US20210024258A1

US20210024258A1 - Tamper-proof screw cap

Info

Publication number: US20210024258A1
Application number: US17/042,295
Authority: US
Inventors: Gunter Krautkramer
Original assignee: Bericap GmbH and Co KG
Current assignee: Bericap Holding GmbH; Bericap GmbH and Co KG
Priority date: 2018-04-10
Filing date: 2019-04-02
Publication date: 2021-01-28
Also published as: EP3774568A1; WO2019197214A1; DE102018108491A1; BR112020017783A2; CN111954630A

Abstract

A screw closure of plastic comprising a head plate (2) and a cylindrical cap skirt (3) which extends downwardly from the head plate and has a female thread (4), and a tamper-evident band (5) connected to the lower edge of the cap skirt (3) and provided with radially inwardly projecting retaining elements (6) which define a smallest inside diameter of the tamper-evident band (5) in such a way that they can engage behind a retaining ring (25) of larger diameter on a container neck (20) in order to remain on the container neck (20) after separation from the cap skirt (2), characterised in that extending between the lower edge of the cap skirt (2) and the tamper-evident band (5) is a peripherally extending tear-off band (7) which is connected by way of a respective tear line (8, 8′) on the one hand to the cap skirt (2) and on the other hand to the tamper-evident band (5).

Description

The present invention concerns a screw closure of plastic comprising a head plate and a cylindrical cap skirt which extends downwardly from the head plate and has a female thread, and a tamper-evident band connected in one piece to the lower edge of the cap skirt and provided with radially inwardly projecting retaining elements which define a smallest inside diameter of the tamper-evident band in such a way that they can engage behind a retaining ring of larger diameter on a container neck in order to remain on the container neck after separation from the cap skirt—if wanted—.
Container closures of plastic of that kind have been standard for many years. When the closure is opened a connection between the lower edge of the cap skirt and the tamper-evident band is torn as the tamper-evident band engages with its radially inwardly projecting retaining elements behind a retaining ring of larger diameter that is arranged on a container neck and consequently cannot follow the axial movement of the closure which in other respects comprises the head plate and the cap skirt, when the screw closure is unscrewed.
The tear line between the tamper-evident band and the lower edge of the cap skirt can be of various different configurations. For example it may involve a portion in the cap skirt and the tamper-evident band, which is intentionally produced in the form of a thin-wall part. Frequently however the connection between the cap skirt and the tamper-evident band is completely separated along larger portions of the periphery, in which case the length of those portions is limited by narrow, easily tearable bridges which interrupt the peripherally extending separation line.
In that arrangement the connection between the cap skirt and the tamper-evident band, which is correspondingly weak along a tear line, is also relatively easy to tear for the reason that, when the screw closure is unscrewed, the thread effectively provides a transmission ratio similarly to a worm transmission as the thread configuration is relatively shallow and the torque acting in the peripheral direction is converted into a comparatively high axial force between the cap skirt and the tamper-evident band. In addition by virtue of the frictional forces between the container neck and the tamper-evident band and the relative rotation caused thereby of the cap skirt with respect to the tamper-evident band shearing forces occur, which make it easier for the cap to be torn off the tamper-evident band.
It has been found however that the conventional screw closures with tamper-evident band, in spite of numerous measures which have also been implemented on corresponding bottle necks, in order for example to prevent the tamper-evident band from being levered off without tearing the connection to the cap skirt, are still not sufficient to exclude manipulation operations. Particularly in the case of containers having a relatively costly content, for example in the agricultural and chemical sector but also in the case of expensive spirits, it seems that in many countries the contents of the containers make it worth incurring relatively great cost and effort to apparently restore a closure which has already been opened and to apply it to a container with counterfeit contents.
In that case for example torn bridges between the tamper-evident band and the cap skirt are restored by adhesive means or the tamper-evident band is glued back on along the entire periphery to simulate an intact tear line. Experience shows that in some cases of forgers screw closures are used which look entirely similar and are produced using the simplest tools in an injection moulding process in relatively small quantities of a few thousand, possibly removed from a mould by hand and screwed by hand on to cleaned empty bottles of a brand owner after filling with counterfeit content. A consumer who is not quite particularly paying attention and taking care cannot see the difference in relation to original closures on a store shelf.
DE 10 2006 001 323 discloses a snap closure which does not have a screwthread but is only latched on the container neck by axial pressure and which substantially comprises a closure cap having a snap edge and a holding ring which are pivotably connected together by way of a hinge portion. The holding ring of a relatively smaller diameter engages behind an annular enlargement of relatively larger diameter on the container neck and thus durably fixes the closure on the container neck. The closure is selectively moved into the closed or the open position by pivotal movement of the closure cap with respect to the holding ring.
A connection between a holding ring and a closure cap similarly to the tear line between a cap skirt and a tamper-evident band in the case of a screw closure is not appropriate in that case because an average consumer would not be in a position to tear that connection simply by lifting the closure cap. For that reason provided on the snap closure in accordance with DE 10 2006 001 323 between the closure cap and the holding ring is a tear-off band which is connected by way of two parallel tear lines on the one hand to the closure cap and on the other hand to the holding ring and which is torn away radially outwardly by means of a gripping tab prior to opening the closure cap and thus separates the connection between the holding ring and the closure cap outside the hinge portion.
In snap closures therefore the provision of tear lines by a tear-off band which is to be pulled off radially is predominantly effected for the reason that tear lines can be separated more easily by shearing forces transversely relative to the axial direction of the closure, than solely by lifting off the cap. For a screw closure which shears the connection off along a tear line by rotation of the screw cap and/or which axially tears away to an increased degree by virtue of the thread transmission ratio such a tear-off band arranged between the cap skirt and the holding ring and provides an indirect connection between the cap skirt and the holding band seems to be unnecessarily complicated.
Such a tear-off band therefore indirectly forms a connection between the cap skirt and the holding band, but is previously not known in relation to screw closures, as in the case of screw closures there is not a corresponding necessity to reduce the force required for separating the tamper-evident band from the cap skirt by the provision of a tear-off band.
A conventional plastic screw closure with tamper-evident band is considered as the most relevant state of the art.
In comparison with that state of the art the object of the present invention is to provide a screw closure having the features set forth in the opening part of this specification, which as far as possible excludes the above-described manipulation actions and which can guarantee even greater security for the container contents.
That object is attained in that extending between the lower end portion of the screw closure, that is in the form of a holding and tamper-evident band, and the upper part which is in the form of the screw cap, is a peripherally extending tear-off band which is connected by way of a respective tear line on the one hand to the cap skirt and on the other hand to the tamper-evident band/holding band, wherein the tear-off band is of such a design and is so connected to the cap skirt and/or the tamper-evident band that it is deformed irreversibly as much as possible upon being torn off.
The closure according to the invention therefore comprises three substantially cylindrical or annular elements which are integrally connected together, namely a screw cap which in turn comprises a head plate and a cap skirt with a female thread, the tear-off band and the tamper-evident band.
The screw closure according to the present invention accordingly has between the cap skirt and the tamper-evident band a completely peripherally extending tear-off band which exclusively by way of two tear lines makes the connection between the cap skirt and the tamper-evident band and which can thus be completely separated at least either from the tamper-evident band or from the cap skirt or from both and thus after being torn off leaves behind a clearly visible and non-closable gap between the tamper-evident band and the cap skirt.
The tear-off band therefore has an essential part to play in the tamper-evident function of the screw closure insofar as its presence or absence between the lower part of the screw closure, referred to as the ‘tamper-evident band’, and the lower edge of the cap skirt, is very clearly perceptible and in particular even more clearly perceptible than the gap between the tamper-evident band and the cap skirt, that in the case of conventional screw closures is produced after a tamper-evident band directly connected to the lower edge of the cap skirt has been torn off but that can also be closed again by displacement of the tamper-evident band which has been separated from the screw cap.
In contrast to the last-mentioned case in the state of the art the gap between the cap skirt and the tamper-evident band in the closure according to the invention is no longer to be readily closed by displacement of the tamper-evident band and glueing to the lower edge of the cap skirt as, with the usual and mutually matched dimensions of the screw closure and the container neck, the retaining ring for the tamper-evident band on the container neck holds the tamper-evident band at a spacing relative to the cap skirt.
Accordingly the tear-off band is connected both to the lower edge of the cap skirt and also to the upper edge of the tamper-evident band by way of a respective tear line, wherein the tear-off band at a suitable peripheral position (at one end of the tear-off band) has a gripping tab, by way of which the tear-off band can be entirely or partially torn open along both tear lines by a radially outwardly acting pulling force and, if desired, can be separated from the closure cap skirt. In this case there is no need for any excessively high forces as the tear-off band is not closed in the peripheral direction but has a free end which is connected to the gripping tab. When the tear-off band is radially pulled off the cap a shearing force can be exerted on the tear lines by way of the tab, more specifically only ever point-wise at the transition between a portion of the tear-off band which has already been detached, to a portion which is still connected, so that the material progressively tears along the tear line until finally the entire tear-off band can be removed or however also remains connected to one of the parts of the tamper-evident band or screw cap, by way of a residual segment of the periphery. The force to be applied in that case is relatively slight and is markedly less than would be required when axially stretching and tearing through the tear lines at the same time along the entire periphery.
The tear-off band which is no longer required in most cases after being torn off and is disposed of by the consumer as waste also makes it substantially more difficult for a fraudster after complete removal of the tear-off band, to restore a closure to the apparently original state again.
In contrast thereto in the case of a conventional screw closure all parts of the closure remain on the bottle neck even after opening.
That measure of separating off the tear-off band and disposing of it separately from the other parts of the closure, considered in itself, could still not prevent a fraudster already gathering up again and fitting together at the point of sale—for example a filling station—all three parts of the closure. In that case in a similar fashion to the situation involving the above-described manipulation operations, it would also be possible for two intact tear lines, namely that between the tear-off band and the cap skirt and that between the tear-off band and the tamper-evident band, to be restored by being glued together to a state which simulates the original condition for a consumer who is only superficially checking.
According to the invention however that is prevented in that the tear-off band is of such a configuration and is so connected to the cap skirt and/or the tamper-evident band that it is irreversibly deformed upon being torn off. The irreversible deformation can then no longer be reversed so that even upon the attempt to restore the connection between the tear-off band and the cap skirt and the tamper-evident band, the deformation of the tear-off band gives a clear indication that the closure has already been opened once and is no longer in its original state.
Therefore, for example to avoid waste, the tear-off band cannot be completely separated from one of the parts of the closure and for example can still remain connected to a portion of the tamper-evident band. Nonetheless however the originally one-part screw closure is dismembered in such a way and in particular the tear-off band is deformed in such a way that it is not possible for the parts to be re-assembled without that being easily visible.
Irreversible deformation of the tear-off band can be achieved inter alia by the tear-off band along its periphery comprising alternately relatively more easily and relatively less easily stretchable portions. During the tearing-off operation the less easily stretchable portions then resist the forces occurring on tearing off the band and the more easily stretchable portions are stretched more greatly. Stretchability at least of the easily stretchable portions is self-evidently matched to the tearing strength of the tear line so that the force required for tearing the tear lines at any event also causes stretching of the more easily stretchable portions.
The reversible deformation can also be promoted inter alia if one or both tear lines are somewhat more resistant in the region of the less easily stretchable portions than in the region of the easily stretchable portions, which further increases the difference in stretch. That is achieved for example by different cross-sections for the connecting points between easily tearable bridges between the tear-off band and the cap skirt and the tamper-evident band respectively or by a fluctuating wall thickness of a peripherally extending weakening line.
A further feature of an embodiment of a closure according to the invention provides that the tear-off band and/or the tamper-evident band on the inside thereof have a tooth arrangement which upon engagement with a corresponding tooth arrangement on a container neck prevents rotation of the tear-off band or tamper-evident band together with the screw cap of the closure in the opening direction. The tooth arrangement makes it difficult to open the closure solely by rotating the screw cap because a multiplicity of teeth are simultaneously in engagement and rotation of the screw cap would require tearing of the tear line at the same time along its entire periphery. The tooth arrangement between the tear-off band and the container neck therefore forces the consumer firstly to tear off the tear-off band and dispose of it.
The individual teeth in the region of the tear-off band and the tamper-evident band, in particular the teeth on the inside of the tamper-evident band and the tear-off band, can involve the same or also different peripheral angle spacings. Preferably to open the screw closure the consumer should be more or less compelled firstly to remove the tear-off band before the screw cap can be turned in the opening direction. Preferably the tear-off band is interrupted along its peripheral direction in the peripheral direction so that, after complete opening of the closure, it is completely released from the container neck and in addition is already irreversibly deformed previously during separation along the tear lines.
The tear line can be provided in different ways, for example by shaping a tear line or by a peripherally extending interruption with axial limbs in an injection moulding process or also, after injection moulding of the closure, as a unit with the tear-off band and the tamper-evident band, by cutting into the connecting region between the tear-off band and the cap skirt and the tamper-evident band, wherein the connection between the tear-off band and the adjacent elements can also be completely separated along individual peripheral portions so that only individual, easily tearable limbs remain. A peripherally formed incision along a tear line can also be implemented at different peripheral positions to differing depth in order to provide more easily tearable and less easily tearable portions, which promote irreversible deformation of the tear-off band.
As already mentioned the tear-off band itself, viewed in the peripheral direction, can also comprise alternately relatively easily and less easily stretchable portions. The alternately relatively more easily and less easily stretchable portions can in particular comprise alternately radially thinner and thicker regions of the tear-off band.
The alternately relatively more easily and less easily stretchable portions can further be of a differing width, that is to say varying from one portion to another, as measured in the peripheral direction.
The stretchability of the tear-off band can also vary in the axial direction and that variation in stretchability, in particular by virtue of differing wall thicknesss of the tear-off band, can also be limited to one or more peripheral portions which in turn can involve differing stretching in the peripheral direction. For example regions of differing wall thicknesses of the tear-off band can extend along a zig-zag line between the tear line towards the tamper-evident band and between the tear line towards the cap skirt along the periphery of the tear-off band.
One of the free ends of the tear-off band can also have a tear-off tab which can be gripped from the outside in order, before turning the screw cap to open the closure, to pull off the tear-off band along the entire periphery in order in that way to permit opening of the closure and to be able to implement that using substantially less force than would be applied if the tear lines would have to be separated solely by the turning movement of the screw cap.
The tear lines could preferably also be of a firm configuration so that opening of the closure without previously releasing the tear-off band along the entire periphery would not be possible or would be possible only with a very great deal of trouble, scarcely, that is to say solely by turning the screw cap, while the shearing action due to transverse forces, as is relatively easily possible upon gripping a tear-off tab and moving the tab radially away to separate the tear lines, because the force for separating the tear lines, if it is to be respectively applied only in point form in the region of a part of the tear-off band which has already been detached to a part which is still connected, progressively along the entire periphery, is substantially less than the force required in order for example when unscrewing the cap to separate the tear lines practically simultaneously along the entire periphery. At any event however the tear-off band is completely separated either from the cap skirt or from the tamper-evident band or from both, either by rotation of the screw cap or preferably by previously tearing off the tear-off band.
An embodiment provides that the tear-off band extends along the entire periphery of the closure, with the exception of an interruption limited to less than 5° peripheral angle. The tear-off band thus has two directly mutually opposite free ends. In that case one of the ends can be provided with a gripping tab which radially outwardly covers over the other end.
The tear-off band can for example firstly be produced in the form of a completely peripherally closed tear-off band, together with the screw cap and the tamper-evident band, by injection moulding, wherein after removal from the mould the tear-off band is severed by an axial cut shortly before the attachment of the gripping tab.
An additional security measure lies in the printing on the closure cap, which is difficult to counterfeit, in particular with a print image, which extends on the outside of the closure cap over one or both tear lines and thus over the cap skirt, the tear-off band and/or the tamper-evident band.
Such a print image is preferably produced by a laser printer or another similarly costly and complex printing machine which can print curved surfaces of 3-dimensional bodies in such a way that forgeries are very difficult.
To make it easier to unscrew the closure cap the cap skirt can also have an external knurling.

Further advantages, features and possible uses of the present invention will be clearly apparent from the description hereinafter of a preferred embodiment and the accompanying Figures in which:

FIG. 1 shows a side view of a closure according to the invention,

FIG. 2 shows a sectional view containing the axis of the closure,

FIG. 3 shows a sectional view of the closure from below along line V-V in FIG. 2,

FIG. 4 shows a side view of a closure fitted on an associated container neck,

FIG. 5 shows a sectional view containing the axis of a closure fitted on to a container neck,

FIG. 6 shows a sectional view along line VI-VI in FIG. 4,

FIG. 7 shows the side view of an associated container neck,

FIGS. 8a, b show two sectional views of the tear-off band and the adjoining parts in the sectional planes containing the closure axis at different angular positions, and

FIGS. 9a, b show a side view and a perspective view of a closure without tear-off band on a container neck.

The external view shown in FIG. 1 illustrates a screw closure 10 having a screw cap 1 comprising a head plate 2 and a cap skirt 3, which in turn is connected by way of a tear line 8 to a tear-off band 7 connected to a tamper-evident band 5 by way of a further tear line 8′. The screw closure comprises a single plastic part, that is to say the screw cap 1 (consisting of cap skirt 3 and head plate 2) is produced in one piece together with the tear-off band 7 and the tamper-evident band 5 in an injection moulding process, wherein the material which has remained—possibly after further processing—in the region of the tear lines 8, 8′ produces the connection between all three parts.
It is also possible to see at a peripheral position of the tear-off band a gripping tab fitted at a free end of the tear-off band 7 which is interrupted at that location in the peripheral direction. The gripping tab 13 can possibly also have an easily tearable connection to the other end of the tear-off band, that is directly opposite the end provided with the gripping tab. References 7′ and 7″ in FIG. 1 indicate different portions of the tear-off band which are of differing wall thickness or which in part form projections and recesses and thereby when the band is torn off provide that the tear-off band 7 is deformed.
The tear-off band has two directly opposite free ends. It can firstly be produced for example in the form of a completely peripherally closed tear-off band with the screw cap 1 and the tamper-evident band 5 and can then be severed by an axial cut shortly before the attachment of the gripping tab 13.
It can be seen from the sectional view in FIG. 2 that the cap skirt 3 of the screw cap 1 on its inside has a thread 4 which can be interrupted by venting grooves 4′. In this case the tear line 8 is formed by a peripherally extending separation line which is interrupted only by easily breakable bridges 12 which hold the tear-off band 7 and the cap skirt 3 together. The tear line 8′ is also formed by a peripherally extending separation line which is also interrupted by easily breakable bridges 12′ between the tear-off band 7 and the holding band 5. When the gripping tab 13 is lifted and moved radially away from the closure the individual bridges 12′ are gradually torn away and the tear-off band 7 is separated from the cap skirt 3 and the tamper-evident band 5 in that way and can be removed along the periphery of the screw closure 10 so that thereafter between the cap skirt 3 and the tamper-evident band a wide gap separates the cap skirt 3 from the tamper-evident band 5 and there is no longer any connection between the cap skirt and the tamper-evident band. The tamper-evident band in turn on its inside also has a so-called folded-over flexband 6 which prevents displacement or removal of the tamper-evident band 5 upwardly in the direction of the cap skirt 3.
Unscrewing of the cap without separation of the tear-off band is prevented by teeth 9 on the inside of the tear-off band 7, that come into engagement with a corresponding counterpart tooth arrangement 19 on a container neck 20 and prevent rotation of the tear-off band. The connection between the tear-off band 7 and the cap skirt 3 by a plurality of easily breakable bridges then prevents the closure cap from being released. Otherwise for simultaneously breaking all bridge 12 it would be necessary to apply a force such as a normal consumer would not apply. The consumer is therefore more or less compelled to remove the tear-off band 7 to be able to open the closure. The easily breakable connection along the tear lines 8 and 8′ could therefore also be comparatively stronger than the connection between the tamper-evident band and the cap skirt in conventional screw closures as, when the tear-off band is radially pulled off, the bridges 12, 12′ are individually successively broken.
In order to open the closure without removal of the tear-off band in contrast all of the easily breakable bridges would have to be practically simultaneously torn, which would require a correspondingly high force.
FIG. 4 shows the screw closure 10 fitted on a container neck 20 while FIGS. 5 and 6 show the screw closure 10 fitted on the container neck 20 in a section containing the axis of the closure and in a section perpendicularly to that axis respectively. It will be seen from FIG. 5 that the spacing between the tamper-evident band and the lower cap edge is initially bridged over by the tear-off band but that spacing is also not noticeably reduced after removal of the tear-off band 7 because the retaining ring 25 at the periphery of the container neck only permits slight axial play of the tamper-evident band 5.
FIG. 7 shows the container neck 20 without the screw closure 10. A particularity of this container neck 20 lies in the provision of a suitable counterpart tooth arrangement 19 to the tooth arrangement 9 at the inside of the tear-off band 7, that prevents rotation of the tear-off band 7 in the opening direction together with the screw cap 1. The retaining ring 25 is disposed beneath the counterpart tooth arrangement 19 at a spacing from the upper opening edge of the container neck, which as usual is slightly less than the internal spacing between the inside of the head plate and the top side of retaining elements on the tamper-evident band, that come into engagement with the underside of the retaining ring, so that the tamper-evident band 5 of the screw closure 10 has only a slight axial mobility. That is also necessary in the case of conventional closures to prevent easy access from the exterior to the tamper-evident band that would permit manipulation of the screw closure.
FIG. 8 shows two sectional views through the region of a tear-off band 7 in section planes respectively containing the axis, but at different peripheral positions 7′, 7″ of the tear-off band 7. The section in each case shows the tear-off band 7 and the two tear lines 8 and 8′ respectively, forming the transition on the one hand to the cap skirt 3 and on the other hand to the tamper-evident band 5. As will be seen the cross-sections of the tear-off band differ markedly from each other at the different peripheral positions and also the directly adjoining portions of the cap skirt 3 and also the tamper-evident band 5 are adapted in respect of their thickness and position to the respective configuration of the cross-section of the tear-off band 7. The result of this is that, on being torn off the closure cap, the tear-off band 7 is more or less deformed depending on the respective local cross-section, in which respect the adjoining portions of the cap skirt and the tamper-evident band 5 are at least partially affected thereby. The result of this is that it is practically impossible for the tear-off band 7 to be subsequently re-inserted into the gap between the tamper-evident band and the cap skirt and there to join it by adhesive or welding to the cap skirt and the tamper-evident band without that manipulation being nonetheless clearly visible.
By virtue of a suitable design in respect of the shape and wall thickness of the tear-off band, that can be varied in many respects, inter alia also by a stepped axial contour, the tooth arrangements 9, the repetition spacing of which, also in relation to the length and the varying repetition spacing of the different peripheral portions 7′, 7″, different wall thicknesses along the periphery and/or in the axial direction, different distribution of the teeth 9 and so forth, and finally also by virtue of the design configuration of the tear lines or the adjustment of their tearing strength, the tear-off band 7 can be such that it is markedly visibly and irreversibly deformed by the forces occurring when tearing off the tear-off band. It is then practically not possible to re-position a tear-off band again once it has been torn off on a closure and to connect it to the cap skirt 3 and the tamper-evident band 5 without that manipulation being clearly recognizable.
FIG. 9 shows a side view (FIG. 9a ) and a perspective view (FIG. 9b ) of the closure 10 fitted on a container neck 20 after removal of the tear-off band 7. As will be seen a clear gap opens up between the lower edge of the cap skirt 3 of the screw cap 1 and the upper edge of the tamper-evident band 5, and that gap makes it clearly discernible that the tear-off band was removed and thus the closure has evidently already been opened.
Admittedly the tamper-evident band 5 has a certain axial play on the container neck 20 but even when the screw cap is firmly screwed on and even when the tamper-evident band 5 is axially pushed up as far as possible there is always a gap between the lower edge of the cap skirt 3 and the upper edge of the tamper-evident band 5, that approximately corresponds to the axial width of the tear-off band previously disposed in that region.

Claims

1. A screw closure of plastic comprising a head plate (2) and a cylindrical cap skirt (3) which extends downwardly from the head plate and has a female thread (4), and a tamper-evident band (5) connected to the lower edge of the cap skirt (3) and provided with radially inwardly projecting retaining elements (6) which define a smallest inside diameter of the tamper-evident band (5) in such a way that they can engage behind a retaining ring (25) of larger diameter on a container neck (20) in order to remain on the container neck (20) after separation from the cap skirt (2), characterised in that extending between the lower edge of the cap skirt (2) and the tamper-evident band (5) is a peripherally extending tear-off band (7) which is connected by way of a respective tear line (8, 8′) on the one hand to the cap skirt (2) and on the other hand to the tamper-evident band (5).

2. A screw closure according to claim 1 characterised in that the tear-off band (7) has an internal tooth arrangement (9) which upon engagement with oppositely directed teeth (19) on a container neck (20) prevents a rotary movement of the tear-off band (7) about the closure axis at least in the opening direction of the closure (10).

3. A screw closure according to claim 1 characterised in that the tamper-evident band (6) has an internal tooth arrangement (11) which upon engagement with oppositely directed teeth (19′) on a container neck (20) prevents a rotary movement of the tamper-evident band (6) about the closure axis in an opening direction of the closure (10).

4. A screw closure according to claim 1 characterised in that the tear line (8, 8′) between the tear-off band (7) and the cap skirt (2) and/or the tamper-evident band (6) is produced by an incision in the plastic material which is initially thicker after production by means of injection moulding along the configuration of the tear line.

5. A screw closure according to claim 1 characterised in that the tear-off band (7) is connected to the cap skirt (2) and/or to the tamper-evident band (6) exclusively by easily breakable bridges distributed along the peripherally extending tear line (8, 8′).

6. A screw closure according to claim 1 characterised in that viewed in the peripheral direction, the tear-off band (7) comprises alternately relatively more easily (7″) and less easily stretchable portions (7′).

7. A screw closure according to claim 6 characterised in that the alternately relatively more easily and less easily stretchable portions (7′, 7″) comprise alternately radially thinner and thicker regions of the tear-off band (7).

8. A screw closure according to claim 6 characterised in that the alternately relatively more easily and less easily stretchable portions (7′, 7″) are of a width varying along the periphery as measured in the peripheral direction.

9. A screw closure according to claim 6 characterised in that the more easily and less easily stretchable portions (7′, 7″) as viewed in the peripheral direction are distributed differently in axially different regions of the tear-off band (7).

10. A screw closure according to claim 1 characterised in that the cross-section of the tear-off band (7), as measured perpendicularly to the peripheral direction, varies along the peripheral direction.

11. A screw closure according to claim 1 characterised in that the tear-off band (7) comprises various axial portions of differing outside diameter, which are connected together by a conical transitional portion.

12. A screw closure according to claim 1 characterised in that the tear-off band (7) has two ends, of which at least one end has a gripping tab (13).

13. A screw closure according to claim 1 characterised in that the tear-off band (7) extends along the entire periphery of the closure with the exception of an interruption limited to less than 5° peripheral angle.

14. A screw closure according to claim 1 characterised in that the gripping tab (13) disposed at a free end of the tear-off band (7) is arranged radially outside the two mutually oppositely disposed free ends of the tear-off band (7) and covers said ends outwardly.

15. A screw closure according to claim 1 characterised in that the cap skirt (3) has an outer gripping knurling.

16. A screw closure according to claim 1 with external printing, which extends on the outside of the closure cap (1) over one or both tear lines (8, 8′).

17. A screw closure according to claim 19 characterised in that the print image on the cylindrical outside surface of the screw closure (1) is so designed that it is to be produced only with a complex printing process.

18. A screw closure according to claim 16 with external printing which extends on the outside of the closure cap (1) over one or both tear lines (8, 8′) and over the cap skirt (3), the tear-off band (7) and/or the tamper-evident band (5).

19. A screw closure according to claim 16 wherein the external printing is a print image.

20. A screw closure according to claim 17 where the complex printing process is laser printing.