DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0019] Referring now to FIG. 1, a schematic view of a tamper evident seal 10 in accordance with one aspect of the invention is shown. Seal 10 generally includes a tamper resistant layer 12 which covers and conceals an anchoring or anchor layer 14. When placed on a product, anchoring layer 14 is not visible and can only become visible when tamper resistant layer 12 is broken, chipped, cracked, torn or otherwise physically destructed. Tamper resistant layer 12, on the embodiment shown, is of a generally oval shape. However, any suitable shape is contemplated. Tamper resistant layer 12 preferably is constructed of a material that will fracture easily in order to show signs of product tampering and to prevent one piece removal. Preferably, tamper resistant layer 12 includes vinyl.

[0020] In one preferred embodiment, the tamper resistant layer is a thermal transfer tamper resistant vinyl with a matte white or substantially white finish and having an acrylic adhesive. The Brady B-351 Thermal Transfer Printable Tamper-Resistant White Vinyl Label Stock, available from Brady Worldwide, Inc., is an example of a suitable material for the tamper resistant layer. The preferred material has an average tack value of about 45.4 oz (1288 g) as measured by ASTM D 2979 on a Polyken™ Probe Tack and has an average tensile strength of approximately 6.3 lbs/in (110N/100 mm) as measured by ASTM D1000 with an elongation of approximately 2%.

[0021] Tamper resistant layer 12 in general completely covers anchoring layer 14. Preferably, anchoring layer 14 has a zoned die-cut format. Anchoring layer 14, in general, will have higher adhesive bonding and strength characteristics than tamper resistant layer 12, and the substrate strength of anchoring layer 14 will provide appropriate anchorage of layer 14 to any container to which it is applied.

[0022] In one preferred embodiment, anchoring layer 14 includes polyethylene. Brady B-656 polyethylene face sheet, also available from Brady Worldwide Inc., has been found to be a suitable material.

[0023] In operation, seal 10 would be applied such that a portion, approximately half of both tamper resistant layer 12 and anchoring layer 14 are positioned on either side of center line 16, which is representative of the border of the container opening to which seal 10 will be applied. The shape of anchoring layer 14 is shown in a chevron-type configuration. However, any suitable die-cut, including polygonal, key-hole or cross shape, is contemplated. Since layer 14 resides under tamper resistant layer 12, layer 14 can be considered to be an underlayer.

[0024] FIG. 2 shows an exploded view illustrating the layers of the tamper evident seal in accordance with one aspect of the present invention. In FIG. 2, the layers of seal 10, or “sealing layers”, are shown. Tamper resistant layer 12 covers anchoring layer 14. Anchoring layer 14 has a topcoat 18. Topcoat 18 generally has a color that is visually distinct from the color of the tamper resistant layer 12 and is generally shaped in the same zoned die-cut as anchoring layer 14. Topcoat 18 preferably includes a contrasting color from tamper resistant layer 12. For example, if tamper resistant layer is substantially white, it is contemplated that anchoring layer (because of topcoat 18) will be substantially non-white or colored. Alternatively, topcoat 18 could simply be clear. The key requirement is that the observer can readily perceive the difference between the two layers. Moreover, as an alternative, anchoring layer 14 may itself be colored, for example, by starting out with a colored cast film. In the case where there is a colored anchoring layer 14, topcoat 18 may be eliminated.

[0025] In a preferred embodiment, topcoat 18 is UV printed. Anchor layer 14 will have an adhesive 20, again preferably in the same zoned die-cut format as anchor layer 14, in order to secure anchor layer 14 to a package or container suitable to the application. Disposed between the tamper resistant layer 12 and the colored topcoat 18 of anchoring layer 14 is a release coating 22. Preferably, release coating 22 is a clear UV printed release coat that is shaped in a similar zoned die-cast shape as anchor layer 14. An example of a preferred material for the release coating 22 is silicon. Release coating 22 permits the portion covering the release coat by tamper resistant layer 12 to peel or break-away. Since the adhesive used with tamper resistant layer 12 that adheres to a container or other product is stronger than the adhesion of the release coating 22, when breakage occurs, it is most likely to occur along the shape of the zoned die-cut. In this manner, when portions of tamper resistant layer 12 break away over an area covering the colored topcoat 18 of anchor layer 14, that colored portion will be exposed and will be visible to provide a visual indication of tampering of seal 10.

[0026] Referring now to FIG. 3, a schematic view illustrating the tamper evident seal of FIG. 1 used on a container opening is shown. FIG. 3 illustrates tamper evident seal 10 in one application of the present invention. In this application, seal 10 is applied along a junction 24 separating an opening portion 26 and a base portion 28 of a cap 30. Cap 30 may be used on a food and/or beverage container such as, for example, a plastic cap of a sports drink bottle, ketchup bottles, etc. Although the cap 30 shown is a “flip-top” type cap, it is contemplated that any type of container opening may be suitably employed including, for example, rotating cap openings, hinged flip tops, screw-off caps, and press-fit or interference-fit caps, among others.

[0027] Seal 10 is placed on cap 30 such that a portion of tamper resistant layer 12 and anchoring layer 14 is present on both sides of junction 24. Seal 10 provides protection in several ways. First, if a direct attempt to peel off seal 10 is made, portions of tamper resistant layer 12 will break, chip away and/or show obvious signs of physical destruction, or at least partial physical destruction. Also, as in this example, lip 32 is flipped up in a known manner. For example, when opening up a sports drink or other beverage container, a lifting force is created about joint 34 and tamper resistant layer 12 will tend to break along the area covering anchoring layer 14 since a release coating (22 of FIG. 2) is also provided around the same zoned die-cut area.

[0028] FIG. 4 is a front view of a tamper evident seal applied to a product container prior to an attempted opening. FIG. 4 illustrates tamper evident seal 10 applied to an unopened container and thus illustrates an untampered condition. In such an unopened, untampered state, only tamper evident seal 10 is visible, thereby indicating that no tampering or opening of cap 30 has occurred. Tamper resistant layer 12 can be said to be in a pre-tearing position. Again, seal 10 is applied along junction 24 such that any opening of the cap will stress seal 10 generally along junction 24.

[0029] FIG. 5 is a front view of a tamper evident seal applied to a product container after an attempted opening and reclosing. FIG. 5 illustrates one embodiment of the result of opening cap 30 and reclosing it. As illustrated, there is clear indication of tampering. Seal 10 operates generally on the principle that an attempted or inadvertent opening will stress the tamper resistant layer. Because anchor layer 14 is stronger, that is, more resistant to those same stresses, tamper resistant layer 12 will break or otherwise at least partially destruct. First, portions of tamper resistant layer 12 have chipped away or been broken to reveal missing portions 40a/b and visible cracks 42a/b. The relatively brittle characteristics of tamper resistant layer 12 will cause these cracks and breakage. Additionally, color topcoat 18 of the anchor layer 14 is revealed through tamper resistant layer 12. In operation, because of the release layer between the color topcoat 18 and tamper resistant layer 12, those portions of tamper resistant layer 12 positioned over the zoned, die-cut area of anchor layer 14 and color topcoat 18 will be more likely to peel away, break off or otherwise be physically removed from seal 10. In this manner, moving cap 30 with respect to the container at least partially, physically destructs tamper resistant layer 12 such that damage to the tamper resistant layer 12 is observable and reveals at least a portion of the color topcoat 18 of the anchoring layer 14 through breaks in the tamper resistant layer 12. Therefore, tearing or partial destruction of seal 10 cannot be reversed to a pre-tearing condition such that the color topcoat 18 of the anchoring underlayer is not visible. This is because, upon unsealing, the seal cannot be covertly resealed without these visible indications of the unsealing being revealed. Thus, partial destruction of the covering layer cannot be reversed to a pre-tearing condition such that the anchoring underlayer is not visible. In addition, upon tearing of the covering layer to produce tears in the covering layer, at least a portion of the anchoring underlayer is irreversibly visible through the tears in the covering layer. Finally, the tamper resistant layer cannot reconceal the colored topcoat of the anchoring layer once the colored topcoat is exposed through the tamper resistant layer breaks.

[0030] In one respect, seal 10 can be said to leave a “footprint” and change in appearance when seal 10 is disturbed, as during an attempted break of the seal to open an underlying product. Seal 10 accomplishes the change of appearance through the use of multiple layers, and the footprint itself is the presentation of the colored underlayer. The tamper resistant layer is unalterably changed as partially represented by its cracks, breaks and tears. The seal as a whole is also changed, with the visibility of the colored underlayer coming through when the seal has been tampered with. Therefore, as a whole, the seal of the present invention uses a mix of tamper resistant layers and stronger anchoring layers to accomplish the functionality of a tamper evident seal.

[0031] It is contemplated that seal 10 is usable in a number of different products. For example, a closure for a container may include an upper portion, a lower portion for closing engagement to the upper portion, and seal 10. Seal 10 is used for secure attachment to the upper portion and the lower portion, the seal including a plurality of sealing layers. When the upper portion and the lower portion of the container are opened with respect to one another, at least one of the sealing layers at least partially destructs to reveal another of the sealing layers that is visually distinct from and disposed beneath the partially destructed sealing layer. Many other products and applications may include seal 10 for a variety of tamper evident applications and general securing of products and product packages.

[0032] The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.