Respirator valve

A personal respiratory protection device comprising a main body (12) carrying an exhalation valve (28), the valve (28) having a grip region (29) which is grippable in use by the user, the grip region (29) being configured to indicate to the user that the valve (28) is to be gripped during opening, donning and doffing of the device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage filing under 35 U.S.C. 371 of PCT/US2015/063322, filed Dec. 2, 2015, which claims the benefit of Great Britain Application No. 1421618.8, filed Dec. 4, 2014, the disclosure of which is incorporated by reference in its/their entirety herein.

FIELD

The present invention relates to personal respiratory protection devices, known as respirators or face masks, which are capable of forming a cup-shaped air chamber over the mouth and nose of a wearer during use.

BACKGROUND

Filtration respirators or face masks are used in a wide variety of applications when it is desired to protect a human's respiratory system from particles suspended in the air or from unpleasant or noxious gases. Generally such respirators or face masks may come in a number of forms, but the two most common are a molded cup-shaped form or a flat-folded form. The flat-folded form has advantages in that it can be carried in a wearer's pocket until needed and re-folded flat to keep the inside clean between wearings.

Such respiratory devices include, for example, respirators, surgical masks, clean room masks, face shields, dust masks, breath warming masks, and a variety of other face coverings.

Flat-fold respirators are typically formed from a sheet filter medium which is folded or joined to form two or more panels. The panels are opened out prior to or during the donning process to form the air chamber. Cup-shaped respirators do not require opening but are not as convenient to store or carry when not being worn. Often an exhalation valve is provided on the respirator in order to reduce the respiratory effort of exhaling.

It is common for the user of the respirator to be wearing additional safety equipment such as goggles, gloves or protective clothing. This can impair the ability of the user to efficiently don or doff the respirator. This can reduce the effectiveness of the respirator due to impaired fit or comfort.

It is also recognized that at times the user holds the outer edges of the respirator during the donning procedure. This causes the user to touch the inside surface of the respirator. This can be disadvantageous in certain environments such as dirty industrial use.

Furthermore it is recognized that the ease of donning affects the perceived comfort of the wearer once the respirator is in position. There is therefore a perceived need to improve the ease of opening, donning and doffing of the respirator. Similarly there is a perceived need to reduce the likelihood that the internal surface of the respirator is handled during the donning and doffing the respirator.

It is an object of the present invention to at least mitigate the above problems by providing a personal respiratory protection device which is easier to open, don and doff.

SUMMARY

Accordingly, the invention provides a personal respiratory protection device comprising a main body carrying an exhalation valve, the valve having a grip region which is grippable in use by the user, the grip region being configured to indicate to the user that the valve is to be gripped during opening, donning and doffing of the device.

Advantageously, the provision of a valve with a grip region which is grippable by the user eases the donning and doffing process since the user is able to firmly grip the respirator. Furthermore, the risk that the user will touch the inside surface of the respirator is mitigated. This risk is further mitigated by the grip region being configured to indicate to the user that the valve is to be gripped.

Preferably, the grip region has a textured surface.

Preferably, the grip region has an upwardly extending ridge.

Preferably, the grip region has an upwardly extending ridge on each side of the valve.

Preferably, the upwardly extending ridge has an outwardly extending rib.

Preferably, the valve includes indicia to indicate to a user the location of the grip region.

Preferably, the indicia is a coloured region on the valve.

Preferably, the grip region and the indicia are coextensive.

Preferably, the main body comprises an upper panel, a central panel, and a lower panel, the central panel being separated from each of the upper and lower panels by a first and second fold, seam, weld or bond, respectively, such that device is capable of being folded flat for storage along the first and second fold, seam, weld or bond and opened to form a cup-shaped air chamber over the nose and mouth of the wearer when in use, wherein the valve is arranged on the central panel.

Preferably, the device has a multi-layered structure that comprises a first inner cover web, a filtration layer that comprises a web that contains electrically-charged microfibers, and a second outer cover web, the first and second cover webs being disposed on first and second opposing sides of the filtration layer, respectively, wherein the nose conforming element is attached to the second cover web.

Preferably, the lower panel has a graspable tab attached to an interior portion of the lower panel, the tab being graspable in use to open the device.

Preferably, the personal respiratory protection device further comprises a headband that comprises an elastomeric material, the headband being secured to the main body.

FIG. 1shows a personal respiratory protection device in the form of a respirator (also commonly referred to as a mask) indicated generally at10. The respirator10is a flat-fold respirator which is shown inFIGS. 1 to 3in its stored (also known as flat-fold or flat-folded) configuration. In this configuration the respirator is substantially flat so that it may be readily stored in the pocket of a user.

The respirator10has a main body indicated generally at12and a headband14formed of two sections14A,14B. The main body12has a central panel16, an upper panel18and a lower panel20. In use, the upper panel18and lower panel20are opened outwardly from the central panel16to form a cup-shaped chamber22(shown inFIG. 6). Once opened, the respirator is then applied to the face (as shown inFIG. 9) as will be described in further detail shortly.

The respirator10is formed from folded and welded portions of multi-layered filter material to form three portions or panels, as will be discussed in further detail below. The respirator10has a multi-layered structure that comprises a first inner cover web, a filtration layer that comprises a web that contains electrically-charged microfibers, and a second outer cover web, the first and second cover webs being disposed on first and second opposing sides of the filtration layer, respectively.

The filter material may be comprised of a number of woven and nonwoven materials, a single or a plurality of layers, with or without an inner or outer cover or scrim. Preferably, the central panel16is provided with stiffening means such as, for example, woven or nonwoven scrim, adhesive bars, printing or bonding. Examples of suitable filter material include microfiber webs, fibrillated film webs, woven or nonwoven webs (e.g., airlaid or carded staple fibers), solution-blown fiber webs, or combinations thereof. Fibers useful for forming such webs include, for example, polyolefins such as polypropylene, polyethylene, polybutylene, poly(4-methyl-1-pentene) and blends thereof, halogen substituted polyolefins such as those containing one or more chloroethylene units, or tetrafluoroethylene units, and which may also contain acrylonitrile units, polyesters, polycarbonates, polyurethanes, rosin-wool, glass, cellulose or combinations thereof.

Fibers of the filtering layer are selected depending upon the type of particulate to be filtered. Proper selection of fibers can also affect the comfort of the respiratory device to the wearer, e.g., by providing softness or moisture control. Webs of melt blown microfibers useful in the present invention can be prepared as described, for example, in Wente, Van A., “Superfine Thermoplastic Fibers” in Industrial Engineering Chemistry, Vol. 48, 1342 et seq. (1956) and in Report No. 4364 of the Navel Research Laboratories, published May 25, 1954, entitled “Manufacture of Super Fine Organic Fibers” by Van A. Wente et al. The blown microfibers in the filter media useful on the present invention preferably have an effective fiber diameter of from 3 to 30 micrometers, more preferably from about 7 to 15 micrometers, as calculated according to the method set forth in Davies, C. N., “The Separation of Airborne Dust Particles”, Institution of Mechanical Engineers, London, Proceedings 1B, 1952.

Staple fibers may also, optionally, be present in the filtering layer. The presence of crimped, bulking staple fibers provides for a more lofty, less dense web than a web consisting solely of blown microfibers. Preferably, no more than 90 weight percent staple fibers, more preferably no more than 70 weight percent are present in the media. Such webs containing staple fiber are disclosed in U.S. Pat. No. 4,118,531 (Hauser).

Bicomponent staple fibers may also be used in the filtering layer or in one or more other layers of the filter media. The bicomponent staple fibers which generally have an outer layer which has a lower melting point than the core portion can be used to form a resilient shaping layer bonded together at fiber intersection points, e.g., by heating the layer so that the outer layer of the bicomponent fibers flows into contact with adjacent fibers that are either bicomponent or other staple fibers. The shaping layer can also be prepared with binder fibers of a heat-flowable polyester included together with staple fibers and upon heating of the shaping layer the binder fibers melt and flow to a fiber intersection point where they surround the fiber intersection point. Upon cooling, bonds develop at the intersection points of the fibers and hold the fiber mass in the desired shape. Also, binder materials such as acrylic latex or powdered heat actuable adhesive resins can be applied to the webs to provide bonding of the fibers.

Electrically charged fibers such as are disclosed in U.S. Pat. No. 4,215,682 (Kubik et al.), U.S. Pat. No. 4,588,537 (Klasse et al.) or by other conventional methods of polarizing or charging electrets, e.g., by the process of U.S. Pat. No. 4,375,718 (Wadsworth et al.), or U.S. Pat. No. 4,592,815 (Nakao), are particularly useful in the present invention. Electrically charged fibrillated-film fibers as taught in U.S. Pat. No. RE. 31,285 (van Turnhout), are also useful. In general the charging process involves subjecting the material to corona discharge or pulsed high voltage.

Sorbent particulate material such as activated carbon or alumina may also be included in the filtering layer. Such particle-loaded webs are described, for example, in U.S. Pat. No. 3,971,373 (Braun), U.S. Pat. No. 4,100,324 (Anderson) and U.S. Pat. No. 4,429,001 (Kolpin et al.). Masks from particle loaded filter layers are particularly good for protection from gaseous materials.

At least one of the central panel16, upper panel18and lower panel20of the respiratory device of the present invention must comprise filter media. Preferably at least two of the central panel16, upper panel18and lower panel20comprise filter media and all of the central panel16, upper panel18and lower panel20may comprise filter media. The portion(s) not formed of filter media may be formed of a variety of materials. The upper panel18may be formed, for example, from a material which provides a moisture barrier to prevent fogging of a wearer's glasses. The central panel16may be formed of a transparent material so that lip movement by the wearer can be observed.

The central panel16has a curvilinear upper peripheral edge24which is coexistent with an upper bond23between the central panel16and the upper portion18. A curvilinear lower peripheral edge26is coexistent with a lower bond25between the central panel16and the lower panel20. The bonds23,25take the form of ultrasonic welds but may alternatively be folds in the filter material or alternative methods of bonding. Such alternative bonds may take the form of adhesive bonding, stapling, sewing, thermomechanical connection, pressure connection, or other suitable means and can be intermittent or continuous. Any of these welding or bonding techniques leaves the bonded area somewhat strengthened or rigidified.

The bonds23,25form a substantially airtight seal between the central panel16and the upper and lower panels18,20, respectively and extend to the longitudinal edges27of the respirator where the central upper, lower panels16,18,20collectively form headband attachment portions in the form of lugs31,33. The central panel16carries an exhalation valve28which reduces the pressure drop across the filter material when the user exhales. The valve28has grip portions29which ease the opening, donning and doffing of the respirator as will be described in further detail below.

The upper portion18carries a nose conforming element in the form of nosepiece30which conforms to the face of the user to improve the seal formed between the respirator10and the face of the user. The nosepiece30is arranged centrally at the upper outer periphery38of the upper portion18and is shown in section inFIG. 3and in greater detail inFIG. 14. The nosepiece operates in conjunction with a nose pad35which is shown inFIG. 7to be located on the opposite side of the upper panel18to the nosepiece30and serves the propose of softening the point of contact between the nose and the upper panel18.

Turning now toFIG. 3, the arrangement of the features of the respirator10in its stored configuration is shown in greater detail. The nosepiece30is shown positioned on the outer surface of the upper portion18. The upper portion18is shown at the rearward side of the folded respirator10overlapping the lower panel20. The lower panel20is folded about a lateral fold36(shown as a long dotted line inFIG. 2). The lateral fold36divides the lower panel20into an outer section40and an inner section42. Attached to the lower panel20is a tab32which assists in the opening and donning of the respirator as will be described in further detail below. The tab32has a base which is attached to an interior portion of the exterior surface lower panel20(that is to say inwardly of a lower outer periphery50(as shown inFIG. 6) and the lower bond25) at a position proximate the lateral fold36and ideally attached at the fold36as shown inFIG. 3. The positioning of the tab32may vary within 10 mm either side of the lateral fold. The width of the tab32at its point of attachment to the lower panel20is 15 mm although this width may vary between 10 mm and 40 mm.

FIGS. 4, 5 and 6show the respirator10in its open configuration. The central panel16is no longer flat as shown inFIGS. 1 to 3but is now curved rearwardly from the valve28to the lugs31,33. The shape of this curve approximately conforms to the mouth area of the face of the user. The upper portion18is pivoted about the curvilinear upper peripheral edge24and is curved to form a peak which matches the shape of the nose of the user. Similarly, the lower panel20is pivoted about the curvilinear lower peripheral edge24to form a curve which matches the shape of the neck of the user.

The opening of the respirator10between the folded configuration shown inFIGS. 1 to 3and the open configuration shown inFIGS. 4 to 6will now be described in greater detail with reference toFIG. 7.

FIG. 7shows a cross-section of the respirator10sectioned along the same line asFIG. 3but with the respirator shown in an intermediate configuration. Dotted lines show the respirator in the open configuration for comparison.

To open and don the respirator, the user first grips the grip portions29of the valve28(seeFIG. 9). With the other hand the user takes hold of the tab32and pulls the tab32in direction A as indicated inFIG. 7in order to apply an opening force to the valley side of the lateral fold36. The tab may be textured to improve grip or may be coloured to better distinguish from the main body of the respirator. This opening force causes the fold36to move rearwardly and downwardly with respect to the central panel16. This causes the lower panel20to pivot about the curvilinear lower peripheral edge24. Simultaneously, load is transferred from the base of the tab32to the lugs31,33. This pulls the lugs31,33inwardly causing the central panel16to curve. The curvature of the central panel16in turn applies a load (primarily via the lugs31,33) to the upper portion18. This causes the longitudinal centre of the upper portion18to elevate as shown inFIGS. 6 and 7.

As the user continues to pull the tab32beyond the intermediate position shown inFIG. 7the lugs31,33continue to move closer to one another as the central panel16become increasingly curved. This in turn causes the continued upward movement of the upper portion18and downward movement of the lower panel20towards the open position (dotted lines inFIG. 7). In this way the tab32improves the opening mechanism of the respirator by ensuring that the load applied by the user to open the respirator10is most effectively and efficiently deployed to open the respirator10.

The lower panel20is shown to include a stiffening sheet in the form of panel40(shown in long dotted lines). The stiffening panel40forms part of the multilayered filter material and is formed from material well known in the art for its stiffening properties. The stiffening panel40is approximately hour-glass shaped and is shown in greater detail inFIG. 8to include a first pair of wings42, a waist portion44, a second pair of wings46and a front section48. The front section48is coexistent with the lower outer periphery50(as shown inFIG. 6) of the lower panel20and the waist section is coexistent with the lateral fold36. When the respirator10is in its folded configuration, the stiffening panel40is folded along al lateral crease indicated at line B-B. As the respirator10opens from the folded position as described above, the stiffening panel40opens out about lateral crease line B-B. As the respirator approaches the open configuration (as shown inFIGS. 4 to 6) the fold along lateral crease line B-B flattens out and the stiffening panel curves about a longitudinal crease indicated at line C-C. The curving of the panel40along longitudinal crease line C-C prevents the folding about lateral crease line B-B which gives the stiffening panel40and thereby lower panel20additional rigidity. This additional rigidity is at least in part imparted by the stiffening sheet40folding about longitudinal crease line C-C as the respirator10opens from a concave external angle to a convex external angle, that is to say a mountain fold is formed when the fold goes overcentre about the longitudinal crease line C-C. This in turn helps to prevent the collapse of the lower panel20and thus improves the conformity of the lower panel20to the chin area of the face.

Once the respirator10is open, the user is able to position the open cup-shaped air chamber of the respirator over the face and position the headbands as shown inFIG. 9in order to don the respirator.

In order to more readily don and doff the respirator10, the respirator is provided with a valve28with grip portions29which are shown in greater detail inFIG. 10. The valve28is adhered to the central portion using an adhesive such as that commercially available under the trade designation 3M™ Scotch-Weld™ Hot Melt Spray Adhesive 61113M™. The valve28has side walls51which include apertures52to allow the exhaled air to pass through the valve28. The side walls51have a curved form with an inwardly extending mid-portion and outwardly extending base54and upper section56. Arranged on a top surface58of the valve28are upwardly extending ridges60which carry outwardly extending ribs62.

The curved side walls51act as a grip region29since the curves match the curvature of the fingers of the user. The performance of the grip region is improved by the provision of the ridges60which extends the grip region. Performance is further improved by the provision of the ribs62which make the grip region29easier to grip and hold. The curved side walls51, ridges60ribs62individually and collectively form an indicia to the user that the grip region29is to be gripped in order to open and don the respirator as described above.

FIG. 10shows an alternative embodiment of valve28′ which differs from valve28in that it has taller ridges60′. It is conceivable within the scope of the invention that other forms of grip region could act as indicia to the user, for example a textured or colored surface to the side walls50, ridges60and/or ribs62.

It will be appreciated that whilst such a grippable valve28,28′ is described with reference to a three panel (central, upper and lower panel20), flat-fold respirator10, it will be appreciated that the valve28,28′ could be equally applied to other respirators including cup respirators.

Turning now toFIGS. 11 and 12, the attachment of the headband14to the headband attachment lug31,33is shown in greater detail. The headband14is attached to the main body12by a head band module indicated generally at70. The module70has a headband14which is bonded on its upper side to an upper tab72and on its lower side to a lower tab74. The tabs72,74are formed of a non-woven material used to form the filter material described above. The non-woven material tabs72,74are bonded to the headband14using a known adhesive78such as that commercially available under the trade designation 3M™ Scotch-Weld™ Hot Melt Spray Adhesive 6111.

The module70is then ultrasonically welded to the lug31,33to form a weld76between the lower tab74and the main body12.

InFIG. 11the head band module is shown with the respirator in its folded position. As the respirator10is opened the headband becomes stretched and pulls outwardly on the lugs31,33.

InFIG. 12the head band module is shown with the respirator in its open position. The stretching of the headband14causes the module70to curve which leads to the lower tab74being held in tension. This causes a high load to act at the point of intersection D of the lower tab74and the lug31,33. However, the weld76is relatively strong in peel mode (that is to say the extreme tension load applied to the edge of the weld at point D by the stretching of the headband). This provides an improvement over prior art attachment techniques which place an adhesive bond in peel mode rather than a weld which is far stronger in peel than an adhesive.

Turning now toFIG. 14, the nosepiece30is shown in greater detail to have a resiliently flexible central portion80and first and second rigid outer portions82extending outwardly from the central portion80. The central portion80is substantially flat when the respirator is in the flat fold configuration. The central portion80is approximately 20 mm wide and 8 mm deep. Each of the outer portions82has a wing which defines a concave elliptical bowl having an outwardly extending major axis X and upwardly extending minor axis Z. Each elliptical bowl has a nadir indicated generally at84and positioned approximately equidistant between a centerline of the nosepiece30and an outer edge86of the wings, the nadir being positioned 26 mm from the centerline of the nosepiece30. The elliptical bowl gives the outer portions82rigidity whilst the flat central portion80is able to flex under load. This allows the central portion80to flex over the bridge of the nose of the user whilst the rigidity of the outer portions82and the varying point of contact offered by the curved profile of the rigid portions offers a close fit between the respirator and the cheek of the user. These features of the nosepiece30therefore improve the fit and comfort of the respirator10over prior art respirators.

The nosepiece30is formed using a known vacuum casting technique using a polymeric material such as polyethylene. Such a material gives the required flexibility in the central portion80whilst having sufficient strength to give the outer portions82the required rigidity. Such a material also allows the nosepiece to return to its flat position which allows the respirator10to be removed and placed in the pocket of the user without the requirement to flatten the nosepiece.

It will be appreciated that certain features described herein could be used in isolation or in conjunction for the benefit of the invention. For example, it is envisaged that any one or more of the following features could be advantageously combined with the current invention:Tab32Stiffening panel40Headband attachment module70Nosepiece30