Vacuum cleaner bag and method for producing a vacuum cleaner bag

Abstract

A vacuum cleaner bag (1) comprises a wall (2) made of filter material, which is folded together via two folds (3) to form two wall layers (21, 22), wherein the two wall layers (21, 22) are connected to one another at the edges by at least one seam (23) to form a bag body (11), and a holding device (4) is fixed to the wall (2) around a circumference (241) of an opening (24). The two folds (3) extend from the circumference (241) of the opening (24) to the at least one seam (23). Furthermore, a method for producing a vacuum cleaner bag (1) is provided.

Description

[0001] The present invention relates to a vacuum cleaner bag with a wall made of filter material which is folded together via two folds to form two wall layers, wherein the two wall layers are connected to one another at the edges by at least one seam to form a bag body and a holding device is fixed to the wall around a circumference of an opening for a vacuum cleaner nozzle, as well as to a method for producing a vacuum cleaner bag.

[0002] EP 1 915 939 B1 discloses a filter bag for a vacuum cleaner, designed as a flat bag with two layers of filter material welded together at the edges. An inlet opening is formed in one of the layers, around which a retaining plate for releasably securing the vacuum cleaner bag in a vacuum cleaner is arranged. When inflated, the vacuum cleaner bag has a pillow shape, which is why the vacuum cleaner bag is unsuitable for small vacuum cleaners, such as cordless sticks, despite its good filtering performance.

[0003] EP 3 911 211 B1 discloses a vacuum cleaner bag with two layers of filter material that are joined together at the edges on three sides to form an interior space, and in which an inlet opening is formed on a fourth side between the two layers. The two layers are biased into the closed position at the inlet opening by a spring element. Due to its elongated shape, this vacuum cleaner bag is suitable for compact vacuum cleaner designs, but it lacks a retaining plate to simplify assembly and sealing of the vacuum cleaner bag.

[0004] EP 3 821 777 A1 discloses a vacuum cleaner bag with a wall made of filter material and a retaining plate with a cylindrical nozzle. The wall is fixed along the nozzle's outer surface. The problem is that sealing the transition between the cylindrical nozzle and the wall is difficult to achieve with adequate quality because the wall is arranged with excess around the nozzle and then has to be fixed to the nozzle in a radial direction. Therefore, despite complex manufacturing, such vacuum cleaner bags do not provide optimal sealing.

[0005] The object of the present invention is therefore to provide an improved vacuum cleaner bag that is particularly easy to manufacture and provides a reliable seal between the filter material and the retaining device. Furthermore, a method for the effective production of a vacuum cleaner bag is to be provided.

[0006] The present invention solves this problem with a vacuum cleaner bag having the features of claim 1, with a method for producing a vacuum cleaner bag having the features of claims 14 and 15.

[0007] The vacuum cleaner bag of the present invention has a wall made of filter material that is folded together via two folds to form two wall layers, wherein the two wall layers are connected to one another at the edges by at least one seam to form a bag body, and a holding device is fixed to the wall around a circumference of an opening. The two folds extend from the circumference of the opening to the at least one seam. Surprisingly, it has been found that such a bag can be compactly designed and easily manufactured, while at the same time ensuring a reliable seal in the region of the opening on the holding device. The arrangement of the opening between the two folds does not require the bag body to be sealed on an open side of the vacuum cleaner bag between two layers of filter material.The opening can be machined into the filter material similar to a flat bag, allowing for precise positioning. Sealing with a vacuum cleaner nozzle is then preferably achieved via the retaining device for holding the vacuum cleaner bag in the vacuum cleaner, and the seal between the retaining device and the filter material can be effectively achieved via at least one circumferential connecting seam.

[0008] The filter material wall is preferably formed in one piece to form the bag body. If the two wall layers lie on top of each other and are essentially rectangular, the bag body is sealed on three sides by a seam, in particular a welded or glued seam, and the opening between the two folds and the holding device are arranged on the fourth side. The two wall layers can be congruent.

[0009] A fold is a deflection of the filter material, which is aligned at an angle to each other on both sides of the fold, preferably at an angle of essentially 180° in the folded position. The filter material is preferably made of a single- or multi-layer nonwoven fabric, which, unlike paper, cannot be folded to retain its shape. The fold can be formed adjacent to a seam by a tight deflection of the filter material and is only curved in the area of ​​the holding device, optionally also with a straight section due to the fixation to the holding device. In order to keep the stresses in the filter material low when the two folds are partially unfolded, the length of the fold is preferably at least 20 mm, for example between 30 mm and 50 mm.

[0010] Preferably, the two folds run collinear to each other, so that the vacuum cleaner bag is optionally designed symmetrically. The two folds can therefore be two sections of a continuous fold during the manufacture of the vacuum cleaner bag, which is then interrupted by the opening.

[0011] The holding device can optionally extend into the opening and the bag body with a tubular portion. A closure element, such as a pivotable flap, can preferably be provided on this tubular portion. The tubular portion extending into the bag body can prevent the filter cake in the vacuum cleaner bag from growing from the filter material to the opening.

[0012] Preferably, the opening and the two folds extend in a first plane, which is arranged perpendicular to a second plane defined by the at least one seam. If the vacuum cleaner bag has substantially rectangular wall layers, the seam is arranged on three sides and thus forms the second plane. This arrangement facilitates inflation of the vacuum cleaner bag when it is inserted into a vacuum cleaner chamber, since any folds in the vacuum cleaner bag can be immediately unfolded by an air stream from a packaging position.

[0013] In a preferred variant, the vacuum cleaner bag has a bag bottom opposite the opening, which is formed by a portion of the seam connecting the two wall layers. This portion of the seam can, for example, be aligned parallel to the opening, so that the bag bottom and the holding device with the opening are arranged on opposite sides of the vacuum cleaner bag. The vacuum cleaner bag preferably has an elongated shape, and the distance between the bag bottom and the holding device is at least twice as large, preferably at least three times as large, as the distance between two long sides of the bag body.

[0014] The seam for connecting the wall layers has two seam sections on two opposite longitudinal sides of the bag body, which extend parallel over a section and taper towards the holding device. The bag body preferably has two parallel longitudinal sides, each of which has a bevel oriented at an angle to the longitudinal direction on the side facing the holding device, so that the vacuum cleaner bag tapers in a wedge-shaped or conical manner towards the holding device when viewed from above.

[0015] Preferably, the two wall layers have at least one longitudinal fold extending along the vacuum cleaner bag from the periphery of the opening, across the bag body, to the bottom of the bag. Preferably, two or three longitudinal folds are provided, which increase the volume of the vacuum cleaner bag when inflated. The longitudinal folds are preferably fixed to the seam of the bag bottom and to the holding device. The width of the longitudinal folds can be between 3 mm and 50 mm, in particular 5 mm and 30 mm.

[0016] For a tear-resistant design, the holding device is preferably connected to the two wall layers of the filter material by welding or gluing.

[0017] In a further embodiment, the holding device for holding the vacuum cleaner bag in a vacuum cleaner, in particular in a tubular chamber of a vacuum cleaner, comprises a mounting part and a holding part, which are connected to one another by gluing or welding. The mounting part can each have film hinges parallel to the folds, so that the mounting part can be applied to the not yet folded filter material during production and then easily folded. This allows the filter material to be guided by the film hinges of the mounting part during folding.

[0018] Particularly preferably, the holding device additionally comprises a flexurally rigid holding part which is connected to the wall or to the mounting part, in particular glued or welded. The holding part can stabilize the mounting part in the mounted position so that the film hinges are no longer movable. A nozzle is preferably arranged or formed on the holding part, which projects through the opening into the wall, in particular into the bag body. Alternatively or additionally, the holding part and / or the mounting part can also comprise a closing flap by means of which the opening or a passage in the holding device can be closed. The closing flap can be formed separately or fastened via a film hinge. The closing flap is preferably pretensioned into a closed position by a spring. This improves the hygiene of the vacuum cleaner bag.

[0019] In one embodiment, the holding device has only the holding part and not the mounting part, wherein the holding part is directly connected to the wall, in particular glued or welded.

[0020] A part of the wall forming the bag body can optionally have a first stiffness, and a peripheral region around the periphery or at least a portion of the periphery of the opening can have a second stiffness that is higher than the first stiffness. By creating a region with higher stiffness, a guide for the filter material during folding can be provided, so that the mounting part can optionally be omitted. This is particularly advantageous when the holding part is directly fixed to the wall.

[0021] The filter material preferably comprises at least one nonwoven layer, and more preferably several nonwoven layers, forming support layers, a coarse dust storage device, and a fine filter. Such nonwovens can be produced as extruded nonwovens (spunbond, meltblown) or using an airlaid process. The holding device can be made, in particular, of plastic. In one embodiment, an elastic sealing element can also be provided around the opening on the holding device, ensuring a reliable seal between the vacuum cleaner bag and a nozzle of the vacuum cleaner.

[0022] In one variant, the bag body can also have angled sections in an edge area that taper toward the holding device. This allows for the reduction or elimination of corners protruding laterally from the holding device.

[0023] The present invention also includes a first advantageous method for producing a vacuum cleaner bag, comprising the following steps: a. Providing at least one layer of a filter material for a wall of the vacuum cleaner bag, b. Introducing an opening with a circumference into the filter material, c. Folding the filter material on two sides of the opening so that the opening is arranged on an edge side of the filter material between two folds, d. Laying the filter material on top of one another to form two wall layers over the two folds, e. Connecting the two wall layers by at least one seam to form a bag body, and f. Fixing a holding part of a holding device to the bag body around the circumference of the opening.

[0024] According to the invention, a second method for producing a vacuum cleaner bag comprises the following steps: a. Providing at least one layer of a filter material for a wall of the vacuum cleaner bag, b. Folding the filter material over a fold to form two superimposed wall layers, c. Making an opening with a circumference at the fold, which opening is then divided into two folds so that the opening is arranged on an edge side of the filter material between the two folds, d. Connecting the two wall layers by at least one seam to form a bag body, e. Fixing a holding part of a holding device to the bag body around the circumference of the opening.

[0025] In both manufacturing processes, the opening can be made in the filter material, as with a flat bag. A retaining part of a retaining device is then fixed around the opening, ensuring a seal through a circumferential connecting seam between the retaining part and the filter material. The retaining part can be fixed to the bag body from the outside, which facilitates the creation of a tight, circumferential connecting seam.

[0026] Preferably, before securing the retaining part, the two folds are unfolded at least around the opening into a substantially flat shape, in order to then secure the retaining part. By unfolding, the retaining part can be pressed and secured to the outside of the bag body with a simple feeding movement. Optionally, a periphery of the opening is completely flat after unfolding, but it can also be arranged at a slight angle, for example, V-shaped or curved, in order to then connect to a V-shaped or curved contact surface of the retaining part.

[0027] In a further embodiment, the holding device comprises a substantially ring-shaped mounting part, and the holding part fixes the mounting part to the filter material before the filter material is folded and folded together with the filter material. For this purpose, film hinges or other hinges can be provided on the mounting part so that a defined fold of the filter material is achieved by the mounting part. The filter material is guided during folding via the mounting part and the film hinges. This guidance during folding can also be used when unfolding the fold. For example, a stop can be provided on the mounting part so that the mounting part remains in a predetermined position during unfolding, preferably in a flat position, in order to then be able to fix the holding part to the mounting part, for example with a circumferential connecting seam as an adhesive or welded seam.For this purpose, a flat contact surface or a receptacle can be formed on the mounting part, into which a section of the holding part is placed or inserted.

[0028] The present invention is explained in more detail below with reference to several drawings. They show: Fig. 1 a perspective view of a vacuum cleaner bag according to the invention, Fig. 2 a plan view of the holding plate of the vacuum cleaner bag according to the invention from Fig. 1 , Fig. 3a view of the vacuum cleaner bag from Fig. 1 without a holding part, Fig. 4 another view of the bag from Fig. 3 , Fig. 5a and a holding device for the vacuum cleaner bag made of Fig. 1 , Fig. 6a to your further design of the holding device for the vacuum cleaner bag from Fig. 5a , Fig. 7a to fSteps of a method according to the invention for producing a vacuum cleaner bag, Fig. 8a part of a vacuum cleaner bag according to a further embodiment.

[0029] In Fig. 1 A view of a vacuum cleaner bag 1 is shown, which has a wall 2 made of filter material, which is folded together via two folds 3, of which only one is visible here, to form two wall layers 21, 22. The two wall layers 21, 22 are connected to one another at the edges by at least one seam 23, which has a plurality of seam sections 23a, 23b, and 23c, to form a bag body 11. In a plan view of a substantially rectangular wall layer 21, the seam sections 23a, 23b, and 23c can close the vacuum cleaner bag 1 on three sides, while the two folds 3 and an opening 24 are provided on the fourth side. The two folds 3 extend from the periphery of the opening 24 to the seam 23.

[0030] A holding device 4 is fixed to the wall 2 around the opening 24. The holding device 4 can be constructed in multiple parts and preferably comprises a holding part 41 and a mounting part 42, which are glued or welded together. An elastic sealing element 411 is provided on the holding part 41 around the opening 24. The sealing element 411 serves to seal a vacuum cleaner nozzle when it is inserted into the opening 24 of the holding device 4.

[0031] The seam section 23c, which is opposite the opening 24, forms a bag bottom 12. The vacuum cleaner bag 1 has an elongated shape, and a distance between the bag bottom 12 and the holding device 4 is at least twice as large as a distance between the two seam sections 23a and 23b on opposite longitudinal sides of the wall layers 21 and 22.

[0032] Fig. 2 shows a top view of the subject of Fig. 1 and illustrates how the two folds 3 extend from a periphery of the opening 24 to the at least one seam 23, i.e., to the seams 23a and 23b. The opening 24, with the folds 3, extends essentially in a first plane, which is arranged perpendicular to a plane defined by the seam sections 23a, 23b, and 23c.

[0033] The opening 24 in the holding device 4 and the filter material can be circular, oval, rectangular, or have another geometry. The holding part 42 can have a ring around the opening 24, on which profiles, locking means, or holding means are provided for fixing the holding part 42 in a chamber of a vacuum cleaner.

[0034] In Fig. 3 is a side view of the bag from Fig. 1 und 2 , whereby the holding part 41 is not shown here. Rather, it can be seen that the mounting part 24 has two film hinges 421 arranged parallel to the collinear folds 3. Fig. 4 This is shown in a perspective top view, in which the course of the two seam sections 23a and 23b is visible. The mounting part 42 can be made as a plastic ring, but also as a film or with such a film.

[0035] Fig. 5a und 5b show views of the holding part 41 for the holding device 4 of the vacuum cleaner bag 1 from Fig. 1 . The holding part 41 has a nozzle 43 which can protrude through the opening 24 into the bag body 11.

[0036] In Fig. 6a bis 6d the holding part 41 is made of Fig. 5a und 5b shown, which has an optional closure flap 44 which is movably fixed to the nozzle 43 via a hinge 45. The closure flap 44 is pretensioned into the illustrated closed position by a spring (not shown). The closure flap 44 rests on a step 46 on an inner side of the nozzle 43. The end of the nozzle 24 is inclined to the plane of the opening 24, but can also be arranged parallel thereto. The nozzle 24 protruding into the bag body 12 makes it more difficult for a filter cake of the filter material to grow into the channel of the nozzle 24, which ensures reliable sealing.

[0037] Fig. 7 shows steps of a method according to the invention for producing a vacuum cleaner bag 1. In Fig. 7a A web 10 of filter material is shown. Optionally, the web 10 can also be formed as a blank, from which the vacuum cleaner bag is then manufactured. The filter material here already contains several longitudinal folds 13, which preferably extend parallel to a conveying direction. The longitudinal folds 13 form a three-layer arrangement of filter material, which are secured by holding means. The width of the longitudinal folds 13 can be between 3 mm and 50 mm, in particular 5 mm and 30 mm. Optionally, the longitudinal folds 13 can also be omitted.

[0038] In Fig. 7b An opening 25 with a circumference 241 is introduced into the filter material, for example by punching. The longitudinal folds 13 are at least partially severed by the opening 25.

[0039] Fig. 7c shows the fixing of a mounting part 42, preferably by gluing or welding, around the circumference 241 of the opening 25. By fixing the mounting part 42, the longitudinal folds 13 are also fixed around the opening 25, so that they can no longer unfold in this area.

[0040] According to Fig. 7d The web 10 or the blank of filter material is now folded in the region of the opening 25, in particular centrally at the opening 25, so that the opening 25 is arranged on an edge of the filter material between two folds 3. The folding can be guided by the mounting part 42, since the mounting part 42 is also folded by the two film hinges 421. By folding along the two folds 3, the filter material is placed on top of one another with two wall layers 21 and 22. The wall layers 21 and 22 are congruent and rectangular.

[0041] In a further step after Figur 7e In the process, the two wall layers 21 and 22 are joined together by a seam section 23c, which later forms the bag bottom. The seam section 23c extends parallel to the folds 3 on the opposite side. The longitudinal folds 13 are thus fixed between the mounting part 42 and the seam section 23c.

[0042] In a Figur 7f In the step shown, the two seam sections 23a and 23b are then produced, which are provided on opposite longitudinal sides of the wall layers 21 and 22. This forms a bag body 12 that is closed except for the opening 25. The seam sections 23a, 23b, and 23c of the seam 23 are preferably ultrasonic welds produced by ultrasonic welding.

[0043] In a further step, the folds 23 are unfolded again, so that the mounting part 42 is again arranged essentially in one plane around the opening 25. For this purpose, restoring forces of the mounting part 42 or suction elements can be used. When the mounting part 42 is unfolded and arranged in a ring shape, the holding part 41 is fixed to the mounting part 42, preferably by gluing or welding. The holding part 41 then fixes the unfolded position of the mounting part 42 and the Figur 1 The shape of the vacuum cleaner bag 1 shown is obtained. The folds 3 are thus folded tightly by approximately 180° adjacent to the seam sections 23a and 23b, while the filter material is fixed to the mounting part 42 in a flat shape and extends in an arcuate manner adjacent to the mounting part 42. The folds 3 are thus differently shaped in their longitudinal direction and spread out at different angles. The plane of the opening 25 is substantially perpendicular to the plane of the seam sections 23a, 23b, and 23c.

[0044] The sequence of process steps described above can be changed. For example, the opening 25 can be introduced into the filter material after folding. The opening 25 in the filter material is preferably larger than the opening 24 in the holding device, so that the seal against a vacuum cleaner nozzle takes place at the elastic sealing element 411. Optionally, both openings 24 and 25 can also be the same size.

[0045] Furthermore, the fixation of a mounting part 42 can also be omitted. In this case, the holding part 41 of the holding device 4 is fixed directly to the filter material, e.g., by gluing or welding. To guide the filter material, reinforcements or other aids can then optionally be used on the filter material, which define a predetermined folding edge.

[0046] When folding the filter material, a blade can be inserted between the two wall layers 21 and 22. Means for spreading the filter material around the folds 3 can then be provided on the blade, so that the holding part 41 is fixed to the filter material and the blade forms a counterpressure element that is removed from the filter material after the holding part 41 is attached.

[0047] Fig. 8 shows a variant of a vacuum cleaner bag 1 according to the invention, wherein no holding part 41 is provided, which is mounted later and can look as in the Figuren 5 and 6 The longitudinal sides of the bag body 11 do not run parallel to the longitudinal folds 13 over their entire length, but each have a bevel 14, so that the folds 3 are shortened compared to the previous exemplary embodiment. As a result, the corner regions at the transition between the seam sections 23a and 23b and the folds 3 are shortened and protrude less laterally, which gives the vacuum cleaner bag a particularly attractive appearance. Optionally, the corners between the seam sections 23c and 23a or 23b can also be rounded or beveled.

[0048] The production of the vacuum cleaner bag 1 according to Figur 8 is carried out as per the Fig. 7a bis 7f described, wherein the corners at the outer end of the respective fold 3 are then cut off to produce the bevel 14. Furthermore, the two wall layers 21 and 22 are glued or welded together adjacent to the bevel 14, so that the seam sections 23a and 23b run parallel over a section and then taper in a wedge shape or cone toward the holding device 4. The attachment of the holding part 41 can take place before or after the production of the bevel 14.

[0049] When unfolding the folds 3 to fix the holding part 41 in a straight, flat position of the mounting part 42, tension can occur in the filter material next to the mounting part 42, which is why a distance from the holding device 4 is necessary at the bevel 14. The length of the fold 3 can therefore be at least 20 mm, for example between 30 mm and 50 mm. As a result of the unfolding, the transition from the fold 3 to the seam 3, with or without a bevel, can lead to protruding ears on both sides of the finished vacuum cleaner bag. In a further embodiment of the method, these protruding ears are either cut off and glued or welded on, or only glued or welded to the bag body 12. Bezugszeichenliste

[0050] 1Vacuum cleaner bag 2Wall 3Fold 4Holding device 10Panel 11Bag body 12Bag base 13Longitudinal fold 14Bevel 21Wall layer 22Wall layer 23aSeam 23bSeam 23cSeam 24Opening 25Opening 241Circumference 31Fold point 41Holding part 411Sealing element 42Assembly part 421Film hinge 43Socket 44Closing flap 45Hinge 46Step

Claims

1. Vacuum cleaner bag (1) with a wall (2) made of filter material, which is folded together via two folds (3) to form two wall layers (21, 22), wherein the two wall layers (21, 22) are connected to one another at the edges by at least one seam (23) to form a bag body (11) and a holding device (4) is fixed to the wall (2) around a circumference (241) of an opening (24) for a vacuum cleaner nozzle, characterized in that the two folds (3) extend from the circumference (241) of the opening (24) to the at least one seam (23).

2. Vacuum cleaner bag (1) according to claim 1, characterized in that that the two folds (3) are collinear with each other.

3. Vacuum cleaner bag (1) according to claim 1 or 2, characterized in that the two folds (3) are connected to the holding device (4).

4. Vacuum cleaner bag (1) according to one of the preceding claims, characterized in thatthe opening (24) and the two folds (3) extend in a first plane which is arranged perpendicular to a second plane defined by the at least one seam (23).

5. Vacuum cleaner bag (1) according to one of the preceding claims, characterized in that the bag body (11) has a bag bottom (12) opposite the opening (24) and that the bag bottom (12) is formed by at least part of the seam (23c) which connects the two wall layers (21, 22) to one another.

6. Vacuum cleaner bag (1) according to claim 5, characterized in that the two wall layers (21, 22) on opposite sides of the opening (24) have at least one longitudinal fold (13) which extends along the vacuum cleaner bag (1) from the circumference of the opening (24), over the bag body (11) to the bag bottom (12).

7. Vacuum cleaner bag (1) according to one of the preceding claims, characterized in thatthe holding device (4) has a mounting part (42) and a holding part (41), wherein the mounting part (42) is materially connected to the wall (2) by means of gluing or welding.

8. Vacuum cleaner bag (1) according to claim 7, characterized in that the mounting part (42) is arranged substantially annularly, preferably concentrically to the opening.

9. Vacuum cleaner bag (1) according to claim 7 or 8, characterized in that the mounting part (42) has film hinges (421) parallel to the folds.

10. Vacuum cleaner bag (1) according to one of the preceding claims, characterized in that the seam (23) has two seam sections (23a, 23b) on two opposite longitudinal sides of the bag body (11), which extend parallel over a section and which taper towards the holding device (4).

11. Vacuum cleaner bag (1) according to one of the preceding claims, characterized in thatthe holding device (4) has a holding part (41) with a nozzle (43) which projects through the opening (24) into the bag body (11).

12. Vacuum cleaner bag (1) according to one of the preceding claims, characterized in that that a part of the wall (2) forming the bag body (11) has a first stiffness and a peripheral region around the circumference (241) or at least a part of the circumference (241) of the opening (24) has a second stiffness which is higher than the first stiffness.

13. Vacuum cleaner bag (1) according to one of the preceding claims, characterized in that the filter material comprises or has at least one nonwoven layer.

14. A method for producing a vacuum cleaner bag (1), comprising the following steps: a. providing at least one layer of a filter material for a wall of the vacuum cleaner bag (1), b. introducing an opening (24) with a circumference (241) into the filter material, c. folding the filter material on two sides of the opening (24) so ​​that the opening (24) is arranged on an edge side of the filter material between two folds (3), d. placing the filter material on top of one another to form two wall layers (21, 22) over the two folds (3), e. connecting the two wall layers (21, 22) by at least one seam (23) to form a bag body (11), and f. fixing a holding part (41) of a holding device (4) to the bag body (11) around the circumference (241) of the opening (24).

15. A method for producing a vacuum cleaner bag (1), comprising the following steps: a. providing at least one layer of filter material for a wall of the vacuum cleaner bag (1), b. folding the filter material over a fold to form two superimposed wall layers (21, 22), c. introducing an opening (24) with a circumference (241) at the fold, which opening is then divided into two folds (3) so that the opening (24) is arranged on an edge side of the filter material between the two folds (3), d. connecting the two wall layers (21, 22) by at least one seam (23) to form a bag body (11), and e. fixing a holding part (41) of a holding device (4) to the bag body (11) around the circumference (241) of the opening (24).

16. The method according to claim 14 or 15, wherein before fixing the holding part (41) the two folds (3) are unfolded at least around the opening (24) to a substantially flat shape in order to then fix the holding part (41).

17. Method according to one of claims 14 to 16, wherein the holding device (4) comprises a substantially annular mounting part (42) and a holding part (41) and, before folding the filter material, the mounting part (42) is fixed to the filter material and folded together with the filter material.

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