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 The present invention is generally related to tamper evident seals. In particular, the present invention is related to tamper evident seals that combine both physical destruction and optically apparent change characteristics for the indication of tampering or opening of an article to which the seal is applied, such as a food or beverage container.
 The use of tamper evident seals is prominent, particularly in the food and beverage consumer goods industry. Shrink-wrap seals are found on many products where evidence of tampering or mishandling of the goods may be made apparent. The need continues for developing seals that are effective as indicators of tampering and as well as minimizing materials and costs associated with the seals.
 Many tamper evident seals, or alternatively labels, operate by one of two operating principles or mechanisms. The first is a seal that provides an easily visible indication of tampering. For example, the color of the label or another aspect of the appearance of the label may change when an attempt is made to remove it. Also, some labels may leave a footprint when removed, such as a pattern or text such as the word “void”, or a combination of both text and a pattern. An important feature is that, to the observer, the presence of a new color or pattern is not reversible, and therefore indicates that an attempt was made to remove the seal. These labels are generally referred to as tamper evident labels.
 Another operating principle is physical destruction of the seal or label. This can result from, for example, an attempt to peel or remove the label, or to open the underlying container to which the seal is attached, causing partial destruction, disintegration or deterioration of the seal. For example, some labels are designed to shred, chip or crack upon removal. These labels are generally referred to as tamper resistant labels.
 In the food and beverage industry, in particular, package containers may have seals to provide evidence of an attempt to open the container. Such seals are also useful to indicate opening of the containers that may occur, for example, during transit.
 Prior solutions have included a single tamper evident or resistant characteristic. It has been found that a need exists for a seal that includes multiple tamper evident qualities such as an obviously torn label as well as the appearance of a readily visible or colored indicator. It would be beneficial to have, for example, in a food product package or container, a seal that both irreversibly tears as well as provides a strong visual indication of an attempt to open the container.
 Therefore, it would be desirable to have a seal having multiple tamper evident or resistant characteristics to provide evidence of tampering or opening of a container or product.
 The present invention solves the aforementioned problems and provides a seal that fills previously unmet needs.
 In one embodiment, a seal comprising a tamper resistant layer is disclosed. The seal further includes an anchoring layer covered and concealed by the tamper resistant layer. The tamper resistant layer is releaseably adhered to the anchoring layer and, upon at least partial physical destruction of the tamper resistant layer and releasing of the tamper resistant layer from the anchoring layer, the anchoring layer displays a color that is visually distinct from the tamper resistant layer.
 In another embodiment, a closure for a container is disclosed. The closure comprises an upper portion, a lower portion for closing engagement to the upper portion and a tamper resistant seal for secure attachment to the upper portion and the lower portion. The tamper resistant seal comprises a plurality of sealing layers, wherein 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 at least a portion of another of the sealing layers that is visually distinct from and disposed beneath the partially destructed sealing layer.
 Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings.
 The drawings illustrate a preferred mode presently contemplated for carrying out the invention.
 In the drawings:
 Referring now to
 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%.
 Tamper resistant layer
 In one preferred embodiment, anchoring layer
 In operation, seal
 In a preferred embodiment, topcoat
 Referring now to
 In one respect, seal
 It is contemplated that seal
 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.