Abstract
A lid ring (7) for sterilizable containers (1) is proposed which is formed from a metal ring (40) coated on both sides with at least one plastic layer (37, 43), a radially outer cut edge and a radially inner flange (31). The radially inner flange (31) is folded back on itself at least once.
Claims
1. A lid ring comprising; a metal ring having two sides, the metal ring being coated on both sides with at least one plastic layer, the metal ring having a radially outer cut edge and a radially inner flange delimited by a cut edge, with a peripheral sealing zone (30) arranged on the flange characterized in that the radially inner flange is folded back on itself at least once and the fold forming a lid opening is compressed.
2. The lid ring according to claim 1, characterized in that the radially inner flange is folded back on itself at least twice, and the cut edge is enclosed almost substantially air-free by the plastic layers lying on the fold inside.
3. The lid ring according to claim 2, characterized in that a lid ring core wall is formed radially on an outside on the folded radially inner flange with a peripheral sealing zone arranged thereon.
4. The lid ring according to claim 3, characterized in that the radially inner flange is folded back on a side of the flange opposite the sealing zone.
5. The lid ring according to claim 1, characterized in that a metal of the metal ring is selected from the group consisting of steel, tin plate, black plate, aluminium and aluminium alloys.
6. The lid ring according to claim 1, characterized in that a plastic of the plastic layers is selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate and polyamide.
7. The lid ring according to claim 1, characterized in that a plastic layer has a layer thickness of 5 m to 100 m.
8. The lid ring according to claim 1, characterized in that a lid film closing a lid opening is sealed onto the sealing zone.
9. The lid ring according to claim 8, characterized in that the lid film is a composite film selected from the group consisting of plastic-coated aluminium, laminated aluminium, painted aluminium and aluminium-free composite films.
10. The lid ring according to claim 8, characterized in that the lid film is a composite film and has an embossing.
11. The lid ring according to claim 8, characterized in that the lid ring is connected to a container body by a fold connection.
12. A method of producing a lid ring wherein the lid ring includes two sides, a radially cut outer edge and a radially inner flange comprising: single folding the radially inner flange in a radial direction forming a multi-layer flange having a folded region, and wherein after folding, the folded region is also compressed.
13. The method of producing a lid ring according to claim 12, further including coating both sides with a plastic layer, double folding the radially inner flange in the radial direction, forming a multi-layer flange having an inside and the radially cut outer edge is enclosed substantially air-free by the plastic layer lying on the fold inside, and wherein after folding, the folded region is also compressed.
14. The lid ring according to claim 8 characterized in that the lid film is a composite film and has a printing.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 illustrates a perspective view of a container with a tear-off lid;
[0029] FIG. 2 illustrates a perspective partial view of a lid ring blank;
[0030] FIG. 3 illustrates a perspective partial view of a lid ring blank in a further production stage;
[0031] FIG. 4 illustrates a cross-section through a first embodiment of a flange of a lid ring according to the invention;
[0032] FIG. 5 illustrates a cross-section through a second embodiment of a flange of a lid ring according to the invention;
[0033] FIG. 6 illustrates a cross-section through a further embodiment of a flange of a lid ring according to the invention;
[0034] FIG. 7 illustrates a cross-section through the first embodiment of a flange of a lid ring according to the invention with lid film sealed on;
[0035] FIG. 8 illustrates a cross-section through the further embodiment of a flange of a lid ring according to the invention with lid film sealed on.
DETAILED DESCRIPTION OF THE TECHNOLOGY
[0036] FIG. 1 shows a container 1 with a container body 5, a tear-off lid 3 itself comprising a lid ring 7 attached to the container body 5, a lid film 10 and a tear-off tab 15. The lid film 10 closes the extraction opening of the tear-off lid 3. The lid film 10 is provided with a tear-off tab 15 for opening the lid 3.
[0037] FIG. 2 shows a perspective partial view of a lid ring blank 18. For the sake of clarity, only part of a complete lid ring blank 18 is shown. The figure shows the container-side form of the lid ring blank 18 for the fold connection of the lid ring to the container body (not shown). In the radial direction towards the middle of the lid ring blank 18, the folded edge 21 may include a fold radius 22 with which the folded edge 21 transforms into the lid ring core wall 23. The lid ring core wall 23 is followed by the lid ring depth radius 24 which transforms into the lid ring base 27. In this production stage of the lid ring blank, as evident from the figure, no lid or extraction opening has yet been punched out.
[0038] FIG. 3 shows a perspective partial view of a lid ring blank 18 in a further stage of production. The lid ring blank 18 may include, on the container side, a folded edge 21, a fold radius 22, a lid ring core wall 23 and a lid ring depth radius 24. In this production stage, the lid ring blank 18 now has an extraction opening 36. The lid ring depth radius 24 transforms into the flange 31 in the direction of the extraction opening 36. The extraction opening 36 is formed by the radially inner cut edge 33 which is produced during the punching step. A sealing zone 30 is arranged on the flange 31 on the top side of the lid ring.
[0039] FIG. 4 shows in cross-section an extract of a lid ring 7. In particular, the folded region d is shown with the cut edge 33 enclosed virtually air-free. In the embodiment shown, the lid ring has a stacked layer structure with the following layers: a plastic layer 37 arranged on the top side of the lid ring, a metal layer in the form of a metal ring 40, and a plastic layer 43 arranged on the underside of the lid ring. The plastic layer which is arranged on the underside of the lid ring faces the filling product space (not shown), and the plastic layer on the top side of the lid ring is the side of the lid ring 7 facing away from the filling product space and hence towards the outside of the container 1. In this embodiment, the radially inner flange 31 has been folded back on itself twice. Folding took place twice towards the underside of the lid ring, so that the enclosed cut edge 33 comes to lie on the side of the lid ring 7 facing the filling product space. The flange 31 is thus formed in three layers in the folded region d. On the top side of the lid ring, the sealing zone 30 is also arranged which extends beyond the folded region d up to maximally as far as the lid ring core wall (not shown). The cut edge 33 is enclosed almost air-free by the plastic layers 37, 43 lying on the fold inside 46, 47.
[0040] FIG. 5 shows in cross-section an extract of a lid ring 7. In this embodiment, the double fold of the flange takes place towards the lid ring top side, so that the enclosed cut edge 33 comes to lie on the side of the lid ring 7 facing away from the filling product space (not shown). In the folded region d, the flange 31 is again formed in three layers. Since now in the folded region d, the plastic layer 43 which is arranged on the inside of the lid ring facing the filling product space comes to lie on the outside of the lid ring, the plastic selected is preferably also sealable. If the folded region d has a sufficient radius, the sealing zone 30 may be limited to the folded region d. It is, however, also possible for the sealing zone 30 to extend beyond the folded region onto the further part of the flange 31 on the outside in the radial direction, up to maximally as far as the lid ring core wall (not shown). In this variant, the sealing zone 30 is, however, interrupted by a gap 45.
[0041] FIG. 6 shows in cross-section an extract of a lid ring 7. As in the embodiment shown in FIG. 5, the radially inner flange 31 is folded back twice onto the top side of the lid ring. By way of a shoulder 48 in region e, corresponding to double the thickness of the lid ring 7 which is plastic-coated on both sides, in the folded region d the lid ring top side comes to lie in the same plane as the radially outer region of the flange 31. The sealing zone 30 can thus in a simple fashion again extend over the entire radial length of the flange 31 up to maximally as far as the lid ring core wall (not shown). In the region of the shoulder 48, the sealing zone 30 is interrupted by a gap 45.
[0042] FIG. 7 shows lid ring 7 according to FIG. 4, wherein this again is shown in extract. In the sealing zone 30, a lid film 51 is sealed onto the upper plastic layer on the lid ring side and hence onto the top side of the lid ring. In the exemplary embodiment shown, the sealing zone 30 extends over the entire flange 31, i.e. over the folded region d in which the flange 31 is formed in three layers, then over the radially outer region of the flange 31 up to maximally as far as the lid ring core wall (not shown). The double fold of the radially inner flange 31 in this embodiment takes place towards the underside of the lid ring and hence towards the filling product space 55. The cut edge 33, which is enclosed almost air-free by the plastic layers 37 and 43 which are arranged on the metal layer in the form of a metal ring 40 and lying on the fold inside (46, 47), therefore lies on the underside of the lid ring facing the filling product space 55.
[0043] FIG. 8 shows the lid ring 7 according to FIG. 6, wherein this again is shown in extract. In the sealing zone 30, a lid film 51 is sealed onto the upper plastic layer on the lid ring side. Since in this embodiment the double fold of the radially inner flange 31 takes place towards the top side of the lid ring, the cut edge 33 which is enclosed between the plastic layers 37 and 43 lies on the top side of the lid ring facing away from the filling product space 55. Due to the shoulder 48 in region e, the plastic layer 43 lying on the top side of the lid ring in the folded region d lies in a plane with the plastic layer 37, which is arranged on the metal layer 40 on the top side of the lid ring facing away from the filling product space 55. The lid film 51 can therefore easily be sealed in the sealing zone 30 arranged on the flange 31. The sealing zone 30 extends over the folded region d and then over the radially outer region of the flange 31 up to maximally the lid ring core wall (not shown). The lid film 51 seals firstly the extraction opening (not shown) and also the gap 45 formed by the shoulder 48 in region e.
