Canister for containing an active material

Abstract

A canister including a canister body containing a bottom wall and at least one sidewall with inner and outer sidewall surfaces and an upper rim, and a closing element containing a top wall with an outer surface and an inner surface, and a fixing portion surrounding the top wall. The top wall or the bottom wall or at least one sidewall include a membrane region with a predetermined permeability. The fixing portion includes an elevated or recessed snap portion around its outer periphery shaped to correspond to the inner sidewall surface of the sidewall of the cylindrical canister body and form a snap connection with the canister body. The closing element is fixed to the canister body such that the outer surface of the top wall does not extend beyond the upper rim of the sidewall of the canister body.

Claims

1. A canister for containing an active material, like an oxygen scavenger, a desiccant or another functional material, comprising a canister body comprising a bottom wall and at least one sidewall with inner and outer sidewall surfaces and an upper rim, wherein the at least one sidewall extends from the bottom wall; and a closing element comprising a top wall with an outer surface and an inner surface, and a fixing portion surrounding the top wall; wherein the top wall and/or the bottom wall and/or at least one of the at least one sidewall of the canister body comprises at least one membrane region with a predetermined permeability to a defined gaseous substance, wherein the membrane region is substantially unperforated; and wherein the membrane region is integrally formed with the top wall and/or the bottom wall and/or at least one sidewall of the canister body; and wherein the fixing portion comprises an elevated or recessed snap portion around its outer periphery which is shaped corresponding to a mating geometry around the inner sidewall surface of the sidewall of the canister body so as to form a snap connection with the canister body; and wherein the closing element is fixed to the canister body in such a way that the outer surface of the top wall does not extend beyond the upper rim of the sidewall of the canister body.

2. The canister according to claim 1, wherein the snap portion of the closing element comprises an elevated portion thereof.

3. The canister according to claim 1, characterized in that the inner sidewall surface of the sidewall of the canister body comprises a peripheral groove close to the upper rim.

4. The canister according to claim 1, wherein the canister body is in a cylindrical shape; and the top wall of the closing element comprises reinforcing ribs extending in a radial direction.

5. The canister according to claim 4, wherein the thickness (T) of the reinforcing ribs is between 0.8 mm and 1.5 mm.

6. The canister according to claim 1, wherein the thickness (t) of the membrane region is between 0.1 mm and 0.6 mm.

7. The canister according to claim 1, wherein the canister body is in a cylindrical shape and the bottom wall of the canister body is provided with a plurality of radially arranged spokes arranged at an inner side of the bottom wall.

8. The canister according to claim 7, wherein the spokes connect a central hub portion to the inner sidewall surface of the sidewall.

9. The canister according to claim 1, wherein the canister is filled with an active material able to trap and/or release a desired substance selected from the group consisting of moisture, oxygen and a fragrance.

10. The canister according to claim 1, wherein a composition material of the closing element is different from a composition material of the canister body.

11. The canister according to claim 10, wherein the composition material of the canister body has a higher resilience than the composition material of the closure element.

12. The canister according to claim 1, wherein the fixing portion of the closure element is axially symmetric with regard to a median plane of the closure element.

13. The canister according to claim 1, wherein the canister body and the closing element are both injection molded.

14. The canister according to claim 1, wherein the canister body is integrated in a lid or cap of a container.

15. The canister according to claim 14, wherein the bottom wall of the canister body is integrally formed with a top wall of the lid or cap.

16. The canister according to claim 2, wherein the snap portion of the closing element comprises a beveled edge between beveled side flanks of the elevated portion.

17. The canister according to claim 4, wherein the reinforcing ribs extending in a radial direction have a geometry of a cross.

18. The canister according to claim 1, wherein the thickness (t) of the membrane is about 0.25 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following drawings, a specific embodiment of the invention will be described in more detail. In the drawings,

(2) FIG. 1 shows a view into the inside of the canister body;

(3) FIG. 2 is a sectional view along line A-A in FIG. 1;

(4) FIG. 3 is a view on the outer surface of the bottom wall of the canister body;

(5) FIG. 4 is a cross-sectional view of an inventive canister;

(6) FIG. 5 is a view on the top surface of the closing element;

(7) FIG. 6 is a view on the inner surface of the closing element, which, in the assembled state, faces the inside of the canister;

(8) FIG. 7 is a cross-sectional view along line A-A in FIG. 5;

(9) FIG. 8 is a three-dimensional view of a canister according to another embodiment of the invention;

(10) FIG. 9 is a three-dimensional sectional view of the canister according to FIG. 8;

(11) FIG. 10 is a sectional view of the canister according to FIG. 8;

(12) FIG. 11 is a three-dimensional view of another embodiment of a lid of a container with an integrated canister according to the invention;

(13) FIG. 12 is a three-dimensional sectional view of the lid according to FIG. 11;

(14) FIG. 13 is a sectional view of the lid according to FIG. 11;

(15) FIG. 14 is a three-dimensional view of another embodiment of a lid of a container incorporating the inventive canister;

(16) FIG. 15 is a three-dimensional sectional view of the lid according to FIG. 14;

(17) FIG. 16 is a sectional view of the lid according to FIG. 14;

(18) FIG. 17 is three-dimensional view of another embodiment of a lid of a container incorporating the inventive canister;

(19) FIG. 18 is a three-dimensional sectional view of the lid according to FIG. 18; and

(20) FIG. 19 is a sectional view of the lid according to FIG. 17.

DESCRIPTION OF PREFERRED EMBODIMENTS

(21) In the following description, the same elements will be denoted by the same reference numerals throughout the drawings.

(22) FIG. 1 shows the cylindrical canister body 12. There are a bottom wall 14 as well as a cylindrical sidewall 16 which extends upwardly from the bottom wall 14 of the canister body 12. In this respect, reference is also made to FIG. 2 showing a cross-sectional view of the canister body along the sectional line A-A in FIG. 1.

(23) The sidewall 16 has an outer sidewall surface 18 as well as an inner sidewall surface 20. The bottom wall 14 is provided with a hub portion 22 which, as can be best seen in FIG. 2, is elevated over the plane 24 of the bottom surface 26.

(24) The bottom wall 14 is provided with a plurality of spokes 28 which are oriented in a radial direction and start from the hub portion 22 and extend up to and are integral with the sidewall 16. The spokes 28 act as reinforcing ribs and have a thickness which is much higher than that of the membrane regions 30 between an adjacent pair of spokes 28. As a non-limiting example, the spokes can have a height H of 0.7 mm, whereas the height h of the membrane region 30 is 0.25 mm.

(25) The sidewall 16 extending upwards from the bottom wall is provided with a snapping geometry comprising a groove 32 which is close to the upper rim 34 of the sidewall 16 and runs in a circumferential direction starting from the inner sidewall surface 20.

(26) As a further optional feature, the canister body 12 can be provided with reinforcing segments 36 which extend in an upwards direction up to the groove 32 and form a step portion 38 which determines the correct insertion position of the closing element as described with reference to FIGS. 5 to 7.

(27) FIG. 3 is a view onto the bottom surface 26 of the canister body 12 which, except for the hub portion 22, can be essentially flat in order to increase the visibility of a gravure 40 which can optionally be provided on the bottom of the canister. Such gravure 40 can either specify the specific type of canister, its active material inside or, as in the example as shown in FIG. 3, include a warning to the user.

(28) The closing element 50 of the canister is depicted in FIGS. 5 to 7. It consists of a top wall 52 with an outer surface 54 and an inner surface 56. The top wall 52 is surrounded by a fixing portion 58 being a circular ring which, around its outer periphery, is provided with a snap geometry 60 which will be described in more detail below.

(29) The top wall 52 includes membrane portions 62 and reinforcing ribs 64 which, in the example as shown in FIGS. 5 to 7, are arranged in the shape of a cross. In the inner surface 56 of the top wall 52 as shown in FIG. 6, the reinforcing ribs 64 might be connected to the ring-shaped fixing portion 58 through reinforcing regions 66 which serve to ensure a uniform introduction of the forces from the fixing portion 58 into the reinforcing ribs 64. In the example as given in the embodiment of FIGS. 5 to 7, the thickness of the reinforcing ribs 64 can be selected to be T=1 mm, whereas the thickness of the membrane t is around 0.25 mm. This can be seen from the cross-sectional view along the line A-A in FIG. 5 which is shown in FIG. 7. The overall height H of the closing element 50 can be H=2 mm and, as can be seen from the cross-section view in FIG. 7, the membrane regions 62 are extending in the median plane in the direction of the thickness H of the closing element 50.

(30) The snapping geometry as shown in FIG. 7 consists of two beveled surfaces 68 which are angled relative to each other and form a circumferential tip 70 in the median plane of the closing element. The angle between the two adjacent beveled surfaces 68 at the tip 70 can be about 140.

(31) As can be seen in FIG. 7, the snap geometry 60 around the outer circumference of the closing element 50 is symmetrical with regard to the median plane of the closing element. As a result of this, the outer surface 54 and the inner surface 56 can be arbitrarily selected which simplifies the assembly of the container. No specific orientation of the circular closing element 50 relative to the canister body 12 is required.

(32) The canister 10 as assembled is shown in FIG. 4. It forms an interior space 72 which is filled with an active material 80. As can be further seen, the snap geometry 60 at the outer circumference of the closing element 50 is received in the groove 32 of the canister body 12. In this way, a snap connection is formed between the canister body 12 and the closing element 50.

(33) FIGS. 8 to 10 show a further embodiment of the inventive canister in a full view (FIG. 8), in a three dimensional view of one half of the canister (FIG. 9) and in a cross-sectional view (FIG. 10).

(34) The canister according to FIGS. 8 to 10 is provided with membrane portions 62 in its closing element as well as membrane regions 30 in its bottom wall 14. Further, there are membrane sections 42 in the sidewall 16 also allowing improved gas exchange to the active material 80 received in the canister body 12.

(35) To this end, the sidewall is provided with longitudinal support sections 44 alternating with membrane sections 42. In the cross-sectional view of FIG. 10, the relative thickness of the membrane sections 42 and the longitudinal support section 44 can be seen. From the cross-sectional view of FIG. 10, it can be seen that the membrane sections 42 at the sidewall 16 are integrally formed with the membrane regions 30 at the bottom surface. In order to provide an appropriate mechanical stability of the canister, the bottom surface is provided with a hub portion 22 and spokes 28 as described above for the previous embodiments. Comparing the cross-sectional views of FIG. 10 and FIG. 2, it can also be seen that the dimensions of the canister body 12 and the volume to be filled with active material can widely vary depending on the specific needs. In comparison to the previous embodiments described above, the embodiment of the inventive canister body as shown in FIGS. 8 to 10 does not only have an increased interior volume for receiving active material 80, but also an increased surface provided with thin-walled membranes in order to provide a quick gas exchange kinetic.

(36) FIGS. 11 to 13, FIGS. 14 to 16, and FIGS. 17 to 19, respectively, show three lids of a container integrating an inventive canister.

(37) In the embodiment as shown in FIGS. 11 to 13, a lid 10 of a container is shown, whereas FIG. 11 is a three-dimensional view, FIG. 12 is a three-dimensional sectional view and FIG. 13 is a cross-sectional view. As can be seen in FIGS. 11 to 13, the canister body 12 filled with an active material 80 is integrally formed with the top wall 92 of the lid of the container. Such integral structure can easily be realized because, after manufacturing the lid 10 including the wall structure of the canister body 12, the active material 80 is filled into the interior space of the canister body followed by the attachment of the closing element 50.

(38) In the embodiment as shown in FIGS. 11 to 19, a geometry of the canister body with membrane portions in the closing element 50 only is described. However, it is also possible to provide the sidewalls with membrane sections as shown in FIG. 8.

(39) As an aside, the lid 10 of the container can be provided in any suitable way as known in the art. In the example as shown throughout the FIGS. 11 to 19, the lid is provided with a tamper evident ring 94 as well as an inner thread 96 cooperating with a mating outer circumferential thread on a container body (not shown in FIGS. 11 to 19).

(40) The embodiment as shown in FIGS. 14 to 16 is a different embodiment of a lid 10 of a container including the integral provision of the canister body 12, i.e. the bottom wall 14 of the container is integrally formed with the top wall 92 of the lid 10 of the container. The lid as shown in FIGS. 14 to 16 is the same as that shown in FIGS. 11 to 13. The lid 10 as shown in FIGS. 14 to 16 differs in that it is provided with a flexible compensating element 98 which serves to hold back products contained in the container, like tablets. Further, the lid differs from that as shown in FIGS. 11 to 13 in that it is not screwed on top of a container body, but clamped onto the upper rim of a container body. To this end, a receiving groove 100 is formed which serves to receive and firmly hold the upper rim of a container body so that the lid of the container will not inadvertently pop off the container.

(41) The compensating element 98 restricts access to the canister body. Therefore, the specific shape of the lid 10 as shown in FIGS. 14 to 16 can be advantageously used together with the inventive canister, because after manufacturing of the lid with the integral bottom and sidewall of the canister and after filling in of the active material 80, the closing element 50 can be easily mounted to the canister body 12.

(42) The embodiment of FIGS. 17 to 19 is very similar to that as shown in FIGS. 14 to 16 except for the omission of a compensating element. Also in this embodiment, the bottom wall 14 of the canister body 12 is integrally formed with the top wall 92 of the lid 10 of the container. The difference between the embodiment according to FIGS. 14 to 16 lies mainly in the absence of a compensating element as shown with reference numeral 98 in the embodiment according to FIGS. 14 to 17.

(43) The membrane regions are unperforated which results in a slower gas exchange rate. To the contrary, perforated membranes nearly have the same gas exchange as the active material itself without any surrounding barrier. Therefore, by the provision of an unperforated membrane, the gas exchange kinetic can be adjusted and slowed down where this is required. A further advantage of the unperforated membrane regions is the suitability of the canister to the filled with a powder, avoiding leakage of very fine particles that could pass through the perforations.

(44) Besides the surface area and the thickness of the membrane regions, the material of the membrane can be selected in order to influence the desired permeability to a specific gas component and its exchange kinetic. Since the canister body and the closing element are injection molded and form unitary pieces, the materials of the canister body and the closing element can be selected according to the behavior of the membrane regions.

(45) Suitable materials are permeable polymers such as for example: polyolefin based polymer, for example polyethylene, HDPE, LOPE, polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), ethylene vinyl acetate (EVA), ethylene vinyl acetate copolymer (EVOH), cyclic olefin copolymer (COC); polyester based polymers for example polycaprolactone (PCL), polylactic acide (PLA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc.; polycarbonate (PC), polyoxymethylene (POM), polyamide, polyethylene sulfide (PPS), BOPP or cellulose.

(46) When the active material absorbs oxygen, preferable materials have an Oxygen Transmission Rate of at least 100 cm.sup.3.Math.100 m/m.sup.2.Math.day.Math.bar at a temperature of 23 C. (ASTM D3985), preferably at least 500 cm.sup.3.Math.100 m/m.sup.2.Math.day.Math.bar.

(47) When the active material absorbs or releases moisture, preferred materials have a water permeability of at least 1 g.Math.100 m/m.sup.2.Math.day.Math.bar at a temperature of 23 C. and a relative humidity of 85%, preferably at least 4 g.Math.100 m/m.sup.2.Math.day.Math.bar, more preferably at least 10 g.Math.100 m/m.sup.2.Math.day.Math.bar.

(48) The material used for the closing element can be different from that used for the canister body. For example, the material used for the canister body can be more resilient than the material of the closing element which facilitates the assembly of the two parts by the snap connection between the closing element and the canister body.

(49) As can be seen from FIG. 4, the closing element 50 is integrally included in the canister body and has an outer diameter which is smaller than the outer diameter of the canister body. In such a way, it is possible to position the closing element such that its top wall 52 is flush with the upper rim 34 of the canister body 12. In such a way, the overall height of the canister 10 can be made very small. The total height of the canister including the closing element 50 can be less than 2.5 mm. A further advantage is the difficulty to remove the closing element 50 from a canister once it has been closed.