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AssigneeMinnesota Mining and Manufacturing Company
InventorsDavid L. Braun, Donald L. Melvin
Estimating the term…
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.
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.
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
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.
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:
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:
Dependencies are inferred from the claim text.