Holding plate for a vacuum cleaner filter bag

Abstract

The invention relates to a holding plate for a vacuum cleaner filter bag having a bag wall, the holding plate including a base plate made of a first plastic material with a passage opening, and a connecting element that is connected to the base plate by a material bond and is made of a second plastic material, for connecting the base plate to the bag wall by a material bond, in particular by means of ultrasonic welding, characterized in that the connecting element is arranged on the side of the base plate that is to be connected to the bag wall.

Claims

1. A holding plate for a vacuum cleaner filter bag with a bag wall, the holding plate comprising: a base plate comprising a first plastic material, wherein the base plate comprises a passage opening, and one or several energy directors for ultrasonic welding on the side to be connected to the bag wall; a connecting element comprising a second plastic material connected to the base plate by a material bond, the second plastic material being different than the first plastic material, the second plastic material comprising an injectable material so that the connecting element is injected to the base plate, the connecting element for connecting the base plate to the bag wall by a material bond; wherein the connecting element is arranged on a side of the base plate to be connected to the bag wall so that the connecting element is positioned between the base plate and the bag wall when the holding plate is connected to the bag wall, wherein the holding plate is an injection-molded part.

2. The holding plate according to claim 1, wherein the first or the second plastic material comprises a thermoplastic.

3. The holding plate according to claim 1, wherein the second plastic material has a higher melt flow index than the first plastic material.

4. The holding plate according to claim 1, wherein the second plastic material has a lower melting temperature than the first plastic material.

5. The holding plate according to claim 1, wherein the connecting element is continuous or interrupted.

6. The holding plate according to claim 1, wherein the connecting element is arranged to partially or completely surround the passage opening.

7. The holding plate according to claim 1, wherein the base plate comprises an indentation and the connecting element is partially or completely arranged in the indentation.

8. The holding plate according to claim 1, wherein the connecting element is arranged in a region of the base plate which is at least partially or completely restricted or surrounded by energy directors.

9. The holding plate according to claim 1, comprising a sealing lip for the passage opening in the holding plate.

10. A vacuum cleaner filter bag with a holding plate according to claim 1.

11. The vacuum cleaner filter bag according to claim 10, wherein the bag wall is connected with the base plate of the holding plate, by a material bond.

12. The holding plate according to claim 1, wherein the material bond connecting the base plate to the bag wall comprises an ultrasonic weld.

13. The holding plate according to claim 1, wherein the second plastic material has a melt flow index higher than the first plastic material by a factor of 10 to 20.

14. The holding plate according to claim 1, wherein the connecting element is linear.

15. The holding plate according to claim 9, wherein the sealing lip consists of the same material as the connecting element.

16. The holding plate according to claim 1, wherein the holding plate comprises a molded part made by two-component injection molding.

17. The holding plate according to claim 1, wherein the one of several energy directors comprise one or several elevations on the surface of the base plate extending outward from the surface of the base plate, the one or several energy directors positioned between the base plate and the bag wall when the holding plate is connected to the bag wall.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Below, the invention will be described more in detail with reference to examples and the figures. In the drawings:

(2) FIG. 1 schematically shows the design of an exemplary vacuum cleaner filter bag;

(3) FIG. 2 shows the schematic design of an exemplary holding plate in a plan view;

(4) FIG. 3 shows a plan view onto the side of an exemplary holding plate to be connected with the bag wall; and

(5) FIG. 4 shows a cross-section through an exemplary holding plate.

DETAILED DESCRIPTION

(6) FIG. 1 shows the schematic design of an exemplary vacuum cleaner filter bag. The filter bag comprises a bag wall 101, a holding plate with a base plate 102, and an admission port through which the air to be filtered flows into the filter bag. The admission port is here formed by a passage opening 103 in the base plate 102 and a passage opening in the bag wall 101 aligned with it. The holding plate 102 serves to fix the vacuum cleaner filter bag in a chamber of a vacuum cleaner.

(7) The bag wall 101 comprises at least one non-woven layer, for example of a melt-spun fine fibrous non-woven (meltblown non-woven).

(8) The holding plate comprises a base plate 102 of a first plastic material and a connecting element of a second plastic material connected to the base plate 102 by a material bond, wherein the connecting element is arranged on the side of the base plate 102 connected to the bag wall. The base plate 102 is connected to the bag wall 101 by means of ultrasonic welding by a material bond.

(9) The first plastic material of the exemplary holding plate 102 comprises polypropylene with a melt flow index of 100 g/10 min, and the second plastic material comprises polypropylene with a melt flow index of 1000 g/10 min.

(10) The melt flow index is defined according to ISO 1133 and is measured by means of a capillary rheometer. The melt flow index indicates the mass of thermoplastic melt pressed through a predetermined nozzle within 10 minutes under a predetermined pressure application.

(11) As second plastic material, a thermoplastic elastomer (TPE) can also be used. Block copolymers as well as elastomer alloys can be used.

(12) In FIG. 2, a plan view onto a front side of an exemplary holding plate with a base plate 202 is shown. The front side here corresponds to the side of the holding plate or base plate 202 not provided for the connection with the bag wall. The base plate 202 comprises a passage opening 203. Through the passage opening 203, a connecting piece of the vacuum cleaner can be guided into or to the filter bag. Thereby, the air to be filtered can be introduced into the filter bag. A sealing lip 204 is provided to prevent dust from escaping between the connecting piece and the bag wall of the vacuum cleaner filter bag.

(13) The front side of the base plate 202 can also comprise an attachment face for a sonotrode and/or positioning elements for positioning a sonotrode. By this, a more precise positioning of the sonotrode for ultrasonic welding can be achieved.

(14) The base plate 202 comprises a first plastic material comprising a thermoplastic, for example polypropylene. The sealing lip 204 comprises a thermoplastic elastomer, for example based on polypropylene. The sealing lip 204 is here made of a softer plastic material than the base plate 202.

(15) The exemplary base plate 202 is here designed as a square plate. However, very diverse geometries or shapes are conceivable for the base plate 202.

(16) FIG. 3 shows a plan view onto the side of an exemplary holding plate to be connected with the bag wall. The exemplary holding plate comprises a base plate 302 with a passage opening 303 and a sealing lip 304 surrounding the passage opening 303. Moreover, FIG. 3 shows two rows of energy directors 305 and 306 for welding the base plate 302 to the bag wall by ultrasonic welding. Moreover, FIG. 3 shows a connecting element 307 which is arranged between the two rows of energy directors 305, 306.

(17) The connecting element 307 comprises the same plastic material as the sealing lip 304 and was simultaneously injected to the base plate 302 with a two-component injection molding process.

(18) In particular, the exemplary holding plate is formed with a two-component injection molding process, wherein in a first injection molding step, the base plate 302 is injection molded, and in a second injection molding step, the connecting element 307 is injected to the base plate 302 simultaneously with the sealing lip 304 for the passage opening 303.

(19) The base plate 302 comprises an above-described first plastic material, and the connecting element 307 an above-described second plastic material.

(20) The first plastic material comprises polypropylene, and the second plastic material corresponds to a thermoplastic elastomer. As an alternative or in addition, the second plastic material can also have a lower melting temperature than the first plastic material. In this manner, a plastic material can be used for the base plate 302 which usually cannot be well connected to the material of the bag wall, for example polyamide.

(21) FIG. 4 shows a cross-section through an exemplary holding plate with a base plate 402, comprising a passage opening 403, a sealing lip 404 surrounding the passage opening 403, and a connecting element 407 arranged at the base plate 402. The connecting element 407 is arranged to be surrounded by energy directors 405 and 406, respectively. The holding plate moreover comprises a closure flap 409 which is connected to the base plate 402 of the holding plate via an integral hinge 410. By the closure flap 409, the passage opening 403 can be closed when the vacuum cleaner is not in operation.

(22) The closure flap 409 can be injection molded simultaneously with the base plate 402 in a first injection molding step. In particular, the closure flap 409 and the integral hinge 410 can be embodied as one element. In particular, the closure flap 409 and the integral hinge 410 can comprise the above-described first plastic material or consist of it.

(23) In the exemplary embodiment of FIG. 4, the connecting element 407 is partially arranged in an indentation 408 of the base plate 402 and projects beyond the surface of the base plate 402. The connecting element can also project beyond the surface of the base plate 402 flush with the energy directors 405, 406.

(24) The connecting element 407 can also be arranged completely in the indentation 408 of the base plate 402. In this case, the connecting element 407 can be flush with the surface of the base plate 402.

(25) The connecting element 407 is arranged to completely surround the passage opening 403. As an alternative, the connecting element 407 can also be arranged only in the region of the integral hinge 410.

(26) In FIG. 4, energy directors 405, 406 and the connecting element 407 are shown separate from each other. The energy directors 405, 406, however, can also comprise the connecting element 407. In particular, the connecting element 407 can be arranged in the region of the tips of the energy directors 405, 406. By this, the energy required for the connection of the base plate 402 with the bag wall can be further reduced.

(27) By the connecting element 407, the base plate 402 can be connected to the bag wall by means of ultrasonic welding with only little welding energy. By this, the risk of damages to sensitive regions of the holding plate, for example the closure flap 409 and its integral hinge 410 or the sealing lip 404, is reduced. Simultaneously, the pull-off strength, that means the force that is necessary to release the base plate 402 from the bag wall connected to it, is clearly higher, for example by about a factor 2, than without the connecting element 407.

(28) It will be understood that features mentioned in the above described embodiments are not restricted to these special combinations and are also possible in any other combinations. It will be furthermore understood that in the figures, neither the shown vacuum cleaner filter bag nor the elements of the holding plate are represented in realistic dimensions. Moreover, the geometries or shapes of the shown elements are not restricted to the shown examples.