Disposable filter respirator with inner molded face flange

A filter respirator forming a face mask to be worn upon the face of a user including a support layer of flexible material. The support layer is molded to conform to the contours of the face of the user and forms a flexible support layer for filter material. A separate layer of filter material filters out impurities. An exhalation valve extends through the support layer and the filter layer in a central position. The exhalation valve includes an inside surface surrounding the central position. A molded non-porous flexible inner flange forms a flexible half-mask for sealing to the face of the user. The inner flange is attached to the peripheral edges of at least the support layer and extends inward to the central position. The inner flange includes a central opening with a surrounding portion conforming and adjacent to the inside surface of the exhalation valve. This forms an inhalation valve between the inside surface of the exhalation passage and the surrounding portion of the central opening of the inner flange.

BACKGROUND OF THE INVENTION 
1. Field of the Invention The present invention relates to face masks and 
in particular to a face mask forming a disposable filter respirator with 
an inner molded face flange and inhalation/exhalation valves. 
2. Description of the Prior Art In the prior art, disposable face masks 
have been constructed, in their simplest form, of a layer of material, 
such as fiberfill material which layer forms both the filter material 
itself and the support to position the mask over the nose and mouth of a 
user. The mask is typically held in position by elastic straps which are 
attached at the sides of the mask and extend around the back of the head. 
Other disposable face masks have been constructed of layers of fiberfill 
material supporting a separate layer of filter material, such as a layer 
of filter material supported between two outer layers or by a single layer 
of fiberfill material Other types of disposable face masks have used other 
materials to form the support surface, such as the use of an openwork 
plastic material forming a self-supporting net to hold and support the 
filter material. These more complicated structures include a self 
supporting layer to provide for a better fit of the mask against the face 
of the user when the mask is held in place by the elastic straps. 
Two problems which occur with the use of any face mask are: (1) a proper 
fit of the face mask to the face of the user so as to eliminate as much as 
possible, any passage of air to the user before it has passed through the 
filter material and (2) a heat and moisture buildup which can occur within 
the mask, especially if the user of the mask is engaging in strenuous 
work. It can be seen that these two problems are somewhat interrelated 
since it is desirable to provide for a good fit of the mask to the face of 
the user and the better the fit, the tighter the seal and the more the 
problem of heat and moisture buildup. This is because if the fit is not 
proper, then exhaled air, including heat and moisture can leak around the 
edge of the mask to the exterior. However, an improper fit can be 
dangerous since if exhaled air can leak out, inhaled air can leak in and 
as indicated above, all inhaled air should pass through the filter 
material. 
One solution to the problem of heat and moisture buildup within the mask is 
the use of an exhalation valve located within the mask. For example, 
reference is made to prior U.S. Pat. No. 4,454,881 having the same 
inventors as the present application and with this patent disclosing a 
disposable filter mask having an exhalation valve. In addition, this 
patent discloses the use of a sealing bead located around the peripheral 
edge of the mask to provide an edge seal between the mask and the face of 
the user and additionally including membrane portions extending from the 
bead member to enhance the fit of the mask at least in the areas of the 
sides of the nose and the upper cheekbone of the user. 
Although the mask shown in U.S. Pat. No. 4,454,881 is an improvement over 
prior disposable face masks, it still has some deficiencies. Specifically, 
it is desirable to provide for an ever better fit of the mask to the face 
of the user and to provide for a check of this fit and further to channel 
inhaled air more directly to the nose area of the user and to direct the 
exhaled air out of the mask to more completely eliminate the problem of 
heat and moisture buildup. 
There have been other prior art attempts to solve the above described 
problems. For example, reference is made to U.S. Pat. No. 4,630,604 
listing Edward N. Montesi as the inventor which patent discloses an 
inhalation/exhalation valve assembly for a disposable filter respirator. 
The Montesi patent describes a respirator having a disposable filter and 
includes a valve having a central aperture providing concentric inhalation 
and exhalation valves. The filter structure of the Montesi patent is 
generally formed from relatively rigid molded plastic members supporting a 
filter material and with an inner 0 rubberlike face piece of the type well 
known in the art providing for the sealing of the mask to the face of the 
user. The Montesi respirator, although providing for a good seal of the 
mask to the face of the user and also providing for the substantial 
elimination of heat and moisture buildup, suffers from a number of 
deficiencies. First, the mask is relatively expensive to make since it is 
formed from relatively rigid molded plastic members which are expensive to 
manufacture and difficult to assemble. Second, the mask is somewhat 
cumbersome because of its large size and rigid construction. 
SUMMARY OF THE INVENTION 
The present invention provides for a disposable filter respirator with an 
inner molded face flange which accomplishes substantially all of the 
results as the Montesi patent, but is simpler in construction, less 
expensive in cost, more efficient in use, lighter in weight and much more 
comfortable for the user and thereby much more likely to be worn. 
The present invention is directed to a disposable filter respirator which 
includes an inner molded flexible face flange and with a portion of the 
flange forming in combination with an other structure an inhalation 
passage which in one embodiment of the invention forms a valve. The mask 
also includes an exhalation valve. The structure of the inhalation passage 
and exhalation valve are interrelated with each other to minimize the cost 
of these structures. All of the inhaled air passes through the filter 
material and through the inhalation passage at a central position to 
provide for a cooling effect as air is inhaled. All of the exhaled air is 
directed at the central position through the exhalation valve so that 
substantially all of the exhaled air passes easily out of the mask to 
avoid heat and moisture build up. 
In addition to the above, the inner face flange provides for the proper fit 
of the mask to the face of the user and with the flange accommodating to 
the contours of different sizes and shapes of the face of different users 
so that the same basic mask may be worn by a large percentage of potential 
users of the mask. The inner flange is formed to have a structure similar 
to that of a rubber half mask except that the inner flange is attached to 
the filter mask at the periphery of the mask and extends inward to a 
central position and is unattached at this central position. At the center 
of the mask, an exhalation valve is fitted and with the unattached central 
portion of the inner flange concentric around the exhalation valve and 
forming in combination with a portion of the exhalation valve an 
inhalation passage which in one embodiment of the invention forms a valve. 
The fit or seal of the mask on the face of the user may be checked by 
placing the palm of the hand over an exhaust port for the exhalation valve 
and pressing lightly to block exhalation. The user then exhales to form a 
slight positive pressure within the mask. If the mask is properly sealed, 
then no air will leak around the periphery of the mask while the exhaust 
port of the exhalation valve is blocked. If air does leak, then the mask 
can be readjusted to properly fit the mask in position. 
The disposable filter respirator of the present invention may include 
filter and supporting layers similar to prior art structures. For example, 
the supporting layer may be formed from openwork plastic resembling a net 
in a similar manner to prior art filter masks and the filter material 
itself may be formed from any of the known types of filter material to 
provide for filtering of impurities in the air. This filter material may 
take a wide variety of forms and the present invention is not limited to 
any particular type of filter material. In general, however, the type of 
filter material that would be used would be an efficient filter material 
that would tend to somewhat restrict inhalation and exhalation and thereby 
the use of the inhalation/exhalation valves of the present invention 
combined with the inner flange is particularly desirable.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
As shown in FIGS. 1, 2 and 3, a filter mask is generally formed including 
an outer layer 10 of resilient material forming a supporting layer. 
Specifically, this outer layer 10 may be formed of an openwork plastic 
material to form a support for the filter respirator and specifically to 
support the filter material. The outer layer 10 generally retains its 
shape while at the same time allowing for the free passage of inhaled air 
through the filter material. As shown in FIG. 3, filter material 12 is 
supported by the outer supporting layer 10. The filter material 12 is 
shown to extend completely out to the periphery of the support layer 10 
but it is to be appreciated that the filter material may be terminated 
short of the periphery as long as no inhaled air can bypass the filter 
material. 
The filter material may be formed of any known type of filter material so 
as to provide for filtering of particulate elements in the air. For 
example, the following types of filter material have been used to provide 
for filtering, but it is to be appreciated that other filter material may 
be used: activated charcoal treated sheets or sheets formed by charcoal 
articles, fiberglass material, fine denier, non-woven polyethylene or 
polypropylene materials which may be or may not be electrostatically 
treated, natural material such as wool. The filter layer 12 may be formed 
from any one of these materials or any other known filter material. 
Supported at a center position of the mask and extending from the interior 
to the exterior is an exhalation valve 14. The exhalation valve 14 may be 
of a known type but preferably is similar in structure to an exhalation 
valve shown in co-pending application Ser. No. 933,879 filed Nov. 24, 1986 
and assigned to the same assignee as the instant application. The 
exhalation valve of the present application is somewhat different than the 
co-pending application in that it includes an outer member 16 having an 
L-shaped cross section which extends forwardly to form an exhaust channel 
or port and with the outer member 16 also supporting an internal spider 
member 18. The exhalation valve may, therefore, be closed off by placing 
the palm of the hand at the outside of the valve to cover the lip of the 
outer member 16 to thereby seal off the exhaust channel or port. 
The exhalation valve is essentially formed of three members including the 
outer member 16 with the spider member 18 suspended within, an inner 
member 20 also having a L-shaped cross section which supports an inner 
spider member 22 and a flexible membrane 24. The inner spider member 
includes a pin portion 26 which extends through an opening in the membrane 
24 and is in turn received within a tubular portion 28 extending from the 
outer spider member 18. The flexible membrane 24 is, therefore, captured 
between the pin member 26 and the tubular member 24 and as described in 
the co-pending application this provides for an efficient and accurate 
positioning of the flexible membrane 24. The outer perimeter of the 
flexible membrane 24 rests on a portion of the inner member 20. The inner 
member 20 nests within the outer member 16 and captures the support layer 
10 and filter layer 12 therebetween. In this way, the exhalation valve 14 
is sealed in a central position in the mask. The specific operation of the 
exhalation valve 14 will be described with reference to the operation of 
the entire valve and passage structure at a later portion of this 
specification. 
As shown in FIGS. 2 and 3, a flexible inner flange 30 is supported at the 
periphery of the disposable filter and extends inward to form essentially 
a flexible non-porous face mask. This inner flange 30 may be made of any 
appropriate plastic or rubber like material and includes an outer 
peripheral portion 32 which extends completely around the perimeter of the 
disposable filter and is sealed to the filter material 12 and outer 
supporting layer 10 at the perimeter to form an integral structure. The 
inner flange may be sealed directly to the outer layer 10 if the filter 
material 12 does not extend out to the periphery of the outer layer. 
As can be seen in FIGS. 1 and 2, integral flange portions 34 formed by all 
three layers 10, 12 and 30 of the mask may extend from both sides of the 
mask and may be used to support strap holders 36. It is to be appreciated 
that, as an example, only the outer layer may extend outward to form the 
flange portions 34. The peripheral portion 32 of the flange 30 forms a 
flat profile in a plane around the circumference of the flange. This can 
be seen clearly in FIG. 2. Extending into the center of the mask, the 
inner flange 30 includes portions 38 and 40 which puff out to enhance the 
sealing of the inner flange to the face of the user while other portions 
of the inner flange round off from the flat periphery 32 into the center 
of the flange. This configuration may be clearly seen in FIG. 8 which 
shows in cross section the outside profile of the inner flange 30. 
The particular configuration of the inner flange 30 allows for a superior 
fit of the mask to the face since it provides for an accommodation to the 
contours of the face. Specifically, face masks generally are made with a 
configuration wherein the nose bridge and chin portions tend to be 
relieved relative to the side portions of the mask. However, with the 
inner flange 30 of the present invention, the outer peripheral portion is 
flat and in a single plane for ease of manufacture. In order to provide 
for the relieved profile and produce a better fit to the face of the user, 
the puffed out portions 38 extend outward in the areas of the cheeks as 
shown in FIGS. 2 and 7 and the portions 40 extend inward in the areas at 
the sides of the nose so that the sealing perimeter does conform to the 
desired shape for sealing to the face of the user. The puffed out portions 
effectively provide for a recess in the nose bridge and chin areas. 
The outer perimeter 32 is flat to allow for an easier and more efficient 
attachment of the inner flange 30 to the layers of filter and supporting 
material 10 and 12. This attachment is normally accomplished with a 
welding, such as an ultrasonic welding and it is much simpler to provide 
for this welding in a flat configuration as opposed to trying to provide 
for the welding to follow an irregular configuration as shown by the 
portions 38 and 40. 
The inner portion of the inner flange 30 terminates with a circular opening 
42. This can be seen clearly in FIG. 4 and can also be seen in the various 
cross sectional views. In general, in a first embodiment of the invention 
a flattened portion 44 of the inner flange 30 is provided to surround the 
circular opening 42. As can be seen in FIG. 3, the flattened portion 44 is 
immediately adjacent a flat inner surface of the inner member 20 and the 
combination of the flattened portion 44 with the inner surface of the 
inner member 20 forms an inhalation passage. 
The inner flange 30 may also include integrally molded elongated air 
channels 45 which extend away from the filter material 10. The air 
channels 45 insure that inhaled air is channelled to the circular opening 
42 even if the filter material 10 collapses since the channels 45 provide 
for air passages. 
FIGS. 5 and 6 illustrate the operation of the first embodiment of the 
disposable filter respirator of the present invention. Specifically, as 
shown in FIG. 5, when air is inhaled the air passes through the openings 
in the outer supporting layer 10 and through the filter material as shown 
by the arrows 46. This occurs throughout the entire surface of the mask 
wherever air can enter. Because the inner flange 30 is non-porous the 
filtered air is channeled down to the center of the mask as shown by the 
arrow 48 and passes through the inhalation passage formed by the flattened 
portion 44 and the inner surface of the inner member 20. The filtered air 
enters the interior of the mask, as shown by the arrow 50, and through the 
circular opening 42 of the inner flange 30. 
As shown in FIG. 5 as compared with FIG. 3 the inner flange 30 may be 
constructed to be flexible enough so that the flattened section 44 may 
move further away from the inner member 20 so as to provide for an 
efficient flow of filtered air into the center of the mask as shown by the 
arrow 50. When the filtered air enters the center of the mask it may, 
therefore, be directed to the nose and mouth of the user of the mask as 
shown by the arrows 52. The inhalation, therefore, is provided through the 
central opening 42 which tends to produce a cooling effect since the air 
is concentrated through the center opening and is not distributed over a 
wide interior portion of the mask. Also, the air is concentrated through 
the center of the mask and aimed directly at the nose and mouth to provide 
for a more efficient inhalation. 
The small movement of the inner flange 30 to allow for the free passage of 
the air through the opening 42 does not in any way disturb the sealing of 
the mask to the face of the user since the peripheral sealing portions 38 
and 40 are compressed against the face of the user by resilient straps 
(not shown) which are attached to the strap holders 36. The peripheral 
sealing portions 38 and 40 are specifically designed to have a flexible 
cushioning contour to seal over a broad portion of the face and to 
eliminate leakage of the mask even with the minor flexing of inner 
portions of the flange 30. As can also be seen in FIG. 5 during 
inhalation, the flexible membrane 24 is pulled tight against a portion of 
the member 20 to thereby prevent the inhalation of any air through the 
exhalation valve 14. During exhalation, exhaled air is directed by the 
inner flange 30 to the exhalation valve 14. The membrane 24 opens to 
exhaust the exhaled air. 
FIG. 6 illustrates the operation of the disposable filter respirator of the 
present invention during a seal check. Specifically, the user may place 
the palm of the hand, as represented by portion 60 against the exhalation 
valve 14 and lightly push, as shown by arrows 62 to slightly deform the 
mask as shown by deformed portion 64 to seal the flattened portion 44 
against the member 20. As will be later explained, this provides a check 
of the fit of the mask to the face of the user. 
FIG. 7 illustrates the operation of a second embodiment of the mask of the 
present invention during exhalation. The second embodiment includes a 
flattened portion 44' which extends from a ring portion 66 to increase the 
flexibility of the flattened portion 44' relative to the inner flange 30. 
If necessary, additional ring portion 66 may be used to further increase 
the flexibility, or portions may be thinned to increase the flexibility or 
the flattened portion 44' may be a separate flexible membrane if desired. 
As shown in FIG. 7, during exhalation of air as illustrated by the arrows 
54, the exhaled air is directed again to the central opening 42 since the 
inner flange 30 is non-porous. During exhalation the pressure of the air, 
as shown by the arrows 54, pushes the flattened portion 44' against the 
member 20 to thereby seal the flattened portion 44' of the inner flange 30 
against the inner surface of the member 20. This completely prevents air 
from passing into the chamber between the inner flange 30 and the filter 
material 12. All of the air is therefore directed outward, as shown by the 
arrow 56, to pass through the exhalation valve and exit the respirator as 
shown by the arrows 58. It will be appreciated that with the first 
embodiment of the invention, some air during exhalation can pass into the 
chamber between the inner flange 30 and the filter material 12 but this 
will be minimized due to the use of the inner flange 30 directing the 
exhaled air to the exhalation valve 14. 
During the exhalation period, the pressure of the air flexes the flexible 
membrane 24 outward to create an opening between the flexible membrane 24 
and the member 20 to allow for the free exit of the air. Again, the air is 
directed to a central opening to exhaust the air easily and relatively 
completely from the interior of the respirator. This helps to eliminate a 
buildup of heat and moisture within the mask and also prevents this heated 
and moisture laden air from interacting with the filter material 12. This 
increases the life of the filter material and allows for the disposable 
respirator to be worn for a longer period of time without reducing the 
effectiveness of the filter material. It should be appreciated that the 
filtering efficiency of the filter material can be degraded if it 
interacts with exhaled air and it is, therefore, preferable to have the 
filter material only interact with inhaled air. 
It can be seen, therefore, that the present invention provides for a 
disposable filter respirator with an inner molded face flange which is 
simple in construction, inexpensive in cost and efficient in operation. 
The inner flange 30 may be first molded to have the desired face 
conforming configuration and yet with a flat outer peripheral portion 32. 
Similarly, the outer support layer 12 may be also molded to have the 
desired face conforming configuration and also with a flat outer 
periphery. The filter material 12 may also be formed to fit within the 
outer supporting layer and similarly have a flat outer periphery. 
Alternatively, the filter material may not extend completely to the 
periphery of the mask. It is also to be appreciated, that if the filter 
material has enough structural integrity to be self supporting, the outer 
layer 10 may be eliminated and the mask formed only from filter material 
12 and the inner flange 30. 
The exhalation valve 14 may be fitted into position through a central 
opening in the outer supporting layer 10 and filter material 12. The valve 
14 is actually formed to have an inner surface which forms part of an 
inhalation valve. The inner flange 30 may be welded in position at the 
flat periphery and yet have peripheral sealing portions extending outward 
and inward to produce the maximum efficiency for sealing the respirator to 
the face and with the inner flange having a central opening and a 
flattened portion with serves, in cooperation with a surface of the 
exhalation valve, to form an inhalation passage or an inhalation valve. 
The structure, therefore, is simple and inexpensive and yet provides for 
the efficient inhalation and exhalation to reduce heat and moisture build 
up and eliminate this heat and moisture buildup from interacting with the 
filter material. 
The fitting of the mask to the face of the user may be easily accomplished 
with the respirator of the present invention. Specifically, once the mask 
is positioned on the face, the user merely places the palm of the hand 
against the exhalation valve and gently presses to close off the 
exhalation valve. The inhalation passage or valve is also closed off as 
shown in FIGS. 6 and 7. The user now can exhale gently to determine 
whether any air is escaping around the periphery of the respirator. If air 
does escape, then the user can adjust the respirator so that the flange is 
sealed properly to the face so no air can escape. The check of the fit of 
the mask to the face of the user can, therefore, be accomplished very 
quickly and actually can be periodically checked during the day to insure 
that the mask is still fitting properly. 
The present invention, therefore, provides for a simple, yet reliable 
disposable filter respirator which produces substantially all of the 
advantages of prior art respirators without being cumbersome in 
construction and expensive in cost. Moreover, the respirator of the 
present invention is very comfortable to wear and yet provides for an 
efficient and reliable seal or fit of the respirator which can be 
periodically checked. The respirator includes both an inhalation passage 
or valve and exhalation valve which is simple in construction yet reliable 
in operation. All of the above is accomplished in a relatively low cost 
disposable respirator without sacrificing reliability and efficiency of 
filtering. 
Although the invention has been described with reference to a particular 
embodiment, it is to be appreciated that various adaptations and 
modifications may be made and the invention is only to be limited by the 
appended claims.