Patent Application
20220204196
The present invention relates to a packaging machine for producing a package from a web material comprising paper, and to a method for producing the package from a web material comprising paper.
In the case of plastic packaging, for example packaging for foodstuffs, it is known that a packaging body is produced from one web, for example by means of deep-drawing, and is then sealed with a covering film from a further web. The forming of the packaging body web to create the actual packaging body can here be performed in different forming steps. For example, it is possible to draw the web material freely into a cavity but this causes pronounced crease formation on the packaging body. Alternatively, the packaging body web is fixed upstream from the actual forming process along one edge of a cavity to be formed but this results in limited forming depths and again the formation of creases which, although less pronounced, are still present. Furthermore, a forming method with a punch and die and hold-down clamps is also known in principle, in which a precise degree of slippage of the web material is permitted. As a result, in particular a greater forming depth can be achieved and the formation of creases reduced. These methods are applied mainly for plastic-based webs.
However, attempts have recently increasingly been made, from an environmental perspective, to produce packaging as much as possible from recyclable materials such as, for example, paper materials. Paper materials can hereby be used exclusively or, for example, also composite materials which consist of a paper material coated with plastic. However, such materials comprising paper are relatively difficult to form and undesired creases and microscopic cracks which can result in damage to the packaging body can occur during the forming. It would therefore be desirable to have a method and a device which enable webs comprising paper to be formed reliably.
The packaging machine according to the invention for producing a package enables the production of the package from a paper material which is unreeled from a web reel as the web material. It is here possible according to the invention to produce three-dimensional paper packages which are at least comparable to previously used plastic packages in particular with regard to barrier properties and have significant improvements in particular in the visual appearance and to the touch. A particularly big advantage of the packaging machine according to the invention is that the package to be produced is crease-free and in particular also has no microscopic cracks or the like and can nevertheless be produced from paper. The occurrence of microscopic creases, which could result in an unattractive appearance in paper packages, can moreover also be prevented. This is achieved according to the invention by the packaging machine having a first pretensioning device for pretensioning and expanding the web material comprising paper in the transporting direction of the web material, and a second pretensioning device for pretensioning and expanding the web material in a direction transverse, in particular perpendicular, to the transporting direction. The packaging machine moreover comprises a forming device for producing a depression in the web material in order to receive a filling, a filling device for placing the filling into the depression, and a covering web which serves as a cover for the depression. The covering web is fixed by means of a fixing device as a cover over the depression. The packaging machine moreover comprises an output device which outputs the package, sealed with the cover, from the packaging machine. Smoothing of the web material before the forming step can thus be ensured by expanding in two directions which expand the web material comprising paper both in the transporting direction and transversely to the transporting direction such that no microscopic cracks or microscopic creases or the like occur during the forming step.
The first pretensioning device is preferably arranged upstream from the second pretensioning device in the transporting direction of the web material. This means that the web material is first expanded in the transporting direction and is then expanded transversely to the transporting direction. The duration of the expanding process by means of the first and second pretensioning device is here preferably the same. More preferably, the expanding force exerted on the web material is also the same for both pretensioning devices.
The first pretensioning device particularly preferably comprises a draw roll device with a first and second draw roll, between which the web material is guided, and a pretensioning roll. The pretensioning roll can be moved perpendicular to a center axis of the pretensioning roll. As a result, the process of expanding the web material in the transporting direction can be performed simply.
The packaging machine more preferably comprises a dancer roll arrangement with a first, second, and third roll, wherein the second roll is the pretensioning roll and the third roll is the first draw roll. As a result, a particularly simple and compact and cost-effective structure of the packaging machine is obtained. The dancer roll arrangement furthermore makes it possible that, in addition to the expanding, web material can also be unreeled from the web reel and the production of the package can nevertheless be performed in discrete steps, in particular during the forming step.
The second pretensioning device preferably comprises a plurality of retaining grippers which are arranged on the sides of the web material. The retaining grippers clamp the web material between its gripper jaws and enable the web material to be expanded transversely to the transporting direction. A transverse force exerted on the web material is here preferably perpendicular to the actual transporting direction of the web material.
The forming device more preferably comprises a die, a hold-down clamp, a pneumatic device for generating a pneumatic forming force, and a final forming device for the final forming of the formed depression from the die. The forming device is here particularly preferably configured to perform the forming process in two stages, i.e. with a preliminary forming step and a final forming step. The preliminary forming step is preferably performed pneumatically and the final forming step by means of a punch. Alternatively, the final forming step is also performed pneumatically. Moreover, a detailed embossing step can also be performed in order to emboss detailed structures in the package. The detailed embossing step is preferably performed pneumatically by means of high pressure.
The packaging machine more preferably comprises a control unit which is configured to move the hold-down clamp during the forming step into a position in which web material can be adjusted. As a result, significantly a formation of creases and cracks during the forming step of the package cannot be ensured. Alternatively, the hold-down clamp remains in the lowered position during the forming step and retains the web material.
According to a further preferred embodiment of the invention, the packaging machine moreover comprises a third pretensioning device which is arranged on the covering web for the package. The third pretensioning device here pretensions and expands the covering web in the transporting direction of the covering web. The third pretensioning device is preferably a dancer roll arrangement such that the covering web can likewise be unreeled continuously from a web reel and can be applied on the web material provided with the depression in discrete steps.
The covering web preferably likewise comprises paper and particularly preferably is exclusively produced from paper.
The web material for the packaging body and in which the depression is formed is likewise preferably produced 100% from paper. A plastic coating may optionally be provided on the web material. The plastic coating is preferably provided on that side of the web material which later forms the inner side of the package.
The packaging machine more preferably comprises a fixing device which is arranged movably. As a result, alignment of the fixing device relative to the formed depression in the web material can be performed such that the covering web can be applied to the web material reliably and in a precise position. The alignment is preferably effected by means of printed marks and sensors which detect the printed marks. The movably arranged fixing device can here preferably be moved both in the transporting direction and transversely to the transporting direction.
According to a further preferred embodiment of the present invention, the packaging machine comprises a heating device which is arranged downstream from the first and second pretensioning device but upstream from the forming device, in the transporting device of the web material. More reliable and quicker forming of the web material comprising paper can be enabled by heating the web material before the forming step. The heating device here preferably heats the web material to a maximum of 160° C.
The packaging machine preferably comprises a moistening station which is configured to moisten the web material. The moistening station is preferably arranged downstream from the first and second pretensioning device but upstream from the forming device, in the transporting direction of the web material. If a heating device is provided, the moistening station is more preferably arranged downstream from the heating device in the transporting direction.
It should be noted that a heating device and/or a moistening station can preferably also be provided for the covering web.
The packaging machine preferably also comprises a station for applying an adhesive or the like. The adhesive can be applied to the web material with the depression and/or to the covering web. As a result, a particularly reliable bond between the web material and covering web is possible.
Transport grippers are more preferably also provided. The transport grippers are particularly preferably arranged between the retaining grippers of the second pretensioning device. Alternatively or additionally, one or more draw roll devices can also be provided for transporting.
The present invention moreover relates to a method for producing a package. The method enables the production of a package which has no microscopic cracks and no microscopic creases. The method is performed according to the invention with a web material comprising paper in order to produce a packaging body with a depression in the web material for receiving a filling. The method here comprises the steps of a first pretensioning and expansion of the web material in the transporting direction, a second pretensioning and expansion of the web material transversely to the transporting direction, and forming a depression in the web material into which the filling is subsequently placed. A crease-free package with no microscopic cracks can be produced by the expansion in at least two directions which differ by approximately 90 degrees.
The web material is preferably unreeled continuously from a web reel and the first pretensioning and expansion are performed in the transporting direction by means of a roll of a dancer roll arrangement.
A covering web for sealing the depression in the web material is preferably pretensioned and expanded before the sealing step in the transporting direction of the covering web. As a result, it is ensured that the cover of the depression, which is produced from the covering web, also has no creases and microscopic cracks.
The forming step of the method is preferably performed in two stages. A third step of detailed embossing of structures in the package is here also particularly preferably performed.
A preferred exemplary embodiment of the invention is described in detail below with reference to the attached drawings, in which:
A packaging machine 1 according to a preferred exemplary embodiment of the invention and a production method according to the invention are described below with reference to
The packaging machine makes it possible to produce a package 20 comprising paper. The package can here be produced completely from paper and in particular contain no plastics or the like.
As can be seen from
In order to produce the package 20, a depression 21, which is then sealed by a cover 31 provided by the covering web 3, is introduced into the web material 2 after a filling has been introduced into the depression 21. The packages 20 produced in this way can then be discharged from the packaging machine 1, for example by means of a conveyor belt 13.
The packaging machine 1 hereby comprises a web reel 22 onto which the web material 2 is reeled and from which the web material is continuously unreeled. The packaging machine 1 moreover comprises a first pretensioning device 4 for pretensioning and expanding the web material in a transporting direction 16 of the web material, and a second pretensioning device 5 for pretensioning and expanding the web material 2 in a second direction transversely to the transporting direction 16. This second expansion is indicated in
The packaging machine 1 moreover comprises a forming device 6 for producing the depression 21 in the web material 2. The forming device is shown schematically in
The preliminary forming is preferably performed by means of compressed air and the final forming by means of the punch 63. It is moreover also possible that detailed structures are additionally introduced into the depression which are preferably introduced by means of high pressure.
The packaging machine 1 furthermore comprises a filling device 7 which places a filling to be packaged, for example a foodstuff, into the produced depression 21.
After filling, the depression 21 must be covered and sealed by means of the cover 31 from the covering web 3. For this purpose, a fixing device 10 is provided which is a sealing device in this exemplary embodiment.
Before the actual sealing process, the covering web 3 and the web material 2 with the produced depression 21 are again aligned relative to each other. The alignment can be effected, for example, by means of printed marks on both webs. The fixing device 10 is moreover also provided movably, as indicated in
After the covering web 3 has been fixed on the web material 2, the packages which are still joined together on the covering web 3 are transported onward to an output device 13 which has, for example, a die cutter 8 or the like for separating the packages 20. The packages 20 can then be discharged from the packaging machine 1.
As can be seen from
In contrast, the web material 2 is expanded by the first pretensioning device 4 in the transporting direction 16 and by the second pretensioning device 5 in the second direction 17 transversely to the transporting direction 16. The first pretensioning device 4 hereby comprises a draw roll device 40 and a dancer roll arrangement 44. The dancer roll arrangement 44 comprises three rolls. The draw roll device 40 comprises two rolls, namely a first draw roll 41 and a second draw roll 42, wherein the web material 2 is guided between the first and second draw roll 41, 42.
The first draw roll 41 of the draw roll device 40 here forms the third roll of the dancer roll arrangement 44 such that the draw roll device 40 and the dancer roll arrangement 44 share a roll.
The dancer roll arrangement 44 moreover also comprises a first roll 46 which is arranged immovably and a pretensioning roll 45. The pretensioning roll 45 can here move in a direction perpendicular to a center axis of the pretensioning roll 45, as indicated in
After the web material 2 has been expanded in the transporting direction 16, a second expansion transverse to the transporting direction is effected by means of the second pretensioning device 5. As can be seen in
The web material 2 is thus expanded in two successive steps in two directions oriented perpendicularly to each other. As a result, it is ensured that a crease-free web material is fed to the forming device 6 and moreover that no microscopic cracks or the like or creases can occur during the forming process. Additionally, the prevention of creases is further promoted by the forming process being performed in two stages, wherein the hold-down clamp 61 can be lifted off the web material 2 for the final forming step such that material can flow into the die 62 for the final forming step.
In order to further facilitate the forming step in the forming device 6, a heating device 11 is also additionally provided. The heating device 11 is provided downstream from the draw roll device 40 and upstream from a device 12 for applying adhesive, in the transporting direction. This device 12 here enables adhesive to be applied precisely to regions of the web material 2 on which it is intended for the covering web 3 to be fixed later in order to provide the cover 31.
It should moreover be noted that for the forming step the web material is moved on in discrete steps, which can be performed, for example, by transport grippers (not shown) on the side of the web material or also by the retaining grippers 50 of the second pretensioning device 5.
It should furthermore be noted that, depending on the material chosen for the web material 2 and the covering web 3, different fixing devices 10 can be provided. In the exemplary embodiment shown, the web material 2 and the covering web 3 are produced completely from paper and fixing is effected by means of the adhesive from the device 12 for applying the adhesive. It would, however, also be conceivable that the web material 2 can be a composite material of paper and a plastic film and the fixing device 10 can then be, for example, an ultrasound fixing device. Hot-air welding or laser welding, or alternatively also a thermal contact method, would also be possible.
A novel method for producing a package 20 from a material comprising paper can thus be provided by means of the packaging machine 1 according to the invention. The web material 2 providing the depression 21 is here expanded in two directions and additionally the covering web 3 provided for the cover 31 is also expanded in one direction.
The joining process between the covering web 3 and the web material 2 can hereby be assisted owing to the use of paper as the basic material, in particular when the web material 2 and the covering web 3 are 100% made of paper, and preferably further by heating and/or moistening at least the regions at which the covering web 3 is later joined with the web material 2. It may then hereby also be possible to completely dispense with a device 12 for providing adhesive. This device 12 is, for example, also not required if a plastic coating or the like, which is heated in the fixing step and thus enables a bond between the web material 2 and the covering web 3, is provided on at least one web.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2019 205 173.1 | Apr 2019 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/055283 | 2/28/2020 | WO | 00 |
