WO2006113951A1

WO2006113951A1 - Method for producing a lid comprising a removal opening

Info

Publication number: WO2006113951A1
Application number: PCT/AT2006/000105
Authority: WO
Inventors: Lambert Nekula; Klaus Gerstl; Franz Kaufmann; Robert Afflenzer; Adolf Schedl; Herbert Tiefenbacher
Original assignee: Teich Aktiengesellschaft
Priority date: 2005-04-28
Filing date: 2006-03-13
Publication date: 2006-11-02
Also published as: AT501789A1; AT501789B1; RU2007144084A; EP1874510A1

Abstract

The invention relates to a method for producing a lid (1) comprising an aid (5) for opening and closing containers (7). Said lid consists of a composite comprised of at least two layers, the composite layer facing towards the container (2) adhering more firmly to the container edge (7') than to the outer heat-resistant composite layer (3), in such a way that when said outer composite layer is removed, at least one opening (6, 6') is formed. One opening (6) is used, for example, for removing the contents and another opening (6') for the evacuation of air.

Description

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Method for producing a lid with removal opening

The invention relates to a method for producing a lid with opening aid for sealing containers, which consists of an at least two-layer composite, wherein the container facing composite layer of plastic adheres more strongly on the container edge than on the outer heat-resistant composite layer, so that when peeling the outer composite layer at least one opening forms. The invention further relates to a sealing device for carrying out this method and the use of the lid produced for closing containers.

It is known to use multi-layer lid for closing containers to allow, for example, the flavor protection required for food. Furthermore, it has been found that, especially in the case of large packs, a partial removal of the packaged goods is desired, wherein the formation of an optionally closable opening is useful. To form this opening, the contour of the opening, for example, by weakening lines or by cuts, is specified in the multi-layer composite used on the side facing the container. The disadvantage here is that, especially in mass production, the uniformity of the opening leaves something to be desired. If this is determined by cuts, it has also been shown in many places that the knives used for this tend to wear and it therefore also comes to inaccuracies regarding the dimensional accuracy of the opening. Furthermore, quite tolerable material fluctuations, for example in terms of material thickness, lead to a nonuniform design of the opening within a production series. These inaccuracies in the manufacture of the apertures subsequently lead to packaging problems, i.e., the sealing of the lid to the container rim. These process delays are undesirable in that for sensitive packaged goods, such as dairy products, this should be sealed as quickly as possible after filling with a lid to prevent the ingress of contaminants, as well as bacteria.

For the production of weakening lines, instead of the aforementioned use of knives according to EP-A-262,652 and US-A-4,913,307, sealing tools are proposed. However, these sealing tools only engage in the sealed cup rim area, so that the use of these sealing tools - -

Witness is not suitable to form on a side facing the packaged a possible opening. Multilayer blanks of the type mentioned above are further known from EP-A-812 782 and FR-A-2 503 036. In this case, the packaged material facing thermoplastic layer has cuts, so that when peeling off the upper layer of the cup board an opening for removal of the packaged product is formed. The cuts ^' within the thermoplastic layer are formed with sealing tools, which attack at elevated temperature and pressure directly to the thermoplastic layer. In the aforementioned method for producing incisions, however, there is a risk that the sealing tools used soiled by molten thermoplastic residues and thus a relatively imprecise process process is made possible. Accordingly, it is an object of the present invention to avoid the drawbacks known from the prior art relating to the production of openings in multilayer lids for closing containers, but at the same time this method is to be carried out simply and quickly in order to simplify the packaging process, in particular special with sensitive packaged goods, not unnecessarily delay.

According to the invention, this object is achieved by a method of the type mentioned above, which is characterized in that one or more openings a sealing tool with at least one projection, which corresponds to the shape of the opening, is used and that the sealing tool in the range of at least one Advantageously brought to elevated temperature and applied to the outer, heat-resistant composite layer of the lid with a contact pressure such that heat is transferred from the heat-resistant Verbund- läge in the container facing composite layer of plastic, so that the plastic is squeezed out of the lid, and so a material separation between the potential opening and the remaining composite layer takes place. The invention further relates to a sealing device consisting of sealing tool and counter-plate, wherein one or more projections for forming an opening or superficial embossing are attached to the sealing tool. Further embodiments are disclosed according to the subclaims.

The lid produced according to the invention is further used for closing containers, advantageously by According to a present between the composite layers adhesive layer reclosability of the package is possible.

The invention will be explained in more detail below with reference to FIGS. 1-8 and with reference to possible embodiments of the invention. 1 shows the production of a lid using a correspondingly shaped sealing tool, wherein the lid material, for example consists of two composite layers. 2, an analogous process sequence, as shown in Fig. 1, shown, but between the layers of the lid member, an adhesive layer is provided. Fig. 3 shows a partially heated sealing tool with a plastic insert for the back plate of the sealing tool. Fig. 4 shows a sealing tool which is heated over its entire cross section. Fig. 5 shows a partially heated sealing tool with recesses in the backing plate. According to FIG. 6, the use of the lid produced according to FIG. 1 is shown, whereas in the case of the use according to FIG. 7 the repossibility of the pack is given by the provision of an adhesive between the composite layers of the lid. FIG. 8 shows a cover produced with a sealing tool according to FIG. 4, which additionally shows a ventilation opening in addition to a removal opening.

To produce the lid 1, an aluminum foil with a thickness of 10-100 μm is used, for example, as the outer composite layer 3. However, it is also conceivable to use instead a film composite, which in addition to the aforementioned aluminum foil also plastic and / or paper layers. Furthermore, an informative or decorative imprint may be provided on the side of the composite layer 3 facing the consumer.

As a result, by laminating or extruding, the composite layer 2 facing the container is applied to the outer composite layer 3 in the form of a sealable plastic layer. This advantageously has a thickness of 6 - 100 microns and may be formed in one or more layers. The plastics used for this purpose are provided predominantly from the group of polystyrenes, polyethylenes, polyesters and polypropylenes and their copolymers, as well as mixtures thereof. The plastics themselves may be filled or unfilled, with talc, silicic acid or chalk being advantageously used as fillers. It is decisive that the material selection for the composite layers 2 and 3 takes place such that the composite adhesion produced between the composite layers 2 and 3 is lower than the composite adhesion which exists between the composite layers. 2 and the container edge 7 'is present.

The usually present in roll cover material consisting of the composite layers 2 and 3 is punched out in a conventional manner in individual lids, which are stored in stacks. In order to avoid the glass pane effect formed by adhesion forces here, at least one surface side of the lid is completely or partially embossed. Furthermore, it is possible to provide one or both surface sides of the lid completely or partially with a surface-gray print pattern. This has the effect of trapping sufficient air between the surface bumps which serves to enhance the aforementioned glass pane effect, i. the sticking together, to avoid and so improve the Entstapelbarkeit the stored lid.

These lids are then lifted off the stack in a discontinuous process with a gripper and placed between a sealing tool 9 and a counterplate 12. However, it is also possible to continuously process the lid material in the form of rolls. As shown in Fig. 1, the sealing tool 9 has a projection 10, between which a sealing plate 11 is arranged. The sealing tool 9 is now, depending on the plastics used in the composite layers 2 and 3 heated to a temperature of 50 ° C - 300 ° C and then with a contact pressure in a range of 50 to 700 N / cm ² , preferably 75 to 250 N. / cm ² in the direction of arrow 13 - see Fig. Ia - introduced. Due to the elevated temperature and the applied contact pressure, the plastic is displaced in the composite layer 2, so that dividing lines 15 - see FIG. Ic - are formed, which correspond in dimensioning substantially the projection 10. The projection 10 is heated to a temperature of for example 250 ^' C and pressed against the composite layer 3 with a contact pressure of, for example, 150 N / cm ² . Since this consists of heat-resistant material, such as aluminum, the heat is transferred to the plastic layer 2, so that the plastic is converted into a softened or molten state and squeezed out of the composite. As a result, a bead 16 is formed on both sides of the dividing lines 15. This process is shown schematically in Fig. Ib or in sections in the region of the projection 10 with reference to FIG. Ic. The formation of the bead 16 can take place simultaneously with the lifting of the counter-plate 12 in the direction of the arrow 14, so that the lid 1 formed again stored in a stack or can be fed directly to the packaging machine.

According to the process diagram of FIG. 2, the procedure is analogous to that of FIG. 1, see in particular FIGS. 2 a and 2 b, but with the difference that an adhesive layer 4 is present between the composite layers 2 and 3. This is to make it possible that, after the opening 6 has been formed when the composite layer 3 is peeled off from the adhesive layer 4, the container 7 can be at least loosely closed again. The adhesive layer 4 is applied either to the composite layer 3 or to the composite layer 2 by laminating, suitable as an adhesive, for example acrylic acid copolyesters or conventional hotmelt extrusion coatings consisting of polyethylene and its copolymers. As shown in Fig. 2c is pressed by the projection 10 in the sealing tool 9 not only the composite layer 2 but at the same time the adhesive layer 4 from the composite, so formed in the region of the projections 10 on the one hand, the dividing lines 15 and on the other hand, the both sides adjacent bead 16 become.

As shown in Figures 1 and 2, the pressed out of the composite layer 2 plastic mass causes the formation of beads 16. These are on both sides of the dividing lines 15, wherein the dividing lines 15 represent the outlines of a potential opening, for example, for the removal of the packaged goods , By forming the beads 16 now forms an irregular surface of the lid member, which makes storage in a stack difficult.

It has therefore begun to form a special sealing tool, with which an opening 6, for example, for the removal of the packaged goods, or superficial increases, which are in the form of embossments or spacers, are generated in order to unstack after storage in a stack continue to improve.

According to FIG. 3, a sealing tool 9 is shown here in conjunction with a counterplate 12. In this case, in the plan view of the sealing tool 9 - see Fig. 3a - the projection 10 for the formation of the potential opening, such as the öffnungntnahmeöffnung 6 is provided, which here shows the shape of an ellipse. Flanking this are the elevations 10 ', in this case with a circular design - see the sectional view taken along the line AB-CD of FIG. 3b -, provided. These elevations 10 'cause during pressing a deformation of the composite layer 2, so embossing or Spacer 19 with a height x, see Fig. 3c, are formed. The height of this embossing bars is adjustable insofar as in the counter-plate 12, a rubber-elastic plastic insert 18 is provided, which causes a cushioning of the soft-elastic composite layer 2 during pressing. Because of this, these are elevations with a relatively low layer thickness, namely the layer thickness x. Due to the partial heating in the region 17, however, takes place here by the projections 10 a material separation within the composite layer 2, so that the dividing lines 15 are formed. Due to the heating and simultaneous application of pressure, here the plastic of the composite layer 2 is pressed out of the composite and forms a bead 16 on both sides of the separation lines 15.

Furthermore, it has been shown that, in addition to the opening 6, for example for the removal of packaging material, an opening 6 ¹ is also useful for draining gases formed in the interior of the package. This is, see Fig. 4c, formed in the area 6 '. This smaller in their dimension removal opening corresponds to a projection 10 'in the sealing tool 9 - see top view of FIG. 4a and the corresponding sectional view along the line AB of FIG. 4b. In order to achieve a material separation here also in the region of the projection 10 ', according to the embodiment according to FIG. 4, both the counter plate 12 and the sealing tool 9 are made of steel and heated. In this way, not only an opening 6 for the removal of packaging material, but also a smaller sized opening 6 ', for example, for venting, are generated. Of course, it is also conceivable to provide these circular openings 6 'over the entire cross section of the cover 1, so that in particular the storage of pourable material, such as spices and salt, is possible, which then metered through these openings 6' - see Fig. 4c - can be scattered.

According to FIG. 5, the sealing tool 9 is partially heated in the region 17. This, in turn, according to FIG. 5a shows in plan view the projection 10 and, in addition, circular elevations 10 '. However, in order to be able to configure the elevations 19 'by deep-drawing here in the finished lid and thus to achieve a higher layer thickness y compared to the height x according to the embodiment of FIG. 3, the counter-plate 12 has recesses 21 with the function of a male, see the sectional view of FIG. 5b along the line ABCD. Thus, in area 22, a deep-drawing Operation in which the elevations 19 'take over the function of a die and are formed in their thickness substantially stronger than those according to the embodiment of FIG. 3a. The layer thicknesses y produced can be seen from FIG. 5c. According to FIG. 6, the use of the cover 1 produced according to the method of FIG. 2 for closing a container 7 is shown. In this case, the opening aid 5, for example a gripping tab, is tightened in the direction of the arrow 8, so that the composite layers 2 and 3 are separated from each other by the applied tearing force (peeling). Due to the material-like dividing lines 15 - not shown in FIG. 6 - the opening 6 is formed during the opening process, wherein in a compound layer 2 'corresponding to the opening adheres to the upper composite layer 3. This is also due to the proviso of the integrated sealing plate 11 - not shown in Fig. 6 - conditionally, which leads to a partial increase of the composite adhesion in the region of the opening between the cover layer 2 and 3. The remaining composite layer 2 ', however, continues to adhere to the container edge 7'; This is due to the increased adhesion between the container edge 7 'and the composite layer 2'.

In Fig. 7, the use of a lid 1 is shown, which was prepared according to the process scheme of Fig. 2. By applying a force in the direction of the arrow 8, the opening 6 is formed. Due to the adhesive layer 4, the opening 6 can be at least loosely closed by pressing the upper composite layer 3. In Fig. 8 the use of a lid 1 is shown, which is made with a sealing tool of FIG. 4. The dimensioning of this sealing tool materialized separations are generated for each two openings, wherein the opening 6 acts as a removal opening and the opening 6 'as a vent. Both openings 6, 6 'are formed during peeling off the cover layer 3 from the cover layer 2.

In summary, it can be said that, by carrying out the method according to the invention, lids with openings 6 or 6 'can be produced in a simple manner. The often circular or ellipsoidal in its dimensioning opening 6 serves for example for the removal of packaging. In contrast, the reduced in their dimensioning opening 6 'is used for example for venting or for scattering pourable packaged goods, such as spices, salt or the like .. To the during the manufacturing process formed beads 16 to balance out of squeezed out plastic and thereby ensure a proper storage in a stack, can be generated with the sealing tool used according to the invention in an elevation by deep drawing. These elevations act as embossing bars or spacers, so that a correct storage in a stack, without this tipping over, is guaranteed.

Claims

_ _Patent claims

1. A method for producing a lid (1) with opening aid (5) for closing containers (7), which consists of an at least two-layer composite, wherein the container facing composite layer of plastic (2) stronger on the container edge (7 ¹ ) adheres to the outer heat-resistant composite layer (3) so that at least one opening (6, 6 ') forms during peeling of the outer composite layer, characterized in that one or more openings (6, 6') are provided with a sealing tool (9) at least one projection (10,10 '), which corresponds to the shape of the opening (6,6') is used, and that the sealing tool (9) in the region of at least one projection (10, 10 ') brought to elevated temperature and at the outer, heat-resistant composite layer (3) of the cover (1) is applied with a contact pressure in such a way that heat is transferred from the heat-resistant composite layer (3) into the plastic composite layer (2) facing the container, so that the plastic from the lid (1) is squeezed out and so a material separation (15) between the potential removal opening (6,6 ') and the remaining composite layer (2 ") takes place.

2. The method according to claim 1, characterized in that the sealing tool used (9) has one or more projections (10, 10 ') with a sealing plate (11) integrated therein.

3. The method according to claim 1 or 2, characterized in that the production of the material dividing lines (15) in the

Composite layer of plastic (2) at elevated temperature, preferably in a range of 50 ° C - 300 ° C, and a pressure in a range of 100 to 1500 N / cm ² , preferably in a range of 75 - 250 N / cm ² he follows.

4. The method according to any one of claims 1 to 3, characterized in that the plastics of the composite layer (2) in the region of the projections (10,10 ') are brought into melt and form a bead (16) on both sides of the dividing line (15).

5. The method according to any one of claims 1 to 4, characterized in that the plastics of the composite layer (2) for forming elevations (19, 19 ') in the region of the projections (10') are deep-drawn.

6. The method according to any one of claims 1 to 5, characterized in that as plastic in the container facing composite layer (2) sealable plastics are used. -

7. The method according to claim 6, characterized in that the sealable plastics from the group polyethylene, polypropylene, polyesters, polystyrenes, their copolymers and mixtures thereof are selected.

8. The method according to claim 6 or 7, characterized in that the plastic for the formation of the container facing composite layer (2) fillers are added.

9. The method according to claim 8, characterized in that the fillers talc and / or silica and / or chalk are.

10. The method according to any one of claims 1 to 9, characterized in that is used as an outer heat-resistant composite layer (3) an aluminum foil or an aluminum-containing multilayer composite.

11. The method according to any one of claims 1 to 10, characterized in that between the container facing composite layer

Plastic (2) and the outer heat-resistant composite layer (3) an adhesive layer (4) is attached.

12. The method according to claim 11, characterized in that a pressure-sensitive adhesive is used as the adhesive.

13. The method according to any one of claims 1 to 12, characterized in that the lid (1) either on the composite layer of plastic (2) or on the heat-resistant composite layer (3) is completely or partially coined.

14. The method according to any one of claims 1 to 12, characterized in that the cover (1) is provided either on the composite layer (2) or on the heat-resistant composite layer (3) with a full-surface or partial, surface-rough imprint.

15. The method according to claim 14, characterized in that the surface-gray imprint has the form of geometrically arranged spacers.

16. The method according to any one of claims 1 to 15, characterized in that as opening aid (5) a grip tab is formed.

17. The method according to claim 16, characterized in that in the region of the grip tab (5) an adhesive layer (4), preferably a pressure-sensitive adhesive is applied.

18. Sealing device for use in a method according to one of claims 1 to 17, consisting of a sealing tool (9) and a counter-plate (12), characterized in that the sealing tool (9) one or more projections (10, 10 ' ) having. - -

19. A sealing device according to claim 18, characterized in that the sealing tool (9) has a circular, ellipsoidal or the like. formed projection (10).

20. Sealing device according to claim 19, characterized in that the sealing tool (9) is heated in the region of the projection (10).

21. Sealing device according to claim 20, characterized in that the counter-plate (12) has a plastic insert (18).

22. Sealing device according to one of claims 18 to 21, characterized in that the sealing tool (9) and the counter-plate (12) consist of steel.

23. Use of a lid (1) produced according to one of claims 1 to 17 for closing containers (7).

24. Use according to claim 23, characterized in that the lid (1) used between the composite layers (2,3) an adhesive

(4), so that after opening at least a loose resealing of the container (7) is made possible.