EP3981702A1 - Metallic can lid - Google Patents

Abstract

Process for the production of a metal can end with a resealable opening, with a microgap (4) or weakening line (4', 4") provided in the metal end face and surrounding the opening, one connected to the fixed end face (2) and enclosing the opening area sealing frame (5) made of plastic material, a closing unit (6) made of plastic material which is connected to the metallic cover area (3) that can be pivoted up and is located inside the microgap (4) or the weakening line (4', 4"), which can be pivoted via a pivot bearing (7). is attached to the fixed cover surface (2), which is diametrically opposite the pivot bearing (7) and is connected to the closing unit (6) so that it can be pivoted upwards, with the sealing frame (5) and the closing unit (6) cooperating in a sealing manner and which within the circumferential micro-gap ( 4) or the weakening line (4', 4") located metallic cover area (3) in the opening area of the deck els (1) is received and held, with the sealing frame (5) being connected to the fixed cover surface (2) and the closing unit (6) to the metal cover area (3) which can be swung up, using an adhesion promoter, the adhesion promoter being materially connected the shaping of the sealing frame (5) and/or the closing unit (6) is added to the respective plastic material.

Description

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

From the EP 1 607 341 A1 a can end with a resealable opening is known in which an opening is made in the metal can end and the edge of this opening is crimped to provide an anchoring possibility for a prefabricated plastic closure part. The plastic closure part comprises a base part to be connected to the flanged edge of the can opening, in which base part an opening closed by a flat stopper is formed. The flat stopper is connected to the edge of the opening via a plastic tear seam, so that the flat stopper connected to a tear-off tab can be detached from the plastic base part by exerting a pull on the tear-off tab and can be pivoted into an opening location. The opening can be temporarily closed again by pressing in the flat stopper, which is preferably conical on its underside.

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

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

This object is achieved by a metallic can end having the features of claim 1.

A micro-gap ensures that the can lid can be opened particularly easily, but a weakened line is also fundamentally 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 materially connected to the fixed cover surface and the closing unit is connected to the metallic cover area that can be swung up. The omission of laminations and the like, for example plastic films, on the inside of the can lid leads to cost-effective production.

Production is particularly favorable when the entire inside of the lid is free of laminations and the like, except for a paint layer that may be provided. During production, the sealing frame and the closing unit only have to be attached to the outside of the lid and firmly connected to the lid. The inside can be coated with a lacquer layer that is particularly suitable for use with food. Such a lacquer layer can be applied inexpensively to the raw material of the lid. The punched edges of a micro-gap can be covered again later with paint, e.g. by spraying or pad printing.

According to another preferred embodiment of the invention, the inside of the lid is provided with a sealing film that covers the microgap or the weakening line, 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 foil and the connection of the foil 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 foil has an annular shape corresponding to the shape of the microgap or the weakening line. The film can extend beyond the microgap or the weakening line on both sides by only a few tenths of a millimeter, in particular 3 to 4 tenths of a millimeter. A very small film can thus be used to reliably cover the microgap or the weakening line, 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 weakening line. This film also needs to extend outwardly beyond the microgap or line of weakness by only a few tenths of a millimeter, preferably 3 to 4 tenths of a millimeter. The disc shape is again very easy to manufacture and to attach to the inside of the lid. This in turn saves production costs.

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

According to a further preferred embodiment of the invention, the closing unit covers the microgap or the weakening line from the outside as long as the lid is not open. Even without a film on the inside of the lid, the lid can thus be sealed tightly. The capping unit covers the microgap or the weakening line 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 weakening line and runs all the way around and is connected to the metallic lid area that can be swung up, in particular in a materially bonded manner, and a second sealing area, which is radially outside the microgap or the weakening line is arranged all the way around and is connected to the fixed lid surface, in particular materially, 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 sealing of the interior of the container in relation to the exterior, with a desired closure strength being able to be set. In the case of a micro-gap in a can end without inner liner, the seal and closure strength is achieved solely by the seaming unit, in the case of an end with a weakened line, the majority.

When the can lid is opened for the first time, the seal between the closing unit and the fixed lid area is broken in the manner of a peel closure. On the other hand, the seal between the closing unit and the lid area that can be swung up remains intact. When the can lid is closed again, the tightness is then brought about by the seal between the closing unit and the lid area that can be pivoted up on the one hand and between the sealing frame and the closing unit on the other.

According to a preferred development, the cover area that can be swung up has a kind of teardrop shape with a pointed area at the point of application of the ripping element and a round area at the end facing away from it at the pivot bearing on. This results in an advantageous tearing 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 weakening line, with a plastic part being inserted into the elongated hole in a sealing manner, in particular by means of a mushroom-shaped design on both sides of the lid and an integral connection with the can end, and wherein the plastic part is in turn provided with a line of weakness connecting opposite ends of the microgap and line of weakness, respectively, of the metal can end. The weakening line in the plastic part can be produced by embossing, in particular when producing the seal. The opening forces can be advantageously reduced as a result.

According to a further embodiment of the invention, the weakening line in the can lid is formed by a pressed-in, sharp-edged notch. According to another embodiment of the invention, the weakening line is produced by deep-drawing the can end material. This latter variant allows a very thin-walled tear line to be formed which can be easily torn open. But the sharp-edged notch also offers advantageous tearing properties.

To produce 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 metallic lid area that can be swung up, are bonded using an adhesion promoter that is preferably suitable for food and/or has lubricating properties, in particular adhesive lacquer, 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 is formed. In particular, can the adhesion promoter can be added to a plastic granulate that is used to produce a plastic injection molded part. A separate application of the adhesion promoter to the parts mentioned is not necessary, which means that the production costs can be reduced.

In a further method for producing a metal 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 is bonded to the metal can lid, in particular by a thermal process, using an adhesion promoter, in particular adhesive lacquer is connected, the adhesion promoter is preferably designed as a film. This is also favorable in terms of production, since the two films can be easily connected to one another.

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

Otherwise, the adhesion promoter can also be applied as an adhesive lacquer to one or both parts to be connected, ie to the metal cover material and/or the sealing frame and the closing unit as well as the sealing foil.

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. It shows, each in a schematic representation,

1

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

2

a plan view of the top of the can lid of FIG 1 ,

3

a cut according to line AA in 2 ,

4

a cut according to line BB in 2 ,

figure 5

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

6

Detail B of figure 5 ,

7

Detail C of figure 5 ,

8

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

9

Detail B of 8 ,

10

Detail C of 9 ,

11

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

12

Detail B of 11 ,

13

Detail C of 12 ,

14

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

15

a plastic part used in a can end according to the invention,

16

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

17

a top view of the section of a can lid according to the invention,

18

a cut according to line BB in 17 ,

19

a cut according to line CC in 17 , and

20

a cut according to line DD in 17 .

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

A sealing frame 5 made of plastic material enclosing the opening area is connected to the fixed cover surface 2, in particular by a so-called hot melt method using an adhesion promoter to ensure a firm connection with the aluminum of the cover. Furthermore, a closing unit 6 is connected to the metal lid area 3 that can be swung up, which is also made of plastic and is pivotably attached to the fixed lid surface 2 via a pivot bearing 7 . The swivel bearing 7 and the closing unit 6 are in turn connected to the fixed cover surface 2 or the cover area 3 that can be swung 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 ripping member 8 that can be swung up and is arranged parallel to the top side 9 of the lid when it is not swung up. The ripping member 8 is ring-shaped in a known manner and can be pivoted up about a pivot bearing 11 by engaging a finger in an engagement end 10 opposite 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, through which the opening area of the can lid is sealed. Even if a microgap 4 is used between the cover area 3 that can be swung up and the fixed cover area 2, the tightness of the can cover is thereby ensured.

In the embodiment of Figures 5 to 7 the can lid 1 is provided with a micro gap 4. This is overlapped by the closing unit 6 , a first sealing area 26 being formed between the closing unit 6 and the cover area 3 that can be swung up and a second sealing area 27 between the closing unit 6 and the fixed cover area 2 . The first sealing area is designed in such a way that the closing unit 6 is connected to the cover area 3 that can be swung up and cannot be torn open. In contrast, the second sealing area 27 is designed in such a way that it can be detached from the fixed lid area 2 when the can lid 1 is torn open with a predetermined maximum force. The maximum force is preferably ≦10 N, in particular ≦5 N. Both sealing areas 26, 27 are formed all the way around the opening portion of the can lid so that the inside of the can is completely sealed by these two sealing portions.

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

the Figures 8 to 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 lid section 3 that can be swung up and a second sealing area 27 between the closing unit 6 and the fixed lid section 2, which are each designed in accordance with the previous variant. The difference from the previous variant is that instead of a micro-gap 4, here a weakening line 4' is provided between the fixed cover area 2 and the cover area 3 that can be swung up. The weakening line 4' is designed as a sharp-edged notch.

At the in the Figures 11 to 13 The variant shown is also provided with a weakening line 4" between the fixed lid area 2 and the lid area 3 that can be pivoted up. Unlike the previous variant, this is designed as a deep-drawn deformation. The weakening line 4" is also overlapped by the closing unit 6, with a first sealing area 26 between the closing unit 6 and the cover area 3 that can be swung up and a second sealing area 27 is provided between the closing unit 6 and the fixed cover area 2 . The rest of the configuration is again the same as in the previously described variants.

At the in the Figures 15 to 20 variant shown, a plastic part 28 is inserted into a slot 29 provided in the can lid 1 . The microgap 4 adjoins the two narrow ends of the elongated hole 29 in each case. As in 16 It is easy to see that the plastic part 28 is deformed in the shape of a mushroom in order to overlap the fixed cover area 2 on the one hand and the cover area 3 that can be swung up on the other hand on both sides. 15 shows the undeformed state.

The mushroom-shaped deformed plastic part 28 is materially connected to the can lid 1, in particular by a thermal process using an adhesion promoter. A weakening line 30 is also embossed into the plastic part 28 and is preferably produced during the sealing process of the can end 1 . This weakening line 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.

At the 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. Deviating from this, the plastic film can also be ring-shaped and extend only a few tenths of a millimeter, in particular 3 to 4 tenths of a millimeter, beyond the microgap 4 or the weakening line on both sides. Another possibility is to use a disk-shaped sealing film that extends radially outwards beyond the microgap 4 or the weakening line by a few tenths of a millimeter, for example 3 to 4 tenths of a millimeter. In this case, the sealing foil can be designed as a largely flat disk. Both the ring-shaped and the disc-shaped sealing foil 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 end 1 and connected to the can end via an adhesion promoter, the inside of the end can deviate from the exemplary embodiment also be at least largely free of laminations and the like. However, the inside of the lid can be provided with a lacquer layer, in particular suitable for use with foodstuffs, in order to prevent the goods in the can from coming into contact with the metal lid material.

The in the Figures 5 to 13 illustrated embodiments show can lids without 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 leak-tight and that the closure is secure.

Reference List

1

can lid

2

fixed lid area

3

lift-up lid area

4

microgap

4', 4"

line of weakness

5

sealing frame

6

capping unit

7

swivel bearing

8th

ripping organ

9

lid top

10

intervention end

11

Swivel bearing from 8

12

Sealing and locking rib

13

Sealing and locking rib

14

Sealing and locking rib

15

receiving groove

16

receiving groove

17

receiving groove

18

sealing edge

19

sealing edge

20

sealing edge

21

hook

22

head Start

23

breakthrough

24

extension

25

sealing foil

26

first seal area

27

second seal area

28

plastic part

29

Slot30 line of weakness

Claims (1)

Process for producing a metal can end with a resealable opening, in particular for beverage cans and containers for storing food and other liquid, pasty, powdered or solid products, with a microgap (4) or weakening line provided in the metal end surface and surrounding 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 with the inside of the microgap (4) or the weakening line (4', 4"), which can be swung up Closing unit (6) made of plastic material and connected to the metal lid area (3), which is pivotably attached 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), wherein the sealing frame n (5) and the closing unit (6), preferably via sealing and latching ribs (12, 13, 14) and associated receiving grooves (15, 16, 17), working together in a sealing manner and within the circumferential micro-gap (4) or the weakening line ( 4', 4") located metal 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 metal lid area that can be swung up (3) using an adhesion promoter that is preferably suitable for food and/or has lubricating properties, in particular an adhesive lacquer, in particular by a thermal process, are materially connected, characterized in that the adhesion promoter is added to the respective plastic material before the sealing frame (5) and/or the closing unit (6) is formed, in particular a plastic granulate for the production of a plastic injection molded part.

Images