Filtering device

Abstract

The invention provides a filter device (10) for a breathing apparatus, the filter device (10) comprising: a housing (12) having a wall (13) made of paper material and defining a volume, two openings (14, 16) in the wall (13) communicating with the volume, and a filter mounting portion (18), the filter mounting portion is configured for mounting a filter medium in the volume between the openings (14, 16). The invention also comprises an adapter for connecting the filter device (10) to a breathing device, which adapter is also made of a paper material.

Description

Technical Field

[0001] The present invention relates to a filtering device for a breathing apparatus.

[0002] The present invention also relates to a filter assembly including the filtering device.

[0003] The present invention also relates to a method of manufacturing the filtering device.

[0004] The present invention also relates to an adapter for use with the filtering device.

[0005] The present invention relates to a combination of a filtering device and an adapter coupled to each other.

[0006] The present invention also relates to a breathing apparatus including a filter assembly. Background Art

[0007] A breathing apparatus is a device through which a user breathes to medically assist the user. The breathing apparatus includes a diagnostic device that measures aspects of the user's breathing cycle, such as a spirometer, and a device that assists the user to breathe, such as a resuscitation bag, a ventilator, a face mask, a biPAP machine, and a CPAP machine.

[0008] A filtering device is typically positioned between the user and the breathing apparatus to filter particulates from the air stream reaching the user through the breathing apparatus. The filtering device typically includes a housing having a passage through which the air stream passes, and a filter medium located in the passage, the filter medium being configured to remove particles including bacteria and viruses from the air stream.

[0009] Although filtering devices are typically made of recyclable materials, usually polymers, they are difficult to recycle and are typically landfilled or incinerated. These disposal methods are not ideal. Filtering devices may take decades or even centuries to decompose in landfills, and the exhaust gases generated by incineration are harmful to humans and the environment.

[0010] It is desirable to improve at least one of the above disadvantages or at least provide a useful alternative.

[0011] The above description is not an admission of common general knowledge in Australia or elsewhere. Summary of the Invention

[0012] The present invention provides, individually or in combination, a filtering device for a breathing apparatus and an adapter for use with the filtering device.

[0013] The present invention provides a filtering device for a breathing apparatus, the filtering device including: a housing having a wall made of a paper material and defining a volume, two openings in the wall in communication with the volume, and a filter mounting portion configured to mount a filter medium in the volume between the openings.

[0014] The filtering device is configured such that in use, with the filter medium installed in the filter installation portion within the housing, a user can inhale through one of the openings such that air is inhaled through the other opening to flow through the filter medium and into the user's lungs. When air is drawn through the filter medium, particles in the air stream, including bacteria and viruses, can be filtered out from the filter medium.

[0015] In the context of the present application, the term "paper material" includes any material containing plant fibers, such as cellulose. The plant fibers can be aggregated or woven to provide structure. Sheets of plant fibers can be arranged in layers to provide structure. The paper material can include plant fibers and water, such as in the form of pulp, which is then dried to provide a solid material. The plant fibers can be derived from trees or recycled paper.

[0016] In one example, the housing is formed from a slurry in a mold under negative pressure, i.e., a vacuum.

[0017] Those skilled in the art will understand that the housing should have sufficient strength to maintain its structural integrity while a user creates pressure in the housing due to inhaling or exhaling through one of the openings.

[0018] The filter installation portion is configured to hold the filter medium relative to the housing.

[0019] The filter installation portion can be configured to restrict at least one of lateral, rotational, translational, or bending (i.e., deflection) movement of the filter medium relative to the housing. The filter installation portion can generate a holding force that clamps the filter medium.

[0020] Those skilled in the art will understand that the holding force should be sufficient to hold the filter medium in place while a user creates pressure in the housing due to inhaling or exhaling through one of the openings.

[0021] An advantage of the present invention is that since the housing is made of a paper material, it is easier to handle. When compared to plastic alternatives, the paper material decomposes quickly in compost or landfills. Compared to plastic alternatives, the paper material is also more flammable and produces less harmful exhaust when burned.

[0022] An advantage of the filter installation portion is that it allows the filter medium to be fixed without movement relative to the housing. This enables the performance of the device to be enhanced by maintaining a sufficient seal between the housing and the filter medium.

[0023] The filter installation portion can include protrusions that extend inward from the wall into the volume and define a support for the filter medium.

[0024] The filter mounting portion may include at least a pair of opposing protrusions, each protrusion extending inwardly from opposite portions of the wall into the volume and configured to sandwich the filter medium therebetween, thereby holding the filter medium in place.

[0025] The advantage of the protrusion is that it not only serves as the filter mounting portion but also as a reinforcing rib. This is particularly important for paper materials which are generally less rigid than polymers.

[0026] The protrusion may be integrally formed in the wall of the housing.

[0027] The advantage of integrally forming the protrusion with the wall is that no additional fasteners are required, thus reducing the manufacturing cost.

[0028] However, the protrusion may be a separate component which is attached to the wall of the housing to form an assembly as part of the process of assembling the filter device.

[0029] The protrusion may be a ridge in the wall. The ridge may extend completely or partially around at least one of the openings. The groove or ridge may extend completely or partially around both openings.

[0030] The wall may be recessed inwardly into the volume to form the protrusion.

[0031] The filter mounting portion may include a plurality of protrusions.

[0032] The plurality of protrusions may be arranged around at least one of the openings. The plurality of protrusions may be arranged around both openings.

[0033] The advantage of the above arrangement of the protrusions is that it is used to align / position the filter medium in the correct position. This enhances the performance of the device by ensuring a proper seal between the housing and the filter medium.

[0034] The housing may include a first half-shell defining a part of the wall and a second half-shell defining another part of the wall, the first half-shell and the second half-shell being releasably coupled together.

[0035] The advantage of releasably coupling the first and second half-shells is that one of the first and second half-shells can be replaced without replacing the other. This is particularly important for a housing made of paper material as one of the first and second half-shells may fail before the other.

[0036] Another advantage is that the filter medium can be accessed and replaced.

[0037] The filter device may include corresponding engagement elements for releasably coupling the half-shells together.

[0038] The first half-shell may be dish-shaped.

[0039] The second half-shell may be dish-shaped.

[0040] In the context of the present application, the term "dish-shaped" refers to a shape having the appearance of a dish. In other words, it is circular in shape when viewed in a first plane and is also concave / convex when viewed in a second plane perpendicular to the first plane.

[0041] However, the first and / or second half-shells can be of any other shape. For example, box-shaped, conical or frustoconical.

[0042] The engaging element can fix one half-shell relative to the other half-shell.

[0043] The engaging element can be integrally formed in the wall of the housing.

[0044] Alternatively, the engaging element can be formed of separate parts which are then attached to the wall of the housing as part of the process of assembling the filtration device.

[0045] The engaging element can include a male element and a female element.

[0046] In one example, one half-shell has the male element while the other half-shell has the corresponding female element. The male part can be inserted into the female part in a friction fit manner.

[0047] The male element can be configured to be frictionally inserted into the corresponding female element.

[0048] The female element can be configured to frictionally receive the corresponding male element.

[0049] The advantage of the friction fit arrangement is that few or no other fasteners are required for assembly. In addition, fewer machines or no machines are required for assembly. For example, the fit can be done by hand and by the user. In contrast, prior art devices require machines for assembly as they involve processes such as crimping, adhesives or ultrasonic welding.

[0050] The paper material can have a rough surface finish which, when similar surfaces meet, increases the frictional resistance compared to a rough surface on a smooth surface or a smooth surface on a smooth surface. It is advantageous to provide frictional resistance at the friction fit arrangement of the male and female elements in order to maintain the structural integrity of the housing under pressure.

[0051] In one example, the male element is a lip. The lip can be defined by the contour of the wall or the curvature in the wall. The lip can extend completely or partially around the perimeter of one half-shell.

[0052] In one example, the female element is a channel. The channel can be defined by the contour of the wall or the curvature in the wall. The channel can extend completely or partially around the perimeter of the other half-shell.

[0053] It is also conceivable that the joining element can be any element capable of fixing one half-shell relative to the other half-shell. Examples of joining elements include permanent fasteners (such as rivets), reusable fasteners (such as hook-and-loop fasteners, i.e., ) and adhesives.

[0054] The filter mounting portion may include a first protrusion on the first half-shell and a second protrusion on the second half-shell, each protrusion extending inwardly from a corresponding portion of the wall into the volume, the protrusions being configured to frictionally engage a filter medium therebetween when the first and second half-shells are coupled together. Suitably, when the first and second half-shells are coupled together, the filter medium is sandwiched between the protrusions.

[0055] When the first and second half-shells are coupled together, the filter medium can be sandwiched between the protrusions.

[0056] The first protrusion may include a plurality of protrusions.

[0057] The second protrusion may include a plurality of protrusions.

[0058] The plurality of protrusions may be arranged such that the filter medium is supported around its perimeter.

[0059] Suitably, when the first and second half-shells are coupled together, the filter medium is clamped around its perimeter.

[0060] The first half-shell may include an inlet configured to be attached to a breathing device. The inlet is one of the aforementioned openings of the filter device. In one example, the inlet is a cannula arrangement protruding from the first half-shell. The inlet may have a circular cross-sectional shape. However, it is also conceivable that the inlet may have any suitable cross-sectional shape, such as: rectangular, triangular, trapezoidal or oval.

[0061] The second half-shell may include an outlet configured to fit the user's mouth. The outlet is one of the aforementioned openings of the filter device. In one example, the outlet is a cannula arrangement protruding from the second half-shell. The outlet may have an oval cross-sectional shape. However, it is also conceivable that the outlet may have any suitable cross-sectional shape, such as: rectangular, triangular, trapezoidal or oval.

[0062] The first half-shell may be shaped such that a plurality of first half-shells can be stacked in a nested arrangement.

[0063] The second half-shell may be shaped such that a plurality of second half-shells can be stacked in a nested arrangement.

[0064] The advantage of stacking the first and second half-shells in a nested arrangement is that it can reduce the packaging volume, which can help reduce shipping costs.

[0065] The present invention also provides a filter assembly, which includes the filtering device as described above and a filter medium installed in the housing on a filter mounting portion.

[0066] The filter medium can be a barrier that provides restricted channels for particles including bacteria and viruses but allows air to pass through relatively unrestrictedly.

[0067] The filter medium can provide 90% to 100% bacteria / virus filtration. Optionally, the filter medium can provide approximately 99.9999% bacteria / virus filtration.

[0068] The filter medium can provide a resistance of 0.5 cm - 1.0 cm H 2 O / L / s at a flow rate of 12 L / s. Optionally, the filter medium can provide a resistance of approximately 0.71 cm H 2 O / L / s at a flow rate of 12 L / s.

[0069] The filter medium can be of any suitable shape.

[0070] For example, the filter medium can be disc-shaped.

[0071] The filter medium can be porous.

[0072] The filter medium can be electrostatic.

[0073] The filter medium can be hydrophobic.

[0074] The present invention also provides a method for manufacturing a filtering device for a breathing apparatus, the filtering device including: a wall housing made of paper material and defining a volume, two openings in the wall communicating with the volume, and a filter mounting portion configured to mount a filter medium in the volume between the openings, the manufacturing method including: molding the paper material into the shape of the housing in a mold; drying the housing; and removing the housing from the mold.

[0075] The present invention also provides an adapter for use with a filtering device, the adapter including an adapter housing having a first end configured to be attached to the filtering device, a second end configured to be attached to a breathing apparatus, and an internal channel extending between the first end and the second end, such that in use, airflow is allowed to pass through the internal channel between the breathing apparatus and the filtering device.

[0076] The advantage of the adapter is that it allows the filtering device to be used with a greater variety of different breathing apparatuses. For example, some breathing apparatuses have a bayonet connection that includes a protrusion designed to mate with a track on a component to be connected to the breathing apparatus. It can be said that the adapter increases the flexibility of the filtering device.

[0077] The adapter housing can be made of paper material.

[0078] The paper material can be the same paper material as that forming the filtration device, to provide the same advantages as described above.

[0079] The adapter housing can be made of any suitable material. For example, polymer or stainless steel.

[0080] The second end can have a mating portion that allows releasable connection to a breathing device.

[0081] The releasable connection between the second end and the breathing device can include an insertion and a twisting motion.

[0082] The housing can include a side wall that defines an inner surface and an outer surface.

[0083] The side wall can be cylindrical.

[0084] The mating portion can include a track or a protrusion on the inner surface or the outer surface, which mates with a corresponding track or protrusion on the breathing device.

[0085] The track can be an opening that extends through the entire side wall.

[0086] The track can be a recess that enters the inner surface of the side wall.

[0087] The track can be a protrusion that mates with a corresponding groove on the breathing device.

[0088] In use, the first end of the adapter can be connected to the inlet sleeve of the filtration device. The first end can be connected to the inlet sleeve by a friction fit. For example, the first end can be configured (shaped and / or sized) such that it can be inserted into the opening of the inlet sleeve in a force fit relationship. In another example, the first end can be configured (shaped and / or sized) such that the sleeve can be inserted into the inner channel of the adapter in a force fit relationship.

[0089] The track can be curved or bent such that the releasable connection between the second end and the breathing device involves an insertion and a twisting motion.

[0090] The advantage of this two-step connection process is that it provides additional security over other methods that involve only one of an insertion or a twisting motion.

[0091] The present invention also provides the filtration device coupled to the adapter.

[0092] The present invention also provides the filter assembly coupled to the adapter.

[0093] The present invention also provides a combination of the above filtration device and the above breathing device, which are operatively coupled together.

[0094] The present invention also provides a breathing device including the above filter assembly.

[0095] The present invention also provides a breathing device, which includes the above filter assembly and the above adapter. BRIEF DESCRIPTION OF THE DRAWINGS

[0096] Embodiments of the present invention are further described by way of example with reference to the accompanying drawings, wherein:

[0097] Figure 1 is a top perspective view of a filtering device according to an embodiment of the present invention;

[0098] Figure 2 is Figure 1 a bottom perspective view of the filtering device of

[0099] Figure 3 is according to Figure 1 a disassembled perspective view of the filtering device of

[0100] Figure 4 is Figure 3 a bottom view of the disassembled filtering device shown in

[0101] Figure 5 is Figure 1 a top view of the filtering device of

[0102] Figure 6 is Figure 1 a bottom view of the filtering device of

[0103] Figure 7 is Figure 1 a side view of the filtering device of

[0104] Figure 8 is Figure 7 a view of the filtering device shown in rotated 90 degrees axially;

[0105] Figure 9 is a top perspective view of a filter assembly in a disassembled form according to an embodiment of the present invention, the filter assembly including a first half shell, a second half shell and a filter medium;

[0106] Figure 10 is Figure 9 a cross-sectional view of the first half shell shown in

[0107] Figure 11 is Figure 9 a cross-sectional view of the second half shell shown in

[0108] Figure 12 is a flowchart showing the method steps involved in manufacturing a filtering device according to an embodiment of the present invention;

[0109] Figure 13 is a schematic side view of an adapter according to another embodiment of the present invention;

[0110] Figure 14 is Figure 13 a schematic top view of the adapter of;

[0111] Figure 15 is Figure 13 a schematic cross-sectional view of the adapter of taken along line A-A, showing a joint portion including angled tracks having a first portion and a second portion arranged orthogonally to each other;

[0112] Figure 16A is Figure 13 the adapter shown, wherein a protrusion is inserted into the first portion of the track;

[0113] Figure 16B is Figure 16A the adapter shown, wherein the protrusion is inserted towards the end of the first portion of the track; and

[0114] Figure 16C is Figure 15 the rotated adapter shown in A, such that the protrusion has traveled towards the end of the second portion of the track. DETAILED DESCRIPTION

[0115] Figures 1 - 8 shows a filtering device 10 according to an embodiment of the present invention.

[0116] The filtering device 10 includes: a housing 12 having a wall 13 made of a paper material and defining a volume, a pair of openings 14, 16 in communication with the volume, and a filter mounting portion 18 configured to mount a filter medium in the volume between the openings 14, 16.

[0117] As Figure 3 and 4 best shown in, the housing 12 includes a first half-shell 12a defining a part of the wall 13a, and a second half-shell 12b defining another part of the wall 13b, which are releasably coupled to each other via respective coupling elements. When the first half-shell 12a and the second half-shell 12b are coupled to each other, they define the housing 12 and the volume defined by the wall 13.

[0118] The filter mounting portion 18 includes a plurality of protrusions extending inwardly into the volume. The protrusions are defined by the contours of the respective walls 13a, 13b. When the first half-shell 12a and the second half-shell 12b are coupled together, the filter medium 25 can be sandwiched between the opposing protrusions 18.

[0119] The first half-shell 12a includes an inlet sleeve 20 configured to be attached to a breathing device (seeFigure 3 )。The inlet cannula 20 includes a circular inlet opening 14.

[0120] The second half-shell 12b includes an outlet cannula 22 configured to fit with the user's mouth (see Figure 4 ). The outlet cannula 22 includes an oval outlet opening 16.

[0121] Figures 9 - 11 A filter assembly 30 including a filter device 10 and a filter medium 25 is shown. The filter device 10 has the features described above and includes first and second half-shells 12a, 12b.

[0122] To assemble the filter assembly 30, first the filter medium 25 is positioned on the second half-shell 12b such that it is supported by the protrusions 18. Then the first half-shell 12a is coupled to the second half-shell 12b such that the filter medium 25 is sandwiched and fixed between the opposing protrusions 18 on the first and second half-shells 12a, 12b.

[0123] Alternatively, the filter medium 25 is first positioned on the first half-shell 12a such that it is supported by the protrusions 18. Then the second half-shell 12b is coupled to the first half-shell 12a to sandwich and fix the filter medium 25 between the opposing protrusions 18 in a manner similar to that described above.

[0124] It will be appreciated that the filter medium 25 can be removed from the filter device 10 by separating the first half-shell 12a from the second half-shell 12b.

[0125] The ability to remove the filter medium 25 from the filter device facilitates easy replacement of the filter medium 25.

[0126] As Figure 10 and Figure 11 best shown in, each of the first and second half-shells 12a, 12b includes a joining element.

[0127] The first half-shell 12a includes a female joining element in the form of a channel 24. The channel 24 is defined by the contour of the wall 13a, as Figure 10 shown.

[0128] The second half-shell 12b includes a male joining element in the form of a lip-shaped protrusion 26. The lip-shaped protrusion 26 is formed by the contour of the wall 13b, as Figure 11 shown.

[0129] Both the channel 24 and the lip protrusion 26 extend completely around the perimeter of the respective half-shells 12a, 12b.

[0130] The channel 24 is configured (sized and shaped) such that the lip protrusion 26 can be received within the channel 24 to form a friction fit therebetween, thereby coupling the first half-shell 12a to the second half-shell 12b.

[0131] The shape of the first half shell 12a is such that a plurality of first half shells 12a can be stacked in a nested arrangement.

[0132] The shape of the second half shell 12b is such that a plurality of second half shells 12b can be stacked in a nested arrangement.

[0133] The advantage of stacking the first and second half shells 12a, 12b in a nested arrangement is that it can reduce the packaging volume, which can help reduce transportation costs.

[0134] Figure 12 A method of manufacturing a filter device 10 for a breathing apparatus is shown. The manufacturing method includes the following steps:

[0135] Step 100: Mold pulp into the shape of the housing 12 in a mold;

[0136] Step 200: Dry the housing 12; and

[0137] Step 300: Remove the housing 12 from the mold.

[0138] Each half shell 12a, 12b is manufactured in a separate mold. The molding is carried out under negative pressure, i.e., vacuum. The mold includes a porous surface to ensure uniform pressure distribution throughout the mold.

[0139] The step of drying the housing is carried out in an oven.

[0140] Figures 13 - 1 6 shows an adapter 40 as described above for use with the filter device 10 according to another embodiment of the present invention.

[0141] The adapter 40 includes a tubular housing formed by a cylindrical side wall 41. The housing has a first end 42 configured for attachment to the filter device 10 and a second end 43 configured for attachment to a breathing apparatus (not shown). The breathing apparatus can be any suitable breathing apparatus.

[0142] As Figure 14 shown, the housing has an internal channel 44 extending between the first and second ends 42, 43, thereby allowing air flow through the internal channel 44 between the breathing apparatus and the filter device 10 during use.

[0143] The second end 43 has an engagement portion 45 that permits selective engagement with a breathing device. The engagement portion is in the form of a track 45 on the inner surface of the sidewall 41 that mates with a corresponding projection 46 on the breathing device. The track 45 has a first portion 45a that extends in a direction substantially parallel to the longitudinal extent of the housing and a second portion 45b that extends from the first portion 45a in a direction transverse to the longitudinal extent of the housing. Thus, the track 45 is angled, i.e., has an L-shaped appearance when viewed in cross-section. While in this embodiment the track 45 is described as L-shaped, it is contemplated that any other curved or bent shape may be applied.

[0144] Alternatively, the engagement portion may be a projection that mates with a track on the breathing device. The track may have an L-shaped appearance when viewed in cross-section.

[0145] In another alternative, the engagement portion may be a helical groove or projection that forms a threaded connection with a corresponding helical groove or projection on the breathing device.

[0146] In the presently described embodiment, the track 45 is an opening that extends through the sidewall 41. However, it is understood that in other forms, the track 45 may be a recess that enters the inner surface of the sidewall 41.

[0147] In use, the first end 42 of the adapter 40 is connected to the inlet sleeve 20 of the filtration device 10, and the first end 42 is connected to the inlet sleeve 20 by a friction fit. For example, the first end 42 may be sized such that it can be inserted into the opening 14 of the inlet sleeve 20 in a force fit (i.e., interference fit) relationship. In another example, the first end 42 may be sized such that the sleeve 20 can be inserted into the inner channel 44 of the adapter in a force fit (i.e., interference fit) relationship.

[0148] Once the adapter 40 and the filtration device 10 are connected, the adapter 40 can be releasably connected to the breathing device.

[0149] Figures 16A - 16C The steps involved in releasably connecting the adapter 40 to the breathing device are shown. These steps include:

[0150] 1. Move the adapter 40 in a direction parallel to the longitudinal extent of the housing (see the arrow in Figure 16A ) such that the projection 46 of the breathing device enters the first portion 45a of the track 45, as shown in Figure 16A ;

[0151] 2. Move the adapter 40 in a direction parallel to the longitudinal extent of the housing (see the arrow in Figure 16A ) such that the projection 46 travels towards the end of the first portion 45a of the track; and

[0152] 3.Once the projection 46 reaches the end of the first part 45a of the track 45, as Figure 16B shown, the housing is rotated in the counterclockwise direction (when viewed from the second end 43) so that the projection enters and travels along the second end 45b of the track 45, as Figure 16C shown.

[0153] As can be understood from the above, the selective engagement of the adapter and the breathing device involves insertion and twisting movements, similar to a bayonet connection.

[0154] The adapter 40 can be disconnected from the breathing device by following steps 1 - 3 in the reverse order, i.e., step 3 - 1.

[0155] In the claims of the present invention and the foregoing description, except where the context requires otherwise, the word "comprising" or variations thereof such as "comprises" or "comprising" are used in an inclusive sense, i.e., to specify the presence of the stated features, but not to exclude the presence or addition of other features in the various embodiments of the present invention.

Claims

1. A filtering device for a breathing apparatus, the filtering device comprising: a housing having a wall made of a paper material and defining a volume, two openings in the wall in communication with the volume, and a filter mounting portion configured to mount a filter medium in the volume between the openings.

2. The filtering device according to claim 1, wherein, the filter mounting portion includes a protrusion that extends inwardly from the wall into the volume and defines a support for the filter medium.

3. The filtering device according to claim 1 or claim 2, wherein, the housing includes a first half-shell defining a part of the wall and a second half-shell defining another part of the wall, the first half-shell and the second half-shell being releasably coupled together.

4. The filtering device according to claim 3, including a joining element for releasably coupling the half-shells together, and wherein the joining element includes a male element and a female element, the male element being configured to be inserted into the female element in a friction fit arrangement.

5. The filtering device according to claim 4, wherein, the joining element includes a channel and a lip.

6. The filtering device according to any one of claims 3-5, wherein, the filter mounting portion includes a first protrusion on the first half-shell and a second protrusion on the second half-shell, each protrusion extending inwardly from a respective part of the wall into the volume, the protrusions being configured to frictionally engage a filter medium therebetween when the first half-shell and the second half-shell are coupled together.

7. The filtering device according to any one of claims 3 to 6, wherein, the first housing includes an inlet configured to be attached to a breathing apparatus.

8. The filtering device according to any one of claims 3 to 7, wherein, the second housing includes an outlet configured to fit with a user's mouth.

9. A filter assembly comprising a filtering device according to any one of the preceding claims and a filter medium mounted in the housing to the filter mounting portion.

10. A method of manufacturing a filtering device for a breathing apparatus, the filtering device comprising: a housing having a wall made of a paper material and defining a volume, two openings in the wall in communication with the volume, and a filter mounting portion configured to mount a filter medium in the volume between the openings, the manufacturing method including: molding the paper material into the shape of the housing in a mold; drying the housing; and removing the housing from the mold.

11. An adapter for use with a filtering device, the adapter including an adapter housing having a first end configured to be attached to the filtering device, a second end configured to be attached to a breathing apparatus, and an internal channel extending between the first end and the second end such that in use, airflow is permitted to pass between the breathing apparatus and the filtering device through the internal channel.

12. The adapter according to claim 11, wherein, the adapter housing is made of a paper material.

13. The adapter according to claim 11 or claim 12, wherein, the second end has an engagement portion that permits releasable connection to the breathing device.

14. The adapter according to claim 13, wherein, the releasable connection between the second end and the breathing device involves an insertion and a twisting movement.

15. The adapter according to claim 14, wherein, the housing includes a cylindrical wall defining an inner surface and an outer surface.

16. The adapter according to claim 15, wherein, the engagement portion includes a track or a protrusion on the inner surface or the outer surface, and the track or the protrusion mates with a corresponding track or protrusion on the breathing device.

17. The adapter according to claim 16, wherein, the track is curved or bent such that the releasable connection between the second end and the breathing device involves an insertion and a twisting movement.

18. The filtering device according to claims 1-8, connected to the adapter according to claims 11-17.

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