ES2912663T3 - Film packaging as well as method and sealing station for the production of a film packaging - Google Patents

Abstract

Method for the manufacture of a film packaging (1), comprising: providing a base (3) in a lower part of the sealing tool (21) with a product (5) placed on the base (3), feeding a sheet upper part (7), which is a sheet of film, above the product (5) and the base (3), close a sealing tool chamber (45) by pressing on each other a first frame (23) of an upper part of the sealing tool (19) and a second frame (25) of the lower part of the sealing tool (21), wherein the upper sheet (7) and the base (3) are clamped circumferentially between the first and the second. second frame (23, 25) and the sealing tool chamber (45) are closed in a gas-tight manner by pressing on one another, and whereby inner sections (49, 50) of the upper sheet (7 ) and base (3) inside the sealing tool chamber (45) and outer sections (51, 52) are fu was from the sealing tool chamber (45), suck the inner section (49) of the top sheet (7) into a dome (35) of the sealing tool top (19) by establishing a vacuum in the area between dome (35) and top sheet (7), heat the inner section (49) of the top sheet (7), create a vacuum in the space between the top sheet (7) and the base (3), produce atmospheric pressure between dome (35) or upper part of sealing tool (19) and upper sheet (7), whereby the upper sheet (7) rests on the base (3) and the product (5) that is on it , characterized in that the method further comprises that when the sealing tool chamber (45) is closed, the upper sheet (7) and the base (3) are clamped in an edge area (11) of the film package (1). ) outside a sealing area (9) between the first frame (23) of the upper part of the sealing tool (19) and the second frame (25) of the lower part of the sealing tool (21), so that this edge area (11) of the upper sheet (7) and of the base (3) is neither deformed nor heated by a pressure difference and therefore No sealing of the top sheet (7) with the base (3) takes place in this edge area (11).

Description

DESCRIPTION

Film packaging as well as method and sealing station for the production of a film packaging

The present invention relates to a method and a sealing station for the production of film packaging.

Vacuum packaging, that is, packaging from which as much air as possible has been sucked inside, is often used to pack food products in order to prolong their shelf life. An improvement in this respect is the so-called film packaging, in which an elastic top sheet, the film sheet, is placed without tension and closely supported on a base and a product placed on it. The base can also be designed in this connection in the form of a tray on which the product is placed. After the packaging process, the seal, base and top sheet are connected to each other in a gas-tight manner in a circumferential sealing area. Film packaging has properties that allow a particularly advantageous presentation of the product. This fixes the product in the tray and prevents the product from falling apart or liquid from escaping from the product into the tray space. Due to the stable connection of the base and the top sheet in the sealing area, the product is securely fixed during transportation and accidental opening of the film packaging is prevented. However, the fixed connection of the base and top sheet also makes it more difficult for a consumer to open the package to remove the product.

From US 6,044,622 a package is known in which a double-layer film sheet covers a product placed on a tray. A tab is formed to tear off the top of the two sheets of film.

From WO 97/25258 A1 another film packaging is known. Document EP3450327 is prior art according to article 54(3) EPC and also discloses a film packaging and a method and a sealing station for the production of such a packaging.

It is the object of the present invention to provide an improved opening possibility for a film package.

The object is achieved by a method for producing a film package according to claim 1 as well as a sealing station for producing a film package according to claim 5. Advantageous developments of the invention are indicated in the claims. dependents.

A film package comprises a base and a top sheet, wherein the top sheet is a film sheet and wherein the base and top sheet are sealed together in a gas-tight manner along a circumferential sealing zone . In this case, the base and the top foil extend in one or more edge regions outside the sealing region, in particular in the form of a peel-off corner, and are not sealed to one another there. If the sealing area were to extend to the outermost edge of the film packaging, i.e. to the cut edge, it would be difficult for the consumer to separate a small section of the topsheet from the base, grasp it and pull it from the base. to open the packaging. However, if the top sheet and base are only guided loosely on top of each other at an edge section adjacent to the sealing area, the consumer can easily grab the top sheet and separate it from the base. Therefore, you do not have to use any additional tools.

In an advantageous variant, the sealing area comprises a sealing seam. The sealing seam is likewise a circumferential region that is usually relatively narrow and runs in the edge region. To this end, additionally for the peeling process explained below, the top sheet and the base are bonded to one another in a particularly stable manner under pressure and heat. Therefore, the sealing seam has an even higher strength than the remaining sealing area, whereby accidental opening of the film packaging is reliably prevented, even when particularly heavy or large products are packed or the packaging is damaged. exposed to particularly high mechanical loads during transport and sale.

In a particularly advantageous variant, the base has an offset in the edge region, which prolongs the top sheet to facilitate gripping of the top sheet and thus opening of the film packaging by pulling on the top sheet. The offset, which can be designed, for example, in the form of a downwardly directed step or bevel, allows the top sheet to be held directly without first having to separate it from the base by bending or pressing against the edge of the packaging. The offset can also be in the form of bumps or a rib pointing upwards, so that the topsheet is pressed upwards and protrudes into the unsealed edge area. All variants make it particularly easy to open the film packaging.

Preferably, the base is designed as a tray, in particular as a deep-drawn bottom sheet. A tray offers advantages when introducing the product, for example, it prevents spillage of liquids, and also offers additional protection of the product through the side edges when the package is closed. In this way, a higher torsional rigidity is also achieved than with flat surfaces.

In a common variation, the sealing area is slightly angled adjacent to the peel corner. If the topsheet is pulled from the peel corner towards the angle or one corner of the sealing area, the force is particularly advantageously concentrated at one point in the corner or angle and is then evenly distributed on both sides of the corner. angulation. The top sheet can then be removed especially well, in particular when the top sheet and the base are joined together by a sealing seam.

A sealing station according to the invention for producing a film package comprises an upper sealing tool part with a first frame and a concave dome having air ducts, and a lower sealing tool part with a second frame and basic accommodation. In this regard, the upper sealing tool part and/or the lower sealing tool part are mounted such that they can be adjusted in height to approach each other and contact each other on their first and second frames, thereby forming a tool chamber. gas-tight seal. The sealing station is further configured to gas-tightly bond a base with a top sheet, which is a film sheet, together by forming a sealing zone. In this regard, the first frame of the sealing tool top part and the second frame of the sealing tool bottom part are configured to clamply hold a base section and a top sheet section so that they are free. heating and deformation during the sealing process. In this way, the required pressures and temperatures can be created within the sealing tool chamber, which are necessary for the sealing process, ie the bonding of the top sheet with the base. At the same time, the clamped sections of top and base sheet are not affected, whereby the formation of a sealing zone, ie a top and base sheet joint, is prevented there. The sections can also extend further outwards and protrude beyond the frames, so that no sealing process takes place there either.

Preferably, the sealing station has a height-adjustable sealing plate, the sealing plate having a sealing surface that is suitable for gas-tight joining of a base to a top sheet by forming a sealing seam. . By means of the movable sealing plate, the sealing surface is pressed onto the top sheet and the base, these being mounted on a support surface so that the desired compressive pressure can be applied. This creates a particularly stable connection of top sheet and base. Additionally, the sealing surface can be heated to further promote the formation of the sealing seam.

Usually the first frame of the upper part of the sealing tool and the second frame of the lower part of the sealing tool are formed of a material approved for the food sector. The same applies to the dome as well as the sealing plate on top of the sealing tool. In this regard it may be helpful if the material(s) from which the first frame and second frame are formed have a lower thermal conductivity than the material of the dome and sealing plate to allow energy efficient heating of the dome and sealing plate, to however minimize heat transfer to the frames. Thus, the frames could be made of stainless steel and the dome and sealing plate of aluminium.

In a convenient variant, the first frame of the sealing tool upper part and/or the second frame of the sealing tool lower part are formed at least by sections of a plastic and/or ceramic material. Thus, for example, the sections clamping the top sheet can have a particularly low thermal conductivity, whereby no heat is transferred to the top sheet either. Therefore, in particular in the area of the peel corner it is useful to use such materials, so that, for example, no heat is transmitted from the heated dome or sealing surface to the top sheet and the base.

In a common variant, the first frame of the sealing tool upper part and/or the second frame of the sealing tool lower part are cooled, in particular water-cooled, by channels running in them. With this, any unwanted heat transmitted to the frame can also be dissipated. This is not only useful for the formation of the unsealed opening aid or tear corner, but also offers protection for a sealing station or packaging machine operator from heat related injuries from touching the frame.

Preferably, the frame of the lower part of the sealing tool has a notch that is designed to accommodate a downward protruding base offset so that the offset is not deformed when the base and top sheet are clamped between the two. backstage. Correspondingly, the frame of the upper part of the sealing tool can also have a notch for accommodating an offset projecting upwards from the flat base surface of the lower sheet. The offset, which creates a distance between the base and the top sheet in order to be able to grip the latter better, is thus placed in the notch and retains its shape and therefore its function even when the frames are pressed against each other.

Ideally, the lower part of the sealing tool is at least in part interchangeable to accommodate bases of different shapes, in particular tray-shaped bases. In this way, the same sealing station can seal different packages as required. One possibility to realize this are corresponding inserts in the lower part of the sealing tool. The bases can then be placed in or on these inserts.

Embodiments of the invention are described in more detail below with reference to the figures. In this regard, they show

Figure 1A: a side sectional view of a film package with product and a flat base with a downwardly directed displacement in the form of a step,

Figure 1B: a side sectional view of a film package with product and a flat base with a bevel-shaped downward displacement,

Figure 1C: a side sectional view of a film package with product and a flat base with an upwardly directed displacement in the form of a bulge,

Figure 2: a side sectional view of a film packaging with product and a base in the form of a tray,

Figure 3: a perspective side view of a sealing station comprising an upper sealing tool part and a lower sealing tool part, as well as four bases arranged interconnected,

Figure 4: a bottom top view of a sealing tool top,

Figure 5: An oblique perspective sectional view from below of an upper part of a sealing tool, and

Figure 6: a side sectional view of a sealing station.

Corresponding components are in each case provided with the same reference numbers in the figures.

Figure 1A shows a sectional view of a film package 1 with an essentially flat base 3, on which a product 5 is placed and sealed with a top sheet 7 which is a film sheet. In a circumferential sealing area 9, the base 3 and the top sheet 7 are sealed to each other in a gas-tight manner. On the left side of the film packaging 1, an unsealed edge region 11 is formed, in which the base 3 and the top sheet 7 are not sealed against each other. Additionally, an optional step-shaped offset 13 is formed on the base 3, so that the base 3 and the top sheet 7 are separated from each other and the top sheet 7 can be more easily grasped to separate it from the base 3 to open. the film packing 1.

Figure 1B corresponds to the film packaging 1 as shown in Figure 1A, however the offset 13 is designed in the form of a bevel.

Figure 1C shows another variant of the film packaging 1, in which the displacement 13 is designed as a protrusion protruding upwards. As shown, the bulge may be conical in shape. In the same way, the protrusion can also be an upwardly printed, essentially round and/or hollow point-shaped section of the base 3. However, it can also be a rib that has a certain longitudinal extension on the base 3 in the unsealed edge area 11.

Figure 2 shows a sectional view of a film package 1 with a base 3 in the form of a tray. The film sheet 7 encloses the product 5 placed on the tray 3, fixes it and rests snugly against the inner side of the tray 3. The tray 3 has a raised horizontal and circumferential edge 15 on which the upper sheet 7 forms with the base 3 a circumferential sealing zone 9 and non-sealed edge zones 11 follow by section. Optionally one or more offsets 13 can also be designed in the non-sealed edge regions 11.

Figure 3 shows a perspective side view of a sealing station 17, comprising an upper sealing tool part 19 and a lower sealing tool part 21. The upper sealing tool part 19 comprises a first frame 23 and the lower part of the sealing tool 21 the second frame 25. For the sake of clarity, components for raising and lowering the first frame 23 and/or the second frame 25 or the components of the transport path are not shown. The frames 23, 25 are configured so that they can seal four packages of film 1 per work cycle. To do this, the four bases 3, usually joined together, are placed on the second frame 25, in this case in the form of trays. In this connection, base receptacles 27 for the trays 3 themselves as well as recesses 29 for the offsets 13 are formed on the second frame 25. The non-sealed edge areas 11 in the form of detachable corners are advantageously oriented towards the edges parallel to the transport direction T, i.e. towards the transport chains leading to the top sheet 7. In the figure, the circumferential sealing area 9 as well as the unsealed edge area 11 are marked in the form of a corner detachable by means of the base 3. At the detachable corners 11, the sealing zone 9 has a discreet angle 31, which improves the opening behavior when the top sheet 7 is removed.

Laterally in the second lower frame 25, holes 33 are arranged, which serve to evacuate the film package 1.

Figure 4 shows the top of the sealing tool 19 from below. Inside the first frame 23, four concavely bulging domes 35 are arranged. The space between the dome 35 and the top sheet 7 can be evacuated through air channels 37 in the domes 35, so that the top sheet 7 rests against the respective dome 35 and can be heated by it. The first frame 23 has the form suitable for creating, corresponding to figure 3, in the area inside the first and second frames 23, 25, the sealing area 9 and, adjacent to it, the unsealed edge area 11 of the film package 1. Furthermore, In the first frame 23, cutouts 39 are designed to allow an evacuation of the area between the upper sheet 7 and the base 3, that is, the interior of the film packaging 1 by means of the holes 33.

Figure 5 shows an oblique bottom perspective sectional view of an upper part of the sealing tool 19. The first frame 23 has the shape that defines the sealing zone 9 and the unsealed zone 11 of the film package 1 (see figure 3). In this embodiment, the two domes 35 are formed as part of a sealing plate 41. The sealing plate 41 is disposed movably with respect to the first frame 23. Thus, the sealing plate 41 can be moved downwards. when the sealing tool chamber is already closed and a sealing surface 43 can be pressed onto the top sheet 7 and the base 3 to join them together in a particularly stable manner. In this connection, an edge support of the lower part of the sealing tool 21, on which the corresponding sections of the upper foil 7 and of the base 3 rest, generates the necessary back pressure. The notches 39 allow the evacuation of the film packaging 1 by means of the holes 33 arranged in the second frame 25.

Figure 6 shows a side sectional view of a sealing station 17 for a film package 1. The base 3 is mounted on the second lower frame 25. The first frame 23 is lowered onto the second frame 25, being clamped a part of the base 3 as well as the top sheet 7, and thus forming a gas-tight sealing tool chamber 45 . Shown within the first frame 23 is an optional sealing plate 41 which is in an upper position and can be slid to press down a sealing surface 43 of the sealing plate 41 to form a sealing seam 44. Edge 47 serves in this connection as a counter element to establish the desired pressure. The topsheet 7 is still aligned straight, with an inner section 49 of the topsheet 7 and an inner section 50 of the base 3 being inside, and outer sections 51 of the topsheet 7 and outer sections 52 of the base 3 outside the topsheet. sealing tool chamber 45 closed. Parts of the outer sections 51, 52 are clamped between the first and second frames 23, 25. Through channels 53 inside the frames 23, 25, water can be conducted to cool the frames 23, 25.

In the following, the mode of operation of the sealing station 17 for the production of a film package 1 is described in more detail by means of the figures. The base 3 is provided in a lower part of the sealing tool 21 with a product 5 placed on the base 3 and then a top sheet 7, which is a film sheet, is fed on top of the product 5 and the base 3. Then , the sealing tool chamber 45 is closed by pressing the first frame 23 of the sealing tool upper part 19 and the second frame 25 of the sealing tool lower part 21 onto each other, the upper sheet 7 being clamped. and the base 3 circumferentially between the first and second frames 23, 25 and the sealing tool chamber 45 being closed in a gas-tight manner by pressing one onto the other. Therefore, the inner foil sections 49, 50 top 7 and base 3 are inside sealing tool chamber 45 and outer sections 51, 52 outside sealing tool chamber 45.

The inner section 49 of the top sheet 7 is now sucked into a dome 35 of the top of the sealing tool 19 by establishing a vacuum in the area between the dome 35 and the top sheet 7. There the inner section 49 of the top sheet is heated. .

By closing the sealing tool chamber 45, the top sheet 7 and the base 3 in an edge area 11 of the film package 1 are clamped together outside a sealing area 9 between the first frame 23 of the tool top sealing 19 and the second frame 25 of the lower part of the sealing tool 21, so that this edge area 11 of the upper sheet 7 and the base 3 is neither deformed nor heated by a pressure difference and therefore A sealing of the upper foil 7 with the base 3 does not take place in this edge area 11.

A vacuum is then established in the space between the top sheet 7 and the base 3. By producing atmospheric pressure between dome 35 or top of sealing tool 19 and top sheet 7, the top sheet 7 rests on the base 3 and the product 5 that is on it.

In a common variant, the base 3 is provided in the form of a tray with a product 5 placed on the tray.

Preferably, a sealing plate 41 is pressed onto an edge abutment 47 of the lower part of the sealing tool 21 and the upper sheet 7 and the base 3 located thereon and thus a sealing seam 44 is formed.

Usually, the evacuation and supply of air takes place above the upper sheet 7 through air channels 37 in the dome 35 of the upper part of the sealing tool 19.

Starting from the previously shown embodiments of a film package 1 and a sealing station 17, many variations thereof are possible. For example, the sealing station 17 can be configured to seal more than two rows of film packages 1 at the same time. If flat bases 3 are used, these can also have ribs or other embossing, whereby the rigidity of the film is increased. the base 3. In addition to the variants shown here, the offset 13 can also have any other shape that is suitable for separating the base 3 from the top sheet 7.

Claims (10)

1. Procedure for the manufacture of a film packaging (1), comprising: providing a base (3) on a sealing tool bottom (21) with a product (5) placed on the base (3), feeding a top sheet (7), which is a sheet of film, above the product (5) and the base (3), closing a sealing tool chamber (45) by pressing one on the other a first frame (23) of an upper sealing tool part (19) and a second frame (25) of the lower sealing tool part (21), wherein the upper sheet (7) and the base (3) are clamped circumferentially between the The first and second frames (23, 25) and the sealing tool chamber (45) are closed in a gas-tight manner by pressing on one another, and whereby inner sections (49, 50) of the foil top (7) and base (3) inside the sealing tool chamber (45) and outer sections (51, 52) are outside the sealing tool chamber (45), suck the inner section (49) of the upper sheet (7) into a dome (35) of the upper part of the sealing tool (19) establishing a vacuum in the area between the dome (35) and the upper sheet (7), heating the inner section (49) of the upper sheet (7), generate a vacuum in the space between the upper sheet (7) and the base (3), produce atmospheric pressure between the dome (35) or upper part of the sealing tool (19) and the upper sheet (7), whereby the upper sheet (7) rests on the base (3) and the product (5) that is is on it, characterized in that the procedure further comprises that as the sealing tool chamber (45) is closed, the top sheet (7) and the base (3) are clamped in an edge area (11) of the film package (1) outside a sealing area ( 9) between the first frame (23) of the upper part of the sealing tool (19) and the second frame (25) of the lower part of the sealing tool (21), so that this edge zone (11) of the upper sheet (7) and the base (3) are neither deformed nor heated by a pressure difference and therefore a sealing of the upper sheet (7) with the base (3) does not take place in this zone of edge (11). Method according to claim 1, characterized in that the base (3) is provided in the form of a tray with a product (5) placed on the tray (3). Method according to one of claims 1 or 2, characterized in that a sealing plate (41) is pressed down onto an edge support (47) of the lower sealing tool part (21) and the upper foil (7). ) and the base (3) that are on it and a sealing seam (44) is formed. Method according to one of Claims 1 to 3, characterized in that the evacuation and supply of air takes place above the top sheet (7) via air channels (37) in the dome (35) of the upper part. top of sealing tool (19). 5. Sealing station (17) for producing a film package (1), wherein the sealing station (17) comprises a sealing tool top (19) with a first frame (23) and a concave dome ( 35), which has air channels (37), and the sealing station (17) comprises a lower part of the sealing tool (21) with a second frame (25) and a base housing (27), where the sealing tool upper part (19) and/or sealing tool lower part (21) are height-adjustably mounted to approach each other and contact their first and second frames (23, 25) and form thus a gas-tight sealing tool chamber (45) and sealing station (17) is configured to gas-tightly join together a base (3) to a top sheet (7), which is a film sheet, forming a sealing zone (9), where the sealing station (17) is characterized in that the first frame (23) of the upper part of the sealing tool (19) and the second frame (25) of the lower part of the sealing tool (21) are configured to clamp a section (52) of the base and a section (51) of the upper sheet (7) so that they are exempt from heating and deformation during the sealing procedure. Sealing station according to claim 5, characterized by having a height-adjustable sealing plate (41), in which the sealing plate (41) has a sealing surface (43) that is suitable for sealingly joining Gas-tight a base (3) to a top sheet (7) by forming a sealing seam (44). Sealing station according to one of claims 5 or 6, characterized in that the first frame (23) of the sealing tool upper part (19) and/or the second frame (25) of the sealing tool lower part (21) are made at least in sections of a plastic and/or ceramic material. Sealing station according to one of claims 5 to 7, characterized in that the first frame (23) of the upper sealing tool part (19) and/or the second frame (25) of the lower sealing tool part (21) are cooled, in particular water-cooled by channels (53) running therein. Sealing station according to one of Claims 5 to 8, characterized in that the frame (25) of the lower part of the sealing tool (21) has a recess (29) which is designed to accommodate a displacement (13) of the base (3) so that, when clamping the base (3) and the upper sheet (7) between both frames (23, 25), the displacement (13) is not deformed. Sealing station according to one of Claims 5 to 9, characterized in that the lower part of the sealing tool (21) is at least partly interchangeable to accommodate bases (3) of different shapes, in particular bases (3) of different shapes. of tray.