Respirator having optically active exhalation valve
Various embodiments of a respirator ( 10 ) that includes a harness ( 13, 16 ), a mask body ( 12 ), and an exhalation valve ( 14 ) are disclosed. The exhalation valve ( 14 ) can include a valve seat ( 20 ) and a flexible flap ( 22 ) that is in engagement with the valve seat. The flexible flap can have one or more materials that can cause the flap to flash ( 26 ) when moving from a closed position to an open position or vice versa. The flashing valve can make it easier for a user to ascertain whether the valve is operating properly.
1. A respirator that comprises: a harness;
a mask body; and
an exhalation valve disposed on and attached to the mask body, wherein the exhalation valve comprises:
a valve seat; and
a flexible flap that is in engagement with the valve seat, the flexible flap comprising at least a specularly reflecting film that causes the flap to flash when moving from a closed position to an open position or vice versa, and wherein the flexible flap has indicia thereon created by altering specular reflection of the flexible flap.
2. The respirator of claim 1 , wherein the exhalation valve further comprises a valve cover that is sufficiently transparent to enable the flashing to be seen through a solid portion of the valve cover.
3. The respirator of claim 1 , wherein the flexible flap exhibits band shifting.
4. The respirator of claim 1 , wherein the flexible flap comprises a band shifting film.
5. The respirator of claim 4 , wherein the band shifting film is attached to an outer surface of the flexible flap.
6. The respirator of claim 4 , wherein the band shifting film comprises a multilayer polymeric film.
7. The respirator of claim 6 , wherein the multilayer polymeric film comprises a colored mirror.
8. The respirator of claim 6 , wherein the multilayer polymeric film comprises a polarizer.
9. The respirator of claim 1 , wherein the flexible flap comprises a diffusely reflective optical film.
10. A respirator comprising: a mask body;
a harness attached to the mask body; and
an exhalation valve disposed on and attached to the mask body, wherein the exhalation valve comprises a valve seat and a flexible flap that is in engagement with the valve seat, wherein the flexible flap comprises a band shifting film that is tailored to provide visible indicia.
11. The respirator of claim 10 , wherein the band shifting film is attached to an outer surface of the flexible flap.
12. The respirator of claim 10 , wherein the band shifting film comprises a multilayer polymeric film comprising alternating layers of first and second polymers.
13. The respirator of claim 12 , wherein the multilayer polymeric film comprises a colored mirror.
14. The respirator of claim 12 , wherein the multilayer polymeric film comprises a polarizer.
15. The respirator of claim 10 , wherein the band shifting film comprises a specularly reflecting film, and further wherein the indicia are created by altering specular reflection of the band shifting film at selected areas without distorting or warping the film.
16. The respirator of claim 10 , wherein the band shifting film comprises a diffusely reflective optical film comprising a birefringent continuous phase and a disperse phase.
17. The respirator of claim 16 , wherein the band shifting film comprises a first zone and a second zone, wherein the second zone comprises visible indicia, and further wherein a birefringence in the second zone is less than a birefringence in the first zone.