HEATING PLATE WITH A MULTIPLICITY OF HEATING CARTRIDGES
The present invention relates to a packaging machine with a forming station, which forms depressions in a sheet of film, wherein a heating element heats the sheet of film before the deforming, in which the heating element has a multiplicity of discrete heating means which can be activated individually or in groups, and so the sheet of film has temperature gradients.
Latest CFS Germany GmbH Patents:
- PACKAGING MACHINE AND PROCESS FOR PRODUCING INDIVIDUALLY EVACUATED AND/OR GAS TREATED PACKS
- PACKAGING MACHINE AND METHOD FOR PRODUCING EVACUATED AND/OR GASSED PACKAGINGS
- Method for Changing the Upper and Lower Tool of a Packaging Machine
- HEATING PLATE WITH A MULTIPLICITY OF HEATING CARTRIDGES AND METHOD OF HEATING
- PACKAGING WITH A SUBSEQUENTLY MOLDED FORM-FIT CONNECTION
The present invention relates to a packaging machine having a forming station which forms cavities in a film web, a heating element heating the film web before the deformation.
The packaging machines of the generic type are known from the prior art. In said packaging machines, a cavity is formed in a planar film web by deep drawing. For this purpose, the film web has to be heated with a heating element before the deep drawing. During the deep drawing, the film web is loaded variably. In particular in the region of corners and in the edge region, the film web is expanded to a substantially more pronounced extent than, for example, on the base of the cavity or in the region of the sealing seam. In order to avoid the film becoming too thin in these regions, thicker film webs are used, which has a disadvantageous effect on the costs, the transport and the disposal of the packaging which is to be produced.
It was therefore the object of the present invention to provide a packaging machine which does not have the disadvantages of the prior art.
The object is achieved by a packaging machine having a forming station which forms cavities in a film web, a heating element heating the film web before the deformation, in which packaging machine the heating element has a multiplicity of discrete heating means which can be actuated individually or in groups, with the result that the film web has temperature gradients before the deformation.
According to a further subject or a preferred subject of the abovementioned invention, the packaging machine has a sealing mold, by way of which an upper film is sealed to the packaging cavity, the sealing mold having a heating element to heat it, the heating element having a multiplicity of discrete heating means which can be actuated individually or in groups.
According to the invention, the heating element has a multiplicity of discrete heating means which can be actuated individually or in groups. As a result, it is possible to produce a very defined temperature profile in the film web, which temperature profile corresponds to the respective deep drawing requirements. For example, the temperature should be lower in the corner regions of the packaging, with the result that no weak points are produced in the packaging cavities which are to be manufactured. In the other regions of the film web, from which the packaging is manufactured, the temperature is higher, for example. Desired temperature profiles can also be achieved in the sealing mold by the discrete heating means. Sealing seams of different strengths can be achieved by the level of the temperature in the region of the sealing frame which is in contact with the film web and which produces the actual sealing seam, wherein a higher temperature as a rule results in a stronger sealing seam. The remainder of the sealing mold is preferably heated to a less pronounced extent than the region of the sealing frame. This not only saves energy but is also advantageous, for example, in the processing of shrinkable films which are not to shrink, or are to shrink only a little, in the sealing mold.
The heating means can preferably be operated with a different voltage, with the result that the individual heating means can not only be switched on and off, but can also be operated in each case with a different heat output.
The heating means very particularly preferably has temperature sensors, for example thermocouples, by way of which the temperature of the heating means can be measured locally. In one particularly preferred embodiment of the packaging machine according to the invention, the signal of said temperature sensors is used to regulate the electrical voltage at one or more heating means.
Furthermore, the packaging machine according to the invention preferably has means for improving the thermal exchange between the film web and the heating means. These means can be, for example, vacuum channels, by way of which the film is sucked onto the heating element. A further possibility comprises pressing the film against the heating means by way of pressure.
In a further preferred embodiment, the heating element has means for local cooling. This embodiment of the packaging machines according to the invention is advantageous, in particular, when the heating plate is to have regions which are not to be heated or are to be heated only very slightly, but which are nevertheless heated by the thermal conduction in the heating plate.
The heating means is preferably controlled by a computer. This computer can be used to determine which heating element is loaded with voltage and how high this voltage is. The distribution of the heat output can therefore be programmed freely and stored. An optimum temperature distribution can therefore be stored and called up as required for each packaging format which is manufactured on the packaging machine according to the invention. This temperature distribution can also be a function of the film type to be processed in each case. The deep drawing mold and/or the sealing mold particularly preferably have/has an identification, for example a barcode or a transponder. As soon as said identification has been input or automatically read into the computer, the desired temperature profile is called automatically and the heating means are actuated correspondingly in each case.
The invention will be explained in the following text using
In the drawing:
- 1 Heating element
- 2, 2′, 2″ Heating means, heating cartridge
- 3 Packaging cavity
- 4 Packaging machine
- 5 Sealing frame
- 42 Underfilm web
- 43 Forming station
- 44 Top mold of the forming station
- 45 Lower mold of the forming station
- 46 Support of the lower mold of the forming station
- 48 Sealing station
- 49 Top mold of the sealing station
- 50 Lower mold of the sealing station
- 51 Cutting station
- 52 Top mold of the cutting station
- 53 Lower mold of the cutting station
- 54 Material to be packaged
- 55 Upper film
- 56 Punches
Claims
1. A packaging machine having a forming station which forms cavities in a film web, a heating element heating the film web before the formation of the cavities, characterized in that the heating element has a multiplicity of discrete heating means which can be actuated individually or in groups, with the result that the film web has temperature gradients.
2. The packaging machine preferably as claimed in patent claim 1, characterized in that it has a sealing mold, by way of which an upper film can be sealed to the packaging cavity, the sealing mold having a heating element to heat it, characterized in that the sealing mold heating element has a multiplicity of discrete heating means which can be actuated individually or in groups.
3. The packaging machine as claimed in claim 1, characterized in that the heating means can be operated with a different voltage.
4. The packaging machine as claimed in claim 1, characterized in that the heating element has at least one temperature sensor, the signal of which serves for controlling one or more heating means.
5. The packaging machine as claimed in claim 1, characterized in that it has means for improving the thermal exchange between the film web and the heating element.
6. The packaging machine as claimed in claim 2, characterized in that the heating element of one or both of the forming station or the sealing mold has means for local cooling.
7. The packaging machine as claimed in claim 1 characterized in that the heating element means are controlled so that sections of the film web are heated to different temperatures prior to drawing to control flow of the film web in selected locations during drawing.
8. The packaging machine as claimed in claim 2 characterized in that either or both of the heating element or the sealing mold heating element are controlled so that sections of the film web are heated to different temperatures prior to drawing to control flow of the film web in selected locations during drawing.
9. The packaging machine as claimed in claim 2 characterized in that the machine includes a sealing station at which the sealing mold is located, which is operationally downstream from the forming station.
10. The packaging machine as claimed in claim 8 characterized in that the machine includes a sealing station at which the sealing mold is located, which is operationally downstream from the forming station.
11. The packaging machine as claimed in claim 1 characterized in that the machine includes a sealing station at which a sealing mold is located, which is operationally downstream from the forming station.
12. The packaging machine as claimed in claim 9 characterized in that the machine operates to deep draw an underfilm that unrolls from a reel at the forming station, to form a plurality of cavities that receive material to be packaged, and to seal the cavities having the material therein, with an upper film at the sealing station.
13. The packaging machine as claimed in claim 10 characterized in that the machine operates to deep draw an underfilm that unrolls from a reel at the forming station, to form a plurality of cavities that receive material to be packaged, and to seal the cavities having the material therein, with an upper film at the sealing station.
14. The packaging machine as claimed in claim 11 characterized in that the machine operates to deep draw an underfilm that unrolls from a reel at the forming station, to form a plurality of cavities that receive material to be packaged, and to seal the cavities having the material therein, with an upper film at the sealing station.
15. The packaging machine as claimed in claim 11, characterized in that the heating element of one or both of the forming station or the sealing mold has means for local cooling.
16. The packaging machine as claimed in claim 12, characterized in that the heating element of one or both of the forming station or the sealing mold has means for local cooling.
17. The packaging machine as claimed in claim 13, characterized in that the heating element of one or both of the forming station or the sealing mold has means for local cooling.
18. The packaging machine as claimed in claim 4 characterized in that the heating means are controlled so that sections of the film web are heated to different temperatures prior to drawing to control flow of the film web in selected locations during drawing.
19. The packaging machine as claimed in claim 18 characterized in that the machine includes a sealing station at which the sealing mold is located, which is operationally downstream from the forming station.
20. The packaging machine as claimed in claim 18 characterized in that the machine operates to deep draw an underfilm that unrolls from a reel at the forming station, to form a plurality of cavities that receive material to be packaged, and to seal the cavities having the material therein, with an upper film at a downstream sealing station.
Type: Application
Filed: Sep 21, 2007
Publication Date: Nov 5, 2009
Applicant: CFS Germany GmbH (Biedenkopf-Wallan)
Inventor: Klaus Meyer (Breidenbach)
Application Number: 12/440,656
International Classification: B65B 47/02 (20060101);