WO2015107032A1

WO2015107032A1 - Plastic closure having tamper-proof surface

Info

Publication number: WO2015107032A1
Application number: PCT/EP2015/050449
Authority: WO
Inventors: Hans Lohmann
Original assignee: Bericap Gmbh & Co. Kg
Priority date: 2014-01-20
Filing date: 2015-01-13
Publication date: 2015-07-23
Also published as: DE102014100588A1

Abstract

The invention relates to a plastic closure (10) for containers, comprising at least one outer face (1) that is visible once the closure is put on the container. Such plastic closures are e.g. known in the form of screw caps, snap caps or the like. In order to devise a container closure having a security feature that cannot be readily imitated by third parties because the additional security feature requires substantial technical knowhow and has corresponding additional complexity, a flip image structure is embossed on the visible outer face (1), said structure producing different optical images under at least two different angles of observation.

Description

Plastic closure with warranty surface

DESCRIPTION The present invention relates to a plastic closure for containers with at least one outside visible after the closure has been applied to a container. Such plastic closures are known for example in the form of screw caps, snap caps or the like. Typically, corresponding plastic closures are made in injection molds which generally have a plurality of cavities into which the liquid plastic material is injected after the mold has been closed by a mating counterpart with a corresponding number of mold cores engaging the cavities. The volume remaining between the mold core and the cavity of the cavity is filled by the initially flowable plastic material of the closure, whereupon the finished molded plastic closures can be ejected from the cavities after a short cooling time and the opening of the corresponding molds. Typical injection molding tools have at least 24 or more cavities, so that a corresponding number of closures is produced simultaneously with each injection molding process.

For many users of such plastic closures provides the tamper-evident and guarantor! The function of the container closures is one of the most important criteria according to which the closures for the containers are selected. Numerous safety and guarantee systems for plastic closures are already known, with most closures consisting of or having a so-called safety ring or guarantee ring, which is arranged on the lower edge of a closure cap and fixedly connected to this cap via rupturable elements or a material weakness. The guarantee ring engages after the attachment of the closure to a container a projecting bead or flange on a container neck. When opening or removing or unscrewing the closure such a circlip is inevitable tear off from the other closure parts, so that it is easy to see that the closure has already been opened. It happens, however, that in particular for containers that contain relatively expensive or valuable liquids, the original seals of counterfeiters are modeled in detail, so that it is possible for fraudsters to dilute or replace the container contents and then return to the market as a supposed original product bring.

Compared to this prior art, the present invention seeks to provide a container closure, which has a security feature that is not readily imitated by third parties by the additional security feature requires considerable technical expertise and a corresponding additional effort.

This object is achieved in that on the visible outer side of the closure, a tilt image structure is impressed, which causes a different optical appearance under at least two different viewing angles. Such embossed tilt image structures as an integral part of a closure are very difficult to imitate.

In this case, according to one embodiment of the invention, it is provided that the tilting image structure consists of a visible surface of the closure uniformly structured by elevations and depressions, wherein at least part of the elevations or depressions each have at least one structural deviation, wherein the entirety of the structure deviations has a visible image structure the surface defined.

It is useful if the elevations and / or depressions are each formed identically.

That the structural deviations are formed by recesses in individual otherwise uniformly shaped elevations or by projections of otherwise uniformly shaped depressions. The recesses should in their turn be of the same design, but may well vary in size from, for example,

Furthermore, an embodiment is expedient in which the structural deviations each have partial surfaces which have a different inclination in space from the adjacent surfaces of the gelatinous structures. At the same angle of view, this leads to a different light reflection from the surfaces of the structure deviations compared to the surfaces of the uniform structures and thus makes the deviations or a corresponding image structure visible at least at certain viewing angles. It is also expedient if the structural deviations have at least partially planar partial surfaces. Flat surfaces reflect light in the same direction, which improves the visibility of the structure deviations at certain angles, especially if the uniform structures are formed entirely or predominantly by non-planar surfaces. Conversely, even the uniform structures could be formed wholly or predominantly by flat surfaces, while the structural deviations have wholly or predominantly non-planar surfaces, which also leads from certain angles to the desired contrast and easy recognition of the image structure. The elevations and depressions of the structural deviations or the partial surfaces thereof are at least in one dimension almost microscopically small (typically in the order of 1/100 to a few 1/10 mm). On the one hand, such small structures are extremely difficult to forge, since their production requires a certain amount of technical know-how and suitable tools, and on the other hand the image resolution of the image structure formed by the sub-areas is improved since each sub-area effectively becomes a kind of "pixel" of a digital image represents.

Even the uniform structures have at least in one, preferably in two dimensions very small dimensions in the submillimeter range. Because the surface is provided with a group-preferably flat-partial surfaces which are all parallel to one another but not parallel to corresponding sub-surfaces of non-deviating structures, a different reflectivity or reflection behavior results for all these sub-surfaces under certain viewing angles as it show the adjacent areas. If the (planar) partial surfaces are arranged in a specific formation, they define an image structure which, at certain viewing angles, stands out from the surface surrounding these partial surfaces. In this case, the elevations and / or depressions of the surface may have planar surfaces, which altogether consist of at least two different groups of planar partial surfaces, the groups differing from one another in that the associated partial surfaces are each parallel to another plane. In this way it is possible, for example, to visualize two or more different image structures that stand out from the background at different angles.

It is self-evident that the surfaces adjacent to the planar partial surfaces each have a different orientation than the planar partial surfaces, and are preferably also not designed as flat surfaces but as concave or convex surfaces. The projections and depressions should, in order not to be readily reproducible, in at least one or two dimensions have minimum dimensions or structures whose size is in the range of 0.05 to 0.3 mm. Specifically, the peaks and valleys could be in the form of a plurality of similar parallel ribs and grooves impressed on a visible surface, with both the width of the ribs and grooves and their height or depth being on the order of 0.1, for example to 0.3 mm. The grooves and ribs can have a substantially U-shaped cross-section and thus form a curved wave structure as a whole. The length of the ribs and grooves need not be limited to small dimensions. Rather, the ribs and grooves can extend continuously over the respectively provided therewith surface.

Structure deviations may be formed in such a structure, for example, in that the ribs in certain predetermined areas, which in sum define an image structure, have recesses with at least one (preferably flat) surface whose spatial orientation deviates from that of the surfaces adjacent to the recess , For example, the recesses could be substantially parallel to the longitudinal direction of the rib and have a depth that is between 0.1 and 1.2 times the height of the ribs, with a partial area of the recess optionally over a fraction of the depth or extends approximately over the entire depth of the recess and extends approximately perpendicular to the surface into which the ribs and grooves are impressed, while a second partial surface may for example be perpendicular to the former and over the groove bottom or along the groove bottom of the rib extending directly adjacent groove or below, and may also be formed as a flat surface. Of course, other orientations of the part surfaces defining the recesses conceivable.

Correspondingly, parallel to the ribs and grooves, the partial surfaces can have a more or less arbitrary length, which is delimited at the bottom by the optical perceptibility and at the top only by the length of the respective image structure, which optionally covers the total length of the ribs or grooves can. Perpendicular to the ribs, the dimensions of the partial surfaces are substantially limited to the corresponding width and depth dimensions of the ribs or grooves or slightly smaller or slightly larger.

However, if possible, the recesses should not extend over the entire width, but only approximately to the middle or to the apex of the rib, since the recess or its partial surfaces do not or only at a first viewing angle to the rib in question should be slightly visible and only by tilting the structured surface should be visible relative to the viewer, because only thereby creates the impression of a tilt image with different structures from different angles. This assumes that a rib is not completely severed or is not detected in full width by a recess.

It would also be conceivable for the material of the plastic closure to be transparent or partially transparent at least in a surface layer so that corresponding ribs can act as cylindrical lenses, an underlying layer containing a photosensitive material which corresponds to the arrangement of the ribs and grooves, ie Cylindrical lenses, strip-shaped with different image information can be described. When viewed from different angles, the cylindrical lenses then each form a different partial image in the respective viewing direction, d. H. sees the viewer from different perspectives in each case different partial images. However, the variant is preferred in which spatially physical microstructures are impressed into the surface, which cause the image impression or a different image impression at different viewing angles. This is preferably done by a corresponding microstructuring of the mold or cavity, more precisely, the surface of the cavity, which forms the material surface to be structured during injection molding. Although this requires considerable effort in the production of molds, it is more expedient for mass production and productivity of production than printing with corresponding image structures.

In the case of different image structures, the individual structures may differ in terms of color and / or brightness and / or a (possibly only angle-dependent) different reflection behavior of the respective partial surfaces.

Moreover, the present invention also relates to a method for producing a tamper-proof plastic closure, wherein the closure is produced in a mold by injection molding, wherein to achieve the above object by an inner surface of the injection mold facing a negative structure of a tilting image on the corresponding inner side of the mold Outside of the closure is imprinted directly, which causes a different optical appearance under at least two different viewing angles. Furthermore, the present invention also relates to an injection molding tool for container closures made of plastic with at least one cavity, which has a negative of the closure outside, wherein at least one surface of the cavity, which produces an outside of the closure. to solve the above problem has a fine structure having a negative of the tipping image structure einzuprägenden on the outside.

In other words, in one embodiment, a corresponding surface of a cavity also has a plurality of parallel ribs and grooves which are a negative of the ribs and groove structure of the closure surface, wherein individual ribs of the mold surface concerned have lateral projections which preferably have planar boundary surfaces and the In this way, impress appropriate recesses with preferably flat surfaces during injection molding in the relevant side of the ribs on the closure surface.

Appropriately, a plastic material is used for such closures, which is characterized in the hot, flowable state by a relatively low toughness. For example HDPE (high density polyethylene) or polypropylene (PP) are possible. Further advantages, features and possible applications of the present invention will become apparent from the following description of a preferred embodiment and the associated figures. Show it:

FIG. 1 is a schematic view of a screw cap with a lettering embossed as a tilted image;

FIG. 2 shows schematically a fine structure of the surface with embossed flat partial surfaces, which in their sum define an image structure and

Figure 3 is a plan view of a closure surface from above, which has embossed ribs and grooves, wherein the additionally embossed planar faces form the shape of the letter P.

FIG. 1 shows a closure cap which is designed, for example, as a screw cap and which has a substantially cylindrical basic shape with a cylindrical cap casing 2, a guarantee ring 3 integrally formed on the lower edge of the cap shell 2 and a flat, circular disk-shaped top plate 1.

In the perspective view of Figure 1 is visible on the finely textured flat top of the letter B as a logo of the applicant. In this case, the top plate 1 on its outer side visible on top of a plurality of parallel ribs and grooves, as shown for example as an enlarged section in Figure 2. As can also be seen in FIG. 2, which partially reproduces a section of the top plate 1 in perspective and moreover perspectively, the ribs 4 and the grooves 5 have recesses 6, have the planar faces 7 approximately perpendicular to the surface of the top plate 1 and planar faces 8 approximately parallel to the top plate 1 level. Even if such flat partial surfaces are preferred, this does not necessarily apply, but essentially only to the different inclination of the partial surfaces of the recesses compared to corresponding adjacent surfaces or corresponding surfaces of ribs without recess. However, planar partial surfaces can improve the conspicuousness and visibility of the structure image formed by the recesses.

In order to generate an image structure, a corresponding plurality of such recesses 6 are arranged on the surface in a specific manner and thus cause a corresponding image impression at certain viewing angles. In Figure 2, only two such recesses 6 are shown to illustrate the basic principle, the recesses in Figure 2 also be different depths or each could have a different depth.

The arrangement of corresponding recesses 6 and planar partial surfaces 7, 8 is clearly reproduced again in a plan view according to FIG. The wave-shaped rib and groove structure is indicated only schematically at the lower edge of the picture. As can be seen in FIG. 3, here too the ribs 4 have recesses 6, wherein the bottom of the grooves 5 is also leveled in the region of the recesses 6 and is reproduced here by straightened surfaces 8.

The hatched areas 8 differ from the rest of the surface of the ribs 4 and grooves 5 neither by the material nor by the color but only by a different reflection behavior, which is due to their deviating orientation in space and the other due to the fact that the surfaces 8 and the other surfaces of the ribs 4 and grooves 5 are concave or convex curved. To reinforce the different reflection behavior or reflection and absorption capacity of said surfaces, the flat surfaces 7 and 8 could also have a greater or lesser roughness than the other surfaces. For this purpose, for example, the ribs and grooves of the corresponding surface of the molding tool could be mechanically or chemically pretreated before the fine structure of the recesses 6 is generated.

It is understood that the surface 7 does not have to be exactly perpendicular to the surface 8 or to the plane defined by the top plate 1, but may also be slightly inclined relative to a perpendicular to the top plate for easier removal from the mold. However, the correspondingly inclined surfaces 7 are not shown in FIG. 3 and would be recognizable, for example, as narrow strips on the right-hand edge of the respective recesses 6. However, the faces 7 should not be approximately parallel to the lateral flanks of the ribs, because they then light in similar Reflecting would be like the flanks of the ribs or grooves and thus would be less visible.

As can be seen, the entirety of the recesses 6 in Figure 3 form the shape of the letter P, but only visible when, under a given angle of view, the reflectivity of the surfaces 7 and 8 of the recesses 6 is clearly different from the reflectivity of the adjacent surfaces of the ribs 4 and grooves 5 is different. Of course, this depends on the specific orientation of the flat surfaces 7 or 8 and on the microscopic surface texture of these surfaces and also on the adjacent surfaces of the ribs 4 and grooves 5.

By complying with the above conditions, namely, orienting planar sub-areas defining the image structure parallel to each other or parallel to a common plane, while the adjacent areas of the ridges and grooves have a different orientation and / or convex or concave, one always obtains Result that the structure of the flat faces significantly different from the environment under certain angles, as is schematically indicated in Figure 1, which may optionally be further enhanced by further microstructuring, as explained above. It goes without saying that the entire top plate 1 does not necessarily have to have a corresponding rib and groove structure, even if the greatest possible fine structuring fundamentally further improves safety because the large-area fine structuring of corresponding surfaces of injection molds requires considerable know-how and technical skills.

Claims

P a n t a n s p r e c h e

Plastic closure for containers, with at least one visible after application of the closure on a container outside, characterized in that on the visible outside of a tilted image structure is imprinted, which causes a different optical appearance under at least two different viewing angles.

Plastic closure according to claim 1, characterized in that the tilting image structure consists of a uniformly structured by elevations and depressions visible surface of the closure, wherein at least a portion of the elevations or depressions each having at least one structural deviation wherein the totality of the structure deviations defines a visible image structure on the surface ,

Plastic closure according to one of the preceding claims, characterized in that the elevations and / or depressions are each formed identically.

Plastic closure according to one of the preceding claims, characterized in that the structural deviations are formed by recesses in individual otherwise uniformly shaped elevations and / or by projections of otherwise uniformly shaped recesses.

Plastic closure according to one of the preceding claims, characterized in that the structural deviations each have partial surfaces which have a different inclination in space with respect to the surfaces not deviating from the structure.

Plastic closure according to one of the preceding claims, characterized in that the structural deviations have at least partially planar partial surfaces.

Plastic closure according to one of the preceding claims, characterized in that the tilting image structure consists of a plurality of elevations and / or depressions on the visible surface of the closure, wherein at least a part of the elevations or depressions in each case at least one of the orientation of corresponding surfaces of the wells and / or elevations deviating partial area, wherein the totality of the partial areas defines a visible image structure

8. Plastic closure according to one of the preceding claims, characterized in that the partial surfaces are each aligned parallel to an imaginary plane which is common to at least one group of the plurality of elevations or depressions.

9. Plastic closure according to one of the preceding claims, characterized in that the elevations and / or depressions have flat surfaces, which consist altogether of at least two different groups of flat surfaces, wherein the groups differ from each other in that the associated surfaces each to another Plane are parallel.

10. Plastic closure according to one of the preceding claims, characterized in that the plane parallel to a common plane, planar partial surfaces adjacent surface has a different orientation than the flat partial surfaces. 1 1. Plastic closure according to one of the preceding claims, characterized in that the non-group of planar surfaces belonging surfaces are curved convexly or concavely.

12. Plastic closure according to one of the preceding claims, characterized in that the elevations and depressions have minimum dimensions which are in the range of 0.05 to 0.3 mm.

13. Plastic closure according to one of the preceding claims, characterized in that the elevations and depressions consist of parallel ribs (4) and grooves (5) extending therebetween.

14. Plastic closure according to one of the preceding claims, characterized in that the ribs and grooves have an approximately U-shaped cross-section. 15. Plastic closure according to one of the preceding claims, characterized in that the flat partial surfaces are formed by recesses (6) in particular of ribs (4)

16. Plastic closure according to one of the preceding claims, characterized in that the closure material is at least partially transparent and the elevations and / or depressions act as an optical lens.

17. Plastic closure according to one of the preceding claims, characterized in that the elevations are formed as cylindrical lenses

18. Plastic closure according to one of the preceding claims, characterized in that the different optical appearances differ with regard to their image structure and / or color and / or brightness and / or their reflectivity.

19. A method for producing a tamper-proof plastic closure, wherein the closure is produced in a mold by injection molding, characterized in that by an inner surface of the injection mold, a negative structure of a tilting image, through which in the said inner surface facing the outer side of the closure imprinted a tilt image structure which causes a different optical appearance under at least two different viewing angles. 20. Plastic closure according to one of the preceding claims, characterized in that casting tool for container closures made of plastic, having a cavity which has a negative of the closure outer side, characterized in that at least one surface of the cavity which produces an outer side of the closure, a negative of this embossed tilted image structure embossed outside.