Bags and filter material for absorbing flammable dusts

Abstract

Vacuum cleaner bag (1) made of a filter material (2) that is generally air-permeable, with at least two air-permeable, electrically conductive layers (4) separated by a filter layer (3) lying between them, characterized in that several or the at least two of said electrically conductive layers (4) are electrically conductively connected to each other at several spatially spaced points far from the edge through said filter layer (3).

Description

[0001] The present invention relates to a vacuum cleaner filter with an air-permeable filter material for separating flammable dusts and to such a filter material according to the preamble of the respective main claim. STATE OF THE ART

[0002] Collecting flammable dusts with vacuum cleaners that separate these dusts into a filter bag creates a significant risk of fire or explosion.

[0003] This is especially true if the flammable dusts are separated so effectively by the vacuum cleaner's filter bag that, for example, the brush spark from the vacuum cleaner motor, which may not be brushless, or its waste heat is eliminated as an ignition source.

[0004] It is a known problem that there is a risk of spontaneous combustion, particularly when combustible dust remains in a filter bag for a longer period of time.

[0005] The problem is particularly acute with electrically non-conductive dust or dust particles that tend to become so electrostatically charged when vacuumed that potential equalization occurs within the dust bag through spark discharge.

[0006] The resulting bag fire, which is already a cause for concern in itself, is often the lesser problem, because in a stationary pile, combustion after spontaneous combustion is slow, as little air can flow to the smoldering nest.

[0007] However, if the smoldering nest in the filter bag occurs before the vacuum cleaner is switched off, or if it is stirred up in the filter bag after it has been switched on again, then it is surrounded by a dangerously strong air flow, causing the flames to spread very quickly and even cause a dust explosion.

[0008] To eliminate this problem when vacuuming flammable dusts with filter bag vacuum cleaners, one or more highly electrically conductive aluminum layers are vapor-deposited onto the filter bag material. The outer and inner aluminum layers are then electrically conductively connected to each other by sewing, gluing, or welding the edges to be sealed to form the bag. This ensures timely potential equalization within the filter bag and counteracts electrostatic charges strong enough to cause spontaneous combustion.

[0009] However, the metal or aluminum layers deposited so far are not yet satisfactory in many cases.

[0010] This is because they are only partially reliable. Especially when the dust load to be vacuumed contains a more than insignificant amount of abrasive particles, the inner aluminum layer can be worn down too much to fully fulfill its potential equalization function for the entire operating life of the filter bag, i.e., until the point at which the bag's maximum absorption capacity is exhausted.

[0011] A further disadvantage, which occurs particularly with vapor-deposited aluminum layers, is that their high electrical conductivity tends to discharge the inner layer of the filter bag, which has been deliberately charged for the purpose of electrostatically filtering out tiny particles in the sub-micrometer range, so that the filtration of the smallest particles gradually deteriorates. THE PROBLEM UNDERLYING THE INVENTION

[0012] Against this background, the object of the invention is to create a vacuum cleaner filter bag with an air-permeable filter material for improved separation of flammable dusts. THE INVENTIVE SOLUTION

[0013] The solution to the problem is a vacuum cleaner bag made of a completely air-permeable filter material, which is specially constructed and processed and in which each wall consists of several strips

[0014] The vacuum cleaner bag has walls made of at least two air-permeable, electrically conductive webs separated by at least one filter web 3 located between them, which is inherently non-conductive or insufficiently conductive. According to the invention, the vacuum cleaner bag is characterized in that several of said electrically conductive webs 4 are electrically conductively connected to one another at several spatially spaced-apart points remote from the edges through said filter web, often with a connection resistance of more than 500 Ω and preferably with a connection resistance of no more than 2,000 Ω.

[0015] The term “electrically conductive sheet or filter sheet” used above and below has a broad meaning. It includes not only sheets that are electrically conductive in the narrower sense with a surface resistance of up to 1,000 Ω, but also those sheets whose surface resistance is preferably up to a maximum of 10 5 Ω or up to 10 8 Ω.

[0016] However, the previously used term “electrically conductive sheet” or “filter sheet” also has a narrower meaning and then only includes sheets that are electrically conductive in the narrower sense, whose surface resistance is a maximum of 1,500 Ω, better only up to 1,000 Ω and ideally only up to 250 Ω.

[0017] The inventive contact points of its conductive strips, often provided in addition to the conventional bag edge contact, make the vacuum cleaner bag significantly more reliable. Even if the electrical conductivity of the coating or finish on the inside of the vacuum cleaner bag has significantly deteriorated in places, for example, due to the suction of abrasive dust or due to dust being drawn into the material, the vacuum cleaner bag essentially retains its antistatic function.

[0018] This is because the potential equalization between the conductive inner layer and the conductive outer layer, which is not at risk from abrasion or other impairments, no longer necessarily has to be achieved over a greater distance from the inner layer, whose conductivity may already be impaired—namely, up to the area of ​​the bag edge where the conductive inner and outer layers are electrically connected to one another according to previous teachings. Rather, the inner layer must always retain at least enough conductivity to achieve potential equalization along the significantly shorter distance extending from the current, internal location of the charge along the inner layer to the next electrical connection with the conductive outer layer, provided according to the invention far from the edge.

[0019] This also opens up the possibility of using an inner and an outer layer which (e.g. due to its lower thickness or its lower coating thickness) has an initially lower conductivity and therefore has a lower or even no tendency to discharge the filter web or the part of the filter web which has been provided with a static charge at the factory, with the help of which microparticles can be better filtered out.

[0020] In many cases, the contacting according to the invention also opens up the possibility of designing the electrically conductive tracks in such a way that they offer less air resistance to the air flow passing through the vacuum cleaner bag.

[0021] In other words, this also means that a material can optionally be used for the electrically conductive tracks which has less good conductive properties than the conductive layers made of metal or aluminum that are vapor-deposited on conventional vacuum cleaner bags, but which has better filter properties and a lower air passage resistance.

[0022] In many cases, the cost-intensive process of vapor deposition can be avoided by making the conductive track itself from conductive material instead of just being vapor-deposited.

[0023] The air permeability of the vacuum cleaner bag according to the invention is preferably at least 250 liters per (m 2 / s) better of at least 300 liters per (m 2 / s) and ideally at least 400 liters per (m 2 / s) measured according to DIN EN ISO 9237. FURTHER DETAILS OF THE INVENTIVE SOLUTION

[0024] The following can be said in general terms regarding the details of the construction of the vacuum cleaner bag according to the invention: The fact that the vacuum cleaner bag is made “of” the material mentioned in the main claim does not exclude additional layers or webs or areas, for example for the purpose of deodorization - even if the vacuum cleaner bag preferably consists only of the materials or webs mentioned in the claim. The at least two air-permeable, electrically conductive conductor layers are usually designed as one or on a material layer initially formed separately from the intermediate filter layer, usually made of woven or nonwoven fabric. They are then supported by separate layers (in the case of a mere coating) or formed (in the case of their complete composition of inherently conductive material) before sewing or welding. They do not necessarily contribute significantly to the filter effect. However, the internal conductive layer can optionally do so.

[0025] The filter layer provided between the conductive webs usually consists of one and usually even several material webs that are at least initially separate.

[0026] Typically, at least the outer conductive strip, or at least its conductive coating, is conductively connected to the connection flange. The connection flange is usually located on a grounded counterpart of the vacuum cleaner and is designed accordingly.

[0027] The spaced-apart, edge-removable points through which the said filter strips are electrically conductively connected to one another are generally provided in sufficient number and distributed (usually evenly) across the vacuum cleaner bag in such a way that only small areas remain between them, namely areas that are not large enough to give rise to potential differences that can drive an electrostatic spark discharge.

[0028] The risk of sparking is thus significantly reduced. In addition to the spatially spaced, edge-distant locations where the conductive tracks are electrically conductively connected to one another through the at least one filter track(s), a further conductive connection can also be created by connecting the edges of the conductive tracks.

[0029] The edge relevant for the term "far from the edge" is the entire area where the filter material is sewn, welded, and / or glued to create a closed bag of filter material from the flat sheet(s) of filter material. A location that is not itself an edge is an area that is more than 3 cm, or better still, more than 6 cm, away from the area that constitutes the edge in this sense.

[0030] A material is "dissipative" if it is not conductive in the low-voltage range, but is capable of generating electrostatic discharges in a voltage range. Thus, a "dissipative" material is not electrostatically chargeable when in contact with ground. Nevertheless, a conductive layer can also be used that is dissipative in the low-voltage range, so the term "dissipative" is to be understood in the broader sense of the invention as "dissipative or conductive." PREFERRED DESIGN OPTIONS

[0031] There are a number of ways to design the invention in such a way that its effectiveness or usefulness is further improved.

[0032] It is particularly preferred that the electrically conductive tracks consist of a material which, due to its doping, is electrically conductive in the installed state.

[0033] Doping allows the conductive layer to be made from a material that is normally non-conductive and has good filtering properties, which only becomes electrically conductive after doping. Optionally, the vapor deposition of an electrically conductive layer can be omitted. Depending on the design of the "doping," this also reduces the risk of a loss of electrical conductivity of the vacuum cleaner bag's inner conductive layer due to abrasion.

[0034] "Doping" in the sense of the invention refers to the addition of conductive fillers to the web-forming fiber material, such as the addition of graphite or metal particles as fillers to the respective plastic. This renders the plastic inherently conductive.

[0035] In a broader sense, this term can also refer to, for example, the subsequent powdering or “slurrying” of a fabric or nonwoven or nonwoven material with conductive particles in order to achieve its conductivity.

[0036] Preferably, the surface conductivity of the material "doped" in this way is lower than the surface conductivity of a textile or nonwoven web coated with a metal vapor. This prevents the filter material's filter web, which is deliberately charged for the purpose of electrostatically filtering out tiny particles in the submicrometer range, from discharging, which would lead to a gradual deterioration of the filtering effect of the filter material.

[0037] In a further preferred embodiment, the electrically conductive connections are arranged in the manner of a grid—preferably composed essentially of straight individual lines. The grid divides the vacuum cleaner bag into a plurality of individual cells. Within the boundaries of the individual cells, the conductive tracks or their conductor layers are not directly connected to one another in a conductive manner.

[0038] In particular, if the conductive tracks or their conductor layers are not conductive in the low-voltage range, this counteracts an unwanted discharge of the electrostatically charged filter track located between the conductive tracks.

[0039] Ideally, the individual lines connecting the conductive paths are arranged in such a way that the overall result is a checkered, or possibly a penta-, hexa- or octagonal grid, although the latter are increasingly less preferred.

[0040] The surface area of ​​each cell is so large that even if the conductivity of the individual cell has been impaired due to abrasive wear, no electrostatic potential can develop across a single cell large enough to generate an electrostatic discharge. Ideally, the majority, and preferably the entirety of the cells, have a surface area of ​​at least 750 mm, apart from any partially formed cells in the edge area of ​​the filter material blanks. 2 , better at least 1500 mm 2 , but preferably not more than 4500 mm 2 and better not more than 3000 mm 2The “surface” of a cell refers to the surface of the inner conductive path facing the interior of the bag, which is surrounded by several connections.

[0041] The term “multiplicity” of individual cells includes at least 200 cells / m 2 , better 300 cells / m 2 and ideally at least 400 cells / m 2 cells Ideally, the electrically conductive connections—at least those far from the edges—are areas within which the conductive conductor layers are welded and / or bonded together, locally displacing the filter layer between them. The electrically conductive connections are preferably calendered and ideally ultrasonically calendered.

[0042] The production of the distal edge connections of the conductive strips by welding and / or gluing is efficient and cost-effective. In particular, heat and pressure welding using a roller or (ultrasonic) friction welding can be used to securely and efficiently bond the conductive strips or their conductive layers. This type of connection can be implemented efficiently, especially in mass production. It therefore represents a suitable manufacturing process for the cost-intensive field of vacuum cleaner bag production.

[0043] A “calendered joint” is a joint which has been produced under the pressure and heat generated (possibly by or in addition to ultrasound) by a calender roll and which permanently exhibits the specific physical characteristics imposed on it by the calender roll.

[0044] Preferably, the electrically conductive conductor layers or the corresponding tracks have a more than insignificantly higher melting point than the filter layer or track or tracks located between them.

[0045] This ensures that the electrically conductive tracks, or in the case of a coating, their conductive layers, are welded together, displacing the filter layer or the intermediate non-conductive track material. The melting point of the conductive tracks or their conductive layers is ideally at least 20°C, and preferably at least 30°C, higher than the melting point of the filter layer or its track(s).

[0046] In a further preferred embodiment, the electrically conductive connections remote from the edge are also or only realized by riveting and / or also or only by sewing.

[0047] Riveting or sewing is a particularly cost-effective and at the same time safe way of making a connection when producing smaller quantities or when joining non-weldable materials.

[0048] If a riveting process is used, the use of conductive plastic rivets or, preferably, blind rivets is particularly advantageous. The use of blind rivets eliminates the need for access to the interior of the bag, making this a suitable method of choice, especially for very large and / or highly stressed vacuum cleaner bags for industrial vacuum cleaners.

[0049] Sewing, on the other hand, may be the method of choice where maximum filtration quality is paramount. Unlike welding, the filter material remains intact during sewing. An electrically conductive thread is preferably used for the seam to ensure a conductive connection between the conductive strips or their conductive layers.

[0050] Ideally, the electrically conductive layer inside the bag is a voluminous material.

[0051] This counteracts the risk that the internal conductive track or its conductive layer loses its electrical conductivity as a result of abrasion.

[0052] A material is considered “voluminous” if not only a conductive layer is applied to a non-conductive carrier material, but the material is conductive over its entire thickness or at least part of its thickness.

[0053] The vacuum cleaner bag preferably has a conductive flange for an airtight connection to the vacuum cleaner. The flange is conductive and directly connected to at least one of the conductive strips or their conductive layer. The connection is preferably made by welding, ideally by ultrasonic welding or by gluing. The flange can have a closure that can be used to close the flange opening after use. This prevents dust from escaping from the vacuum cleaner bag.

[0054] The flange also has at least one contact for connection to the protective conductor of the vacuum cleaner.

[0055] This ensures that the conductive tracks do not remain electrostatically charged and that the currents flowing as a result of the potential equalization are dissipated. In particular, by creating a connection between the flange and at least one conductive track or its conductive layer using an electrically conductive adhesive, production can be made very cost-effective. It is also conceivable to manufacture a section of the flange from a weldable plastic, which is welded to at least one conductive track or its conductive layer.

[0056] In a further preferred embodiment, the conductive flange is also or only connected to at least one electrically conductive track or its conductor layer via at least one electrically conductive connection remote from the edge.

[0057] Ideally, the vacuum cleaner bag – while still fresh – is filled with loose wool made of electrically conductive material.

[0058] The wool is therefore inserted into the vacuum cleaner bag before it is put into operation. This prevents electrostatic discharges not only on the inner conductive layer of the vacuum cleaner bag, but also in the free space of the bag. The risk of so-called sliding brush formation and the subsequent discharge is thus effectively counteracted.

[0059] Preferably, the filter material of the vacuum cleaner bag, viewed from the inside of the bag to the outside, preferably consists of only one of the aforementioned electrically conductive webs, a filter web made of spunbond material, a filter web made of meltblown material, a filter web made of spunbond material and another of the aforementioned webs made of electrically conductive material.

[0060] For the purposes of this invention, meltblown material is understood to be a highly efficient material capable of filtering out fine dust particles with a particle size of 5 µm down to 0.3 µm. It is characterized by numerous, extremely thin fibers. As in the manufacturing process for spunbonded nonwovens, plastic, preferably polypropylene, is heated, liquefied, and forced through thin nozzles. Additionally, the fibers are stretched in a turbulent hot air flow to several times their original length, creating threads with a diameter in the range of 1 to 3 µm. The fibers are then deposited on a belt continuously moving beneath the spinnerets. Additionally, the meltblown material can be electrostatically charged.

[0061] Spunbonded nonwovens, also known as spunbonded materials, also use a melted plastic process, but without stretching the fibers. Additionally, the spunbonded material is calendered, meaning small sections of the fibers are fused together using a point calender roll. This gives the spunbonded material significantly greater strength than meltblown materials.

[0062] The difference between meltblown and spunbond material is that the spunbond material has fewer fine fibers and therefore has significantly poorer separation or filtration performance.

[0063] The meltblown filter sheet located between the two spunbond filter sheets ensures that even very fine dust particles are retained in the vacuum cleaner bag. The two spunbond filter sheets, on the other hand, filter the slightly larger dust particles from the airflow and simultaneously protect the meltblown filter sheet from abrasion. The spunbond filter sheets also serve as an insulator between the conductive sheets and their conductor layers. and the filter web made of meltblown material, so that the meltblown material always remains electrostatically charged and retains even the finest dust particles.

[0064] In a further preferred embodiment, at least one of the aforementioned electrically dissipating paths itself develops a more than insignificant filtering effect.

[0065] This further increases the overall filtering effect of the filter material that makes up the vacuum cleaner bag.

[0066] In general, the following materials can be considered as conductive, air-permeable materials: - Nonwoven or nonwoven fabric dusted with graphite powder - Nonwoven or nonwoven fabric made of conductive thermo-, duro-, plastic or elastomer - Electrically conductive nonwoven or nonwoven fabric or electrically conductive foam - Carbon fiber nonwoven or nonwoven fabric or / and carbon fiber-infused staple fiber nonwoven fabric - Nonwoven or nonwoven fabric made with graphite additive - Staple fiber nonwoven fabric interwoven with metal threads - Electrically conductive vapor-deposited nonwoven or nonwoven fabric - Fleece sewn with conductive threads - Woven material with conductive threads - Metal mesh, metal braids, metal mesh or metal nets - Steel wool, aluminum wool, copper wool, brass wool LIST OF FIGURES Fig. 1 shows a vacuum cleaner bag according to the invention in plan view. Fig. 2 shows the flange of the Fig. 1 shown vacuum cleaner bag in the detailed view. Fig. 3 shows the structure of the filter material of the vacuum cleaner bag from individual webs. EXAMPLE OF IMPLEMENTATION

[0067] The functioning of the invention is exemplified by the Fig. 1-3. The peripheral connections 5 of the conductive path 4 and the cells 6 are provided with reference symbols for illustrative purposes only.

[0068] The vacuum cleaner bag 1 comprises the filter material 2 and a flange 8 connected to the filter material 2.

[0069] The flange 8 is used, as usual, to connect the vacuum cleaner bag 1 to the vacuum cleaner housing in such a way that the air-dust particle mixture sucked up by the vacuum cleaner flows through the opening 13 of the flange and the filter material 2 into the interior of the vacuum cleaner bag 1. While the air sucked in by the vacuum cleaner leaves the vacuum cleaner bag 1 through the filter material 2, the sucked-up dust particles are completely or almost completely retained by the filter material 2.

[0070] As shown by Fig. 3, the filter material 2 consists of several layers or webs 3 and 4. Viewed from the inside of the vacuum cleaner bag 1 to the outside, the filter material 2 consists of a first electrically conductive web 4, which is coated in a conductive manner facing the inside of the bag or consists entirely of per se conductive material.

[0071] This is followed by three filter strips 3. This is followed by a further conductive strip 4 in the sense just mentioned. If this conductive strip also derives its conductivity solely from a coating, this is preferably facing the outside of the bag. For better illustration, the Fig. The arrows shown in Figure 3 indicate the direction from the inside of the vacuum cleaner bag 1 to the outside. It is particularly preferred (also completely independent of this embodiment) that the conductive tracks have a surface resistance of 50 Ω + / - 20 Ω.

[0072] Of the filter webs 3, the two filter webs 3 adjacent to the conductive webs 4 are preferably each made of spunbond material. The filter web 3 made of spunbond material facing the inside of the bag is preferably approximately 20% thinner than the filter web 3 made of spunbond material facing the outside of the bag.

[0073] The filter web 3 provided between these two filter webs 3 consisting of spunbond material consists of meltblown material.

[0074] All three filter sheets 3 are made of a plastic material and are therefore electrostatically chargeable or poor conductors for electrostatic charges.

[0075] In fact, the meltblown material in particular is usually electrostatically charged at the factory.

[0076] This makes it possible for the finest dust particles, usually even those smaller than 0.3 / 1000 mm, which flow through the air-permeable web 4 facing the inside of the bag, to be held by the filter web 3 made of meltblown material as a result of the electrostatic attractive forces.

[0077] By surrounding the fine-pored filter sheet 3 made of meltblown material by the two filter sheets 3 made of spunbond material, this helps to prevent the meltblown filter sheet 3 from losing its electrostatic charge too quickly. This is because the two outer filter sheets 3 provide a certain degree of insulation for the middle filter sheet 3. However, the prevention of unwanted discharge of the meltblown sheet can only be perfected with the invention.

[0078] Such an arrangement and choice of material for the individual layers of the filter material is generally conceivable for any design of a vacuum cleaner bag according to the invention.

[0079] The two electrically conductive tracks 4 are also electrically conductively connected or plated through each other along the connections 5 formed here by weld seams. Ideally, ultrasonic welding is used, as this is the best way to displace the insulating track material located between the conductive tracks to be connected or their conductor layers.

[0080] Based on Fig. 1 shows that the weld seams 5 are arranged such that four weld seams 5 each enclose a square surface section 6 of the surface of the outer conductive track 4. The square surface sections 6 thus formed are also referred to as cells 6.

[0081] The weld seams bordering them can be continuous in the direction parallel to the surface. Alternatively, they can also consist of individual "line segments" alternating with (usually shorter) unwelded sections between them. This facilitates precisely defined ultrasonic welding. This technical approach applies generally, even beyond the example shown.

[0082] Although this cannot be determined by Fig. 1, the weld seams 5 form a multitude of square cells 6, especially on the electrically conductive strip 4 facing the interior of the bag—with edges that are each conductive and directly connected to the conductive outer strip. As already described in the general section, each of the cells has such a small surface area that no potential difference can build up across them that would be sufficient to cause an electrostatic spark discharge.

[0083] The outer, and in rare cases also the inner, conductive strip 4 is directly connected to the flange 8 in an electrically conductive manner. The flange 8, in turn, forms a contact surface through which it is connected, i.e., "grounded," to the protective conductor of the vacuum cleaner during bag use. This means that the filter material 2 is not electrostatically charged in a harmful manner when the inner conductive strip 4 of the bag comes into contact with the electrostatically charged dust particles, but essentially dissipates their charge.

[0084] Finally, it should be noted that the filter material 2 of the vacuum cleaner bag 1 consists of two, preferably rectangular, blanks. Each of these blanks consists of two electrically conductive strips 4 and usually three filter strips 3 in between. The two blanks are preferably welded together at their edges 7. They thus form a closed bag. The connections at the edges 7 are also usually electrically conductive connections of the strips 4. LIST OF REFERENCE SYMBOLS 1 vacuum cleaner bag 2 Filter material of the vacuum cleaner bag 3 filter track 4 Conductive track 5 Edge-distant connections of the conductive layers or conductive paths / weld seams 6 cell 7 Edge / edge connection 8 Flange can be omitted 10 Opening of the flange QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] DIN EN ISO 9237

[0023]

Claims

[1] Vacuum cleaner bag (1) made of a completely air-permeable filter material (2) with at least two air-permeable, electrically conductive webs (4) separated by a filter web (3) between them, characterized by that several or at least two of said electrically conductive tracks (4) are electrically conductively connected to one another at several spatially spaced-apart locations remote from the edge through said filter track (3). [2] Vacuum cleaner bag (1) according to claim 1, characterized by that the electrically conductive tracks (4) consist of a material which is conductive due to its electrical coating. [3] Vacuum cleaner bag (1) according to claim 1, characterized bythat the electrically conductive tracks (4) consist of a plastic material doped with electrically conductive particles and / or of conductive fibers, in particular those made of metal, better of carbon and preferably of graphite. [4] Vacuum cleaner bag (1) according to one of the preceding claims, characterized by that the electrically conductive connections (5) are arranged in the manner of a grid which divides the vacuum cleaner bag (1) into a plurality of individual cells (6), within the boundaries of which the conductive tracks or their conductor layers (4) are not directly connected to one another in a conductive manner. [5] Vacuum cleaner bag (1) according to one of the preceding claims, characterized bythat in any case the electrically conductive connections (5) remote from the edge are regions within which the conductive tracks or their conductor layers (4) are welded and / or glued to one another with local displacement of the filter track (3) located between them and, if appropriate, further track components, wherein the electrically conductive connections (5) are preferably calendered and ideally ultrasonically calendered connections (5). [6] Vacuum cleaner bag (1) according to one of the preceding claims, characterized by that the electrically conductive tracks (4) have a higher melting point than the at least one filter track (3) lying between them. [7] Vacuum cleaner bag (1) according to one of the preceding claims, characterized by that in any case the electrically conductive connections (5) remote from the edge are also or only realized by riveting and / or also or only by sewing. [8] Vacuum cleaner bag (1) according to one of the preceding claims, characterized by that the electrically conductive web or its conductive layer (4) located inside the bag is a voluminous material. [9] Vacuum cleaner bag (1) according to one of the preceding claims, characterized by that the vacuum cleaner bag (1) has a conductive flange (8) for airtight connection to the vacuum cleaner, which is conductively and directly connected to at least one of the conductive webs (4), preferably by welding, ideally by ultrasonic welding, or by gluing, and has at least one contact for connection to the protective conductor of the vacuum cleaner. [10] Vacuum cleaner bag (1) according to claim 9, characterized by that the conductive flange (8) is connected to at least one electrically conductive track or its conductor layer (4) via at least one electrically conductive connection (5) remote from the edge. [11] Vacuum cleaner bag (1) according to one of the preceding claims, characterized by that the vacuum cleaner bag (1) - while still fresh - is filled with loose wool made of electrically conductive material. [12] Vacuum cleaner bag (1) according to one of the preceding claims, characterized by that its filter material (2), from the inside of the bag to the outside, preferably consists of only one of the aforementioned electrically conductive webs (4), a filter web (3) made of spunbond material, a filter web (3) made of meltblown material, a filter web (3) made of spunbond material and a further web (4) made of electrically conductive material. [13] Vacuum cleaner bag (1) according to one of the preceding claims, characterized by that at least one of the aforementioned electrically conductive paths (4) itself develops a more than insignificant filtering effect. [14] Filter material (2) for producing a vacuum cleaner bag (1) according to claims 1 to 12.

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