EP0309277A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Respiratory mask having a rigid or semi-rigid, insert-molded filtration element and method of making
Assignee: 3M Co
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Filing: 1988-09-23
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Granted: —
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Expires: 2008-09-23
Abstract
Abstract A filtering device is made by inserting into an injection mold a porous, rigid or semi-rigid filtration element that has inflow and outflow faces separated by a peripheral surface and then injecting resin into the flow channel of the mold at a pressure and temperature such that the resin does not significantly penetrate into the peripheral surface beyond its surface pores. The resin can be a thermoplastic rubber and can form the facepiece of the respirator mask. An inhalation plenum for the mask can be formed at the same time by inserting into the flow chanel of the mold a thin layer of a second resin which substantially does not melt at the pressure and temperature at which the first resin is injected. A complete respirator mask can be produced at a single station in a single insert-molding operation by inserting an exhalation valve and harness attachments together with said filtration element before injecting the first resin. Hence, the respiratory mask can be manufactured inexpensively while affording extraordinarily long service life.
Inventors
- 👤 David L. C/O Minnesota Mining And Braun
- 👤 Donald L. C/O Minnesota Mining And Melvin
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 23:57
CPC Classifications
A; A62; A62B; A62B18/00; A62B18/02; A62B18/025; A61; A61M; A61M16/00; A61M16/06; A61M16/0605; A61M16/0616; A61M16/10; A61M16/105; A61M16/106; A61M16/107; B; B29; B29C; B29C45/00; B29C45/14; B29C45/14336; B29C45/14778; A61M2207/00; B29L; B29L2031/00; B29L2031/48; B29L2031/4807; B29L2031/4835
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
59 words
Filtering device characterized in that it comprises a porous, rigid or semi-rigid filtration element which protects against hazardous gases and vapors and has inflow and outflow faces separated by a peripheral surface at which the filtration element is supported by a resin mount that seals the peripheral surface without significantly penetrating beyond the surface pores of the filtration element.
Claim 2
Dependent Claim
59 words
Filtering device characterized in that it comprises a porous, rigid or semi-rigid filtration element which protects against hazardous gases and vapors and has inflow and outflow faces separated by a peripheral surface at which the filtration element is supported by a resin mount that seals the peripheral surface without significantly penetrating beyond the surface pores of the filtration element.
Claim 3
Dependent Claim
20 words
Filtering device as defined in claim 1 further characterized by the feature that the filtration element comprises bonded absorbent granules.
Claim 4
Dependent Claim
29 words
Filtering device as defined in any of claims 1-2 further characterized by the feature that the resin mount is a facepiece of a respirator mask comprising resilient conformable resin.
Claim 5
Dependent Claim
18 words
Filtering device as defined in claim 3 further characterized by the feature that the facepiece comprises foamed resin.
Claim 6
Dependent Claim
23 words
Filtering device as defined in claim 3 or 4 further characterized by the feature that the face piece comprises an oil-modified styrene-ethylene/butylene-styrene copolymer.
Claim 7
Dependent Claim
21 words
Filtering device as defined in any of claims 1-5 further characterized by the feature that the resin mount comprises thermoplastic rubber.
Claim 8
Dependent Claim
65 words
Filtering device as defined in any of claims 1-6 further characterized by the feature that the resin mount comprises 1) a barrier layer which conforms to said peripheral surface but substantially does not penetrate said element, and 2) a sealing layer which is bonded to the barrier layer and does not contact the filtration element except at the perimeter of its inflow and outflow faces.
Claim 9
Dependent Claim
34 words
Filtering device as defined in claim 7 further characterized by the feature that the sealing layer comprises a resilient, conformable thermoplastic rubber, and the barrier layer comprises a relatively thin and rigid thermoplastic resin.
Claim 10
Dependent Claim
38 words
Filtering device as defined in any of claims 7-8 further characterized by the feature that an extension of the sealing layer forms the facepiece of a respiratory mask and an extension of the barrier layer forms a plenum.
Claim 11
Dependent Claim
47 words
Filtering device as defined in any of claims 7-9 further characterized by the feature that the barrier layer is formed with at least one perforation, and the resin of the facepiece extends through said perforation and into surface pores of the filtration element at its peripheral surface.
Claim 12
Dependent Claim
158 words
Method of making the filtering device defined in any of the claims 1-10 characterized in that an injection mold is adapted to receive as an insert a resilient, porous, substantially rigid filtration element that has inflow and outflow faces separated by a peripheral surface, the mold being formed so that, upon being closed, it partially compresses the filtration element at the peripheral surface to seal off the inflow and outflow faces from the flow channel of the mold, the method comprising the steps of: 1) inserting the filtration element into the flow channel of the mold, 2) closing the mold, 3) injecting resin into the flow channel of the mold at a pressure and temperature such that the resin does not significantly penetrate beyond the surface pores of the peripheral surface of the filtration element, and 4) removing from the mold a filtering device of which the filtration element is supported by a mount formed by the resin.
Claim 13
Dependent Claim
50 words
Method as defined in claim 11 further characterized by the feature that step 1) also involves inserting into the flow channel of the mold a thin piece of a thermoplastic resin that rests against the peripheral surface and provides a barrier layer between the injected resin and the filtration element.
Claim 14
Dependent Claim
55 words
Method as defined in claim 12 further characterized by the feature that step 3) comprises injecting resin into the flow channel at a pressure and temperature such that the piece of thermoplastic resin is softened and conforms to and seals the peripheral surface of the filtration element but substantially does not extend into its pores.
Claim 15
Dependent Claim
33 words
Method as defined in any of claims 11-13 further characterized by the feature that the mold is shaped so that the mount formed by the resin is a facepiece of a respirator mask.
Claim 16
Dependent Claim
45 words
Method as defined in claim 14 further characterized by the feature that step 1) further involves inserting into the mold an exhalation valve and harness attachments so that the filtering device obtained in step 4) can immediately be put to use as a respirator mask.
Claim 17
Dependent Claim
14 words
Filtering device made by the method as defned in any of the claims 11-15.
References Cited (Backward Citations)
No citation records indexed.
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