WO2023078920A1

WO2023078920A1 - Sealing tool comprising a heating plate with stacked conductor tracks

Info

Publication number: WO2023078920A1
Application number: PCT/EP2022/080539
Authority: WO
Inventors: Reiner Paul
Original assignee: Gea Food Solutions Germany Gmbh
Priority date: 2021-11-05
Filing date: 2022-11-02
Publication date: 2023-05-11
Also published as: EP4426544A1

Abstract

The present invention relates to a sealing or forming tool with which packaging trays or packagings of different cross-sections and/or sealing seams of different shapes are produced and which has a heating element, characterized in that the heating element, in particular for each tray/packaging to be produced, has a multiplicity of stacked conductor track planes (25, 26, figure 7) that are parallel to the conveying plane of the material web (8, 14). Preferably, at least one conductor track module comprises a multiplicity of individually controllable conductor tracks (27) for forming or closing packagings of different shapes and cross-sections.

Description

Sealing tool with a heating plate with stacked traces

The present invention relates to a sealing or forming tool with which packaging trays or packaging of different cross-sections and/or sealing seams of different shapes are produced and which has a heating plate. Furthermore, the present invention relates to a packaging machine.

The generic sealing or forming tool is known from the prior art and is used in particular in packaging machines. With these packaging machines, a trough is formed by deep-drawing in a planar web of material, for example a film web. To do this, the material web must be heated with a heating element before deep-drawing. The heating must be flexibly adaptable to different packaging cavities and/or formats.

It was therefore the object of the present invention to provide a sealing or forming tool and a packaging machine that meets these requirements.

The object is achieved by a sealing or forming tool with which packaging cavities or packaging of different cross-sections and/or sealing seams of different shapes are produced and which has a heating element, the heating element having a large number of conductor track levels, in particular for each cavity/packaging to be produced. which are provided parallel to the transport plane of the material web and one above the other.

The statements made on this subject matter of the present invention apply equally to the other subjects and vice versa. Features of this subject of the present invention may be incorporated into other subjects and vice versa.

This subject matter of the present invention relates to a sealing or forming tool with a heating element, which is used for heating a material web, in particular in a packaging machine. Preferably, the web of material is stationary when heated and rests against the heating element. For this purpose, the heating element can have a means that improves the contact between the web of material and the heating element, which is provided in particular in such a way that the web of material bears against the heating element over its entire surface. Preferably the heating element is a plate, but not necessarily but preferably such a flat two-dimensional object. But it can also be curved or be shaped differently 3-dimensionally. The heating element is preferably located upstream of the forming tool, in relation to the transport direction of the material web, for example as a so-called preheating before the forming tool or in the sealing tool. Alternatively or additionally, the heating element is integrated into the mold, for example as a so-called cover heater. The heating element can be connected directly to a carrier that is part of the packaging machine, in particular part of the forming station and here in particular part of the upper tool, or be an integral part of the carrier. This carrier can be provided to be vertically movable, so that it can be moved towards and away from the material web. Thermal insulation is preferably provided between the heating element and the carrier.

The heating element, which is operated with electrical energy, heats the material web preferably from one side, for example from above as in a lid heater or from below as in a so-called "preheating from below", or from both sides, for example from above and below as in a sandwich heating as so-called "pre-heating from above and below", especially if the energy input into the material web should be even faster.

According to the invention, the heating element has a large number of conductor tracks which are provided parallel to the plane of transport of the material web and one above the other. The conductor tracks are consequently provided as a stack. Each conductor track level consists of an arrangement of one, preferably several, electrically conductive material in the form of a web, which is provided on a carrier material. A number of conductor track modules are preferably provided next to one another in each conductor track. Each trace module may include one or more separate traces of electrically conductive material. The conductor track modules are preferably identical for each conductor track level. The conductor track modules of a conductor track level can preferably be controlled individually or as a group, for example all at the same time, with electrical energy. The number of conductor track modules at least in one conductor track level preferably corresponds to the number of packages and/or the arrangement of the packages that can be produced in one cycle of the packaging machine. One or more conductor tracks can be involved in the heating of the material track.

The conductor track levels are preferably designed differently. According to a particularly preferred embodiment, the arrangement of the conductor tracks and/or the material of the conductor track and/or the material of the carrier material and/or the cross section of the conductor track and/or the cross section of the carrier material is different. Also preferably, at least one conductor track module has a multiplicity of separate, separately controllable tracks of electrically conductive material.

A plurality of conductor track modules, in particular of one conductor track level, can preferably be controlled individually or in groups. The electrical voltage can preferably be individually controlled per module or in groups.

The modules of a conductor track level are preferably of identical design.

The sealing and/or forming tool preferably has a pressure means that presses the conductor track planes together. In a particularly preferred manner, the body planes are not connected to one another in a materially bonded manner.

Another object of the present invention is a packaging machine with a forming station that forms troughs in a lower web of material, with a heating element heating the lower web of material before and/or during shaping, and a sealing station that connects an upper web of material with the lower web of material and has a heating means for this, wherein the forming station has a forming tool or the sealing station has a sealing tool with a heating element according to one of the preceding features.

This subject matter of the present invention relates to a packaging machine for producing packaging in which a base material web, for example a plastic film or a material web, which in particular has a cardboard, paper or other layer different from plastic, is unwound from a supply roll and preferably intermittently/cyclically is transported along the packaging machine in a transport plane. In a forming station, this web of lower film is then initially shaped by means of a deep-drawing tool in order to form, for example, a trough and/or a structure, in particular an anti-slip structure, in the web of lower material. As a rule, the forming station has a lower and an upper tool, which are used for forming towards one another and for further transport of the lower web of material from one another be moved away. The lower tool is located below and the upper tool above the transport level of the lower web of material. As a rule, in the packaging machine according to the invention, several packages arranged in a so-called format are processed simultaneously and subsequently transported along the packaging machine at the same time. Before and/or during deep-drawing, the web of base material is heated with a hotplate. The lower web of material is then covered with a packaged product, in particular a foodstuff such as sausage, ham or cheese, and in a next step is sealed with an upper film in a sealing station, the upper film usually being sealed to the lower web of film. A heating plate is used for this, which provides the thermal energy required for sealing. The packaging thus finished is then separated by cutting out the packaging from the lower and upper web of material. The facestock is also unwound from a supply roll. In relation to the transport direction of the respective film web, a dancer is preferably located downstream of at least one supply roll, which dancer keeps the tension in the respective material web at least substantially constant. The dancer can be a linear or a rotary dancer.

The present invention has at least one of the following features, which apply equally to all objects of the present invention:

- a different format can be heated with each conductor track level.

- by switching between the levels you can switch back and forth between different formats.

- The heating element can be used in the forming and/or sealing tool.

- Preferably, two or more conductor track levels are applied simultaneously with electrical energy. These levels are particularly preferably directly adjacent.

- Individual modules of one or more conductor track levels can preferably also be combined with one another.

- A protective layer that may be present for the electrical conductor track levels should preferably be designed in such a way that it has a high ohmic resistance, keeps moisture out and/or provides mechanical protection.

- Preferably, the conductor track levels lie loosely on top of each other.

- If there is a connection between the conductor track levels, it is preferably loose. The conductor track levels are preferably not bonded to one another and/or not pressed together. - The thickness of a conductor track level is preferably 0.05-0.15 mm, particularly preferably 0.8-1.2 mm.

- preferably the layer that is closest to the material web to be heated is also a protective layer against cleaning agents and/or serves as an anti-adhesive agent,

- The conductor tracks are preferably electrically insulated from one another.

The invention is explained below with reference to FIGS. 1 to 7f. These explanations are merely exemplary and do not limit the general inventive concept. The explanations apply equally to all objects of the present invention.

FIG. 1 schematically shows the packaging machine according to the invention.

Figures 2a - d show different formats of packaging trays

Figures 3 - 5 show a further embodiment of the packaging machine.

Figures 6a and 6b show two possible formats

Figures 6c - 6e shows two embodiments of the heating element

FIG. 7 shows two stacked trace levels

FIG. 1 shows the packaging machine 1 according to the invention, which optionally has a forming station 2 , a filling station 7 and a sealing station 15 . The packaging machine can be a so-called thermoformer or a so-called traysealer. A base material web 8, here a plastic film 8, is pulled off a supply roll and transported intermittently along the packaging machine according to the invention from right to left. With each cycle, the sub-material web 8 is transported further by one format length/advance length. For this purpose, the packaging machine has two transport means 21 (see FIG. 5), in the present case two endless chains each, which are arranged to the right and left of the base web 8 . At least one gear wheel is provided for each chain both at the beginning and at the end of the packaging machine, around which the respective chain is deflected. At least one of these gears is driven. The gear wheels in the input area and/or in the output area can be connected to one another, preferably by a rigid shaft. Each transport means 21 has a multiplicity of clamping means/grippers 22 which hold the sub-material web 8 in Grip the inlet area and transfer the movement of the transport means to the base web 8 . In the outlet area of the packaging machine, the clamping connection between the transport means and the base material web 8 is released again. A heating means can be provided downstream of the inlet area, which heats the base material web 8, in particular when the latter is stationary. The forming station 2 has a lower tool 4 and an upper tool 3 . As indicated by the double arrow, the lower tool 4 can be moved up and down, being moved upwards in the direction of the lower material web 8 for shaping and downwards for further transport of the lower material web 8 . In the raised position, the web of base material is preferably clamped between the two tools 3, 4. The lower tool 4 can be arranged on a lifting table 5, which, as symbolized by the double arrow, can be vertically adjustable in order to produce the movement of the lower tool described above. In the further course of the packaging machine, the packaging troughs 6 indicated here formed in the base material web or the base material web 8 are then filled with the packaged goods 16 in the filling station 7 . In the subsequent sealing station 15, which also consists of an upper tool 12 and a lower tool 11, which can be vertically adjusted if necessary, an upper film 14 is fixed to the lower web of material 8 by sealing in a materially bonded manner. As a result, the movement of the lower material web 8 is transferred to the upper material web 14 . In the sealing station, too, the upper tool and/or optionally the lower tool are lowered or raised before and after each film transport. The upper film 14 can also be guided in transport means or transported by transport chains, with these transport means then only extending in front of the sealing station and possibly upstream. Otherwise, the statements made regarding the means of transport for the lower film apply. The top film can also be heated and/or thermoformed with a heating means. For example, a sealing frame is provided as the lower tool 11 for sealing, which has an opening per packaging trough, into which the packaging trough, if present, dips during sealing, ie during the upward movement of the lower sealing tool. For sealing, the upper and lower webs of material 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, can be provided between the supply roll of the upper material web 14 and the sealing tool, which keeps the material web 14 at a constant tension as far as possible. The person skilled in the art understands that a dancer is preferably also provided in the area of the base material web 8, preferably downstream of the supply roll. The dancer is preferably a linear dancer. Before and/or when sealing the A gas exchange preferably takes place in each packaging cavity between the upper material web and the lower material web. For this purpose, the air present in the packaging tray is first of all partially sucked off and/or replaced by an exchange gas. For this purpose, holes can be made in the base web 8 in the area of the transport chains in the area of each format, through which the air between the webs 8, 14 is sucked out and/or the exchange gas is blown in. In the further course of the packaging machine, the finished packages are separated, which is done with the cross cutter 18 and the longitudinal cutter 17, for example. In the present case, the cross cutter 18 can also be raised or lowered with a lifting device 9 . According to another embodiment, the sealing tool 11, 12 has a punch that cuts through the lower and upper material web before, during and/or after the sealing. Preferably, several packages are produced at the same time in each cycle, which are arranged in a so-called format as a matrix. Such formats are shown in Figures 2a - 2d, 6a and 6b.

FIGS. 2a to 2d show four different formats that can be produced when the material web 8 is preferred. The heating element or the packaging machine is preferably provided in such a way that all formats 19 shown here can be produced on packaging trays 6 or packaging without having to replace the heating element 20 in the sealing station 15 or the upper tool 12 or the heating in the area of the forming station. The control of the heating plate is preferably adjusted automatically, in particular under computer control.

Figures 3 and 4 show an embodiment of the packaging machine according to the invention. The material web 8 or the material webs 8, 14 are transported along the packaging machine on the right and left by a transport means 21, here a chain 21, on which gripper or clamping means 22 are provided. The width of the heating means 20 is now provided such that it is smaller than the distance A between the clamping means 22 to one another (shown differently), so that the heating means 20, at least the clamping means or the grippers 22, do not protrude. In the present case, the heating element 20 is provided in a stationary manner. For sealing (cf. FIG. 4), the lower tool 11 is raised. The heating element is preferably provided in such a way that it does not cover the transport means (shown differently).

FIG. 5 shows a further embodiment of the packaging machine according to the invention. In the present case, too, a material web 8, 14 is transported in the transport direction T along the packaging machine. The material web 8, 14 is in her lateral edge region each taken by a transport means 21, 22 and transported further. The material web has an edge strip 23 on the right and left for this gripping or in order to also be able to provide recesses for gas exchange, if necessary, which cannot be used for the production of packaging. The material web 8, 14 accordingly has a useful width N. According to an inventive or preferred embodiment, the width of the heating means, i.e. its extent transverse to the transport direction T of the material web, is narrower or equal to the useful width N of the material web 8, 14.

FIGS. 6a and 6b again show two different formats of packaging troughs or packaging, which are produced when the web of material is preferred. In the embodiment on the left, four packaging trays and in the embodiment on the right, sixteen packaging trays are produced simultaneously.

FIGS. 6c to 6e show a possible embodiment of a heating element with which the formats according to FIGS. 6a and 6b can be produced without converting the heating elements, the heating plate being shown in only one quadrant for the sake of simplicity. In the present case, two conductor track levels 25, 26 are provided, which can be supplied with electrical current independently of one another. In the representation according to FIG. 6d, the conductor track level 25 and in the representation according to FIG. 6e the conductor track level 26 are supplied with electric current. The person skilled in the art understands that in Figures 6d and 6e only one conductor track module is shown, but preferably more, here preferably three more are present, which are preferably individually or in groups, in particular per conductor track level all at the same time, but preferably with regard to the electric current individually, are controllable. The person skilled in the art also understands that the same applies to the production of the weld seam.

The heating element is preferably made up of conductor track modules, in particular identical conductor track modules, each of which has a width BM or a length LM. The conductor track modules are preferably arranged in a butt joint in one plane or can be designed in one piece or separated by a gap. In the present case, four modules are shown that form the heating plate. The width BM or length LM of a module can be the same or different. In particular, the width BM of the module can be selected in such a way that its multiple does not correspond to the useful width N of the material web 8, 14. A region of the web of material that is sufficient for the production of several packs is preferably heated with one module. Alternatively, two modules are required to heat the material web to produce a single pack. FIG. 7 shows the two conductor track levels 25, 26, which are each provided parallel to the material web transport level 8, 14. The conductor track levels are on top of each other and on each other. They are preferably braced against one another in order to improve heat conduction.

Reference list:

1 packaging machine

2 forming station, deep-drawing station

3 Upper die of the forming station, upper die of the deep-drawing station

4 Lower tool of the forming station, upper tool of the deep-drawing station

5 lifting table, carrier of a tool for the sealing, deep-drawing station and/or the cutting device

6 packaging goods carriers, packaging trough, lower shell, tray

7 filling station, insertion station

8 material web, sub-material web

9 lifting device

10 punches

11 Lower tool of the sealing station

12 Sealing station upper die

13 Severed section, corner

14 face material web, lid material web

15 sealing station

16 packaged goods

17 longitudinal cutters

18 cross cutters

19 format

20 heating element, heating plate

21 means of transport, chain

22 clamping means, gripper

23 edge strips

24 trace module

25 first track level

26 second trace level

27 track

N usable width A Distance between means of transport

B Dimensions of the heating plate transverse to the transport direction of the web

BM dimension module, width module

LM dimension module, length module

T Transport direction of the material web

Claims

Patent Claims:

1. Sealing or molding tool (3, 12) with which packaging cavities (6) or packaging of different cross sections and/or sealing seams with different shapes are produced and which has a heating element (30), characterized in that the heating element, in particular per Trough/packaging, one of a plurality of conductor track planes (25, 26) which are provided parallel to the transport plane of the material web (8, 14) and one above the other.

2. Sealing or molding tool (3, 12) according to claim 1, characterized in that in each conductor track level (25, 26) a plurality of conductor track modules (24) are arranged side by side.

3. Sealing or molding tool (3, 12) according to claim 1 or 2, characterized in that the conductor track levels (25, 26) are different.

4. Sealing or molding tool (3, 12) according to claim 3, characterized in that the arrangement of the conductor tracks and/or the material of the conductor track and/or the material of the carrier material and/or the cross section of the conductor track and/or the cross section of the Carrier material are different.

5. Sealing or molding tool (3, 12) according to any one of claims 2-4, characterized in that at least one conductor track module has a multiplicity of separate, separately controllable conductor tracks (27).

6. Sealing or molding tool (3, 12) according to claim 3, characterized in that a plurality of conductor tracks (32) can be controlled individually or in groups.

7. sealing or molding tool (3, 12) according to any one of claims 2-6, characterized in that the modules of a conductor track level are of identical design. Sealing or molding tool (3, 12) according to one of the preceding claims, characterized in that it has a pressure medium which presses the conductor track planes (25, 26) together. Sealing or molding tool (3, 12) according to one of the preceding claims, characterized in that no material connection is provided between the conductor track levels (25, 26). Sealing or molding tool (3, 12) according to one of the preceding claims, characterized in that the conductor track planes (25, 26) are provided in one piece or in several pieces. Sealing or molding tool (3, 12) according to one of the preceding claims, characterized in that each conductor track level (25, 26) has recesses which can be subjected to negative pressure. Sealing or forming tool (3, 12) according to Claim 11, characterized in that the recesses of the respective conductor track level are provided at least partially congruently Packaging machine (1) with a forming station (2) which forms depressions (6) in a sub-material web (8), wherein a heating element (20) heats the base material web (8) before and/or during shaping, and a sealing station which connects a base material web (14) to the base material web (8) and has a heating means (20) for this, characterized in that the forming station is on Forming tool or the sealing station has a sealing tool according to one of the preceding claims. Packaging machine (1) according to Claim 13, with transport means (21, 22) which transport the sub-material web in a transport direction (T), the transport means being provided at a distance (A) transversely to the transport direction (T), characterized in that the Extension (B) of the heating plate transverse to the transport direction (T) < than the distance (A). Packaging machine (1) according to one of claims 13 or 14,

16. wherein the base material web (8) has a useful width (N), characterized in that the extent (B) of the heating plate transverse to the transport direction (T) is < the useful width (N).