Respiratory mask having a rigid or semi-rigid, insert-molded filtration element and method of making
First Claim
1. Filtering device comprising 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.
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Accused Products
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 resirator mask. An inhalation plenum for the mask can be formed at the same time by inserting into the flow channel 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.
111 Citations
21 Claims
- 1. Filtering device comprising 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.
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5. Filtering device comprising a porous, rigid or semi-rigid filtration element which protects against 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 comprising
(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.
- 8. Respirator mask comprising a porous, substantially rigid filtration element that has broad inflow and outflow faces separated by a peripheral surface and is supported by a facepiece comprising resilient, conformable resin which seals the peripheral surface without significantly penetrating beyond the surface pores of the filtration element.
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14. Method of making a filtering device using an injection mold 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 said peripheral surface to seal off said inflow and outflow faces from the flow channel of the mold, said method comprising the steps of:
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(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 said peripheral surface of the filtration element, and (4) removing from the mold a filtering device of which said filtration element is supported by a mount formed by said resin. - View Dependent Claims (15, 16, 17, 18, 19)
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20. Method of making a filtering device using an injection mold 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 said peripheral surface to seal off said inflow and outflow faces from the flow channel of the mold, said method comprising the steps of:
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(1) inserting into the flow channel said filtration element and a piece of thermoplastic resin covering said peripheral surface of the filtration element, (2) closing the mold, (3) 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, and (4) removing from the mold a filtering device of which said filtration element is supported by a mount formed by both said injected resin and said piece of thermoplastic resin. - View Dependent Claims (21)
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Specification