Sealable package

Abstract

 A tamper-evident sealable package such as an envelope has an adhesive-coated flap 10 with a window 14 therein. The flap 10 is adhesively securable against an adjacent region 12 of the package to seal the latter. An identification area 16, which can be externally viewed through the window 14 in the sealed package, is marked in an identifiable way before sealing. The marking in the area is destroyed or defaced if opening of the package is attempted, thereby providing evidence of tampering.

Description

[0001] This invention relates to envelopes, folders, packets, cartons, boxes and other sealable packages (hereinafter simply called "sealable package" for convenience). The present invention is more particularly concerned with tamper-evident sealable packages, i.e. packages which are of a design such that it can be discerned quite easily that an unauthorised attempt to open the package has been made.

[0002] According to one aspect of the present invention, there is provided a sealable package (as defined herein) having a closure flap which is adapted to be adhesively secured to an adjacent region of the package to seal the package, wherein a window is provided in a region of the package such that the window is adhesively secured to an abutting area of the package when the closure flap is adhesively secured to said adjacent region.

[0003] Whilst the sealable package may be of the type in which the closure flap is adhesively secured to said adjacent region by means of a user-applied layer of adhesive, it is particularly preferred for the package itself to be provided with at least one adhesive layer. The adhesive layer is preferably formed of a layer of pressure-sensitive adhesive protected by a peel-away or otherwise removable protective strip. Alternatively, if the adhesive layer is of the appropriate type and/or consistency, it is within the scope of the present invention for the protective strip to be omitted. The adhesive layer preferably extends over the window in the sealed state of the package.

[0004] The window may be formed in or by the closure flap or it may be formed in or by said adjacent region of the package to which the closure flap is adhesively secured when the package is sealed. In other words, the window may constitute the whole or only part of the closure flap or the whole or only part of said adjacent region of the package. The abutting area of the package (i.e. the area against which the window abuts and is adhesively secured when the flap is closed) may therefore be defined either by said adjacent region of the package or a portion thereof, or by the closure flap or a portion thereof, depending upon the location and size of the window.

[0005] The window may be formed by a film of transparent plastics material which may be arranged to tear, eg into strips, during the act of peeling away the sealed flap.

[0006] The flap may be formed at any convenient location on the package, eg at the top or side of the package.

[0007] It will be appreciated from the above that said abutting area of the package will be viewable externally of the package through the window. Thus, the abutting area of the package can be used as an area which can be signed, stamped or otherwise marked in an identifiable way by the person sealing the package. Thus, unauthorised tampering of the package by attempting to open the closure flap by separating it from its adhesive securement to the adjacent region of the package will lead to destruction or defacement of the identification marking, thus providing evidence of tampering.

[0008] It is within the scope of the present invention for the package to be of the one-use or of the multi-use type. In the case where the package is of the one-use type, the pressure sensitive adhesive will normally be of the so-called permanent type. In the case of a multi-use package, the adhesive used will be of the re-sealable type, but will have a sufficient strength for the act of opening the closure flap to destroy or deface the identification marking viewable in the window. Thus, in for multi-use packages, it is preferred for said abutting area of the package which is viewable in the window to be formed of a material such as plastics which can be marked with a difficult-to-copy marking by means of an erasable marker such that, when the flap has been opened, the marking can be erased and replaced by another difficult-to-copy marking before the closure flap is re-sealed against the adjacent region of the package. This form of package is useful in situations where sensitive documents are to be passed around a group of authorised persons, each of whom knows the type of difficult-to-copy marking which is supposed to be viewable in the window of the package upon delivery.

[0009] It is within the scope of the present invention to use an automatic printer (eg an automatic ink jet printer) such as is currently used in many envelope-processing departments to print the required identification marking(s) adjacent the window. This procedure can also allow for automatic envelope sealing, thus removing the need for human intervention at this stage.

[0010] Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which Figs. 1 to 6 are schematic views of the closure flap regions of various forms of envelope according to the present invention.

[0011] Fig. 1 shows one embodiment of envelope having a closure flap 10 which can be folded down so as to overlap an adjacent region 12 of the envelope so as to seal the pocket of the envelope. In this embodiment, the closure flap has a window 14 therethrough made from a transparent plastics film. The whole of the area of the flap 10 including the window 14 is covered with a layer of permanent, pressure-sensitive transparent adhesive (indicated by the shading) which is protected with a peel-away strip of waxed paper (not shown). An abutting identification area 16 of said adjacent region 12 of the envelope is delimited by a rectangular line and is viewable through the window 14 when the flap 10 is folded to seal the envelope.

[0012] In use, the documents to be mailed are inserted into the pocket of the envelope in the usual way, and the user of the envelope then inserts his signature or any other form of identification mark in the area 16, following which the peel-away strip is removed and the closure flap 10 folded down so as to seal the envelope. It will thus be appreciated that the marking in the area 16 is viewable in the window 14 and that the adhesive layer firmly secures the window 14 itself to the previously marked area 16. Thus, if an attempt is made to open the envelope by peeling away the closure flap 10, the adhesive layer between the window 14 and the marked abutting area 16 will prevent the flap 10 from being opened without destruction or defacement of the marking on the area 16, thus providing evidence of tampering.

[0013] In the embodiment of Fig 2, the positions of the window 14 and the abutting identification area 16 are reversed so that the window 14 together with the adhesive layer are provided on said adjacent region of the envelope, whilst the abutting area of the envelope to be signed or otherwise marked by the user is provided on the flap 10. In this case of course, the window 14 is provided in both walls of the envelope so that viewing of the marking in the area is possible when the envelope is in a sealed condition.

[0014] Instead of the adhesive over the window 14 being formed of the same adhesive as that used for securing the flap 10 to the adjacent region 12, two different types of adhesive may be employed, if desired.

[0015] In the embodiment of Fig 3, the window 14 occupies the whole of the area of the flap 10 (i.e. the flap 10 is formed completely of the clear film forming the window), whilst in the embodiment of Fig 4, the window 14 occupies the whole of the adjacent region 12 of the envelope.

[0016] In the embodiment of Fig 5, the adhesive employed to secure the flap 10 to the adjacent region 12 is of the non-permanent, peel-away, re-sealable type. However, in this embodiment, the area 16 which is exposed in the window 14 is formed of a suitably hard plastics material to allow a difficult-to-copy marking to be applied thereon with a suitable "wipe-clean" ink pen. In this case, the adhesive, whilst being weak enough to allow the flap 10 to be peeled away, is strong enough to adhere sufficiently strongly to the ink so that the ink marking on the hard plastic abutting area 16 is removed or at least defaced sufficiently to provide evidence of tampering. When an authorised recipient of the envelope has opened it, the abutting area 16 can be wiped clean and a fresh difficult-to-copy marking applied before the recipient re-seals the envelope and sends it to the next authorised recipient.

[0017] In the embodiment of Fig. 6, there is shown another design of re-usable envelope in which a plurality (five in this particular embodiment) of windows 14 are provided, each with its own layer of adhesive and each being protected with its own peel-away protective strip. A respective area 16 is provided for each window 14. Each time that the envelope is sent, a different window is exposed by removal of the strip thereon and stuck down over an identification mark on the respective area 16.

Claims

1. A sealable package having a closure flap (10) which is adapted to be adhesively secured to an adjacent region (12) of the package to seal the package, wherein a window (14) is provided in a region (10 or 12) of the package such that the window (14) is adhesively secured to an abutting area (16) of the package when the closure flap (10) is adhesively secured to said adjacent region (12).

2. A sealable package as claimed in claim 1, including at least one adhesive layer by means of which the window (14) can be secured to said abutting area.

3. A sealable package as claimed in claim 2, wherein the adhesive layer extends over the window when the package is in a sealed state.

4. A sealable package as claimed in claim 1, 2 or 3, wherein the window (14) is formed in or by the closure flap (10).

5. A sealable package as claimed in claim 1, 2 or 3, wherein the window (14) is formed in or by said adjacent region (12) of the package.

6. A sealable package as claimed in any preceding claim, wherein the window (14) is formed by a film of tearable transparent plastics material.

7. A sealable package as claimed in any preceding claim, wherein said abutting area (16) defines a markable identification area viewable in the window (14) when the package is in a sealed state.

Drawing