Patent Application
20240217187
The present invention relates to a sealing or moulding tool of a packaging machine. Furthermore, the present invention relates to a packaging machine having a moulding station, which forms recesses into a lower material web, wherein a heating element heats the lower material web before and/or during the deformation, and a sealing station, which connects an upper material web to the lower material web and has a heating element for this purpose.
Class-specific packaging machines are known from prior art. In these packaging machines, a recess is formed in a flat material web, for example a film web, by deep drawing. For this purpose, the material web must be heated with a heating element before deep drawing. During deep drawing, the material web is subjected to different stresses. Especially in the area of corners and in the edge area, the material web is stretched much more than, for example, at the bottom of the recess or in the area of the sealing seam. To prevent the material from becoming too thin in these areas, thicker material webs are used, which has a particularly negative effect on the cost, transport and disposal of the packaging to be produced. During sealing, too, the two material webs must be heated exactly but only locally, if possible.
It was therefore the object of the present invention to provide a sealing or moulding tool and a packaging machine which do not have the disadvantages of the prior art.
The object is solved by a sealing or moulding tool of a packaging machine having a heating element with a heating plate provided on a carrier and covered with a cover element, wherein the cover element is connected to the carrier by means of a plurality of connecting means.
The explanations given with respect to this subject matter of the present invention apply equally to the other subject matters and vice versa. Features of this subject matter of the present invention may be incorporated into other subject matters and vice versa.
This subject matter of the present invention relates to a sealing or moulding tool of a packaging machine with a heating element having a heating plate provided on a carrier.
A heating plate within the meaning of the invention is not necessarily, but preferably, a flat two-dimensional object. It can also be curved or otherwise formed 3-dimensionally. The heating plate can be located in the sealing tool and/or in the moulding tool and here in particular in the upper tool and/or upstream of the moulding tool, relative to the transport direction of the lower material web. The heating plate can be connected directly to the carrier. Preferably, however, thermal insulation is provided between the heating plate and the carrier, for example of a very strong, thermally insulating material. Alternatively, the heating plate itself consists at least substantially of thermal insulation. Preferably, the heating plate consists of a heating film. On the side of the heating element facing the material web to be heated, the heating element has a cover element, preferably made of a material with good thermal conductivity, in particular metal, preferably aluminum or stainless steel. Preferably, there is direct and preferably full-surface contact between the heating plate and the cover element. Accordingly, the heating element preferably consists of a heating plate, a carrier and a cover element, wherein, in addition, thermal insulation may be provided between the carrier and the heating plate, or the carrier may be at least partially designed as thermal insulation.
According to the invention, the cover element is connected to the carrier and/or to the insulation by means of a plurality of connecting means. The connecting means are preferably arranged in such a way that there is no contact with the material web.
Preferably, the cover element is a film or plate, in particular a sheet or a sheet film, preferably an aluminum sheet or an aluminum film, the edge area of which is preferably flanged or bent or edged at least in sections. Preferably, the cover element is provided as a porous component.
The cover element can be manufactured as a 3D-printed part. Preferably, the material thickness, in particular the sheet thickness of the cover element, is 0.2-2 mm. This range has proven to be particularly advantageous because with a smaller material thickness, especially aluminum sheet thickness, the cover element tends to warp and/or the heat capacity of the cover element is too low, while with a greater material thickness the desired temperature profile becomes blurred.
Preferably, the connecting means are provided in the flanged/bent/edged section of the cover element. Alternatively or additionally or particularly preferably, the connecting means are provided on the back side of the cover element, in particular on that part of the back side which extends parallel to the film web.
Preferably, sleeves and/or bolts and/or nuts, in particular sleeves/bolts with a thread, are provided on the cover element. The sleeves, bolts and/or nuts are connected to the cover element, in particular by a welded and/or bonded connection. The sleeves may have an internal or external thread. The connecting means are preferably connected with a screw with an internal or external thread. Instead of the screw, a nail can also be used, but this may have the disadvantage that the connection is more difficult to undo. The fastener may also be a riveted connection, such as a connection with blind or pop rivets. A connecting means within the meaning of the invention is not a material connection. The connection between the covering means and the carrier is preferably provided in such a way that the covering means is clamped against the heating plate. A heat-conducting layer, in particular an elastic one, can be provided between the cover element and the heating plate.
Preferably, the connecting elements are provided according to a grid, in particular equidistantly.
Preferably, the carrier is a thermal insulation material. Preferably, the carrier and/or the thermal insulation provided between the carrier and the heating plate is not provided in one piece but in multiple pieces, in particular as a plurality of plate segments. Preferably, the dimensions of at least two segments, preferably all segments, are identical. Preferably, a gap is provided between the segments. A gap is particularly advantageous if it can prevent mutual interference between the segments as a result of thermal expansion, especially of different thermal expansion. Preferably, at least one, preferably several channels are provided in the carrier and/or the thermal insulation, through which a gas can be routed in order to suck the material web onto the covering element and/or to blow out a gas with which the material web is formed. Preferably, the carrier and/or the thermal insulation have at least one cable routing channel. In the case of several channels, these are preferably arranged according to a grid, in particular equidistantly.
The cover element can have cutouts, in particular in a preferably uniform grid, by means of which a negative and/or positive pressure can be generated between the cover element and the material web.
The heating plate is preferably an electric heating plate, wherein the power supply is preferably routed through the carrier and any thermal insulation present, and/or is provided through the carrier and/or the thermal insulation, for example inductively.
Preferably, a connecting means extending at least partially through the thermal insulation and/or the carrier is provided on the cover element and is preferably connectable to the thermal insulation and/or the carrier. The connecting means is preferably located on the side of the cover element facing away from the material web and particularly preferably at a distance from the cover element's edge area, preferably in the area of its center or in the area of one or more symmetry axes.
A further preferred or inventive subject matter of the present invention is a sealing or moulding tool with which packaging recesses or packaging of different cross-sections and/or sealing seams of different shapes are produced and which has a heating plate, wherein the heating plate has a conducting path pattern consisting of a plurality of L-shaped conducting paths per recess/packaging to be produced.
The explanations given with respect to this subject matter of the present invention apply equally to the other subject matters and vice versa. Features of this subject matter of the present invention may be incorporated into other subject matters and vice versa.
According to this subject matter of the present invention, material webs can be locally heated with the same heating plate in such a way that packaging recesses with a different cross-section, i.e. with different dimensions of the packaging in length and/or width, and/or sealing seams with a different shape/geometry can be produced. For this purpose, the conductor plate preferably has a plurality of conducting path patterns, each of which has a plurality of conducting paths, for example straight and/or L-shaped conducting paths or a combination thereof. Several straight and/or L-shaped conductive paths are preferably used per packaging recess or sealing seam.
Bridging elements can be provided between two L-shaped conductive paths at one or both ends, which can be electrically controlled together with the adjacent L-shaped conductive path or separately from it. Several conductive paths can be controlled individually and/or in groups.
Another preferred or inventive subject matter of the present invention is a sealing or moulding tool in which the heating plate is constructed from a plurality of, preferably identical, modules.
The explanations given with respect to this subject matter of the present invention apply equally to the other subject matters and vice versa. Features of this subject matter of the present invention may be incorporated into other subject matters and vice versa.
According to the invention or preferably, the heating plate is constructed from several modules which are arranged next to each other, preferably in one plane. Each module is preferably rectangular, in particular square. The extension transverse to the transport direction resulting from the modules arranged next to each other is preferably greater than the useful width of the material web. The extension in the transport direction resulting from the modules arranged next to each other is preferably greater than or equal to the forward pull in the case of an intermittently transported material web.
Preferably, the extension transverse to the transport direction resulting from the modules arranged next to each other is greater than the distance between the transport means, in particular greater than the distance between the clamping means arranged on the transport means, which clamping means grip the material web.
Each module is preferably individually electrically connected and individually controllable/adjustable.
Each module preferably has a grid/pixel pattern of local heating points/pixels, each of which can be electrically controlled separately or in groups/as a group.
Preferably, there is a gap between the modules, in particular a gap running around the respective module, between the modules of a heating plate.
Particularly preferably, this gap is at least in part completely sealed in such a way that no noteworthy air flow passes through the gap, especially in the case of backside gassing of the conductor plates, for example with compressed air. Preferably, the seal between two modules is provided elastically. For example, the seal is made of a rubber-like material.
Preferably, at least one module, preferably each module, has a cutout, preferably a circular cutout, through which a gas can be extracted and/or blown in the direction of the material web.
A further subject matter of the present invention is a packaging machine having a moulding station, which forms recesses into a lower material web, wherein a heating element heats the lower material web before and/or during the deformation, and a sealing station, which connects an upper material web to the lower material web and has a heating element for this purpose, wherein the heating elements of the moulding station and of the sealing station are of at least substantially, preferably completely, identical construction.
The explanations given with respect to this subject matter of the present invention apply equally to the other subject matters and vice versa. Features of this subject matter of the present invention may be incorporated into other subject matters and vice versa.
This subject matter of the present invention relates to a packaging machine for producing a packaging, in which a lower material web, for example, a plastic film or a material web having in particular a cardboard, paper or other non-plastic layer, is unrolled from a supply roll and transported preferably intermittently/cyclically along the packaging machine in a transport plane. In a moulding station, this lower material web will then first be formed by means of a deep drawing tool, for example to form a recess and/or a structure, in particular an anti-slip structure, in the lower material web. The moulding station usually has a lower tool and an upper tool which are moved towards each other for forming and away from each other for further transport of the lower material web. The lower tool is located below and the upper tool above the transport plane of the lower material web. As a rule, several packagings arranged in a so-called format are processed simultaneously in the packaging machine according to the invention and are subsequently transported simultaneously along the packaging machine.
Before and/or during deep drawing, the lower material web is heated with a heating element. Subsequently, the lower material web is loaded with a material to be packaged, in particular a food product such as sausage, ham or cheese, and in a next step is sealed with an upper film in a sealing station, wherein the upper film is usually sealed to the lower film web. A heating element is used for this purpose, which provides the thermal energy required for sealing. Subsequently, the packaging thus completed is separated by cutting out the packaging from the lower and upper material webs. The upper material web is also unrolled from a supply roll. In relation to the transport direction of the respective film web, downstream of at least one supply roll there is preferably a dancer which keeps the tension in the respective material web at least substantially constant. The dancer can be a linear dancer or a rotational dancer.
According to the invention, at least substantially identical heating elements, in particular identical heating plates, are used for the moulding station and for the sealing station. The heating plates can each be constructed from several modules, in particular identical modules, which are provided next to each other in one plane. Preferably, the heating elements have identical carriers and/or identical thermal insulation and/or cover elements.
A further subject matter of the present invention is a packaging machine having a moulding station which forms recesses into a lower material web, wherein a heating element heats the lower material web before and/or during the deformation, and/or a sealing station which connects an upper material web to the lower material web and has a heating element for this purpose, and having transport means which transport the lower material web in a transport direction, wherein the transport means are provided at a distance transverse to the transport direction, and the extension of the heating element transverse to the transport direction is > than the distance of the transport means.
The explanations given with respect to this subject matter of the present invention apply equally to the other subject matters and vice versa. Features of this subject matter of the present invention may be incorporated into other subject matters and vice versa.
In this subject matter of the present invention, the extension of the heating element transverse to the transport direction of the material web is greater than the distance of the two transport means to the right and left of the material web transporting the material web and/or greater than the distance of the clamping means provided on the transport means.
Preferably, the heating plate and/or its modules can be controlled in such a way that, preferably at least, the area of the heating element that overlaps the transport means and/or the clamping means is not heated.
Another subject matter of the present invention is a packaging machine having a moulding station which forms recesses into a lower material web, wherein a heating element heats the lower material web before and/or during the deformation, and/or having a sealing station which connects an upper material web to the lower material web and has a heating element for this purpose, and having transport means which transport the lower material web in a transport direction, wherein the lower material web has a usable width, wherein the extension of the heating element transverse to the transport direction is ≥ than the usable width.
The explanations given with respect to this subject matter of the present invention apply equally to the other subject matters and vice versa. Features of this subject matter of the present invention may be incorporated into other subject matters and vice versa.
In this subject matter of the present invention, the extension of the heating means transverse to the transport direction of the material web is greater than or equal to the useful width of the material web transverse to the transport direction. Preferably, the extension of the heating element transverse to the transport direction is greater than the distance between the transport means, in particular greater than the distance between the clamping means arranged on the transport means, which clamping means grip the material web. The usable width is the material web width minus an edge strip on the right and left in relation to the transport direction, which is required for gripping the material web or for holes for the gas exchange.
Preferably, the heating element is controllable so that the area of the heating element that exceeds the usable width is not heated.
A further subject matter of the present invention is a method for producing a packaging, in particular with the packaging machine according to the invention described herein, in which a material web is formed by means of compressed air, wherein the compressed air is blown through the heating plate.
The explanations given with respect to this subject matter of the present invention apply equally to the other subject matters and vice versa. Features of this subject matter of the present invention may be incorporated into other subject matters and vice versa.
In this embodiment of the present invention, the heating element is located inside the moulding tool, in particular in the area of the upper tool, and the forming of the material web into a packaging recess is effected and/or assisted by compressed air acting on the material web from above. According to the invention, this compressed air now flows through the heating plate. For this purpose, the heating plate has one or more cutouts, for example bores. Alternatively or additionally, the compressed air flows through one or more gaps between two modules of which the heating plate consists and/or through a gap running around the outer modules.
Preferably, the compressed air is heated, i.e. it has a temperature >20° C. This heating is particularly preferably not effected exclusively by the heating element.
The invention is explained below with reference to
Otherwise, the explanations given for the transport means of the bottom film apply. The upper film can also be heated and/or deep drawn with heating element. For sealing, the lower tool 11 is provided, for example, as a sealing frame which has an opening for each packaging recess into which the, if applicable, present packaging recess dips during sealing, i.e. during the upward movement of the lower sealing tool. For sealing, the upper and lower material webs are pressed together between the upper and lower tools 12, 11 and bond under the influence of heat and pressure. After sealing, the tools 11, 12 are moved apart again vertically. A dancer, for example, a rotary dancer, which keeps the material web 14 at a constant tension to the extent possible, can be provided between the supply roll of the upper material web 14 and the sealing tool. The person skilled in the art understands that a dancer is also preferably provided in the area of the lower material web 8, preferably downstream of the supply roll. Preferably, the dancer is a linear dancer. A gas exchange preferably takes place in each packaging recess before and/or during the sealing of the upper material web to the lower material web. For this purpose, the air present in the packaging recess is first partially extracted and/or replaced by an exchange gas. For this purpose, holes can be made in the area of each format in the lower material web 8 in the area of the transport chains, through which holes the air between the material webs 8, 14 is extracted and/or the exchange gas is blown in. In the further course of the packaging machine, the completed packagings are separated, which, for example, is done with the traverse cutter 18 and the longitudinal cutter 17. In the present case, the transverse cutter 18 can also be raised or lowered by means of a lifting device 9. According to another embodiment, the sealing tool 11, 12 has a punch which severs the lower and upper material webs before, during and/or after sealing.
Preferably, each cycle produces several packagings simultaneously, arranged as matrix in a so-called format. Such formats are shown in
The adjustment of the control of the heating plate is preferably automatic, in particular computer-controlled.
This flanged or bent area is then connected to the carrier or to the insulation layer, if present, preferably reversibly, for example by screws.
On its side facing the heating plates, the cover element can have a connecting means 24, for example a welding stud 24, which extends at least partially through the carrier 27 and with which the cover 25 can be connected to the carrier, in particular reversibly. The connecting means, which is located in an area of the cover element remote from the edge area, can prevent the cover from moving away from the heating plate, in particular from pulsating or vibrating, during heating of the material web and/or during sealing.
The control of the conductive path pattern 29 according to
By a simple change of the control, it is possible to switch from one packaging form to the other.
The cover plate is connected to the carrier plate by means of screws.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 208 238.3 | Jul 2020 | DE | national |
This application is a US National Stage of PCT/EP2021/067903 filed on Jun. 29, 2021, and which claims priority to DE 10 2020 208 238.3 filed on Jul. 1, 2020, all of which are hereby incorporated by reference herein for all purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/067903 | 6/29/2021 | WO |
