GB2280402A

GB2280402A - Bleeding tape

Info

Publication number: GB2280402A
Application number: GB9314919A
Authority: GB
Inventors: Roger William Middleto Bromley
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-07-19
Filing date: 1993-07-19
Publication date: 1995-02-01
Anticipated expiration: 2013-07-19
Also published as: GB9314919D0; GB2280402B

Abstract

A tape includes a first film (1), a second film (2) a first adhesive layer (3) disposed between the first and second films and adhering the films in face to face relationship, the first adhesive layer including at least one blister (8) containing a dye (5) wherein removal of the tape from a surface or tampering with the tape causes a blister to rupture and the dye to stain the surface. <IMAGE>

Description

BLEEDING TAPE The present invention relates to tape and more particularly to tape used for security packaging and for sealing. When shipping goods from one place to another, it is important to seal packages and containers so that if the package or container has been tampered with, it can be detected.

Adhesive tape is generally used to seal packaging.

Some conventional adhesive tapes have a very strong adhesive on one side of a film. To open a package which has been sealed with this tape, the tape may be peeled back. This may cause some damage to the package, but the package may be easily re-sealed by applying new tape.

Alternatively, the package may be opened by cutting the tape along a seam of the package. This may also be resealed by applying new tape.

Another type of tape is used for sealing packages the tape being of a kind which may be written on. Once the package has been sealed, a person signs their name across the package and tape. If the package is opened, it is very difficult to re-construct the seal. However, if the package is being sent from one person to another, then the signature of the sender may not be recognised by the person receiving the package. The package may therefore be opened and the original tape replaced by another piece of tape placed over the original tape and a new signature.

In the United Kingdom, the Aviation and Maritime Security Act 1990 places on the carrier of packages the responsibility to ensure that no articles are removed from packages or containers which are in their care. The carriers are also responsible for ensuring that no prohibited articles are inserted into packages. Tape which indicates tampering is therefore essential if carriers are to carry out their responsibilities cheaply and efficiently.

Goods which pass from country to country must pass through customs controls. Customs Officers seal goods and packaging so that no prohibited items may be added to a cargo. Tape indicating that a cargo has been tampered with is used by customs.

Other users of tape indicating that tampering has occurred includes police forces who must sometimes seal a room containing important evidence, and banks who must seal packages which contain valuable items and which are stored in the bank for safety.

An object of the invention is to construct a tape which indicates removal of or tampering with the tape and which overcomes, or at least reduces some of the abovementioned disadvantages.

The present invention is a tape which includes a first film, a second film, a first adhesive layer disposed between the first and second films and adhering the films in face to face relationship, the first adhesive layer including at least one blister containing a dye, wherein removal of the tape from a surface or tampering with the tape causes a blister to rupture and dye to stain the surface.

A preferred embodiment of the tape includes a second adhesive layer disposed on the first or second film for adhesion of the tape to the surface. It is preferred that the second adhesive layer is disposed in the second film which is friable and crumbles when the tape is removed from the surface.

Removal or tampering with the tape causes delamination of the tape thereby releasing the dye.

According to one embodiment of the invention the first adhesive layer contains a solvent, the dye is contained in a capsule, and the solvent dissolves the capsule to leave a blister of dye in the first adhesive layer.

Preferably, the tape is formed in sections, each section being joined to the next adjacent section, each join being free from dye blisters, and each section being separable from the next adjacent section without releasing dye.

It is also preferred that the second adhesive layer is stronger than the first adhesive layer.

In one embodiment the blisters are staggered along the length or width of the tape so that cutting across or along the tape respectively will cause a blister to rupture. It is preferred that the blisters are staggered along both the length and width of the tape.

The blisters are preferably elongate which may be arranged easily in a staggered manner. Alternatively, many small blisters may be included.

The present invention is also a method of making tape including applying a first adhesive and at least one capsule of dye to a first film, thereby forming a first adhesive layer on the first film, applying a second film to the first adhesive layer, said first and second films being held in face to face relationship.

In the preferred embodiment, the method includes applying a second adhesive to the first or second film thereby forming a second adhesive layer on the first or second film.

Preferably the first adhesive is applied to the first film and then the at least one capsule is placed in the first adhesive layer.

Alternatively, the at least one capsule is added to the first adhesive before the first adhesive is applied to the first film.

Preferably the first adhesive layer includes a solvent which dissolves the at least one capsule and forms a blister of dye in the first adhesive layer.

Embodiments of the invention will now be described by way of example only with reference to the drawings in which: Figure 1 is a schematic sectional view of the tape according to the present invention which is adhered to an object; Figure 2 is a sectional view showing one method of constructing the tape according to the present invention; Figure 3 is a plan view of a length of tape according to the present invention showing an arrangement of blisters according to one embodiment; Figure 4 is a plan view of a length of tape according to the present invention showing an arrangement of blisters according to another embodiment; Figure 5 is a sectional view of the tape of the present invention being removed from an object.

Referring to Figure 1, a tape is applied to an object 6. The object 6 is typically a package such as a freight container or parcel, or alternatively any object which is to be sealed.

The tape includes a first film 1 which is strong, a second film 2 which is friable, and a first adhesive layer 3 disposed between the films 1, 2 which holds the two films 1, 2 together in face to face relationship. The tape is therefore a laminate structure.

A second adhesive layer 4 is disposed on the second film 2 so that the tape may be adhered to the object 6.

The second adhesive layer 4 is a very strong adhesive so that, when the tape is peeled back, the friable second film 2 crumbles due to the sheer stress that it experiences, and the films are separated. The second film 2 need not be friable, but in some instances may be at least as strong as the first film 1. It is important that the films 1, 2 become separated if the tape is peeled back, and this is more easily achieved using a friable second film 2.

The first adhesive layer 3 includes blisters 8 containing a dye 5. The blisters 8 are arranged in the first adhesive layer 3 so that cutting the tape transversely or longitudinally will rupture at least one blister 8 thereby releasing the dye 5 onto the object 6.

The resulting stain on the object 6 clearly indicates that the object 6 has been tampered with.

The first film 1 is very strong, and so the action of peeling the tape from the object 6 results in the first film 1 peeling, the second film 2 crumbling, and the films 1, 2 becoming delaminated. The first adhesive layer 3 is torn open and the blisters 8 of dye 5 are ruptured, thereby staining the object 6. The dye 5 may flow from the blister 8 to the object 6 more easily where the second film has crumbled.

Referring to Figure 2, one method of manufacturing tape according to the present invention is described. The first film 1 is taken, and a first layer of adhesive 3 is applied to the first film 1 in a conventional manner. The adhesive also contains a solvent. Capsules or sachets 7 containing dye 5 are placed in the first adhesive layer 3.

The second film 2 is then applied to the first film 1 over the first adhesive layer 3 to form a sandwich or laminate structure. The first film 1 is very strong, while the second film 2 is less strong or friable. The laminate structure then has a second adhesive layer 4 applied to the second film 2 to enable the tape to be applied to objects 6.

The capsule or sachets 7 are made of a material which is soluble in the solvent which is present in the first adhesive layer 3. Once the capsules or sachets 7 are placed in the first adhesive layer 3, they are dissolved by the solvent in the first adhesive layer 3. The dye 5 which was enclosed by the capsule or sachet 7 is thereafter retained in a blister 8 in the first adhesive layer 3.

During manufacture, it is preferable to start with the first film 1 and add the other layers to that film.

Alternatively, it is possible to start with the second film 2 and add the other layers to that film. The latter is more difficult since the second film 2 is friable.

Another variation on the above manufacturing technique is to add the capsules or sachets 7 to the adhesive used in the first adhesive layer 3 just before the adhesive is applied to the first film 1. This variation would give a random distribution of capsules or sachets 7.

One advantage of placing the capsules or sachets 7 in the first adhesive layer 3 after the layer 3 has been applied to the first film 1 is that the capsules or sachets 7 may be precisely positioned in the adhesive layer 3. The importance of this will be described in relation to figures 3 and 4.

The first adhesive layer 3 is preferably less strong than the second adhesive layer 4 so that when the tape is peeled from the object 6, the tape delaminates and a blister 8 ruptures, releasing dye 5 onto the object 6.

The first and second films are typically made of a plastics material or from other materials such as paper or cloth.

Referring to Figures 3 and 4, the arrangement of the blisters 8 in the first adhesive layer 3 is quite important. The blisters 8 should be arranged in a staggered manner throughout the width and length of the tape so that the tape cannot be cut along its length or across its width and then resealed. This may be achieved by positioning a large number of small blisters 8 in the first adhesive layer 3. Alternatively several elongate blisters 8 may be carefully positioned in the first adhesive layer 3. If a person tried to cut along or across the tape, it would be very difficult to do so without rupturing a blister 8, thereby releasing dye 5 onto the object 6.

The tape will generally be sold on a reel, and lengths of tape will be removed from the reel and applied to an object 6. It is preferred that the lengths of tape may be cut or torn from the reel without releasing dye 5. If dye 5 is released onto the object 6 while the object 6 is being wrapped, then the object 6 will have the appearance of having been tampered with. To prevent accidental release of dye 5, it is proposed to manufacture the tape with break points 9 across the width of the tape where the tape may be cut into lengths, but no dye is released. There are no blisters 8 of dye 5 located at the break point 9, and so the tape may be cut across the break point 9 without causing a mess. It may be useful for the user of this kind of tape if the colour of the tape is different at the break point 9 from the rest of the tape. Alternatively a line may mark the break point 9.Some embodiments may include a row of perforations across the tape at the break point 9 to make it simpler to tear lengths of tape from the reel.

Referring to Figure 5, once the tape has been applied to an object 6, any attempt to peel back the tape will result in the release of dye 5 onto the object 6. Tape is usually used to close a seam of a parcel, or to seal an opening. To enter the object 6 the tape must either be peeled back, or cut. The tape would normally be cut along its length and along the seam of the package.

If the tape is cut, then it would be very difficult to cut across its width or along is length without rupturing a blister 8 of dye 5. This is particularly true where the blisters 8 are arranged in a staggered fashion as described above. The escaping dye 5 would stain the object 6 and indicate that the object 6 had been tampered with. The dye 5 would not only seep through the cut in the tape,but would also run over the tape and stain the object 6 on either side of the tape.

If the tape is peeled back, then the tape will naturally de-laminate. The first film 1 is made from a strong material while the second film 2 is made from a less strong or friable material. To peel the tape back, the first film 1 is pulled away from the object 6. In the event of the second film 2 being pulled, it will crumble, and the pulling force naturally applied to the first film 1. The first film 1 will not break as easily as the second film. The first adhesive layer 3 is not as strong as the second adhesive layer 4. Therefore, as the first film 1 is peeled back, it is the first adhesive layer 3 which fails first, causing the first and second films 1, 2 to separate or de-laminate. The first adhesive layer 3 is not strong enough to pull the second film 2 away from the object 6. As the films 1, 2 separate, the blisters 8 of dye 5 rupture and the dye 5 stains the object 6.The second film 2 remains substantially attached to the object 6 due to the strong adhesive layer 4. The dye 5 which escapes to stain the object 6 indicates that the object 6 has been tampered with. As the dye 5 is released from the blister 8, it flows over the tape which remains attached to the object 6 and stains the object 6 on either side of the tape. The blister 8 should release sufficient dye 5 to cause a substantial stain on the object 6 which would be difficult to cover. The dye 5 leaks out of the tape. The combination of the very strong second adhesive layer 4 and the very fragile second film 2 means that is extremely difficult to separate the second film 2 from the object 6 without the second film 2 crumbling and a blister 8 of dye 5 from rupturing.

Many variations may be made to this invention. In some situations it may be advantageous to form the blisters 8 of dye 5 in the first adhesive layer 8 in such a way that the dye is actually bounded in part by either the first film 1 or the second film 2 or by both films. If the tape is tampered with, the dye 5 will more easily stain the object 6 if the dye 5 can pass directly from the blister 8 to the object 6 through a break in the second film 2.

Adhesive 3 might otherwise obstruct the passage of the dye 5. Normally, the dye 5 will flow across the tape and stain the object 6 around the tape.

Another embodiment of the present invention has the second adhesive layer 4 disposed on the first film 1 instead of the second 2. In this embodiment, the strong film 1 would be disposed between the first and second adhesive layers 3, 4., and the second friable film is outermost. Whilst this embodiment would not be so effective, some staining would be likely to occur if the tape were to be removed. It is preferred that the strong film is on the outside to protect the blister 8 from damage.

Once the tape has been affixed to a surface, it cannot easily be removed from that surface without the dye 5 leaking onto the surface to which the tape has been stuck.

When a person, whether legitimately or otherwise, removes the tape, dye 5 will leak out, and so protective clothing should be worn during removal.

According to another embodiment the dye 5 is a chemical which marks the surface from which the tape has been removed. The chemical itself is not necessarily coloured, but when it comes into contact with the surface, it causes discolouration. Furthermore, the dye 5 may mark the object in other ways, such as by leaving an odour on the object with which it comes into contact. The word "dye" herein refers to all substances and chemicals which could be used to leave a mark on the object 6 whether that mark is visible or detectable by smell.

The present invention is particularly useful when the tape is applied to packaging which has an absorbent outer surface since the dye will enter into the absorbant packaging. However, dyes may be used which will permanently mark any surface, including metal and paintwork.

The size and number of blisters 8 containing dye 5 is not restricted in this invention, but it is preferred that the blisters 8 are sufficiently large to cause a clear indication of leakage, but are not so large as to cause damage to the object 6, particularly where a blister 8 has been accidentally ruptured during the transit of the object 6. A large enough amount of dye must be released if a significant length of tape is removed.

In another embodiment of this invention, the tape is not self-adhesive. The tape includes the first strong film, the second friable film, and the first adhesive layer disposed between the films, with the blisters of dye disposed in the first adhesive layer. The tape does not include a second adhesive layer. The non self-adhesive tape may be applied to objects 6 which themselves have adhesive surfaces.

Alternatively the tape may have a second adhesive layer which only becomes adhesive once it is moistened.

This embodiment is particularly useful where the second adhesive layer 4 would cause the films 1, 2 to separate as the tape is removed from the reed before it is applied to an object 6.

Claims

1. Tape including a first film a second film a first adhesive layer disposed between the first and second films and adhering the films in face to face relationship, the first adhesive layer including at least one blister containing a dye wherein removal of the tape from a surface or tampering with the tape causes a blister to rupture and the dye to stain the surface.

2. Tape according to claim 1 further including a second adhesive layer disposed on the first or second film for adhesion of the tape to the surface.

3. Tape according to claim 2 wherein the second adhesive layer is disposed on the second film.

4. Tape according to any preceding claim wherein the second film is friable and crumbles when the tape is removed from the surface.

5. Tape according to any preceding claim wherein removal of or tampering with the tape causes the films to be de laminated thereby releasing the dye.

6. Tape according to any preceding claim wherein the first adhesive layer contains a solvent, the dye is contained in a capsule, and the solvent dissolves the capsule to form a blister of dye in the first adhesive layer.

7. Tape according to any preceding claim wherein the tape is formed in sections, each section being joined to the next adjacent section, each join being free from dye blisters, and each section being separable from the next adjacent section without releasing dye.

8. Tape according to claims 2 to 7 wherein the second adhesive layer is stronger than the first adhesive layer.

9. Tape according to any preceding claim wherein the blisters are staggered along the length of the tape so that cutting across the tape will cause a blister to rupture.

10. Tape according to any preceding claim wherein the blisters are staggered across the width of the tape so that cutting along the tape will cause a blister to rupture.

11. Tape according to any preceding claim wherein the blisters are elongate.

12. Tape according to any preceding claim wherein the blisters are substantially spherical.

13. A method of making tape including applying a first adhesive and at least one capsule of dye to a first film, thereby forming a first adhesive layer on the first film, and applying a second film to the first adhesive layer, said first and second films being held in face to face relationship.

14. A method according to claim 13 further including applying a second adhesive to the first or second film thereby forming a second adhesive layer on the first or second film.

15. A method according to claim 12 or 13 wherein formation of the first adhesive layer includes applying the first adhesive to the first film and then placing said at least one capsule of dye in the first adhesive.

16. A method according to claim 12 or 13 wherein formation of the first adhesive layer includes placing said at least one capsule of dye into the first adhesive, and then applying the first adhesive and said at least one capsule to the first film, thereby forming the first adhesive layer on the first film.

17. A method according to any of claims 13-16 wherein the first adhesive includes a solvent which dissolves the capsule permitting formation of at least one blister of dye in the first adhesive layer.