0.3 µm.
Claim 7
Dependent Claim
20 words
A gas filter according to claim 4, wherein the porosity of the expanded porous PTFE film is up to 95%.
Claim 8
Dependent Claim
42 words
A gas filter according to any one of the preceding claims, wherein the checking member also comprises a breathable support member (13;23) to which the thin porous film (12;22) is bonded at a plurality of spaced positions (14) over its entire surface.
Claim 9
Dependent Claim
31 words
A gas filter according to claim 7, wherein the checking member is provided on the outlet surface of the filter paper (1) with the support member (13;23) facing the filter paper.
Claim 10
Dependent Claim
18 words
A gas filter according to claim 8, wherein the checking member is bonded to the filter paper (1).
Claim 11
Dependent Claim
22 words
A gas filter according to any one of claims 7 to 9, wherein the support member is a breathable paper member (13).
Claim 12
Dependent Claim
23 words
A gas filter according to any one of claims 7 to 9, wherein the support member is a breathable reticulated fabric member (23).
Claim 13
Dependent Claim
39 words
A gas filter according to any one of claims 7 to 11, wherein the support member (13;23) and the thin film (12;23) are of plastics and are bonded by application of heat and pressure at said spaced positions (14).
Claim 14
Dependent Claim
52 words
An air filter paper assembly comprising a filter paper having superposed thereon a porous film to check the dust generation from said filter paper, wherein the entire surface of said porous film to check the dust generation is spot bonded to a breathable paper member and then superposed on said filter paper.
Claim 15
Dependent Claim
52 words
An air filter paper assembly comprising a filter paper having superposed thereon a porous film to check the dust generation from said filter paper, wherein the entire surface of said porous film to check the dust generation is spot bonded to a breathable paper member and then superposed on said filter paper.
Claim 16
Dependent Claim
53 words
An air filter paper assembly comprising a filter paper having superposed thereon a porous film to check the dust generation from said filter paper, wherein the entire surface of said porous film to check the dust generation is spot bonded to a breathable reticulated fabric member and then superposed on said filter paper.
Claim 17
Dependent Claim
53 words
An air filter paper assembly comprising a filter paper having superposed thereon a porous film to check the dust generation from said filter paper, wherein the entire surface of said porous film to check the dust generation is spot bonded to a breathable reticulated fabric member and then superposed on said filter paper.
References Cited (Backward Citations)
No citation records indexed.
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