Respiratory mask having a rigid or semi-rigid, insert-molded filtration element and method of making
US4790306A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 1987 |
| Grant date | Dec 13, 1988 |
| Priority date | — |
| Expiry date | Sep 25, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2031/4835
- WIPO fieldMedical technology
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.