Device for sealing capsules

Abstract

The invention relates to a device (22) for sealing capsules (10). Each capsule has a capsule shell which is made of a first shell part and a second shell part, said shell parts being provided with a banding liquid in a connection region. The device has a heat source (30) for drying the banding liquid, and the device has at least one diaphragm (32) which is arranged in a radiation region of the heat source between the heat source and the capsules, wherein the diaphragm has at least one passage region for the passage of radiation of the heat source and for irradiating the connection regions of the capsules, and the diaphragm has at least one shielding region which shields sub-regions of the capsules which are offset to the connection region against radiation of the heat source.

Description

[0001] The present invention relates to a device for sealing capsules, wherein the capsules each have a capsule shell formed by a first shell part and a second shell part, wherein the shell parts are or are provided with a banding liquid in a connecting area, and wherein the device has a heat source for drying the banding liquid.

[0002] A method for sealing capsules consisting of two shell parts is known from DE 37 18 320 C2. A drying method using radiation is known from US 4 550 238 A. According to a

[0003] By sliding the edge sections of the first and second capsule parts together, the banding liquid (an aqueous hydroxypropyl methylcellulose (HPMC) or gelatin solution, or generally a solution made from the capsule material) is applied to an overlapping or joining area of ​​the capsules. The subsequent drying of the banding liquid is accelerated by the introduction of heat from the heat source, and a solid band of HPMC, gelatin, or the capsule material is formed.

[0004] However, the heat applied for drying can also heat the contents of a capsule that are enclosed within the capsule shell. This can lead to undesirable overpressure inside the capsule shell and, in the worst case, even to a separation of the shell parts.

[0005] Based on this, the following invention aims to provide a device that enables capsule-friendly drying of the banding liquid.

[0006] This problem is solved in a device of the type mentioned above by arranging at least one aperture between the heat source and the capsules, wherein the aperture has at least one passage area for the passage of radiation from the heat source and irradiation of the connection areas of the capsules, and wherein the aperture has at least one shielding area which shields partial areas of the capsules arranged offset from the connection area from radiation of the heat source.

[0007] The aperture's passage area is designed as at least one elongated opening, the passage area being limited by shielding areas adjacent to the elongated opening. A portion of the thermal radiation incident on the aperture's shielding area(s) is retained. This retention of thermal radiation in the shielding areas can be accompanied by reflection of thermal radiation by the shielding areas and / or absorption of heat by the shielding areas.

[0008] By using the aperture, it is therefore possible to focus the undirected heat radiation emitted by the heat source, which is emitted over a largely undefined area, specifically onto a defined irradiation area.

[0009] Preferably, the distance between the aperture and the capsules, as well as the width of the passage area perpendicular to the elongated extent of the opening, are matched to the size, particularly the length, of the connection area of ​​the capsules. If the capsules are arranged appropriately within the defined irradiation area, the thermal radiation can act precisely at or within the connection area of ​​the capsules with the applied banding liquid, significantly accelerating the drying of the banding liquid. Simultaneously, irradiation of the capsule areas where no banding liquid is present is prevented, and heating of the capsule contents, as well as the associated overpressure inside the capsule, is reduced to a minimum.

[0010] After the application of the banding liquid, the capsules are preferably conveyed by a capsule transport device. The capsule transport device can be designed, in particular, as a conveyor belt. The heat source is arranged at a distance from the conveyor belt. The heat source can extend over a portion of the conveyor belt or over its entire length.

[0011] The capsules arranged on the conveyor belt are aligned with their respective longitudinal axes perpendicular to the direction of transport. Preferably, the capsules are driven to rotate around their respective longitudinal axes during transport in the direction of transport. The design of the conveyor belt allows the positions of the connecting areas of adjacent capsules, each coated with banding fluid, to be kept aligned relative to each other along the direction of transport.

[0012] In a preferred embodiment, a principal axis of the aperture's passage area extends parallel to the transport direction of the capsules. In combination with the capsule orientation described above, this ensures heat input onto the connection areas of the capsules aligned with each other in the transport direction over at least a portion of a transport section of the transport device, while the capsule sections offset from the connection area are not exposed to direct heat radiation.

[0013] Preferably, the heat source comprises at least one infrared emitter. The use of an infrared emitter has the advantage that the frequency range of the infrared radiation can be tailored to the solvent used in the banding liquid, thereby selectively exciting it. This significantly increases the sublimation rate of the solvent and achieves faster drying, enabling a higher capsule throughput. Furthermore, the space required for the device, particularly the transport section, can be reduced.

[0014] Furthermore, it is preferred that the heat source comprises at least two infrared emitters whose radiation differs from each other in terms of its frequency ranges and / or intensities. The frequency ranges can be selected to be specifically tailored to the excitation of different solvents. In this way, different solvents can be dried in rapid succession without any modification of the device. If infrared emitters with different intensities are used, the heat load on potentially heat-sensitive contents of the capsules can be reduced. In this case, too, a complex modification of the device can be avoided.

[0015] Furthermore, it is preferred that the device includes a cooling device for cooling the aperture. The aperture absorbs non-reflected thermal radiation on its side facing the heat source, causing the shielding areas of the aperture to heat up. This can result in heat being transferred to the capsules on the side of the aperture facing away from the radiation source. Cooling the aperture allows the absorbed heat to be dissipated and prevents unwanted heat transfer to the capsules. Cooling can be achieved, for example, by a water line connected to a water circuit, with the water line resting against or integrated into the shielding areas.

[0016] In a preferred embodiment, the device comprises at least one blower unit which supplies an airflow to the area surrounding the capsules and / or the aperture. This airflow can be used to cool the aperture and / or to remove the sublimated solvents from the banding liquid. Optionally, the air in the airflow can be pre-dried, allowing it to absorb a larger quantity of the sublimated solvent. Removing the solvent increases the sublimation rate of the solvent from the banding liquid and thus accelerates the drying process.

[0017] The airflow is particularly advantageous if it flows in a direction opposite to the transport direction of the capsules. This allows the sublimated solvent to be removed quickly and efficiently.

[0018] Furthermore, it is preferred that the blower assembly includes a flow divider that splits the airflow into two parts. A first part of the airflow is used to cool the aperture; a second part of the airflow enables the removal of the sublimated solvent.

[0019] In particular, it is preferred that the first part of the airflow runs in a first sub-space bounded by the heat source and the aperture, and that the second part of the airflow runs in a second sub-space bounded by the aperture and the capsules. In this way, the first part of the airflow can be used specifically for cooling the aperture and the second part of the airflow specifically for removing the sublimated solvent.

[0020] Furthermore, it is preferred that the device has at least one extraction device for extracting the airflow or at least a portion of the airflow. Extraction prevents the accumulation of air that has warmed up after cooling the aperture and / or is saturated with sublimated solvent.

[0021] In a preferred embodiment, a filter is positioned between the heat source and the aperture. The filter can reduce the intensity of the radiation, which in particular reduces the heat load on a potentially heat-sensitive capsule contents. Furthermore, a wavelength-selective filter can be used to optimize the frequency range of the thermal radiation to suit the solvent used.

[0022] A particularly preferred arrangement involves an additional aperture between the heat source and the aperture, with the passage area of ​​the additional aperture aligned with the passage area of ​​the aperture when viewed in the direction of radiation from the heat source. This additional aperture allows a significant portion of the thermal radiation that would otherwise strike the shielding areas of the aperture to be retained. Since the heating of the aperture is significantly reduced, this aperture emits less thermal radiation onto the capsule areas without banding fluid, and the capsule contents are heated less.

[0023] Furthermore, it is preferred that the passage area of ​​the additional aperture is smaller than the passage area of ​​the aperture itself. Since the radiation spreads out conically after passing through the additional aperture, this allows the radiation to be focused onto the passage areas of the aperture, thereby further reducing the heating of the aperture.

[0024] Further features and advantages of the invention are the subject of the following description and the graphic representation of embodiments of the device.

[0025] The drawing shows Fig. 1 a top view of a single capsule, comprising a first shell part and a second shell part with an applied band; Fig. 2 a side view of an embodiment of a device for sealing capsules; Fig. 3 a top view of an aperture of the device according to Fig. 1 ; Fig. 4 a top view of a capsule transport device of the device according to Fig. 1 with capsules; Fig. 5 a side view of another embodiment of a device for sealing capsules; Fig. 6 a side view of another embodiment of a device for sealing capsules; and Fig. 7 a top view of an aperture and an additional aperture of the device according to Fig. 6 .

[0026] Figure 1Figure 1 shows an example of a capsule 10, which has a first capsule shell 12 and a second capsule shell 14. The capsule shells 12 and 14 are telescopically inserted into one another in an overlap or connection area 16 of the capsule 10, with their edge sections facing each other, in a manner known per se. The capsule 10 extends along a central capsule axis 18.

[0027] A banding liquid 20 is applied to an outer surface of the connection area 16, extending along a closed circumference around the capsule axis 18. The banding liquid 20 can be, for example, an aqueous gelatin solution. After the banding liquid 20 dries, a solid band is formed, which seals the capsule 10 and can serve as integrity protection.

[0028] Figure 2Figure 22 shows a device for sealing the capsules 10 with banding fluid 20. After the application of the banding fluid 20, the capsules 10 are conveyed on a capsule transport device 24, for example a conveyor belt 25.

[0029] The conveyor belt 25 can have several transport areas 28 running parallel to a transport direction 26 for the respective reception of a plurality of capsules 10, compare Fig. 4 The capsules 10 are preferably arranged along the respective transport areas 28 such that the capsule axes 18 of the capsules 10 arranged in a transport area 28 are aligned parallel to each other.

[0030] A heat source 30, in particular an infrared radiator, is arranged at a distance from the conveyor belt 25. An aperture 32 is located between the heat source 30 and the conveyor belt 25 (see figure). Fig. 2The aperture 32, for example, is made of stainless steel or a stainless steel alloy and has a plurality of passage areas 34 and shielding areas 36 (see Fig. 3 The passage areas 34 are designed as elongated openings, the respective principal axes of which are aligned parallel to the transport direction 26 of the capsules. The passage areas 34 are bounded by the shielding areas 36.

[0031] The thermal radiation emitted by the heat source 30 and propagating from there strikes the aperture 32. There, the thermal radiation is absorbed in the shielding areas 36 of the aperture 32 and / or reflected back towards the heat source 30 by the shielding areas 36. Only through the passage areas 34 can the thermal radiation reach the conveyor belt 25 and the capsules 10 located on it. By means of the passage areas 34, the thermal radiation is thus focused onto a defined irradiation area 38.

[0032] Preferably, the capsules 10 are arranged on the conveyor belt 25 with their capsule axis 18 perpendicular to the transport direction 26. More preferably, the connecting areas 16 of adjacent capsules 10 are aligned with one another (see figure). Fig. 4 ).

[0033] The distance of the aperture 32 to the conveyor belt 25 and a width 40 of a passage area 36 (compare Fig. 3) is preferably matched to a length of the connection area 16 of a capsule 10 measured parallel to the capsule axis 18, such that a width 42 of the irradiation area 38 corresponds to the length of the connection area 16 of a capsule 10 (compare Fig. 1 and 4 ). In this way, a preferably exclusive heat input to the banding liquid 20 can be achieved, while at the same time the heat load of the capsule areas arranged offset from the connection area 16 is reduced to a minimum.

[0034] The device optionally comprises a blower unit 44 and an extraction unit 46, which are arranged at opposite ends of the conveyor belt 25. The blower unit 44 serves to generate an airflow whose direction of flow is preferably opposite to the transport direction 26 of the capsules 10.

[0035] The blower unit 44 and the extraction unit 46 can optionally each have flow dividers 48, which serve to divide the airflow into two parts. A first part 47 of the airflow (within a first sub-chamber 52 of the device 22) enables targeted application of the aperture 32; a second part 49 of the airflow (within a second sub-chamber 54 of the device 22) enables targeted application of the capsules 10. The first part 47 of the airflow can be used for cooling the aperture 32; the second part 49 of the airflow for removing a sublimated solvent.

[0036] Figure 5 Figure 22 shows a further embodiment of a device 22, wherein a filter 50 is arranged between the heat source 30 and the aperture 32. The filter 50 can be configured as an intensity filter and / or as a wavelength-selective filter.

[0037] A first blower device 44 and a first extraction device 46 are arranged in a first partial space 52 of the device 22, which extends between the heat source 30 and the aperture 32.

[0038] A second blower unit 56 and a second extraction unit 58 are arranged in a second sub-space 54 of the device 22, which extends between the aperture 32 and the conveyor belt 25.

[0039] The aperture 32 extends from a side of the second blower unit 56 facing away from the conveyor belt 25 to a side of the second extraction unit 58 facing away from the conveyor belt 25. In this way, the aperture 32, together with the shielding areas 36, acts as a boundary between a first airflow, which is assigned to the first sub-chamber 52 and serves to cool the aperture, and a second airflow, which is assigned to the second sub-chamber 54 and serves to remove the sublimated solvent. These airflows preferably run in the opposite direction to the transport direction 26 of the capsules 10. The separation of these airflows allows for precise control of the properties of the air used for each airflow.In particular, the air of the second air stream assigned to the second sub-area 54 can be pre-dried, allowing a larger quantity of sublimated solvent to be absorbed by the air of this second air stream.

[0040] Figures 6 and 7 Figure 22 shows a further embodiment of a device 22, wherein, viewed in the direction of radiation from the heat source 30, an additional aperture 60 is arranged between the heat source 30 and the aperture 32. The additional aperture 60 has at least one passage area 62, which is bounded by at least one shielding area 64.

[0041] Preferably, a number of the passage areas 62 of the additional aperture 60 is matched to the number of passage areas 34 of the aperture 32 (see Fig. 7The additional aperture 60 retains a significant portion of the thermal radiation, thereby minimizing the heating of the aperture 32. Preferably, the width 66 of the passage areas 62 of the additional aperture 60 is smaller than the width 40 of the passage areas 34 of the aperture 32, so that the thermal radiation from the heat source 30 is directed onto the passage areas 34 of the aperture 32 by means of the additional aperture 60.

Claims

1. Apparatus (22) for sealing capsules (10), the capsules (10) each having a capsule shell which is formed by a first shell part (12) and a second shell part (14), the shell parts (12, 14) being provided with a banding liquid (20) in a connecting region (16), the apparatus (22) having a heat source (30) for drying the banding liquid (20), characterized in that the apparatus (22) has at least one screen (32) which is arranged in a radiation region of the heat source (30) between the heat source (30) and the capsules (10), the screen (32) having at least one passage region (34) for the passage of radiation from the heat source (30) and irradiation of the connecting regions (16) of the capsules (10), and the screen (32) having at least one shielding region (36) which shields the partial regions of the capsules (10) that are arranged offset from the connecting region (16) against radiation from the heat source (30).

2. Apparatus (22) according to claim 1, characterized in that the apparatus (22) has a capsule transporting device (24) and in that the passage region (34) has a main axis which extends in parallel with a transporting direction (26) of the capsules (10).

3. Apparatus (22) according to either of the preceding claims, characterized in that the heat source (30) comprises at least one infrared radiator.

4. Apparatus (22) according to any of the preceding claims, characterized in that the heat source (30) comprises at least two infrared radiators, the radiations of which differ from one another in terms of their frequency ranges and / or their intensities.

5. Apparatus (22) according to any of the preceding claims, characterized in that the apparatus (22) has a cooling device for cooling the screen (32).

6. Apparatus (22) according to any of the preceding claims, characterized in that the apparatus (22) has at least one fan device (44) which applies an air stream to a surrounding region of the capsules (10) and / or a surrounding region of the screen (32).

7. Apparatus (22) according to claim 6, characterized in that the air stream has a flow direction which extends counter to a transporting direction (26) of the capsules (10).

8. Apparatus (22) according to claim 6 or 7, characterized in that the fan device (44) has a flow divider (48) which divides the air stream into a first portion (47) for cooling the screen (32) and into a second portion (49) for transporting away solvent which has evaporated out of the banding liquid (20).

9. Apparatus (22) according to claim 8, characterized in that the first portion (47) of the air stream flows in a first partial space (52) delimited by the heat source (30) and the screen (32) and in that the second portion (49) of the air stream flows in a second partial space (54) delimited by the screen (32) and the capsules (10).

10. Apparatus (22) according to any of claims 5 to 9, characterized in that the apparatus (22) has at least one suction extracting device (46) for extracting the air stream or at least one portion (47, 49) of the air stream by suction.

11. Apparatus (22) according to any of the preceding claims, characterized in that the apparatus (22) has at least one filter (50) which is arranged between the heat source (30) and the screen (32).

12. Apparatus (22) according to any of the preceding claims, characterized in that the apparatus (22) has an additional screen (60) which is arranged in the radiation region of the heat source (30) and is upstream of the screen (32) in the radiation direction of the heat source (30).

13. Apparatus (22) according to claim 12, characterized in that a passage region (62) of the additional screen (60) is in line with the passage region (34) of the screen (32) when viewed in the radiation direction of the heat source (30).

14. Apparatus (22) according to claim 13, characterized in that the passage region (62) of the additional screen (60) is smaller or larger than a passage region (34) of the screen (32).

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