EP3741701A1 - Metallic can lid - Google Patents

Abstract

Process for the production of a metallic can lid with a resealable opening, with a microgap (4) or weakening line (4 ', 4 ") provided in the metallic lid surface around the opening, one connected to the fixed lid surface (2) and enclosing the opening area Sealing frame (5) made of plastic material, a closing unit (6) made of plastic material connected to the metal cover area (3) which can be swiveled up inside the microgap (4) or the weakening line (4 ', 4 ") and which can be swiveled via a swivel bearing (7) is attached to the fixed cover surface (2) and provided with a tear-open member (8) which is diametrically opposite the pivot bearing (7) and is connected to the closing unit (6) such that it can be swiveled up, the sealing frame (5) and the closing unit (6), About sealing and locking ribs (12, 13, 14) and associated grooves (15, 16, 17), cooperate sealingly and within the umlau fenden microgap (4) or the weakening line (4 ', 4 ") located metallic lid area (3) is received and held in the opening area of the lid (1), the sealing frame (5) with the fixed lid surface (2) and the closing unit (6) are firmly connected to the metal lid area (3) that can be pivoted up using an adhesion promoter by a thermal process, the adhesion promoter being added to the respective plastic material before the sealing frame (5) and / or the closing unit (6) are formed .

Description

The present invention relates to a metallic can lid with a resealable opening, in particular for beverage cans and for containers for storing food and other liquid, pasty, powdery and / or solid products.

From the EP 1 607 341 A1 a can lid with a resealable opening is known in which an opening is made in the metallic can lid and the edge of this opening is flanged in order to create an anchoring option for a prefabricated plastic closure part. The plastic closure part comprises a base part which is to be connected to the flanged edge of the can opening and in which an opening closed by a flat stopper is formed. The flat stopper is connected to the opening edge via a plastic tear seam, so that the flat stopper connected to a pull tab can be detached from the plastic base part by pulling over the pull tab and pivoted into an opening point. The opening can be temporarily closed again by pressing in the flat plug, which is preferably conical on its underside.

Resealable can lids are also for example in the DE 10 2010 013 531 A1 , the DE 10 2015 112 428 A1 and the EP 2 354 022 B1 described.

The object of the invention is to provide a resealable can lid which is particularly inexpensive to manufacture and yet on the one hand easy to operate and on the other hand has good sealing properties.

This object is achieved by a metallic can lid with the features of claim 1.

A micro gap ensures that the can lid can be opened particularly easily, but a line of weakness is also generally suitable. An effective closure and reclosure can be achieved via the sealing and locking ribs and the associated receiving grooves. It is particularly advantageous here that the sealing frame is firmly connected to the fixed cover surface and the closing unit to the metal cover area that can be pivoted up. Dispensing with laminations and the like, for example plastic films, on the inside of the can lid leads to cost-effective production.

Production is particularly favorable if the entire inside of the cover is free of laminations and the like, except for a layer of lacquer that may be provided. During production, the sealing frame and the closing unit then only have to be attached to the outside of the cover and firmly connected to the cover. The inside can be coated with a particularly food-grade lacquer layer. Such a lacquer layer can be applied cost-effectively to the raw cover material. The punched edges of a microgap can be covered with varnish afterwards, for example by spraying or pad printing.

According to another preferred embodiment of the invention, the inside of the lid is provided with a sealing film which covers the microgap or the line of weakness, but leaves the area outside it free.

Only a relatively small film is therefore required, which can also be completely flat. As a result, both the production of the film and the connection of the film to the inside of the ceiling can be carried out in a particularly simple and cost-effective manner.

According to a further preferred embodiment of the invention, the sealing film has an annular shape corresponding to the shape of the microgap or the line of weakness. The film can only extend a few tenths of a millimeter, in particular 3 to 4 tenths of a millimeter, beyond the microgap or the line of weakness on both sides. A very small film can thus reliably cover the microgap or the line of weakness, which on the one hand further reduces the production costs and on the other hand simplifies the production itself.

According to another embodiment of the invention, the sealing film is disk-shaped and covers the entire area within the microgap or the line of weakness. This film also only needs to reach outwards by a few tenths of a millimeter beyond the microgap or the line of weakness, preferably 3 to 4 tenths of a millimeter. The disk shape is again very easy to manufacture and to attach to the inside of the lid. This in turn saves manufacturing costs.

A particularly favorable production of the film can take place if it is designed as a stamped part.

According to a further preferred embodiment of the invention, the closing unit covers the microgap or the line of weakness from the outside as long as the cover is not open. Even without a film on the inside of the lid, the lid can be made leaktight. The closing unit is covered the microgap or the line of weakness preferably on both sides by at least 0.3 millimeters, in particular by about 1 millimeter.

According to a further embodiment of the invention, the closing unit has a first sealing area which is arranged radially inside the microgap or the line of weakness and is completely circumferential and is connected in a tear-proof manner to the metal lid area which can be pivoted up, in particular with a material fit, and a second sealing area, which is radially outside of the microgap or the line of weakness is arranged completely circumferentially and is connected to the fixed lid surface, in particular cohesively, in such a way that it can be detached from the fixed lid surface with a predetermined maximum force when the can lid is torn open. The maximum force is preferably 10 N or less, in particular 5 N or less. These sealing areas result in an advantageous seal between the container interior and the exterior, it being possible to set a desired sealing strength. In the case of a micro gap in a can lid without an inner film, the sealing and sealing strength is achieved solely by the sealing unit, in the case of a lid with a weakening line to a large extent.

When the can lid is opened for the first time, the seal between the closure unit and the fixed lid area is released in the manner of a peel closure. In contrast, the seal between the closing unit and the hinged lid area is retained. When the can lid is closed again, the tightness is then brought about by the seal between the closing unit and the hinged lid area on the one hand and between the sealing frame and the closing unit on the other hand.

According to a preferred development, the cover area which can be pivoted up has a kind of teardrop shape with a pointed area at the point of application of the tear-open member and a round area at the end facing away from it at the pivot bearing on. This results in an advantageous tear-open behavior, in particular with regard to the seal between the closing unit and the fixed lid area.

According to a further embodiment of the invention, the can lid has an elongated hole in the area of the tear-open element, which is adjoined on both sides by the microgap or the line of weakness, a plastic part being inserted into the elongated hole in a sealing manner, in particular through a mushroom-shaped design on both sides of the lid and a material connection with the Can lid, and wherein the plastic part is in turn provided with a line of weakness which connects the opposite ends of the microgap or the line of weakness of the metallic can lid to one another. The line of weakness in the plastic part can be produced by embossing in particular when producing the seal. The opening forces can thereby advantageously be reduced.

According to a further embodiment of the invention, the line of weakness in the can lid is formed by a pressed-in, sharp-edged notch. According to another embodiment of the invention, the line of weakness is produced by deep-drawing the can lid material. With this last-mentioned variant, a very thin-walled tear line can be formed which is easy to tear open. But the sharp-edged notch also offers advantageous tear properties.

For the production of a metallic can lid of the type described above, in which both the sealing frame with the fixed lid surface and the closing unit with the metal lid area that can be pivoted upwards are firmly bonded using an adhesion promoter that is preferably suitable for use with food and / or having lubricating properties, in particular adhesive varnish, in particular by a thermal process is connected, the adhesion promoter is preferably added to the respective plastic material before the sealing frame and / or the closing unit are formed. In particular, can the adhesion promoter can be added to a plastic granulate, which is used to manufacture a plastic injection-molded part. A separate application of the adhesion promoter to the parts mentioned is not necessary, as a result of which the production costs can be reduced.

In a further method for producing a metallic can lid of the type described with a plastic film, in particular on the inside of the lid, in particular for sealing a microgap in the can lid, which, using an adhesion promoter, in particular adhesive varnish, is materially bonded to the metallic can lid, in particular by a thermal process is connected, the adhesion promoter is preferably designed as a film. This is also advantageous in terms of production, since the two films can easily be connected to one another.

The adhesion promoter film with the plastic film is particularly preferably produced as a two-layer film, in particular by coextrusion. This makes production even easier and cheaper.

Otherwise, the adhesion promoter can also be applied as an adhesive varnish to one or both parts to be connected, that is to say to the metallic cover material and / or the sealing frame and the closing unit and the sealing film.

Fig. 1

eine perspektivische Ansicht eines erfindungsgemäßen Dosendeckels,

Fig. 2

eine Draufsicht auf die Oberseite des Dosendeckels von Fig. 1,

Fig. 3

einen Schnitt gemäß Linie A-A in Fig. 2,

Fig. 4

einen Schnitt gemäß Linie B-B in Fig. 2,

Fig. 5

einen Schnitt entsprechend Fig. 4 durch eine Variante eines erfindungsgemäßen Dosendeckels,

Fig. 6

Detail B von Fig. 5,

Fig. 7

Detail C von Fig. 5,

Fig. 8

einen Schnitt entsprechend Fig. 4 durch eine weitere Variante eines erfindungsgemäßen Dosendeckels,

Fig. 9

Detail B von Fig. 8,

Fig. 10

Detail C von Fig. 9,

Fig. 11

einen Schnitt entsprechend Fig. 4 durch noch eine Variante eines erfindungsgemäßen Dosendeckels,

Fig. 12

Detail B von Fig. 11,

Fig. 13

Detail C von Fig. 12,

Fig. 14

eine Draufsicht auf den Öffnungsbereich eines erfindungsgemäßen Dosendeckels,

Fig. 15

ein in einen erfindungsgemäßen Dosendeckel eingesetztes Kunststoffteil,

Fig. 16

das Kunststoffteil von Fig. 15 nach einer pilzförmigen Verformung,

Fig. 17

eine Draufsicht auf den Ausschnitt eines erfindungsgemäßen Dosendeckels,

Fig. 18

einen Schnitt gemäß Linie B-B in Fig. 17,

Fig. 19

einen Schnitt gemäß Linie C-C in Fig. 17, und

Fig. 20

einen Schnitt gemäß Linie D-D in Fig. 17.

An embodiment of the invention is shown in the drawing and is described below. They show, each in a schematic representation,

Fig. 1

a perspective view of a can lid according to the invention,

Fig. 2

a top view of the top of the can lid of FIG Fig. 1 ,

Fig. 3

a section along line AA in Fig. 2 ,

Fig. 4

a section along line BB in Fig. 2 ,

Fig. 5

a cut accordingly Fig. 4 by a variant of a can lid according to the invention,

Fig. 6

Detail B of Fig. 5 ,

Fig. 7

Detail C of Fig. 5 ,

Fig. 8

a cut accordingly Fig. 4 by another variant of a can lid according to the invention,

Fig. 9

Detail B of Fig. 8 ,

Fig. 10

Detail C of Fig. 9 ,

Fig. 11

a cut accordingly Fig. 4 by another variant of a can lid according to the invention,

Fig. 12

Detail B of Fig. 11 ,

Fig. 13

Detail C of Fig. 12 ,

Fig. 14

a plan view of the opening area of a can lid according to the invention,

Fig. 15

a plastic part inserted into a can lid according to the invention,

Fig. 16

the plastic part of Fig. 15 after a mushroom-shaped deformation,

Fig. 17

a plan view of the detail of a can lid according to the invention,

Fig. 18

a section along line BB in Fig. 17 ,

Fig. 19

a section along line CC in Fig. 17 , and

Fig. 20

a section along line DD in Fig. 17 .

The can lid 1 shown in the figures consists of metal, in particular aluminum, and has a resealable opening. For this purpose, a lid area 3 that can be pivoted up is provided in the lid in addition to a fixed lid surface 2. The pivotable lid area 3 is separated from the fixed lid area 2 by a circumferential microgap 4 or a line of weakness (see in particular Fig. 6 ).

A sealing frame 5 made of plastic material surrounding the opening area is connected to the fixed cover surface 2, in particular by a so-called hot melt process using an adhesion promoter in order to ensure a firm connection to the aluminum of the cover. A closing unit 6, which is also made of plastic and is pivotably attached to the fixed cover surface 2 via a pivot bearing 7, is also connected to the metal cover area 3 which can be swiveled up. The swivel bearing 7 and the closing unit 6 are in turn connected to the fixed cover surface 2 or the cover area 3, which can be pivoted up, in particular via a hot melt connection using an adhesion promoter.

On the side diametrically opposite the pivot bearing 7, the closing unit is connected to a pivotable tear-open member 8 which, when not pivoted up, is arranged parallel to the top 9 of the lid. The tear-open member 8 is designed in a known manner in the shape of a ring and, by engaging a finger in an engaging end 10, can be pivoted upward about a pivot bearing 11 relative to the cover surface.

The sealing frame 5 and the closing unit 6 work together in a sealing manner via sealing and locking ribs 12, 13, 14 on the sealing frame 5 and associated receiving grooves 15, 16, 17 on the closing unit 6. As a result, at least three sealing edges 18, 19, 20 are formed, by which the opening area of the can lid is sealed. Even if a microgap 4 is used between the lid area 3 which can be pivoted up and the fixed lid area 2, this ensures that the can lid is leakproof.

In the embodiment of Figures 5 to 7 the can lid 1 is provided with a microgap 4. This is overlapped by the closing unit 6, a first sealing area 26 being formed between the closing unit 6 and the hinged lid area 3 and a second sealing area 27 between the closing unit 6 and the fixed lid area 2. The first sealing area is designed in such a way that the closing unit 6 is connected to the lid area 3, which can be pivoted up, in a tear-proof manner. In contrast, the second sealing area 27 is designed in such a way that, when the can lid 1 is torn open, it can be detached from the fixed lid area 2 with a predetermined maximum force. The maximum force is preferably 10 N, in particular 5 N. Both sealing areas 26, 27 are completely circumferential around the opening area of the can lid, so that the interior of the can is completely sealed by these two sealing areas.

The sealing in the first sealing area 26 and in the second sealing area 27 is preferably carried out in a materially bonded manner by a thermal process, in particular by a so-called hot melt process. The shape of the sealing surfaces 26, 27 is as in FIG Fig. 14 shown, preferably drop-shaped.

The Figs. 8-10 show a further variant of a can lid according to the invention with a first sealing area 26 between the closing unit 6 and the hinged lid area 3 and a second sealing area 27 between the closing unit 6 and the fixed lid area 2, each of which is designed according to the previous variant. The difference to the previous variant is that, instead of a microgap 4, a weakening line 4 ′ is provided between the fixed cover area 2 and the cover area 3 that can be pivoted up. The line of weakness 4 'is designed as a sharp-edged notch.

In the Figures 11 to 13 A weakening line 4 ″ is also provided between the fixed cover area 2 and the swiveling up cover area 3. This is, unlike the previous variant, designed as a deep-drawn deformation is provided between the closing unit 6 and the hinged lid area 3 and a second sealing area 27 is provided between the closing unit 6 and the fixed lid area 2. The rest of the configuration is again as in the variants described above.

In the Figures 15 to 20 In the variant shown, a plastic part 28 is inserted into an elongated hole 29 provided in the can lid 1. The microgap 4 adjoins the two narrow ends of the elongated hole 29. As in Fig. 16 As can be seen clearly, the plastic part 28 is deformed in the shape of a mushroom, on the one hand to encompass the fixed cover area 2 and, on the other hand, the hinged cover area 3 on both sides. Fig. 15 shows the undeformed state.

The plastic part 28, deformed in the shape of a mushroom, is materially connected to the can lid 1, in particular by a thermal process using an adhesion promoter. A line of weakness 30, which is preferably produced during the sealing process of the can lid 1, is also embossed into the plastic part 28. This line of weakness 30 allows the plastic part to be separated into two parts when the can lid is torn open. The opening forces are lower here than without the plastic part 28.

The one in the Figures 3 and 4 illustrated embodiment, the inside of the can lid is laminated with a plastic film 25, which covers the entire inside of the lid. Notwithstanding this, the plastic film can also be designed in the shape of a ring and only extend by a few tenths of a millimeter, in particular 3 to 4 tenths of a millimeter, on both sides beyond the microgap 4 or the line of weakness. Another possibility is to use a disk-shaped sealing film which extends by a few tenths of a millimeter, for example 3 to 4 tenths of a millimeter, radially outward beyond the microgap 4 or the line of weakness. In this case, the sealing film can be designed as a largely flat disk. Both the ring-shaped and the disk-shaped sealing film are preferably designed as a stamped part.

While the sealing frame 5 and the closing unit 6 are always attached to the outside of the can lid 1 and connected to the can lid via an adhesion promoter, the inside of the lid can deviate from the exemplary embodiment also be at least largely free of laminations and the like. The inside of the lid can, however, be provided with a particularly food-grade lacquer layer in order to prevent the goods located in the can from coming into contact with the metallic lid material.

The ones in the Figures 5 to 13 The illustrated embodiments show can lids without a sealing film. The sealing areas 26 and 27 as well as the sealing and locking ribs 12, 13 and 14 with the associated receiving grooves 15, 16, 17 nevertheless ensure that the can lid is sealed and that it is tightly sealed.

List of reference symbols

1

Can lid

2

fixed lid area

3

hinged lid area

4th

Microgap

4 ', 4 "

Line of weakness

5

Sealing frame

6

Closing unit

7th

Pivot bearing

8th

Tear-off device

9

Top of the lid

10

Intervening

11

Swivel bearing from 8

12

Sealing and locking rib

13

Sealing and locking rib

14th

Sealing and locking rib

15th

Receiving groove

16

Receiving groove

17th

Receiving groove

18th

Sealing edge

19th

Sealing edge

20th

Sealing edge

21st

hook

22nd

head Start

23

Breakthrough

24

Appendix

25th

Sealing film

26th

first sealing area

27

second sealing area

28

Plastic part

29

Oblong hole30 line of weakness

Claims (1)

Process for the production of a metallic can lid with a resealable opening, especially for beverage cans as well as for containers for storing food and other liquid, pasty, powdery or solid products, with a microgap (4) or weakening line provided in the metallic lid surface around the opening (4 ', 4 "), a sealing frame (5) made of plastic material connected to the fixed cover surface (2) and enclosing the opening area, one that can be pivoted upwards with the one inside the microgap (4) or the weakening line (4', 4") metallic lid area (3) connected to the closure unit (6) made of plastic material, which is attached pivotably to the fixed lid surface (2) via a pivot bearing (7) and is preferably provided with a tear-open element (8) which is diametrically opposite the pivot bearing (7) and can be pivoted upwards is connected to the closing unit (6), the sealing frame n (5) and the closing unit (6), preferably via sealing and locking ribs (12, 13, 14) and associated receiving grooves (15, 16, 17), cooperate in a sealing manner and within the circumferential microgap (4) or the line of weakness ( 4 ', 4 ") located metallic lid area (3) is received and held in the opening area of the lid (1), the sealing frame (5) with the fixed lid surface (2) and the closing unit (6) with the hinged, metallic lid area (3) using an adhesion promoter that is preferably suitable for use with foodstuffs and / or has lubricating properties, in particular adhesive varnish, in particular are firmly bonded by a thermal process, characterized in that the adhesion promoter is added to the respective plastic material before the sealing frame (5) and / or the closing unit (6) are formed, in particular a plastic granulate for producing a plastic injection molded part.

Images