EP1584448B1 - Sealing device for applying a plastic foil on a substrate material. - Google Patents

Abstract

A sealing unit (8) comprises a sealing plate (11) with heated active surface and back plate (9), die cutting unit (16) with die cutting knife (15), and counter plate for making die cuts at selected locations in the planar substrate material in the region of the applied plastic foil. The sealing plate has set(s) of raised and depressed regions on its active surface. A sealing unit comprises a sealing plate with heated active surface and back plate, die cutting unit with die cutting knife, and counter plate for making die cuts at selected locations in the planar substrate material (1) in the region of the applied plastic foil (7). The sealing plate generates heat and pressure to the substrate material during the sealing process. It has set(s) of raised regions (14) and depressed regions (13) on its active surface facing the back plate and the location of the depressed regions in the sealing plate corresponds to the location of the die cutting knife, so that cut is made at the selected positions in the substrate material where, because of the depressed regions of the sealing plate, there is reduced heating of the substrate material and associated laminations.

Description

The invention relates to a sealing and punching device with a sealing device for applying a plastic film to a flat substrate material by means of heat and pressure with a sealing plate with active surface and a relative to this movable counter-jaw, wherein the sealing device a punching device with punching knife and counter plate for subsequent introduction of Punch cuts at selected locations in the sheet-like substrate material in the region of the applied plastic film is connected downstream.

Sealing devices of the aforementioned type are known in the practice of Verpackungsherstellem. In one example, a filling machine for making and filling a liquid package is known, which is made from a tube of packing material continuously under filling and sealing. The packing material in this known example is a plastic-coated, flat carrier material, with paper or cardboard being used as carrier material. Opening devices of these known packages consist of a hole through the sheet substrate material, wherein the hole is closed on the inside of the package with a plastic film and on the outside with a tear-open. Tear tab and plastic film are welded together, so that when tearing open the tear tab to open the package, the area within the punched hole of the inner plastic film is torn to form the pouring with.

Previously, the tear tab on the outer plastic film of the pack was welded directly through the hole. It has then proved to be disadvantageous in tearing the tear tab that the outer plastic film was torn with such a stain that outside partially the coated, printed cardboard, partly the bare cardboard and partially plastic nets looked for the end user when applying the pack Drinking a bad mouthfeel produced.

Therefore, it has already gone over to aufzusiegeln another plastic film in the area of the later hole, surrounding this at a distance, on the outer plastic layer of the pack. This plastic film or plastic film, which is called prepatch in English-speaking circles, is a so-called OPP film which is transparent and can be applied well on the side of the package on the bottom side of the plastic layer resting on the carrier material and bonds well with it. while only peeling outward towards the tear tab weak connection forces developed, especially if the tear tab is a polyethylene (PE) coated aluminum. The flat substrate material is punched together with this applied plastic or prepatch film made of OPP film. If the tear-open tab is subsequently removed to open the pack, then advantageously no longer the stained small areas with bare cardboard, coated cardboard and plastic nets are formed. Rather, the application of this prepatch plastic film, this plastic look or cut-out to the end user, when drinking the liquid from the package, now gives a good mouthfeel.

In the production of such packages with this type of sheet-like substrate material, a sealing and punching device of the type mentioned is used to aufzusiegeln the stain or the plastic film on the later outer side of the substrate material, after which immediately described the punching of the entire substrate material to form the Ausgießloches he follows. Therefore, the sealing device is followed by a punching device in which a correspondingly shaped punching knife is pressed through the entire substrate material with the various plastic layers and foils.

In this punching process now arises in the prior art, a problem in that the substrate material in the sealing device for applying the plastic film is brought to sealing temperature and shortly thereafter, the selected location for the punching cut is guided into the punching device, so that the punching knife by a still has to press through to almost sealing temperature located substrate material. Unfortunately, the cut lines produced by the punch blade fray more or less, and here and there mere plastic or cardboard chips or fibers remain shredded. Sealing such poorly cut openings with a pull tab, then arise here and there leaks and unusable packages with leakage. For a larger collection of packages, one to three leaky packages are sufficient to make the entire collection unusable and unsaleable. It has therefore made a variety of attempts to avoid this fraying next to the punching blades. So it has been found, for example, that a punch with circular knife in a very sharp new state for a certain time produces clean cuts. After 150 hours of operation, however, the punching knife was so fuzzy and worn that the frayed again. With further disadvantage, the protruding shreds, fringes and snippets collect in the discharge duct of the machine, which resulted in blockages. The frequent replacement of punching tools represents, with further disadvantage, an unbearable cost increase for the packaging manufacturer.

The invention is therefore an object of the invention to improve the sealing and punching device of the type described above so that no longer fibers are torn out of the carrier material or from the plastic at the punch cuts, but create clean cuts without supernatants.

The solution of this object is achieved according to the invention characterized in that the sealing plate of the sealing device on its active, the counter-jaws facing surface raised and recessed areas and the position of the recessed areas in the sealing plate of the position of / the punching blade / s corresponds, so that the punched section the selected locations come to lie in the substrate material where, as a result of the recessed areas of the sealing plate almost no heating of the substrate material with its coatings took place. It must first be assumed that with the specially designed sealing plate with the raised and recessed areas in the active surface of the plastic film is sealed in a larger surface area of the substrate material, where subsequently punched cuts are to be inserted in the punching device, and around them. These die cuts succeed with particularly good quality, i. as sharp cuts without fraying as the punch blade is driven through cooler portions of the substrate material. If now provided by appropriately skillful design of the sealing plate in certain locations at selected locations recessed areas that are offered in the subsequent step in the punching the cutting process, then the punching knife can penetrate into areas of the substrate material, which were not brought to a higher temperature as is necessary in other (raised) areas for the application of the plastic film itself. Thus, the plastic film can be applied to the substrate material with useful adhesion, producing cooler areas at selected locations (through the recessed areas in the sealing plate), because there is virtually no heating due to the recessed areas of the sealing plate. Surprisingly, it has been found that punch cuts produced in this way could be produced sharply and without fraying even when the cutting blade was in operation for many hours of operation. It is surprisingly able to produce cuts without supernatants even with coated substrate material by the sealing plate designed with the recessed areas.

In a further advantageous embodiment of the invention, it is provided that at a predetermined distance in the conveying direction of the substrate material behind the sealing device, the punching device is arranged and a coordinated control of both devices takes place such that the selected locations in the substrate material in the sealing device on the recessed areas and then in the punching device come to rest under the / the punching knife. The sealing device and the punching device may be two separate devices, which are arranged one behind the other in the manner described above, that the substrate material, whether it is now arcuate or web-shaped, is guided first into the sealing device and then into the punching device. The Time that elapses to convey the substrate material from the sealing device into the punching device is between one second and three minutes, and is preferably two seconds. It is essential that the substrate material is heated in the sealing device to sealing temperature, which are about 160 ° C, and that after the elapsed time, the substrate material when it is processed in the punching device, still has a relatively high temperature such that the Plastic layer or layers or films or films are still relatively soft. For then, there would be the fissures described above, would not use the inventively designed seal plate.

If it is said that the substrate material in the sealing device over the recessed areas and then in the punching device under the punching knife, then here by "above" and "below" less a local direction meant, but the position for the intervention ( with corresponding effect) of the recessed areas on the one hand and the punching knife on the other hand on the substrate material. In a preferred embodiment, however, the substrate material also locally comes to rest over the recessed areas, i. The sealing plate approaches the substrate material from below and presses it up against the counter-jaw. In this or another preferred embodiment, it is also preferable in the punching device for the substrate material to lie underneath the punching knife (s), i. the punch blade moves from above the substrate material down through it a little bit to reach the punching. For other machines but also other directions of movement of the sealing plate and the punching knife could be beneficial.

Whether the sealing device is a device separate from the punching device, both devices must nevertheless be coordinated so that the substrate material at the selected locations is protected against an increase in temperature and the punching knife or punches work only in those areas that have remained cold, because it is to be avoided be that a punch blade penetrates into a substrate material with high temperature. Therefore, the coordinated actuation of the devices is primarily localized in order to properly align the position of the punching blades with the cold remaining areas in the substrate material. Only in the second place is the coordinated activation a temporal influence. However, preferred machines in practice include both devices in a processing line in which a sheet-like, flat substrate material is advanced intermittently, first in the sealing device and then in the punching device. Since only because of the space in the machine, the two devices are relatively close to each other, it is also clear that the time between the stay in the sealing device to stay in the punching device is too short, as that increased by the sealing plate temperature of Substrate material substantially cools from one device to another.

According to the invention it is further provided that the recessed areas in the active surface of the sealing plate form a pattern which is an image of the pattern of the / the punching knife (s) of the punching device on the same scale, so that both patterns are congruent. The sealing plate acts in this manner as a template that generates a temperature pattern on the substrate material, such as a thermal image. This pattern of the recessed areas of the sealing plate is substantially the same as the position of the punching knife (s), with the exception that will be explained below. This consistency and congruence of the patterns in the two devices ensures that the punching knife - in whatever shape, position or arrangement - always punches the substrate material only in the areas that have remained cool. As a result, the frays are advantageously avoided, so that there are not the initially mentioned disadvantageous blockages in the punching device of the machine.

The exception mentioned above is that a punching knife and also its action (the cut) are considerably narrower than the groove-like recesses or recesses in the sealing plate. The invention is further characterized in that the recessed portion of the sealing plate is wider than the punching blade of the punch, and the punched cuts of the punching pattern engages on all sides. In compliance with this condition, it is ensured that the punching knife or the punching tool cuts only in cold areas of the substrate material and there is no danger of fraying.

If in a further advantageous embodiment of the invention, the sealing plate consists of metal and is milled on its active surface to form the recessed areas, preferably wherein the active surface is coated with an abrasion-resistant plastic material, the sealing device and in particular the sealing plate can be simple, inexpensive and effective produce. It has proven to be particularly advantageous to use aluminum as the metal for the sealing plate. The recessed areas then give rise to a particular pattern of grooves, with the raised areas, of course, being formed by the retained material (e.g., aluminum).

For a favorable sealing, the active surface of the sealing plate is preferably coated with the mentioned abrasion-resistant plastic material, which in advantageous embodiments is Teflon. After the application of heat and pressure by means of the sealing plate then their active surface is more easily detached from the plastic film, i. the neckline or the attached outer patch.

The substrate material may be any at least partially plastic coated carrier material, eg cardboard or paper. The problem with fraying or punching with fibers arises whenever a plastic film on a substrate at a temperature in the Range of softening temperature of the plastic to be punched. The substrate material may be plate or arcuate parts.

However, it is particularly preferred according to the invention if the planar substrate material in web form is intermittently movable by drive means from the sealing device into the punching device. Such a device, in which both devices are combined, is used in a particularly advantageous manner as an opening unit for a filling machine, said opening unit is provided in the conveying direction of the web-like substrate material in front of the filling machine.

So it has, for example According to the invention, it has proved to be advantageous if the sealing device belongs to an opening unit for a liquid-pack filling machine and the substrate material is a carrier material web provided with a plurality of plastic layers with score lines for producing a tear-open pack and the pattern of the punching knives is a circle. There are liquid packages in the form of a cuboid well known. It is also known to produce such liquid packages made of plastic-coated cardboard as the substrate material, wherein from the cardboard web, which is moved intermittently through the filling machine, ultimately the filled and sealed pack is conveyed away. This pack also has a pouring opening, which consists of a hole inserted in the topsoil of the pack, which is closed from above, the later outside of the pack, by a tear tab and is preferably sealed from the inside by another plastic film (edge protection of the cutting lines).

An upstream paper machine produces the web with the package blanks, this web of packaging material having as a carrier the mentioned carton which is covered with preferably several layers. This includes, for example, an aluminum layer and applied to these polyethylene layers. Prior to sealing the tear tab on the outside and the plastic (polyethylene) film on the inside of the later package to the hole, before making these last two coatings, the substrate sheet provided with the various coatings is punched to form the hole, and in a circular one Hole is then the pattern of the punching knife corresponding to a circle. The coated substrate web is also provided with various "score lines" known in the art to form the packages from the filled with the liquid content and then sealed by sealing the packages by folding. In these packing manufacturing or filling machines, the problem of leakage mentioned at the beginning has been apparent for years without the possibility of offering a reasonable solution on the tool side. Only the invention with the specially designed sealing plate and the recessed areas, with the help of the cutting areas can be left cold, has solved the problems to complete satisfaction. It can now liquid packs in large quantities per unit of time with powerful Filling machines are manufactured and summarized in collection bins, without even showing a package with leakage.

Figur 1

die Draufsicht auf ein abgebrochenes Stück eines bahnförmigen Substratmaterials in Form einer mit Kunststoff beschichteten Kartonbahn nach Anbringung des äußeren Kunststofffleckens auf herkömmliche Weise mit nachfolgendem Ausstanzen eines Loches,

Figur 2

in einer Querschnittsansicht links die Siegelvorrichtung und rechts die Stanzvorrichtung vor dem Stanzen bei einer erfindungsgemäßen Ausführungsform,

Figur 3

in gleicher Querschnittsansicht wie Figur 2 die Stanzvorrichtung kurz nach dem Stanzen des Loches,

Figur 4

eine ähnliche Ansicht wie Figur 1, hier jedoch mit dem erfindungsgemäß hergestellten Produkt, bei welchem der von oben auf die beschichtete Kartonbahn aufgebrachte äußere Kunststoffflecken um das in der Mitte ausgestanzte Loch herum einen siegelfreien Ringbereich hat, und

Figur 5

eine Querschnittsansicht eines bevorzugten Substratmaterials mit gestrichelt gezeigter Stanzlinie und schematisch dazwischen angeordneter Linie zur Veranschaulichung, daß die äußeren Schichten miteinander versiegelt sind.

Further advantages, features and applications of the invention will become apparent from the following description of a preferred embodiment in conjunction with the accompanying drawings. In these show:

FIG. 1

the plan view of a broken piece of a web-shaped substrate material in the form of a plastic-coated board web after attachment of the outer plastic spill in a conventional manner with subsequent punching a hole,

FIG. 2

in a cross-sectional view on the left the sealing device and on the right the punching device before punching in an embodiment according to the invention,

FIG. 3

in the same cross-sectional view as FIG. 2 the punching device shortly after punching the hole,

FIG. 4

a similar view as FIG. 1 here but with the product according to the invention, in which the applied from the top of the coated board web outer plastic patch around the hole punched in the middle has a seal-free ring area, and

FIG. 5

a cross-sectional view of a preferred substrate material with a dashed line shown in phantom and schematically arranged therebetween line to illustrate that the outer layers are sealed together.

FIG. 1 shows the view of a broken piece of a web-shaped carrier material or substrate material 1. The web of this material 1 is in the conveying direction 2 in the FIGS. 1 to 4 promoted intermittently from left to right. With 3 two score lines are indicated, which extend transversely to the conveying direction 2 of the substrate material and form part of the blank of the subsequent packaging. In this schematic representation of the figures, the top wall 4 of the packaging is to be formed by the two score lines 3, in which later the opening device and thus also the hole 5 are arranged. The pouring hole 5 is obtained by introducing the punched cut 6 in the substrate material. In FIG. 5 the punching cut 6 is illustrated by the two dashed lines which pass through the coated substrate material but not through the two outer layers.

However, the punched cut 6 also passes through the externally applied patches of the plastic film 7. In this case, the outside of the later beverage package of this particular embodiment is to be considered in the direction of the viewer's attention to the figures above the substrate material 1 and in the cross-sectional representation of the substrate material 1 of FIG FIG. 5 below; the inside so in the FIGS. 2, 3 and 5 above and at the top of the FIGS. 1 and 2 behind the broken parts. In a first in FIG. 2 Generally denoted by 8 sealing device, the flekkenförmige plastic film 7 is sealed before punching out of the hole 5, but in the example of FIG. 1 in a conventional manner, in which a sealing plate, not shown, with a smooth, flat surface is shown as well as the counter-jaw 9 of the sealing device 8 in FIG. 2 , As a result, the entire in FIG. 1 hatched portion of the plastic film 7 is brought by the sealing to the softening temperature and the punching cut 6 (in in FIG. 1 not shown) frayed and provided with fibrous supernatants. In the case of the conventionally produced hole 5, leaks in the region of the pouring opening can occur again and again. If you are in FIG. 1 ignores the hatch-free area of the hole 5, you can see the square sealing surface 10, which is located practically below the entire plastic film 7.

To avoid the associated disadvantages, the in FIG. 2 below the substrate material 1 arranged sealing plate 11, which is supported, stored and fixed from below in accordance with arrow 12, groove-like recessed areas 13 and adjacent raised areas 14. Assuming that the raised portions 14 are formed in the milling operation by standing, then in the manufacture of the sealing plate at selected locations, the recessed portions 13 of desired width can be milled out to form a pattern. The width of the recessed areas 13 is about 2 to 20 mm, preferably 5 to 15 mm, and the recess provides a height difference of 0.5 to 4 mm, preferably 1.5 to 3 mm, and most preferably 2 mm. The teflon coating is then applied so that it is located on both the raised and recessed areas 13, 14, as in FIG FIG. 2 but not shown. In the case of a pouring hole 5, the line of the punched cut 6 runs approximately after a circle, so that the pattern of a circle results. This circular pattern is followed not only by the punching blade 15 and thus also by the line of the punched cut 6, but also by the recessed regions 13. The web-shaped substrate material 1 extends both through the sealing device 8 of FIG FIG. 2 as well as through the punching device 16 and is continuously moved intermittently in the conveying direction 2. The plastic film 7 in the form of the outer patch is in FIG. 2 shown by a line in the region of the sealing device 8 below the material 1, because the plastic film 7 is to be sealed to the outside of the material 1. If the movable counter-jaw 9 is now pressed onto the sealing plate 11 with substrate material 1 inserted therebetween with plastic film 7, then the gray-applied areas in the material 1 heat up, because these are the raised regions 14 of the sealing plate 11 opposite. In between, the cold regions 17 result in the path of the substrate material 1.

If one transfers this idea to the representation of the FIG. 4 , then one recognizes an almost circular ring area with a hatching from top left to bottom right, which represents the cold area 17. It should be noted, however, that prior to punching the hole 5, this cold area 17 also extends beyond the punched cut line 6 a bit far inward, because the punching cut 6 must be completely surrounded by cold areas 17 on both sides.

In the presentation of the FIG. 2 This can clearly be seen from the fact that the cold regions 17 in the web-shaped substrate material 1 are located almost in the center under the punching knife 15. If the punching knife 15 designed as punch in this embodiment is moved downward in the direction of the arrow 18 through the substrate material 1, then not only the punching cut 6 is laid, but also the hot sealing region 19 of the punched-out circular disk 20 with the plastic film 7 adhering below , and laterally next to the two outer punch cuts 6 close again in FIG. 3 illustrated white cold areas 17 in the substrate 1 at. On both sides of the punched section 6 so parts of the cold areas 17 are with the result that the punching cut 6 was completely passed through cold material. This achieves the fiber-free and fringe-free, clean punching cut 6 in the desired pattern, in the embodiment shown here in the form of a circle.

In FIG. 3 the punch with the punching knife 15 is then pulled up again in the opposite direction to the movement arrow 18, and it is then the in FIG. 4 state shown in plan view.

It is understood that the counter-plate 21 of the punching device 16 at selected locations has the circular boundary of the hole in order to achieve a shearing action for punching the hole 5 with the punching blade 15.

The distance in the conveying direction 2 of the punching device 16 from the sealing device 8 results according to FIG. 2 from the vertical distance of the arrows 9 and 18, which are approximately in the respective center line of the device.

In FIG. 5 schematically shows a broken cross section through the generally designated 1 substrate material. The substrate sheet 22 is shown in this embodiment, a board web and a relatively thick sheet approximately in the middle with a hatching from top left to bottom right. Down from this middle panel 22 are the outer layers laid up, up the inner layers, considering the later package. An aluminum layer 23 is placed on the inside and an aluminized layer 24 on the outside, both of which are represented by cross-hatching. Outward then follows the print layer 25 with a hatching of two mutually phase-shifted sinusoidal lines. It is known to provide packages externally with a pressure, and when applied to an aluminum-coated layer 24 in the form of the printing layer 25, then one can achieve a gloss effect as in this particular embodiment. For protection, a plastic layer is then applied externally to the print layer 25 and on the inside to the aluminum layer 23, preferably made of polyethylene (PE). This is designated on both sides with 26 and practically not provided with hatching.

Up to this PE layer 26 is the web-shaped substrate material 1. This is then sealed in the sealing device 8, the stain-shaped plastic film 7 using the special sealing plate 14. The sealed state is in FIG. 5 shown, and this plastic film 7 is marked with narrow short hatching from top left to bottom right.

In this state, ie substrate material 1 plus plastic film 7, the punching takes place, so that the punched cut 6 shown as dashed lines results. Said substrate material with the plastic patch 7 now has a hole which can later be used as pouring hole 5. But first, the pack must be tight. For a tear strip 27 is sealed from the outside, the in FIG. 5 a hatching from bottom left to top right shows. This tear tab 27 is polyethylene-coated aluminum, as known per se. On the opposite inside, in the representation of the FIG. 5 So above, another polyethylene layer is sealed over the hole and sealed with the pull tab 27. The latter connection by sealing between the inner polyethylene layer 28 and the outer tear tab 27 is in FIG. 5 represented by a solid line 29 with two endpoints. That is, if the end user tears open the tear tab 27 from the filled beverage package, he also tears open the inner polyethylene layer 28 in the region of the pouring hole 5 in order to gain access to the package contents and to be able to use the pouring hole 5. The inner polyethylene layer 28 is characterized by hatching with alternating lines from bottom left to top right and intermediate points.

Claims (7)

1. A sealing (8) and cutting apparatus (16) with a sealing apparatus (8) for applying a plastic foil (7) to a planar substrate material (1) by means of heat and pressure using a sealing plate (11) with an active surface and a back plate (9) which is movable relative thereto, in which the sealing apparatus (8) is linked to a die cutting apparatus (16) with a die cutting knife (15) and a counter plate (21) for subsequently making die cuts (6) at selected locations in the planar substrate material (1) in the region of the applied plastic film (7), characterized in that the sealing plate (11) of the sealing apparatus (8) has raised (14) and depressed (13) regions on its active surface facing the back plate (9) and the location of the depressed regions (13) in the sealing plate (11) corresponds to the location of the die cutting knife (15), so that cut (6) is made at the selected positions in the substrate material (1) where, because of the depressed regions (13) of the sealing plate (11), there is almost no heating of the substrate material (1) and its laminations.
2. A sealing and cutting apparatus according to claim 1, characterized in that the die cutting apparatus (16) is arranged downstream of the sealing apparatus (8) in the machine direction of the substrate material (1) at a predetermined distance therefrom and both apparatuses (8, 16) are controlled in a coordinated manner so that the selected positions in the substrate material (1) in the sealing apparatus (8) come into position over the depressed regions (13) and thereafter come into position under the die cutting knife or knives (15) in the die cutting apparatus (16).
3. A sealing and cutting apparatus according to claim 1 or claim 2, characterized in that the depressed regions (13) in the active surface of the sealing plate (11) form a pattern which is an image of the pattern of the die cutting knife or knives (15) of the die cutting apparatus (16) so that both patterns are congruent.
4. A sealing and cutting apparatus according to one of claims 1 to 3, characterized in that the depressed region (13) of the sealing plate (11) is wider than the die cutting knife (15) of the punch and surrounds the cut (6) of the punch pattern on all sides.
5. A sealing and cutting apparatus according to one of claims 1 to 4, characterized in that the sealing plate (11) is formed from metal which is routed on its active surface to form the depressed regions (13), wherein the active surface is preferably coated with a scratch proof plastic material.
6. A sealing and cutting apparatus according to one of claims 1 to 5, characterized in that the planar substrate material web (1) is moved by drive means in an intermittent manner from the sealing apparatus (8) into the die cutting apparatus (16).
7. A sealing and cutting apparatus according to one of claims 1 to 6, characterized in that it forms part of an opening assembly for a filling machine for liquid packaging and the substrate material (1) is a carrier material web (22) provided with a ply of plastic layers (23, 24, 26) with score lines (3) for the production of a packaging with a tear tab (27), and the pattern for the die cutting knife (15) is a circle.

Images