EP1677660B1 - Filter bag and method for the production thereof - Google Patents

Abstract

Described is a filter bag for a vacuum cleaner which may include a tubular bag with a closed free end area and an opposed, at least partially closed area as well as with a retaining plate. The bag is made from a bag material having at least one non-woven layer, and the at least partially closed area is folded forming a bottomPlies of the bag material which lie the one above the other are formed in areas, and is at least partially closed by a weld seam extending centrally in the bottom, the plies of the bag material which lie the one above the other being at least partially connected to one another.

Description

The invention relates to a filter bag for a vacuum cleaner with a tubular bag and a closed free end portion and an opposite, at least partially closed area and a holding plate, wherein the partially closed area is folded forming a bottom.

Filter bags for vacuum cleaners, which have a tubular bag and in addition to a closed free end region a folded bottom, a so-called. Block bottom, are known in the art. Usually, such dust bag from a paper material, which can be processed on conventional tubular bag systems made. In such filter bags, a corresponding holding plate is usually attached to the bottom of the block, which has an opening through which the cleaning air is performed. The task of the block bottom is to stabilize the filter bag and to form a three-dimensional bag. The block bottom also facilitates the installation of the bag in the vacuum cleaner.

Recently, however, with respect to the vacuum cleaner bag materials, new developments have become known. That's how it describes WO 01/03802 A1 a special fleece material made of several independent layers of filter material. These independent layers are combined into a filter material with special properties. In practice it has been found that vacuum cleaner bags made with such a nonwoven material are clearly superior in terms of the performance of the vacuum cleaner over the previously known.

However, due to the slippery bag material, the formation of a block bottom is difficult or possible with great effort.

The DE 100 64 608 A1 describes a solution as a holding plate can be attached to such a bag. Thereafter, a tubular arrangement of the vacuum cleaner bag is first made to form a longitudinal edge fold. This tubular arrangement is then separated so that a second end region is formed. The opposite free ends of such a hose-like arrangement are closed and a holding plate, after forming a corresponding opening, associated with an end region. According to the teaching of DE 100 64 608 A1 Subsequently, a special fold is made in the region of the vacuum cleaner bag between the area provided with the holding plate and the free end. Due to the special design of transverse folds a stabilization of the limp bag should be achieved.

That in the DE 100 64 608 A1 However, the method described is very expensive.

In the EP 1 059 056 A1 Another solution is described how a holding plate for a bag can be introduced into the filter material. After the solution of EP 1059 056 A1 two independent layers of the filter material are guided on each other and welded in the edge regions. Subsequently, the welded-together material is separated and the two open transverse sides welded. To insert a holding plate, a corresponding hole is punched into the superimposed layers and a reinforcement placed around the two layers.

The disadvantage of this solution is that here no bottom is formed which stabilizes the bag in and of itself, but that inevitably a reinforcement, ie a holding plate must be attached. The holding plate, which is applied according to the European application mentioned above, must also always be foldable, since it is placed around the two superimposed layers. As a result, this bag is subject to great restrictions with regard to the application in the vacuum cleaner sector, since the holding plate must regularly fulfill a number of functions. In fact, in the case of holding plates, it has hitherto been customary to additionally attach sliders or flaps with which the opening for the hygienic removal of the vacuum cleaner bag can be closed. This is not possible with a foldable version of the retaining plate. It is also not possible, the retaining plate z. B. to install on the long sides of the bag, since no bag stabilizing the soil is present.

Proceeding from this, it is the object of the present invention to provide a filter bag made of a nonwoven material, which has at least one end portion which is similar in construction to that of a block bottom, made of paper material, comparable. Another object of the invention is to provide a method for producing such a filter bag.

The object is achieved with respect to the bag by the characterizing features of claim 1 and with respect to the method by the features of claim 19. The dependent claims show advantageous developments.

According to the invention it is thus proposed that the vacuum cleaner bag, which consists of a nonwoven composite material, has an at least partially closed end opposite the free closed end, wherein this is folded forming a bottom. The folding according to the present invention is designed so that at least partially superimposed layers of the bag material are present in the ground and these are at least partially interconnected. By this embodiment, a block bottom-like stabilization of the vacuum cleaner bag is achieved.

The decisive advantage of the solution according to the invention can be seen in the fact that stabilization is achieved by the central weld and the at least partial joining of the layers folded over one another of the floor is sufficient, even to provide a pliable material, a vacuum cleaner bag that can be provided at any point with a holding plate and thereby can be easily installed in a vacuum cleaner. It should also be emphasized in the solution according to the invention that the holding plate can be freely selected in relation to their design. In the solution according to the invention, it is thus possible to attach holding plates, which not only have an opening, but which are additionally provided with sliders or flaps to close the opening. According to the present invention, it is also possible not to attach the retaining plate directly to the ground, but it can also be arranged on the longitudinal surfaces of the vacuum cleaner bag.

When vacuum cleaner bag according to the invention, it is preferred if the central weld is guided over the entire width of the soil. As a result, an increased stability of the bottom formed by the folding is achieved. The joining of the superimposed layers, which have been formed by the folding, is preferably carried out by welding or gluing. This gluing or welding can be linear. As a result, a directed reinforcement of the soil can be realized.

In the vacuum cleaner bag according to the invention, it is also advantageous if over the long sides, ie over those surfaces of the vacuum cleaner bag between the closed free end and the at least partially closed end with the inventively designed bottom are introduced into the thus spanned side surfaces Vorbrüche, so that a convolution becomes possible. The breakouts can be designed so that they, for example, from the respective corners of the bottom, if this is square, for example, quadrangular shaped, go out and are led to the opposite free end. In addition, it is advantageous if in addition, starting from the central weld seam, a further advance is introduced into the bag material. This facilitates the introduction of gussets and increases the surface area of the vacuum cleaner bag. At the same time introduced into the longitudinal sides of the vacuum cleaner bag can serve for further stabilization of the bag material. Under a Vorbruch in the context of the invention material densifications are understood, which are preferably formed linear. The pre-fractures can be introduced by means of a suitable molding tool and / or by welding.

Advantageously, the filter bag according to the invention also has a pre-break which is guided parallel to the central weld seam. This serves to fold over the bottom in the direction of the longitudinal side of the filter bag. It is therefore sufficient if such a pre-break exists. The distance of the pre-breakage is selected so that, starting from the central weld, it corresponds to the width of the floor.

It is preferred in the case of the bag according to the invention if the bottom has an angular, particularly preferably a rectangular shape. In this case, the projections are made starting from the respective short sides of the rectangle to the free closed end. Another pre-break is led from the central weld to the free end. Such an embodiment has proven to be particularly preferred.

With respect to the holding plate, according to the present invention, it is possible to connect them either to the block bottom, as known from paper filter bags, or to mount the holding plate on the free side surfaces of the vacuum cleaner bag. Preferred here is the embodiment in which the holding plate on the bottom of the bag, this at least partially overlapping, is attached. Characterized in that according to the present invention, the bag is stabilized by the formation of the soil, and the holding plate can be mounted inside lying in the bag. This can e.g. be realized by the holding plate is simultaneously introduced and connected with the provided for bottoming punch.

A further advantage is that by the stabilization of the soil as such one-piece holding plates can be used. These can also be provided with a closure mechanism.

The holding plate is constructed as known per se from the prior art and has at least one passage opening, which serves to supply the air to be cleaned. The retaining plate may further comprise an element, e.g. B. have a slider or a flap to close the opening. The holding plate can be connected to the bottom of the bag with all common techniques of the prior art. For this purpose, e.g. sticking or welding in question.

However, according to the present invention, it is also possible that the holding plate is arranged on the side surfaces of the vacuum cleaner bag. It is preferred in this case if the holding plate is mounted in the vicinity of the soil, since thereby through the ground freely clamped interior can be exploited in the bag for the introduction of a filler neck and an advantageous air flow.

The holding plates can, as in and of themselves known from the prior art, consist of plastic or cardboard.

In the filter bag according to the present invention, the bag material is formed from a multilayer nonwoven composite material, as for example in the WO 01/03802 A1 is described. The disclosure of this document is therefore expressly incorporated by reference. However, the invention also includes all other nonwoven materials heretofore known in the art for filter bags.

The invention further relates to a method for producing a filter bag as described above. According to the present invention, in a first method step, a tubular bag is produced with the at least partially closed end region.

The production of this tubular bag with the at least partially closed end region can be carried out cyclically. In this case, the tubular bag is made by the formation of the tubular material by bonding z. B. the two edges of a layer of the bag material is carried out and in which case a closure of the resulting open area is performed.

The joining of the edges of the layers and the closing of the open end can take place cyclically. As well a continuous bonding of the edges of the layers is possible.

For process-economic reasons, it is favorable if the joining of the open end and the closing of the free end of the previously produced filter bag takes place simultaneously. In this case, the separation of the bag can also be done.

The bonding both in the formation of the tube as well as the connection of the open end can be done by ultrasonic welding. Also a thermal welding is possible.

Preferably, the welding is carried out so that the weld is guided over the two superimposed webs.

In the method according to the invention, it is further provided that the formation of the Vorbrüche during the process step a) is performed. According to the present invention, the pre-fractures are thus introduced into the filter bag by means of suitable molding tools or by additional welding seams.

However, the invention also encompasses those embodiments in which the introduction of the preliminary fractions is carried out in a method step which is present before or after method step a). For process-economic reasons, however, the variant described above is preferred in which the pre-fractures are already introduced during process step a).

The formation of the soil is carried out according to the present Invention in that a stamp is introduced from the open side into the bag produced according to method step a). As a result, the closed end automatically folds up in the area of the floor. To stabilize the soil formed thereby, it is then essential that the superimposed layers formed by the folding be at least partially connected. This is preferably carried out so that the superimposed layers are glued or welded. This achieves additional stabilization of the soil. In the methods for joining the superimposed layers, all known from the prior art methods can be applied. In this case, a gluing or welding should be mentioned. Also, a clamping of the individual layers is feasible. If the bonding of the layers is carried out by means of welding or gluing, it is furthermore preferred if this takes place in a linear manner.

Another advantage of the method according to the invention can be seen in the fact that the stamp intended for bottoming is used as an anvil. The anvil can also serve as a sound reflector for a sonotrode in ultrasonic welding. The anvil can also serve as a support element for the formation of Vorbrüchen. Furthermore, it can also be used as a support element when punching the filling opening. A reverse procedure is possible. So also the punch can be used as a sonotrode.

The inventive method thus a folding of the soil is achieved, which leads to a stabilization of the limp material in the soil area leads. This now opens up the possibility that the retaining plate can not only be arranged directly in the region of the ground directly on the ground, but that this retaining plate can also be mounted on the long sides of the bag. The method according to the invention also opens up the possibility of arranging the retaining plate lying on the floor inside. For this purpose, the holding plate is introduced in one operation with the stamp and welded / glued to the bag material. According to the present method, it is still necessary that at the locations where the holding plate is attached, still a corresponding opening is introduced into the bag. If the holding plate is placed directly on the ground, a corresponding opening is introduced into the bottom area. The introduction of this opening can be done either in the not yet formed to the tube web or during the process step a). The introduction of the filling opening can also be carried out in method step b) or even in the not yet formed to the tube web so before step a).

Figur 1

zeigt einen erfindungsgemäßen Filter- beutel im halbfertigen Zustand in ein- seitig offener Form.

Figur 2

zeigt einen erfindungsgemäßen Filter- beutel mit einem rechteckigen Boden.

Figur 3

zeigt eine weitere Ausführungsform mit einer speziellen Faltung des Bodens.

Figuren 4a bis 4c

zeigt den Ablauf des Herstellungsver- fahrens.

The invention will be described below with reference to FIGS. 1 to 4 described in more detail.

FIG. 1

shows a filter bag according to the invention in the semi-finished state in one-sided open shape.

FIG. 2

shows a filter bag according to the invention with a rectangular bottom.

FIG. 3

shows a further embodiment with a special folding of the soil.

FIGS. 4a to 4c

shows the process of the manufacturing process.

FIG. 1 shows the filter bag 1 according to the invention schematically in the state as it results after formation of the tubular bag and closing the free end portion (step a)). The filter bag 1 consists of a composite nonwoven material, as in the WO 01/03802 A1 is described. In the embodiment according to FIG. 1 For example, the filter bag has pre-breaks 3, 4, and 5 that result in the wrinkling depicted. By pre-breaking is meant a material compression. This can, for. B. by pressure or pressure and temperature. Through the pre-breaks 3, 4 and 5 creates a folded, tubular filter bag, which is closed at its closed end 2 by a weld 6.

The central weld 6 is in the embodiment according to FIG. 1 introduced by thermal welding. The welding has been carried out so that the two superimposed layers of the filter material have been joined together by the weld. The filter bag after Fig. 1 additionally has a pre-break 7. This serves to fold over the soil.

FIG. 2 shows the filter bag 1 in a preferred embodiment. The filter bag 1 after the FIG. 2 has a rectangular bottom 9 with two short transverse sides 10 and two longitudinal sides 11. In the inventive filter bag 1 according to the FIG. 2 are analogous to FIG. 1 the breakouts with 3, 4 and 5 are called. By these Vorbrüche 3, 4 and 5 is the Contour of the filter bag 1 determined. Essential to the filter bag according to the invention is now the folding, ie the design of the bottom 9. The bottom 9 now has on its short transverse sides 10 on a folding. The fold is created by superimposing the filter material, as shown in FIG. 1 has been shown. The geometry of the folding is determined by the pre-breaks 3, 4 and 5. In the edge region 10, a triangular gusset is thus covered under the clamped bottom 9. The formed triangular gusset 8 is in the Fig. 2 represented by dashed lines. The outer edge side leg 12 of the triangle is connected according to the invention with the transverse side 10 of the bottom 9. In the example after the FIG. 2 the transverse side 10 of the bottom 9 is glued to the leg 12 with each other. However, in accordance with the present invention, any other embodiment is contemplated employing other interconnection technologies known in the art. Such a connection can also take place, for example, by means of ultrasonic welding or by clamping. In the embodiment of the FIG. 2 Furthermore, a pre-break 7 is still available. This serves to fold over the bottom in the direction of the longitudinal side of the bag 1. The distance of the pre-break 7 of the central weld 6 therefore corresponds to the width of the bottom 9, so that a complete folding of the bottom 9 is possible.

The filter bag 1 is also closed at its free end 13 by a further weld 15. In the case of the filter bag according to the invention, it should be pointed out in particular that stabilization of the bottom 9 is produced by the folding and the connection of the layers as well as the central weld seam 6 as described above. The big advantage of the invention Filter bag can be seen in the fact that the bottom 9 has enough stability without an additional support plate. In the embodiment of the FIG. 2 the floor still has a through opening 16. This passage opening 16 can then be provided with a holding plate (not shown), so that then the filter bag can be hung in a corresponding holder in the vacuum cleaner.

FIG. 3 now shows another way how the folding of the bottom 9 can be made. In the embodiment according to FIG. 3 in turn, a central weld 6 is present. As FIG. 3 shows, in this embodiment, a gusset 19 and 20 is formed, which, as shown in the figure, can be folded in two different directions. Thus, it is possible to fold the gusset down on the side surfaces of the filter bag 1 and stick there (arrow a) or the gusset can be folded back on the remaining part of the bottom 9 and also glued there. Again, stabilization of the bottom 9 is achieved by this embodiment. Also the filter bag after the FIG. 3 has again breaks 3, 4, with which the contour of the filter bag is determined.

Fig. 4 shows now using the FIGS. 4a to 4c the sequence of the manufacturing method according to the invention.

Fig. 4a schematically shows how a layer of the filter material folded and connected at its edges 22 and 23. The contour of the corresponding filter bag is defined by an unillustrated molding tool. During the manufacturing process The filter bag is thereby introduced in the first process step, ie in the formation of the tube, the corresponding projections 3, 4 and 5 in the filter bag material. Preferably, the bonding of the filter material at the edges 22 and 23 takes place cyclically, ie at the in Fig. 4a the position indicated by the term "stop" is used for the welding. Following this cycle, the tube thus formed is then continued up to the point marked "Stop 2". At this point, now the closing of the bag. This is preferably carried out by ultrasonic welding. As Fig. 4a shows, the inventive method preferably operates so that the closing of the tube and formation of the central weld 6, the filter bag previously prepared in the operation at its opposite free end 13 is closed. According to the present method, therefore, closing and separating the filter bag takes place in one operation. This can be done with a split welding tool.

Fig. 4b shows the process step of the method according to the invention in which the folding of the soil is performed. The folding of the bottom is subsequently carried out after closing the filter bag with the weld 6 at its end 2. This is in Fig. 4a shown. For bottom formation, a punch 24 is then inserted from the still open side into the filter bag and guided against the closed end 2. By introducing the punch 24 in the direction of the closed end 2, the folding of the base 9 according to the invention is now achieved by specifying the contours 3, 4 and 5. This fold will be while the punch is in its lower position is ( FIG. 4b ) stabilized by connecting the now superimposed layers.

To complete the filter bag is now by separating this bag from lying in front of the filter bag as described above, the finished filter bag as in Fig. 4c represented, manufactured.

According to the method of the invention, it is further provided to introduce corresponding openings in the filter bag. The opening is preferably introduced into the filter bag material during method step a) or b). Finally, it is still necessary to complete the filter bag to attach the retaining plate. The attachment of the holding plate can be z. B. simultaneously with the bottoming or the holding plate is attached later.

Claims (28)

1. Filter bag (1) for a vacuum cleaner, comprising a tubular bag (1) made from a bag material having a non-woven composite material, said bag having a closed free end area (13) and an opposed, at least partially closed area (2), as well as a retaining plate, the edges of the tubular bag being at least partially interconnected by a weld seam (6) to form the partially closed area (2) and a bottom being formed by the formation at least in areas of plies of the bag material which lie the one above the other and which are at least partially interconnected.
2. Filter bag according to claim 1, characterised in that the weld seam (6) in the bottom (9) extends over the entire width of the bottom.
3. Filter bag according to claim 1 or 2, characterised in that the plies which lie the one above the other and are formed in areas of the bottom (9) by folding are connected by gluing and/or welding.
4. Filter bag according to claim 3, characterised in that the gluing and/or welding are/is linear.
5. Filter bag according to one of claims 1 to 4, characterised in that the bottom (9) is in a square shape.
6. Filter bag according to one of claims 1 to 5, characterised in that the bottom (9) has a rectangular shape.
7. Filter bag according to one of claims 1 to 6, characterised in that, starting from the bottom (9) to the closed free end (13), at least one pre-crease (3, 4, 5) is introduced in the bag material.
8. Filter bag according to one of claims 5 to 7, characterised in that, starting from the respective corners of the bottom (9) to the closed free end (13) in the bag material, pre-creases (3, 4) are introduced in the bag material.
9. Filter bag according to one of claims 1 to 8, characterised in that, starting from the weld seam (6) in the bottom (9), at least one pre-crease (5) is introduced into the bag material up to the closed free end (13).
10. Filter bag according to one of claims 1 to 9, characterised in that a pre-crease (7) is introduced into the bag material parallel to the weld seam (6) in the bottom (9).
11. Filter bag according to claim 10, characterised in that the pre-crease (7) is introduced into the bag material at a spacing from the weld seam (6) which corresponds roughly to the width of the bottom (9).
12. Filter bag according to one of claims 1 to 11, characterised in that the retaining plate is arranged on the bottom (9), at least partially covering same, and has at least one through hole (16).
13. Filter bag according to claim 12, characterised in that the retaining plate covers the entire bottom (9).
14. Filter bag according to one of claims 1 to 13, characterised in that on the area spread between the free end (13) and the partially closed end (2) of the bag is arranged a retaining plate which has at least one through hole.
15. Filter bag according to claim 14, characterised in that the retaining plate is arranged in the region of the bottom (9).
16. Filter bag according to one of claims 1 to 15, characterised in that the retaining plate is connected to the filter bag by means of gluing and/or welding.
17. Filter bag according to one of claims 1 to 16, characterised in that the retaining plate is formed from plastics material.
18. Filter bag according to one of claims 1 to 16, characterised in that the retaining plate is formed from cardboard.
19. Method for manufacturing a filter bag according to one of claims 1 to 18, characterised by the following method steps:

    a) producing a tubular bag and closing it on one side to form the at least partially closed area,

    b) introducing a die from the open side of the bag in the direction of the closed end of the bag so that a bottom is produced by folding,

    c) connecting the plies in the bottom which are arranged the one above the other as a result of the folding.
20. Method according to claim 19, characterised in that the production of the tubular bag (method step a)) takes place in cycles, a tube being produced from a filter material and the open end being closed.
21. Method according to claim 19 or 20, characterised in that, as the open end is closed (method step a)), simultaneously the previously produced bag is closed at its free end.
22. Method according to claim 21, characterised in that in addition the bags are separated in the same working cycle.
23. Method according to claim 22, characterised in that the separation takes place mechanically.
24. Method according to one of claims 19 to 23, characterised in that pre-creases are introduced during method step a).
25. Method according to claim 24, characterised in that the pre-creases are introduced by a suitable forming tool and/or by welding.
26. Method according to one of claims 19 to 25, characterised in that the die is used as a sound reflector for a sonotrode.
27. Method according to one of claims 19 to 25, characterised in that the die is used as a sonotrode for a sound reflector.
28. Method according to one of claims 19 to 27, characterised in that an opening is introduced during method step a) or into the filter material forming the web.

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