WO2019206532A1

WO2019206532A1 - Vacuum cleaner filter bag with film in the region of the holding plate

Info

Publication number: WO2019206532A1
Application number: PCT/EP2019/057052
Authority: WO
Inventors: Ralf Sauer; Jan Schultink
Original assignee: Eurofilters Holding N.V.
Priority date: 2018-04-27
Filing date: 2019-03-21
Publication date: 2019-10-31
Also published as: ES2937794T3; RU2753555C1; AU2019259443A1; CN112105280A; DK3560402T3; AU2019259443B2; PL3560402T3; CN112105280B; EP3560402B1; EP3560402A1

Abstract

The invention relates to a vacuum cleaner filter bag comprising a bag wall and a holding plate which is connected to the bag wall. The bag wall has a film region in which a plastic film is arranged, and the film region comprises a first sub-region in which the bag wall is formed solely by the plastic film or in which the plastic film forms the outermost layer of the bag wall. The film region comprises a second sub-region in which the plastic film is overlapped by a nonwoven fabric element (3). The holding plate is connected to the plastic film and the nonwoven fabric element (3), in particular the holding plate is welded thereto, and the nonwoven fabric element (3) has at least one part (11, 12) which is connected to the bag wall part surrounding the film region.

Description

Vacuum cleaner filter bag with foil in the area of the holding plate

The invention relates to a vacuum cleaner filter bag comprising a bag wall and a holding plate connected to the bag wall, wherein the bag wall has a film area in which a plastic film is arranged.

Such vacuum cleaner filter bags are known, for example from EP 3 066 968. Frequently, the plastic film is a transparent film. The film area is then transparent and thus makes it possible to visually determine the degree of filling of the vacuum cleaner filter bag. It is also known to arrange viewing windows in the form of transparent films in other areas of the bag wall, for example from DE 20 2005 007 503 or DE 102 24 561. However, viewing windows in the region of the holding plate have the advantage in many vacuum cleaner models that these are best visible.

In addition to forming transparent areas, foils also find other uses, for example to avoid the application of a filter cake or to reduce the abrasion of the filter material in particularly stressed areas within the bag. Foils in the area of the bag wall are still known from EP 2 025 278 and DE 20 2008 004 025.

EP 3 066 968 likewise describes non-transparent films in the region of the holding plate in order to facilitate the insertion of the holding plate into the corresponding receptacle in the vacuum cleaner housing. For this, the plastic film forms the outermost layer of the bag wall in this area.

In the latter case and in the case of a transparent film in the region of the holding plate for forming a viewing window, the connection of the holding plate takes place with the plastic film.

The welding of a holding plate with a film, however, turns out to be problematic. The achievable maximum tensile force is usually not sufficient, so that the retaining plate can be easily detached from the bag wall, in particular the film. Often caused by the connection welding holes or weak points in the film, which continue to tear under load.

In order to improve the connection between the holding plate and the foil, it is known from WO 2017/098035 to arrange a textile material between the holding plate and the foil. However, this solution has the disadvantage that several elements must be aligned against each other. It is therefore an object of the present invention to provide a vacuum cleaner filter bag which is more efficient to manufacture and to provide a method which enables such a more efficient production of a vacuum cleaner filter bag.

This object is achieved by a vacuum cleaner filter bag according to claim 1 and by a method according to claim 6. Advantageous developments of the invention are specified in the dependent claims.

According to the invention, it is therefore intended to connect the holding plate not only with the plastic film, but also with a nonwoven fabric element which partially overlaps the plastic film. The nonwoven fabric element has at least one part which is connected to the part of the bag wall surrounding the film area, in particular directly. Thereby, the positioning of the nonwoven fabric member with respect to the plastic film and the holding plate can be improved. In particular, it is not necessary to align the nonwoven fabric element as a separate part with respect to the film and the holding plate. This allows a higher efficiency of the vacuum cleaner filter bag in the manufacture.

As "region" herein is meant a three-dimensional part of an element characterized by one or more particular properties. For example, the film area of the bag wall is the three-dimensional part of the bag wall in which the plastic film is arranged.

The plastic film may be transparent or non-transparent. The plastic film may be referred to as transparent or transparent, in particular, if the proportion of visible light that can pass through the plastic film is at least 25%, in particular at least 50%. In particular, this portion can pass through the plastic film in such a way that it is possible to image an underlying object. In other words, the transmitted light is not a diffused light.

In the case of a transparent plastic film, the first subregion of the film region thus forms a transparent region of the bag wall, which allows a visual insight into the interior of the vacuum cleaner filter bag. The transparent area thus effectively forms a viewing window in the bag wall. In particular in this case, the bag wall in the first partial area can be formed exclusively by the plastic film. At best, a net or another transparent element may be connected to the bag wall and overlap with the first portion, the net or the further transparent element However, they are designed so that they do not prevent the visual insight into the interior of the vacuum cleaner filter bag through the transparent area.

The first portion of the film area need not be contiguous. By way of example, the first subregion may comprise at least two parts which are separated from one another by the second subregion of the film region.

The part of the bag wall surrounding the film region here denotes the part of the bag wall which adjoins the region in which the plastic film is arranged, in particular directly.

The retaining plate can be attached to a holding device in a vacuum cleaner housing. As a result, the holding plate can be arranged in the vacuum cleaner housing in a predetermined position, in particular can be fixed. Alternatively, the vacuum cleaner filter bag can be pushed by means of the holding plate via a vacuum cleaner side connecting piece.

In particular, in the case of an opaque plastic film, the bag wall in the first partial area can form the outermost layer of the bag wall. This makes it possible to facilitate the insertion of the holding plate in the corresponding receptacle in the vacuum cleaner housing. A transparent plastic film can also form the outermost layer of the bag wall. If this does not overlap with non-transparent parts of the bag wall, it can then be used as a viewing window and for easier insertion of the bag into the holder of the vacuum cleaner.

In this case, the plastic film may be referred to as being opaque or opaque if the proportion of visible light that can pass through the plastic film is less than 25%, in particular less than 10%. The plastic film may also be termed opaque or impermeable if the proportion of visible light which can pass through the plastic film is more than 25%, but this proportion passes through the plastic film in such a way that imaging of an underlying object is not possible is. In other words, the transmitted light is then diffused light.

The nonwoven fabric element can in particular be made of the same material as the bag wall surrounding the film region. The nonwoven fabric element may in particular be formed integrally with the bag wall surrounding the film region. In other words, according to a preferred embodiment of the invention, the nonwoven fabric element is concerned not a separate element connected to the bag wall surrounding the film area, but an integral part thereof. This can be achieved in that the part of the bag wall surrounding the film region comprises one or more layers of nonwoven fabric and the nonwoven fabric element is formed as a remaining part of these nonwoven fabric layers in one or more punched portions.

The nonwoven fabric element may have a passage opening, which is arranged concentrically to a passage opening in the plastic film and a passage opening in the holding plate. As a result, an inflow opening can be formed through which dust-laden air can enter the interior of the bag. In particular, a connection of a vacuum cleaner via the passage opening in the holding plate and the passage openings in the plastic film and the nonwoven fabric element are at least partially introduced into the vacuum cleaner filter bag.

The nonwoven fabric element may have an annular region surrounding the passage opening, which is connected via at least one web to the part of the bag wall surrounding the film region, and wherein the holding plate is connected to the nonwoven fabric element in the annular region. The annular region can be dimensioned such that it is completely connected, in particular welded, to the retaining plate. As a result, the ring-shaped region does not produce a different appearance for the direct connection of the retaining plate to the transparent plastic film, as known from EP 3 066 968, for example.

Compared with a direct connection to the film, the essential optical difference thus remains in this example of the at least one web via which the annular region is connected to the part of the bag wall surrounding the film region. However, the bridge can be dimensioned much smaller than the first part. In plan view of the part of the bag wall in which the film area and the holding plate are arranged, the area of the overlapping area of the web with the plastic film is thus smaller than the area of the first area.

There may also be two or more webs to connect the annular region with the part of the bag wall surrounding the film region, in particular two, three or four webs. With two webs, these can connect the annular region, in particular with opposite sides of the part of the bag wall surrounding the film region. This is a particularly advantageous stabilization and localization of the nonwoven fabric the bag wall and the nonwoven fabric element in the production possible. With four webs, the webs can connect in pairs on opposite sides of the film region the annular region with the part of the bag wall surrounding the film region.

It should be noted that the term "annular" herein is not limited to the shape of a circular ring. The actual shape of the annular region may be adapted to the shape of the portion of the retaining plate intended to be connected to the bag wall. In general, the annular region may represent a closed region surrounding the passage opening in the plastic film and in the nonwoven fabric element. The annular region may extend between a closed inner and a closed outer boundary line. The boundary lines may be circular, elliptical or any other shape. The boundary lines can cross the at least one web. The division into "annular region" and "web" serves only to describe the geometry of the nonwoven fabric element. The annular region and the at least one ridge are integral parts of the nonwoven fabric element described herein and merge into one another.

The outer boundary of the film area may be rectangular or square. In other words, the plastic film may be rectangular or square. The plastic film may also have other shapes, such as round or oval. The outer boundary may be formed by a weld joining the plastic film to the nonwoven fabric of the bag wall. At the same time, this weld may be part of or correspond to the part of the bag wall surrounding or delimiting the film region.

As "web" herein is meant an element which emanates from an edge of the outer limiter and connects this edge to another element of the nonwoven fabric element, for example to the annular region. In the simplest form, the web is in plan view of the part of the bag wall, the film area comprises, rectangular or square forms. However, other geometries are conceivable.

As mentioned above, two lands may connect two opposite sides or edges of the outer boundary to the annular area.

The holding plate and the plastic film may be arranged such that the nonwoven fabric element is located between the holding plate and the plastic film. Alternatively, the holding plate and the plastic film may be arranged so that the plastic film between the holding plate and nonwoven fabric element is located.

The bag wall of the vacuum cleaner filter bag, in particular the part of the bag wall surrounding the film area, and the nonwoven fabric element may comprise one or more filter material layers, in particular one or more nonwoven fabric layers. Vacuum cleaner filter bags with a plurality of filter material layers are known, for example, from EP 2 01 1 556 or EP 0 960 645. As a material for the nonwoven fabric layers, a wide variety of plastics can be used, for example polypropylene and / or polyester. The bag wall of the vacuum cleaner bag may also comprise plastic recyclate. For example, the bag wall can be designed as described in EP 3 219 376 A1.

The term nonwoven fabric is used according to the definition according to ISO standard ISO9092: 1988 or CEM standard EN29092. In particular, the terms nonwoven fabric or nonwoven fabric and nonwoven fabric in the field of production of nonwovens are delimited from one another as follows and are also to be understood in the context of the present invention. To produce a nonwoven fabric fibers and / or filaments are used. The loose or loose and still unbound fibers and / or filaments are referred to as fleece or nonwoven web. Finally, by means of a so-called non-woven binding step, such a nonwoven fabric is used to form a nonwoven fabric which has sufficient strength to produce e.g. to be wound up into rolls. In other words, a nonwoven fabric is self-supporting by the solidification. (Details on the use of the definitions and / or methods described herein can also be found in the standard work "Nonwovens", W. Albrecht, H. Fuchs, W. Kittelmann, Wiley-VCH, 2000).

The plastic film can be directly connected, in particular welded, to the one or more nonwoven fabric layers of the bag wall. In addition, the plastic film can be directly connected, in particular welded, to the at least one web of the nonwoven fabric element. As a result, the at least one web can also be used to connect the holding plate to the bag wall, which further increases the stability of the connection between the holding plate and the bag wall.

When referring to "welding" or "welding" herein, it is meant a connection by ultrasonic welding.

The plastic film may be a blown film or a cast film. As a film, an element is called whose thickness is substantially less than its extent perpendicular thereto (Length and width). For example, the film may have a, in particular constant, thickness of less than 300 μm, for example 100 μm. The plastic film may be made of polypropylene, PP, polyethylene, PE, polyethylene terephthalate, PET, polyamide, PA, or polycarbonate, PC.

The invention provides in claim 6 a method for producing a vacuum cleaner filter bag, in particular a vacuum cleaner filter bag described above. According to this method, at least one passage opening is punched in a nonwoven web, so that a nonwoven fabric-free area is formed in the nonwoven web. The nonwoven fabric-free region is formed so that a nonwoven fabric element remains after punching, which is arranged between two opposite edge portions of the nonwoven fabric-free region and spaced from the opposite edge portions by a respective portion of the nonwoven fabric-free area.

According to the prior art, a rectangular or square passage opening would have been punched here in which the plastic film is subsequently arranged. To connect the holding plate with the film, a separate textile element had to be produced and aligned with the holding plate with respect to the film. According to the invention, the nonwoven fabric element remains as part of the nonwoven web after punching the at least one passage opening, which considerably simplifies production and alignment.

When a through hole is punched, the through hole forms the non-woven area. When more than one through hole is punched, the non-woven area is formed by a combination of the punched through holes. The non-woven fabric-free region may comprise a plurality of non-contiguous subregions and / or several contiguous subregions. The subregions can each be formed by one of the through openings.

The nonwoven fabric element is arranged between two opposite edge sections. That is, there are two edge portions of the edge of the nonwoven fabric-free area, which face each other and between which the nonwoven fabric element is arranged. There may also be several pairs of opposite edge portions of the edge of the nonwoven fabric free area between which the nonwoven fabric element is disposed.

The nonwoven fabric element can be arranged completely or partially between two opposite edge sections. It is also possible to arrange further edge sections between the opposite edge sections. The edge of the non-woven fabric-free area is formed by the combination of the edges of the through-openings. The edge of the non-woven fabric-free region can therefore also comprise a plurality of non-contiguous edge portions. For example, the nonwoven area can be formed by two separate, ie non-contiguous through openings. In this case, the edge of the nonwoven fabric-free area consists of the non-contiguous edges of the two through-openings.

The formation of the passage opening in the plastic film can take place simultaneously with the formation of the passage opening in the nonwoven fabric element. However, it would also be conceivable that the passage opening in the nonwoven fabric element is formed in front of the passage opening in the plastic film.

After the welding of the holding plate with the plastic film and the nonwoven fabric element, the nonwoven web can be cut to size and the vacuum cleaner filter bag can be confectioned. In particular, the vacuum cleaner filter bag can be produced as a flat bag. In this case, an upper layer can be welded circumferentially to a lower layer, wherein the film region is arranged with the holding plate, for example in the upper layer.

In particular, two through openings can be punched, which are formed symmetrically to an axis of symmetry running in the machine direction, in particular wherein the through openings are punched so that the nonwoven element remains between the through openings.

It is also conceivable to punch more than two passage openings, for example three or four. In this case too, symmetry with respect to a symmetry axis running in the machine direction is advantageous and possible. The nonwoven fabric member may be partially disposed between each two of the more than two through holes. The region of the nonwoven web in which the nonwoven fabric-free region and the nonwoven fabric element are arranged may have a rectangular, in particular square, boundary.

The nonwoven fabric element may comprise, prior to the formation of the passage opening, a region in the form of a disk and at least one web which connects the region in the form of a disk to the remaining nonwoven web. The area in the form of a disk effectively forms a widening of the nonwoven element extending transversely to the machine direction. There, the passage opening is then to be formed and the retaining plate attached. The region in the form of a disk can be formed annularly by punching, wherein the holding plate is connected, in particular welded, to the annular region of the nonwoven fabric element.

A single bridge is less stable than several. In particular, when pulling on the nonwoven web, the at least one punched through opening may deform and the nonwoven web may warp and / or wave in the area of the through opening. By at least two webs stabilization of the nonwoven web can be achieved, so that it does not or less to the undesirable effects. Accordingly, the web speed between the cycles and thus the production speed can be increased.

The webs may be arranged in particular in the form of a disk on sides of the region which are opposite in the machine direction. In addition, webs may be arranged in the form of a disk on two sides of the area opposite to the machine direction. It is also conceivable that one or more of the webs at an angle of 20 ° to 60 °, in particular of 45 °, extend to the machine direction.

The retaining plate may comprise directional sensors which are arranged in a region of the retaining plate surrounding a passage opening of the retaining plate, the radial extent of which corresponds to that of the annular region of the nonwoven fabric element. In other words, the annular region can be adapted to the region of the holding plate in which the direction sensors are arranged, and which is thus provided for connecting the holding plate with the nonwoven fabric element and the plastic film.

The holding plate and the plastic film can be arranged so that after bonding the holding plate, the nonwoven fabric element between the holding plate and plastic film is located.

Alternatively, the holding plate and the plastic film can be arranged so that after connecting the holding plate, the plastic film between the holding plate and nonwoven fabric element is located.

The two alternatives can be achieved by welding the plastic film to the nonwoven web in plan view of the nonwoven web either from above or from below. Before the at least one passage opening is punched, the region of the nonwoven web in which the at least one passage opening is to be formed can be at least partially thermally compressed. As a result, the through holes can be punched out more accurately. For example, the corresponding regions of the nonwoven web can be ultrasonically compacted or be pre-embossed with a calender.

The plastic film can be connected to the nonwoven web and to the nonwoven element. In particular, the plastic film can be joined, in particular welded, to a region of the nonwoven web surrounding the nonwoven fabric-free region, bonded to the annular region and to the at least one web of the nonwoven fabric element.

The holding plate may additionally also be connected, in particular welded, to the at least one web of the nonwoven fabric element. As a result, the connection between the retaining plate and the bag wall can be made even more stable.

The nonwoven web may comprise one or more filter material layers, in particular one or more nonwoven fabric layers. Such filter material layers are known, for example, from EP 2 01 1 556 or EP 0 960 645. As a material for the nonwoven fabric layers, a wide variety of plastics can be used, for example polypropylene and / or polyester. The bag wall of the vacuum cleaner filter bag may also comprise plastic recyclate. For example, the bag wall can be designed as described in EP 3 219 376 A1.

The plastic film may have one or more of the above features.

The vacuum cleaner filter bag thus produced may have one or more of the above features.

Further features and advantages of the invention are described below with reference to the exemplary figures. Showing:

FIG. 1 is an illustration of a first step of an exemplary method for raising a vacuum cleaner filter bag;

FIG. 2 shows a further step of an exemplary method for producing a

Vacuum cleaner filter bag;

3 shows a further step of an exemplary method for producing a

Vacuum cleaner filter bag; FIG. 4 shows a further step of an exemplary method for producing a

Vacuum cleaner filter bag;

FIG. 5 shows a further aspect of an exemplary method for producing a

Vacuum cleaner filter bag;

FIG. 6 shows an exemplary vacuum cleaner filter bag;

FIG. 7 shows an alternative embodiment of the nonwoven fabric element;

FIG. 8 shows a further alternative embodiment of the nonwoven fabric element; and

FIG. 9 shows a further alternative embodiment of the nonwoven fabric element.

FIG. 1 shows a first step of an exemplary method for producing a vacuum cleaner filter bag according to the invention. In this step, by way of example, two passage openings 1, 2 are punched into a nonwoven web, which during the process is moved stepwise in the machine direction (indicated by an arrow in FIG. 1). As can be seen from FIG. 1, a nonwoven fabric element 3 extending in the machine direction remains between the two through openings 1, 2. Through the two through openings 1, 2, a nonwoven area is formed here, which comprises the two passage openings 1, 2 includes non-contiguous sub-areas. The edge of the non-woven area is formed by the two edges of the through holes 1, 2. The nonwoven fabric element 3 is arranged between two opposite edge portions A, B of the edge of the nonwoven fabric-free region. The nonwoven fabric element 3 is spaced apart from the edge sections A, B by a partial region of the nonwoven fabric-free region, namely through the passage opening 1 or 2.

When the nonwoven web is moved further after punching the through holes 1, 2, it is pulled in the machine direction. In the prior art, in which the nonwoven fabric member 3 was not provided, this pulling in the machine direction resulted in deformation of the then single through hole, resulting in disadvantages in further processing. Therefore, only a slow and careful movement of the nonwoven web could be realized in the prior art. The nonwoven element 3 stabilizes the region of the through openings 1, 2 during a pull in the machine direction, so that higher processing speeds are possible. As can also be seen from FIG. 1, the two passage openings 1, 2 are formed symmetrically with respect to a symmetry axis 4 extending in the machine direction. The region comprising the nonwoven fabric element 3 and the passage openings 1, 2 has in plan view a rectangular, in particular square, boundary.

The nonwoven fabric element 3 here comprises a middle region in the form of a disk and two webs which are opposite one another in the machine direction and which connects the region in the form of a disk to parts of the said boundary.

The nonwoven web is only shown schematically here, in particular its transverse to the machine direction extending boundaries 5, 6.

In a further process step illustrated in FIG. 2, a plastic film is bonded to the nonwoven web from the underside of the nonwoven web, so that the plastic film completely overlaps the nonwoven fabric-free region and the nonwoven fabric element 3 in the plan view of the nonwoven web (as shown in FIG. Shown in dashed lines in FIG. 2 are the points at which welding of the plastic film to the nonwoven web takes place. In particular, the plastic film can be welded to a part of the nonwoven web which completely surrounds the nonwoven fabric-free region, ie with the above-described boundary of the region comprising the through-openings 1, 2 and the nonwoven fabric element 3. As a result, the circumferential weld seam 7 shown in FIG. 2 is formed. Optionally, the plastic film can also be connected to the nonwoven fabric element 3, for example by a weld seam 8 running in the machine direction.

The areas of the plastic film which are not overlapped by the nonwoven element 3 form in the finished vacuum cleaner filter bag a first subarea of a film area, which effectively serves as a viewing window in the case of a transparent film in order to visually determine the filling level of the vacuum cleaner filter bag, and in the case of an opaque film Inserting the vacuum cleaner filter bag contributes to a corresponding receptacle in the vacuum cleaner.

FIG. 3 shows a further method step of the exemplary method for producing a vacuum cleaner filter bag, in which, in particular, the later filling hole is formed in the bag wall. For this purpose, the nonwoven fabric element 3 and the plastic film are punched simultaneously, so that a passage opening 9 is formed. The simultaneous punching of the nonwoven fabric element 3 and the plastic film is procedurally advantageous. However, the method according to the invention is not limited to simultaneous punching. By punching the passage opening 9, the previously disc-shaped central part of the nonwoven fabric element 3 is formed into an annular region 10, which is connected via two webs 1 1, 12 with the remaining nonwoven web, in particular with the weld 7.

The annular region 10 is adapted in shape and radial extent to the region of the holding plate, which is provided for connection to the bag wall. This area of the holding plate usually has directional encoders in order to improve the welding of the holding plate to the bag wall.

Finally, FIG. 4 illustrates the step of connecting the holding plate 13 to the annular region 10 and the plastic film (welding region shown in dashed lines). Because the retaining plate is connected not only to the plastic film but also to the nonwoven element 3, a secure connection between the retaining plate 13 and the plastic film is possible.

The retaining plate 13 has, in a manner known per se, a sealing lip 14 and a closing flap (closure flap can not be seen in FIG. 4). The closure flap can prevent leakage of suction material when the filled bag is removed from the vacuum cleaner housing.

As can be seen in FIG. 4, the holding plate 13 largely overlaps the nonwoven fabric element 3, but only partially overlaps the first portion of the film area. Consequently, the first portion of the film area can be used as a viewing window to control the filling level of the vacuum cleaner filter bag when a transparent plastic film is used. Only of the webs 1 1, 12 are still small parts visible, but these do not disturb the function of the viewing window. In the end, therefore, results comparable to the prior art (for example, comparable to EP 3 066 968), but with a firmer connection between the holding plate 13 and bag wall.

FIG. 5 also shows possible further welding regions in which the plastic film can be connected to the nonwoven fabric element 3. For example, there is also a welding along the annular element 10 and along the webs 1 1, 12 instead. In addition, the circumferential weld 7 is shown again. Depending on the specific configuration, the retaining plate 13 may optionally additionally be connected to webs 11, 12 (in addition to the connection in the region of the annular element 10). Finally, a vacuum cleaner filter bag can be assembled by cutting the nonwoven web accordingly and, for example, bonding two nonwoven fabric layers together with a peripheral weld. One of the two nonwoven fabric layers comprises the film area and the holding plate. FIG. 6 shows a plan view of such a simple vacuum cleaner filter bag. However, in a conventional manner, the vacuum cleaner filter bag can also have other geometries. Example side gussets on the two longitudinal sides and / or transverse sides may be provided in order to achieve the same filter area a smaller pack size.

Instead of the connection of the plastic film from the underside of the nonwoven web, as shown in Figure 2, the plastic film could also be connected in plan view of the nonwoven web from above with the nonwoven web. As a result, in the vacuum cleaner filter bag produced, the plastic film is disposed between the nonwoven fabric member and the holding plate. The inventors of the present application have recognized that, even in this configuration, a stronger connection can be made between the holding plate and the bag wall, since the nonwoven element in this case forms a softer, more flexible support for welding than the conveyor on which the nonwoven web otherwise rests.

Furthermore, it is possible to partially or completely thermally compress the regions of the nonwoven web in which the through-openings 1, 2 are to be punched (compare FIG. 1) before stamping, for example by ultrasound or pre-embossing. This allows the punch holes to be formed with more defined boundaries.

The geometry of the nonwoven fabric element 3 shown in FIG. 1 is only an example. Further examples can be found in FIGS. 7 to 9.

In FIG. 7, the disc-shaped region of the nonwoven fabric element 3 is connected to the remaining nonwoven web by way of four webs, which are arranged in pairs on opposite sides of the disk-shaped region. This geometry is achieved by punching through four through holes 14, 15, 16, 17 to form the nonwoven area. The nonwoven fabric element 3 is arranged between the edge sections A-B, C-D, E-F, and G-H.

In FIG. 8, the disk-shaped region of the nonwoven fabric element 3 is connected to the remaining nonwoven web via three webs. Two of the webs make an angle of 45 ° with the machine direction. This geometry is achieved by punching through three through holes 18, 19, 20 and forming the nonwoven area. The nonwoven fabric element 3 is arranged between the edge sections AB, CD, and CE. But it is also possible that the disc-shaped region is connected via only one web with the übri gene nonwoven web, as shown in Figure 9. In this case, only one passage opening 21 is provided, which forms the nonwoven fabric-free area. The nonwoven fabric element 3 is arranged between the edge sections A and B and is spaced from each of these edge sections A, B by a respective different partial area of the nonwoven fabric-free area. The positioning of the nonwoven fabric element 3 is also simplified by means of only one web, thereby improving the mounting of the holding plate.

It is understood that features mentioned in the embodiments described above are not limited to these specific combinations and are also possible in any other combinations. In particular, it is understood that geometries shown in the figures, for example the holding plate, are only exemplary and are also possible in any other embodiments.

Claims

claims

A vacuum cleaner filter bag comprising a bag wall and a holding plate (13) connected to the bag wall, the bag wall having a film area in which a plastic film is arranged, the film area comprising a first portion in which the bag wall is formed solely by the plastic film or in which the plastic film forms the outermost layer of the bag wall, wherein the film region comprises a second portion in which the plastic film is overlapped by a nonwoven fabric element (3), wherein the holding plate (13) with the plastic film and the nonwoven fabric element (3) connected, in particular welded, and wherein the nonwoven fabric element (3) has at least one part (1 1, 12) which is connected to the part of the bag wall surrounding the film region.

2. Vacuum cleaner filter bag according to claim 1, wherein the plastic film is transparent or non-transparent.

3. Vacuum cleaner filter bag according to claim 1 or 2, wherein the nonwoven fabric element (3) has a passage opening which is arranged concentrically to a passage opening in the plastic film and a passage opening in the holding plate (13).

4. Vacuum cleaner filter bag according to claim 3, wherein the nonwoven fabric element (3) has an annular region (10) surrounding the passage opening, which is connected via at least one web to the part of the bag wall surrounding the film region, and wherein the retaining plate ( 13) in the annular region (10) is connected to the nonwoven fabric element (3).

5. Vacuum cleaner filter bag according to claim 4, wherein at least two webs (1 1, 12) are provided and the two webs (1 1, 12) the annular region (10) with the part surrounding the film region of the bag wall on opposite sides of the film region combines.

6. A method of manufacturing a vacuum cleaner filter bag comprising the steps

Punching at least one passage opening (1, 2) in a nonwoven web, so that a nonwoven fabric area is formed in the nonwoven web and a nonwoven fabric element (3) remains, which between two opposite edge portions of the nonwoven fabric-free area and from the opposite Randabschnit- th each by a portion the nonwoven fabric-free area is spaced;

Bonding a plastic film to the nonwoven web so that the plastic film completely overlaps the nonwoven fabric region and the nonwoven fabric element (3) in plan view of the nonwoven web;

Forming a passage opening (9) in the plastic film and in the nonwoven fabric element (3); and

Welding a holding plate (13) with the plastic film and the nonwoven fabric element

(3).

7. The method of claim 6, wherein two through holes (1, 2) are punched, which are formed symmetrically to a machine axis extending symmetry axis (4), in particular wherein the through holes (1, 2) are punched so that the nonwoven fabric element (3) remains between the passage openings (1, 2).

8. The method according to claim 6 or 7, wherein the region of the nonwoven web in which the nonwoven fabric-free area and the nonwoven fabric element (3) are arranged, has a rectangular, in particular square, boundary.

9. The method according to any one of claims 6 to 8, wherein the nonwoven fabric element (3) before forming the passage opening (9) comprises an area in the form of a disc and at least one web, which forms the area in the form of a disc with the remaining nonwoven web combines.

10. The method according to claim 9, wherein the region in the form of a disk is formed annularly by forming the passage opening (9) and wherein the holding plate (13) is connected to the annular region (10) of the nonwoven fabric element (3), in particular special welded, is.

1 1. The method of claim 10, wherein the holding plate (13) has directional sensors, which in a passage opening of the holding plate (13) surrounding area of the holding plate (13) are arranged, the radial extent of the annular portion (10) of the Nonwoven fabric element (3) corresponds.

12. The method according to any one of claims 6 to 11, wherein the holding plate (13) and the plastic film are arranged so that after bonding the holding plate (13), the nonwoven fabric element (3) between the holding plate (13) and plastic film is located.

13. The method according to any one of claims 6 to 11, wherein the holding plate (13) and the plastic film are arranged so that after the connection of the holding plate (13), the plastic film between the holding plate (13) and nonwoven fabric element (3).

14. The method according to any one of claims 6 to 13, wherein prior to punching the at least one through hole (1, 2) of the region of the nonwoven web in which the at least one through hole (1, 2) is to be formed, at least partially thermally compressed.

15. The method according to any one of claims 6 to 14, wherein the plastic film with the nonwoven fabric element (3) and with a non-woven fabric-free area surrounding part of the nonwoven web is connected.