Vacuum cleaner filter bag

Abstract

The invention relates to a vacuum cleaner filter bag, including a bag wall which is made of filter material and has a through-passage through which the air to be cleaned can flow into the vacuum cleaner filter bag, in which the bag wall includes an at least partially pleated non-woven fabric material and the bag wall includes a first and a second filter material layer which are joined to one another by a peripheral weld seam, wherein the first and/or second filter material layers comprise include the at least partially pleated non-woven fabric material.

Claims

1. A vacuum cleaner filter bag formed as a flat bag and comprising: a bag wall made of filter material that has a through passage through which the air that is to be cleaned can flow into the vacuum cleaner filter bag, the bag wall consisting of an at least partially pleated nonwoven material, and comprising a first and a second filter material layer that are connected to each other by a peripheral weld seam, wherein the first or the second filter material layer consists of the at least partially pleated nonwoven material; wherein folds of the at least partially pleated nonwoven material are connected to one another at least partially by a fixing device; wherein the fixing device is configured to hold the folds of the at least partially pleated nonwoven material at a predetermined distance from one another when the vacuum cleaner filter bag is unfolded during operation of the vacuum cleaner filter bag; and wherein the fixing device is arranged on a first side of the at least partially pleated nonwoven material facing towards an interior of the vacuum cleaner filter bag and a second side of the at least partially pleated nonwoven material on an exterior of the vacuum cleaner filter bad is free from any fixing device.

2. The vacuum cleaner filter bag according to claim 1, wherein folds of the at least partially pleated nonwoven material extend across the entire length or width of the vacuum cleaner filter bag.

3. The vacuum cleaner filter bag according to claim 1, wherein folds of the at least partially pleated nonwoven material have a fold height between 3 mm and 100 mm.

4. The vacuum cleaner filter bag according to claim 1, wherein folds of the at least partially pleated nonwoven material have a fold width between 3 mm and 100 mm.

5. The vacuum cleaner filter bag according to claim 1, wherein at least two folds of the at least partially pleated nonwoven material have fold heights or fold widths that are different from each other.

6. The vacuum cleaner filter bag according to claim 1, further comprising at least one side fold, wherein the at least partially pleated nonwoven material is arranged in the at least one side fold.

7. The vacuum cleaner filter bag according to claim 1, wherein at least two folds of the at least partially pleated nonwoven material have fold shapes that differ from one another.

8. The vacuum cleaner filter bag according to claim 1, wherein the fixing device is glued or welded at least partially to folds of the at least partially pleated nonwoven material.

9. The vacuum cleaner filter bag according to claim 1, wherein the fixing device comprises at least one material strip.

10. The vacuum cleaner filter bag according to claim 1, wherein the fixing device has a predetermined expansion behaviour.

11. The vacuum cleaner filter bag according to claim 1, wherein fibres or absorbents are arranged in the hollow space formed by the fixing device and fold legs of at least one fold of the at least partially pleated nonwoven material.

12. The vacuum cleaner filter bag according to claim 1, wherein folds of the at least partially pleated nonwoven material have a fold height between 5 mm and 15 mm.

13. The vacuum cleaner filter bag according to claim 1, wherein folds of the at least partially pleated nonwoven material have a fold width between 5 mm and 15 mm.

14. The vacuum cleaner filter bag according to claim 1, wherein the fixing device comprises at least one nonwoven material strip.

15. The vacuum cleaner filter bag according to claim 1, wherein the fixing device is formed such that a fold width of the folds connected by the fixing device can be enlarged during operation of the vacuum cleaner filter bag by expanding the fixing device.

16. A method for manufacturing a vacuum cleaner filter bag, the vacuum cleaner bag being formed as a flat bag and comprising a bag wall made of filter material that has a through passage through which the air that is to be cleaned can flow into the vacuum cleaner filter bag, the bag wall consisting of an at least partially pleated nonwoven material, and a first and a second filter material layer that are connected to each other by a peripheral weld seam, wherein the first or the second filter material layer consists of the at least partially pleated nonwoven material, the method comprising: pleating of at least a portion of a nonwoven web; assembling of the vacuum cleaner filter bag using the at least partially pleated nonwoven web; and connecting folds of the at least partially pleated nonwoven material to one another at least partially by a fixing device; wherein the fixing device is configured to hold the folds of the at least partially pleated nonwoven material at a predetermined distance from one another when the vacuum cleaner filter bag is unfolded during operation of the vacuum cleaner filter bag; and wherein the fixing device is arranged on a first side of the at least partially pleated nonwoven material facing towards an interior of the vacuum cleaner filter bag and a second side of the at least partially pleated nonwoven material on an exterior of the vacuum cleaner filter bag is free from any fixing device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics and advantages of the invention are explained in the following on the basis of explanatory figures. Shown are:

(2) FIG. 1 an exemplary vacuum cleaner filter bag;

(3) FIG. 2 a top view onto an interior of an exemplary vacuum cleaner filter bag;

(4) FIG. 3 a top view onto an interior of a further exemplary vacuum cleaner filter bag;

(5) FIG. 4 a cross-section through a subarea of an exemplary vacuum cleaner filter bag;

(6) FIG. 5 a cross-section through a subarea of a further exemplary vacuum cleaner filter bag;

(7) FIG. 6 a cross-section through a subarea of a further exemplary vacuum cleaner filter bag;

(8) FIG. 7 a cross-section through a subarea of a further exemplary vacuum cleaner filter bag;

(9) FIG. 8 a top view onto the back side of an exemplary vacuum cleaner filter bag; and

(10) FIG. 9 an illustrative diagram in which the volume flow through the bag wall of exemplary vacuum cleaner filter bags in dependence on the dust mass stored therein is depicted.

DETAILED DESCRIPTION

(11) The following methods are used for determining the parameters described above and in the following.

(12) The air permeability is determined in accordance with DIN EN ISO9237:1995-12. In particular, work is carried out with a differential pressure of 200 Pa and a test area of 20 cm.sup.2. The air permeability test device FX3300 of Texttest AG was used to determine the air permeability.

(13) The mass per unit area is determined in accordance with DIN EN 29073-1:1992-08. The method according to the standard DIN EN ISO 9073-2:1997-02 is used for determining the thickness of one or more nonwoven layers, whereby method A is used.

(14) The penetration (NaCl permeability) is determined by means of a TSI 8130 test device. In particular, 0.3 m of sodium chloride is used at 86 l/min.

(15) The fold width can be determined as the average distance between two adjacent folds, particularly between the fold backs of two abutting folds. If the folds are connected by means of a fixing element, the fold width can correspond to the average distance between the connection points of a first fold and the connection points of a second, adjacent fold.

(16) The fold height of a fold can be determined as a normalized distance of the fold back to a plane in which the edges of the two fold legs lie that lie opposite the fold back. In the case of reclined folds, the fold height of a fold can be determined as the average length of the fold legs. For this purpose, the extension of a fold perpendicular to the longitudinal direction of the fold, meaning perpendicular to the direction in which the fold back runs, can be measured and the measured extension can be halved.

(17) FIG. 1 shows an exemplary vacuum cleaner filter bag in which one side is shown opened for purposes of illustration. In fact, the side that is shown opened here is formed by a weld seam.

(18) The exemplary vacuum cleaner filter bag of FIG. 1 comprises a bag wall of at least partially pleated nonwoven material. The at least partially pleated nonwoven material comprises a plurality of, particularly more than two, folds 101. The folds 101 are particularly upright folds.

(19) The bag wall has no folds in the area 104. The nonwoven material is thus not pleated in this area 104. The exemplary vacuum cleaner filter bag of FIG. 1 furthermore comprises an inlet opening 102 through which the air that is to be cleaned can flow into the vacuum cleaner filter bag, as well as a retaining plate 103, that is used to fix the vacuum cleaner filter bag in a chamber of a vacuum cleaner, and a through hole in the area of the inlet opening 102.

(20) The folds 101 of the partially pleated nonwoven material are formed along the entire length of the vacuum cleaner filter bag in the exemplary vacuum cleaner filter bag of FIG. 1. Depending on the orientation of the retaining plate 103, the vacuum cleaner filter bag can have a long side and a broad side. The folds 101 can extend along the long side or along the broad side, particularly along the entire long side or broad side.

(21) In the case of the exemplary vacuum cleaner filter bag of FIG. 1, an area 104 of the bag wall is free of folds. Alternatively, folds of the at least partially pleated nonwoven material can, however, also be located on the entire bag wall.

(22) The bag wall can particularly have two or more filter layers, whereby at least one layer comprises an at least partially pleated nonwoven material.

(23) FIG. 2 shows a top view onto an interior of a bag wall of an exemplary vacuum cleaner filter bag. The folds 201 of the at least partially pleated nonwoven material in this example are connected to one another by means of a fixing device in the form of a plurality of material strips 205. In particular, the folds 201 are held at a predetermined distance from one another by means of the material strips 205. In other words, the fold width of the folds 201 is fixed by the material strips 205. The material strips 205 are connected, for example, glued or welded, to the folds 201, particularly to an edge of the folds 201, at connection points 206.

(24) The material strips 205 can, for example, have a width of from 0.5 cm to 4 cm, particularly from 1 cm to 3 cm, for example, 2 cm.

(25) The material strips 205 can comprise a nonwoven material. In particular, the nonwoven material can comprise an extrusion nonwoven, for example, a spunbond nonwoven and/or a carded or air-laid nonwoven. The material strips 205 can also comprise a laminate of a plurality of nonwovens, particularly a laminate of spunbond nonwovenmeltblown nonwovenspunbond nonwoven.

(26) The mass per unit area of the material strips 205 can be less than 200 g/m.sup.2, particularly between 10 g/m.sup.2 and 30 g/m.sup.2.

(27) Some of the connection points 206 can be formed in such a way that the connection detaches during the operation of the vacuum cleaner filter bag. The flow behaviour of the air flowing into the bag can be influenced by means of the at least partially detached material strips 205.

(28) The material strips 205 can also have a predetermined expansion behaviour. In this way, it is possible to achieve a predetermined extension of the bag during operation. The material strips 205 can also have elasticity, so that the extension of the bag can be reduced by elastic restoring forces again after operation, meaning after the vacuum cleaner has been switched off. In this way, dust can also be conveyed from the bag wall into the interior of the vacuum cleaner filter bag.

(29) Alternatively to a plurality of material strips 205, the fixing element can also be formed as a material strip across the entire surface. In this case, the fixing element can have a high level of air permeability, particularly more than 5000 l/(m.sup.2s).

(30) The fixing element can also comprise an air-permeable paper, weave and/or foil. To increase the air permeability, the fixing device can also be perforated or slit.

(31) FIG. 3 shows a top view onto an interior of a bag wall of a further exemplary vacuum cleaner filter bag. In this case, the fixing device is formed in the form of a net 307 that connects the folds 301 of the pleated nonwoven material to one another in a subarea of the surface. In other areas of the surface, the folds of the pleated nonwoven material are not connected by the fixing device. By means of such a partial localization of the folds, it is possible to achieve an optimal fitting of the vacuum cleaner filter bag to the installation space of the vacuum cleaner during operation.

(32) FIG. 4 shows a cross-section through a subarea of the bag wall of an exemplary vacuum cleaner filter bag, whereby the cross-section runs perpendicularly to the run of the folds of the pleated nonwoven material. In particular, FIG. 4 shows a plurality of folds of the at least partially pleated nonwoven material of a bag wall of an exemplary vacuum cleaner filter bag that are connected to one another by means of a fixing device 405. In particular, the fixing device 405 is connected to the fold backs of the folds at connection points 406. The arrow 410 indicates the direction of flow of the air that is to be cleaned toward the bag wall. In this example, the fixing device 405 is consequently arranged on the downstream side of the at least partially pleated nonwoven material.

(33) FIG. 4 furthermore shows a fold leg 409 of a first fold and a fold leg 408 of a second fold that are directly adjacent to each other or that abut each other.

(34) FIG. 4 furthermore illustrates the fold width w (b) and the fold height h. The fold height h and/or the fold width w (b) can lie between 3 mm and 100 mm, particularly between 5 mm and 15 mm.

(35) FIG. 5 shows a further cross-section through a part of a bag wall of an exemplary vacuum cleaner filter bag. In particular, a plurality of folds 501 are shown, and a fixing device 505 arranged on the upstream side with reference to the direction of flow 510, whereby the folds 501 are connected to the fixing device 505 at connection points 506.

(36) In FIGS. 4 and 5, the folds have a cross-section in the shape of an isosceles triangle. The shape of the folds can be chosen arbitrarily, however.

(37) FIG. 6, for example, shows a cross-section through a subarea of a bag wall of an exemplary vacuum cleaner filter bag, in which the folds 601 have fold leg lengths that are different in the cross-section.

(38) In particular when a full-surface, air-permeable fixing device is used for fixing the folds, the hollow spaces formed between the folds and the fixing device can be filled with fibres, particularly electrostatically charged fibres, and/or with absorbents. For example, coated fibres, activated charcoal and/or porous polymers can be used as absorbents.

(39) FIG. 7 shows a cross-section of a subarea of such a bag wall. In particular, a plurality of folds 701 and a fixing device 705 connected to them are shown. Fibres 711 and/or activated charcoal 712 are arranged in the hollow spaces between the fold legs and the fixing device 705.

(40) FIG. 8 shows an exemplary vacuum cleaner filter bag, particularly in a top view on to an outer side of the vacuum cleaner filter bag. The bag wall comprises a multitude of folds 801. The vacuum cleaner filter bag furthermore comprises two side folds 813 and 814, whereby the side folds 813 and 814 likewise comprise an at least partially pleated nonwoven material. In other words, folds 801 of the at least partially pleated nonwoven material are arranged on the fold legs of the side folds 813 and 814, respectively. It can be possible for the side folds 813 and 814 to be partially or completely turned out.

(41) Due to the use of an at least partially pleated nonwoven material, the surface available for filtration can be enlarged given predetermined dimensions of the vacuum cleaner filter bag. This leads to a high filtration performance with a low starting pressure loss. This means a lower media passage speed, which increases the filtration performance, particularly by means of electrostatically-charged fibres of the bag wall.

(42) Due to the greater surface, it is also possible to achieve a greater dust-holding capacity. FIG. 9 is used for illustration purposes, and shows a diagram in which the volume flow through the bag wall of vacuum cleaner filter bags is depicted in dependence on the dust load in grams. Each bag wall consists of a laminate made of spunbond nonwoven and meltblown nonwoven. The corresponding measurements were made with a Miele S 5210 model vacuum cleaner.

Example 1

(43) Corresponds to a bag wall according to the state of the art, meaning without an at least partially pleated nonwoven material. The bag dimensions are (LW) 300 mm320 mm. The SMMS consists of spunbond 35 g/m.sup.2, 220 g/m.sup.2 meltblown nonwoven and spunbond 17 g/m.sup.2.

Example 2

(44) Corresponds to a bag wall comprising a fully pleated nonwoven material. The fold height is 12 mm. The bag dimensions (LW) amounted to 300630 mm (unfolded). The SMMS consists of spunbond 35 g/m.sup.2, 220 g/m.sup.2 meltblown nonwoven and spunbond 17 g/m.sup.2.

Example 3

(45) Corresponds to a bag wall according to the invention comprising a fully pleated nonwoven material and a fixing device formed across the entire surface in the form of a net with a mesh width of 5 mm5 mm. The fold height is 12 mm. The bag dimensions were (LW) 300630 mm (unfolded). The SMMS consists of spunbond 35 g/m.sup.2, 220 g/m.sup.2 meltblown nonwoven and spunbond 17 g/m.sup.2.

Example 4

(46) Corresponds to a bag wall according to the invention comprising a fully pleated nonwoven material and a fixing device in the form of a plurality of nonwoven strips (each 20 mm wide) spaced apart from one another. The fold height is 12 mm. The bag dimensions (LW) amounted to 300630 mm (unfolded). The SMMS consists of spunbond 35 g/m.sup.2, 220 g/m.sup.2 meltblown nonwoven and spunbond 17 g/m.sup.2.

Example 5

(47) Corresponds to a bag wall according to the invention comprising a fully pleated nonwoven material and a fixing device in the form of a plurality of nonwoven strips (each 20 mm wide) spaced apart from one another. The fold height is 12 mm. The bag dimensions (LW) amounted to 300630 mm (unfolded). The SMMS consists of spunbond 35 g/m.sup.2, 220 g/m.sup.2 meltblown nonwoven and spunbond 17 g/m.sup.2. The vacuum cleaner filter bag according to Example 5 additionally comprises at least one element for flow deflection or flow distribution (14 strips, each 11 mm wide, laminate with a mass per unit area of 110 g/m.sup.2) in the vacuum cleaner filter bag.

(48) As can be seen in FIG. 9, the vacuum cleaner filter bags with a bag wall comprising an at least partially pleated nonwoven material have, also at high dust loads, a greater volume flow than a vacuum cleaner filter bag with a bag wall without pleated nonwoven material.

(49) Due to the greater dust-holding capacity, the pressure loss increase of the vacuum cleaner filter bag can also be reduced.

(50) Table 1 lists average values (from five measurements) of the measured pressure loss and of the measured penetration of a vacuum cleaner filter bag material according to the state of the art with a bag wall made of a laminate of a spunbond nonwoven (mass per unit area 35 g/m.sup.2), 2 layers of meltblown nonwoven (mass per unit area of each is 20 g/m.sup.2) and a spunbond nonwoven (mass per unit area 17 g/m.sup.2).

(51) TABLE-US-00001 TABLE 1 Measured with TSI Volume flow Pressure loss P Penetration 8130 [l/min] [mm H.sub.2O] [%] Average values 86.92 14.46 32.2

(52) Table 2 lists average values (from five measurements) of the measured pressure loss and of the measured penetration of a vacuum cleaner filter bag with a bag wall made of a pleated laminate of a spunbond nonwoven (mass per unit area 35 g/m.sup.2), 2 layers of meltblown nonwoven (mass per unit area of each is 20 g/m.sup.2) and a spunbond nonwoven (mass per unit area 17 g/m.sup.2).

(53) TABLE-US-00002 TABLE 2 Measured with TSI Volume flow Pressure loss P Penetration 8130 [l/min] [mm H.sub.2O] [%] Average values 42.98 6.86 18.72

(54) As can be seen in Tables 1 and 2, the pressure loss and the penetration in the case of a vacuum cleaner filter bag with an at least partially pleated bag wall are considerably less than in the case of known vacuum cleaner filter bags without a pleated bag wall.

(55) Table 3 lists average values (from two measurements) of the measured pressure loss and of the measured penetration of a vacuum cleaner filter bag according to the state of the art with a bag wall made of an HEPA laminate of a spunbond nonwoven (mass per unit area 35 g/m.sup.2), 4 layers of meltblown nonwoven (each with a mass per unit area of 19 g/m.sup.2) and a spunbond nonwoven (mass per unit area 17 g/m.sup.2).

(56) TABLE-US-00003 TABLE 3 Measured with TSI Volume flow Pressure loss P Penetration 8130 [l/min] [mm H.sub.2O] [%] Average values 86.1 32.05 0.025

(57) Table 4 lists average values (from two measurements) of the measured pressure loss and of the measured penetration of a vacuum cleaner filter bag with a pleated bag wall made of an HEPA laminate of a spunbond nonwoven (mass per unit area 35 g/m.sup.2), 4 layers of meltblown nonwoven (each with a mass per unit area of 19 g/m.sup.2) and a spunbond nonwoven (mass per unit area 17 g/m.sup.2).

(58) TABLE-US-00004 TABLE 4 Measured with TSI Volume flow Pressure loss P Penetration 8130 [l/min] [mm H.sub.2O] [%] Average values 43.05 15.5 0.004

(59) As can be seen in Tables 3 and 4, the pressure loss and the penetration in the case of a vacuum cleaner filter bag with an at least partially pleated bag wall are considerably less than in the case of known vacuum cleaner filter bags without a pleated bag wall. The reduction in the penetration is disproportionately more pronounced in the case of the HEPA laminate than in the laminate used in Tables 1 and 2.

(60) In Tables 1 and 2 and in Tables 3 and 4, respectively, it is also possible to detect a lower volume flow for a bag wall made of a pleated nonwoven material due to the greater surface of such a bag wall.

(61) It shall be understood that characteristics mentioned in the previously described embodiments are not limited to these special combinations and are also possible in any other combinations. In particular, the vacuum cleaner filter bag can be formed with different geometric shapes and/or sizes.