GB2508264A

GB2508264A - Tamper evident label / tape having an adhesive with a UV resistant additive.

Info

Publication number: GB2508264A
Application number: GB201315671A
Authority: GB
Inventors: Adrian Steele; Timothy Joseph Murphy; Hugo Anthony Thomas Gell
Original assignee: MERCIAN LABELS Ltd
Current assignee: MERCIAN LABELS Ltd
Priority date: 2013-09-03
Filing date: 2013-09-03
Publication date: 2014-05-28
Also published as: GB2508264A8; GB201315671D0

Abstract

A tamper evident label or tape comprises a translucent film and a hot melt adhesive applied to the translucent film. The label/tape comprises a UV resistant additive to reduce degradation of the hot melt adhesive. The UV resistant additive is preferably added to the hot melt adhesive. An inked tampering message 130 is preferably applied to the translucent film followed by a corona discharge treatment. Preferably, a serial number or identifier 140 is printed and a layer of coloured ink 150 is applied leaving a window which may have a different coloured ink applied to it. A release layer and a dry peel layer 165 may be included before the hot melt adhesive layer.

Description

A TAMPER EVIDENT LABEL OR TAPE. AND A METHOD OF MAKING A TAMPER

EVIDENT LABEL OR TAPE

The invention relates to a tamper evident abel or tape, and a method of making a tamper evident label or tape.

It is known to apply a tamper evident label or tape to a surface of an object. In summary, a tamper evident label or tape is designed so that when it is removed or partially removed by a person, the physical properties of the label or tape change and so too does the visual appearance of the label or tape. Some types of label or tape also transfer part of the label or tape to the surface of the object, so that tampering is evident once the label or tape has been removed, An aim of the present invention is to provide an improved, or at least an alternative, tamper evident label or tape, and/or a method of making a tamper evident label or tape.

According to a first aspect of the invention there is provided a tamper evident label in accordance with Claim i or 9.

According to a second aspect of the invention there is provided a tamper evident tape in accordance with Claim 2 or 9.

According to a third aspect of the invention there is provided a method of making a tamper evident label or tape, preferably in accordance with Claim 6, 7 or 8.

The tamper evident label or tape in accordance with Claim 1, 2, 6, 7, 8 or 9 is advantageous because the UV resistant additive in the hot melt adhesive reduces degradation of the hot melt applied liv adhesive in the translucent areas of the hbel or tape. 1-lence a label in accordance with the invention or a tape in accordance with the invention can have a longer lifespan particularly in outside use.

Other optional and preferred features of the tamper evident label or tape, and advantages of said features, are set out in the dependent claims, and the description and drawings below.

Features of the tamper evident label or tape disclosed in the claims, description and drawings can be combined in any complimentary manner, where such a combination of features would provide a working embodiment of the invention.

Tamper evident labels in accordance with the invention, and a tamper evident tape in accordance with the invention. wifl now be described, by way of example only, and with reference to the accompanying drawings, in which, Figure 1 is a schematic cross section of tamper evident labds and tape in accordance with the invention.

Figure 2 is a plan view of a tamper evident label in accordance with the invention,

I

Figure 3 shows a tamper evident label of Figure 2 being removed from a surface to which it has been applied, iii particular the part of the tamper evident label which is removed, and the surface to which it was applied, Figure 4 is a plan view of a further tamper evident label in accordance with the invention, Figure 5 shows a tamper evident label of Figure 4 being removed from a surface to which it has been applied, in particular a part of the tamper evident label which is removed, and another part of the tamper evident label which remains on the surface to which it was applied, Figure 6 shows the part of the tamper evident label of Figure 4 which remaths on the surface to which it was applied, Figure 7 shows the part of the tamper evident label of Figure 4 which is removed, Figure 8 is a plan view of a tamper evident tape in accordance with the invention, Figure 9 shows a tamper evident tape of Figure 8 being removed from a surface to which it has been applied, in particuhr a part of the tamper evident tape which is removed, and another part of the tamper evident tape which remains on the surface to which it was applied, Figure 10 shows the part of the tamper evident tape of Figure 9 which remains on the surface to which it was applied, Figure 11 shows the part of the tamper evident tape of Figure 9 which is removed.

Low residue label Figure 1 shows the construction of a low residue label 1, and the physical colour (or appearance) of the thw residue label 1.

Referring to Figures 1 to 3. a low (or no) residue label I is a composite product made of rnu1tipe layers. and comprises, inter alia, a first colour fiexographic printing ink 10, a clear film 20, a clcar flcxographic printing ink 30 of an "OPENED" mcssagc which denotes tampering (or a message or indicia having the equivalent effect), an inkjet identifier such as a number 40, a second flexographic colour printing ink 50, a third flexographic colour printing ink 60, a hot melt adhesive 70, and a release liner 80.

In figure 1, the words "PARTIAL" or "FULL" denote the extent, or coverage, of the various layers (as a proportion of the area of the label 1).

The film 20 can be made from polyester (PET), polypropylene (PP), polyethylene (PE), polyviny' cifioride (PVC), or other suitable material.

The film 20 is transparent i.e. visible light is able to pass through it, and it appears to be clear.

The surface of the film 20 is chemically inert and nonporous, and it has a low surface tension, so it is not receptive to bonding of ink.

Therefore, an upper surface of the film 20, i.e. the surface of the film 20 remote from the surface X of the object to which the label will be applied, has a corona treatment 15 to modify the properties of the outer surface of the film 20. The corona treatment employs a temperature corona discharge or plasma treatment to impart changes in the properties of a surface. The upper surface of the film 20 material is passed through the corona plasma curtain thereby changing the surface energy of the outer surface of the film 20. The corona treatment 15 allows improved adhesion of ink thereto in the following process. Instead or corona electrostatic treatment, (atmospheric or vacuum) plasma treatment can be used.

The first fiexographic colour printing ink 10 is then printed onto the corona treated 15 upper surface (as defined above) of the film 20. The first flexographic colour printing ink 10 is printed in a generafly rectangubr region 12, with the exception of rectangular region 22 of the film 20 which is not printed and which remains clear. The first flexographic colour printing ink 10 is conveniently white. It will be appreciated that a first clear frame 14 of the film 20 surrounds the generally rectangular region 12 of the first flexographic colour printing ink 10 on the film 20.

Referring to Figures 1 and 3, a clear flexographic printing ink 30 is then used to print an "OPENED" message onto the untreated lower surface of the film 20. In this embodiment of the invention, the "OPENED" message comprises four rows of the word OPENED, each row comprising the word OPENED apurality of times. Although the word "OPENED" is used in this example as the message, the clear flexographic printing ink 30 can be used to print any message (any suitable word, words, character or characters, such as but not limited to alphanumeric characters) which has the effect of denoting the label 1 has been tampered with when it is read.

The clear flexographic printing ink 30, in other words the "OPENED" message, is confined to an area of the film 20 corresponding to the generally rectangular region 12 of the first flexographic colour printing ink 10, but the clear flexographic printing ink 30 is not printed on the clear rectangular region 22. Furthermore, the "OPENED" message formed by the clear flexographic printing ink 30 is "in register", in other words all of the words "OPENED" are complete and thuly within the border, as opposed to a wallpaper' style tamper message where the words are truncated at the edges of the label.

The lower surface (in other words the surface of the film 20 closest to the surface of the object X to which the label I will be applied) of the film 20 then has a corona treatment 35 applied to it, over the "OPENED" message formed by the clear flexographic printing ink 30.

The inkjet identifier such as a number 40 is applied to a part of the corona treated 35 lower surface of the film 20. The inkjet applied number 40 can be sprayed onto the film 20. The ink can be water, solvent or UV cured. The ink 40 is typically black. Because the number 40 is applied below the surface of the film 20 the film must be destroyed to remove it.

The second tiexographic colour printing ink 50 comprises a (blue) ink block 52 which is applied to part of the corona treated 35 lower surface of the film 20, corresponding to the generally rectangular region 12, but not the clear rectangular region 22. In other words, the block of the second tiexographic colour (blue) printing ink 50 substantially coincides with the first (white) flexographic colour printing ink 10. The second flexographic colour printing ink also comprises a (blue) ink indicia 54 applied to the first clear frame i4 which surrounds the generally rectangular region 12 of the first flexographic colour (white) printing ink 10.

The third flexographic colour printing ink 60 comprises a rectangular region 62 of white ink applied to part of the corona treated 35 lower surface of the film 20, in particular printed within the clear rectangular region 22 of the film 20, thereby providing a second clear frame 64, defined between the clear rectangular region 22 of the film 20 (bounded by the first flexographic colour printing ink 10 and the second flexographic colour printing ink 50 when viewing the label 1 from above) and the rectangular region 62 of white ink. The rectangular region 62 of white ink is designed to contrast with the identifier 40, which is typically black ink, making it easier to read the identifier 40.

The hot melt adhesive 70 is a hotmelt adhesive using either rubber or acrylic chemistry which iS are standard in pressure sensitive label and tape applications.

Whilst the first (generally) clear frame 14 and the second clear frame 64 are useful for security purposes, the hot melt adhesive 70 coinciding with the position of the first generally) clear frame 14 and the second clear frame 64 is prone to UV depolyrnerisation, which can cause the hot melt adhesive 70 to become a semi fluid mess that can be difficult to remove from the surface X to which the label is applied.

In accordance with the invention, the hot melt adhesive 70 comprises a UV resistant additive in the hotmelt as a pigmented additive.

The release liner 80 is a paper which is completely covered with a "release layer" of silicone or the 111cc. The release liner 80 is sometimes called "backing paper", glassine" or "carrier".

The OPENED message PARTIAL 30 will always stack between the flexo colour PARTIAL layers lOandSO.

Prior to applying the label 1 to a surface X of an object to be secured, the rest of the low residue label I (i.e. parts 10 to 70) is removed from the release liner 80. Certain physical andJor characteristics of the low residue label 1 mean that the entire content of the low residue label i maintains its integrity when the low residue label 1 is removed from the release liner 80. In particular, the hot melt adhesive 70 sticks (indirectly) to the label film 20 better than it sticks to the silicone of the rdease liner 80 (which it cannot bond with), so the release liner 80 comes away easily from the rest of the low residue label I. and the rest of the low residue label 1 keeps its integrity when the label film 20 is removed from the release liner 80.

The rest of the low residue label 1 (i.e. parts 10 to 70) is then applied to a surface X of an object to be secured.

The rest of the low residue label I (i.e. parts 10 to 70) can be tampered with whilst it is applied to the surface X of an object to be secured.

Certain physical andlor chemical interactions occur between the different layers of the low residue label I, and the surface X to which the low residue label 1 is applied, to cause the reveal of the "opened" message 30 when the film 20 of the low residue label 1 is removed from the surface X. The bond strength of the hot melt adhesive 70 to the application surface X is stronger than the bond strength of the OPENED message 30 to the film 20. upon removal of the film 20 from the surface X, in the regions of the fUn 20 where the "OPENED" message 30 has been printed on the film 20, the adhesive 70 sticks to the surface X sufficiently to deform the adhesive 70 relative to the film 20. The clear adhesive 70 pulls the blue flexo ink layer 50 away from the film 20, which in turn breaks away the dear OPENED message 30 from the film 20. All end up in a gooey mess, and obviously with different refractive properties when viewed through the label, hence you see the OPENED message. In short, when the film 20 is peeled off the application surface X at a moderate speed, the OPENED message 30 breaks from the fUn 20 and causes an air gap to form.

forming the message.

If the adhesive 70 binds too well to the surface X it will break from the film 20 and leave a residue. The adhesive 70 directly under the OPENED message 30 could theoretically after breaking away from the film 20 stay on the surface X, leaving the adhesive 70 on the application surface X exactly in the pattern of the word OPENED. However, in this embodiment of the invention one of the purposes of the label 1 is not to leave a residue. The adhesive 70 directly under the OPENED message 30 must come away from the application surface X and stay with the label 1. Therefore, the bond strength of the adhesive 70 to the application surface X has to be weaker than the cohesive strength of the adhesive 70 to itself.

So, upon continued removal of the film 20, the adhesive 70 does not stay adhered to the surface sufficiently for the adhesive 70 to detach entirely from the film 20, as the adhesive eventually releases from the surface X and stays adhered to the film 20. The adhesive 70 springs back towards the film 20, but does not spring back quite to its original position, hence the "opened" message shows. The critical features of the adhesive 70 are its high coat weight.

elasticity and bond strength.

Certain physical andior chemical characteristics of the low residue label 1 mean that the other layers (i.e. parts 10 to 70) of the low residue label 1 do not delaminate or leave a residue when the "opened" message 30 is revealed when the low residue label I is removed from the surface X in the region A (shown in Figure 3) where the label 1 and surface X overlapped.

The reason the other layers do not bond (to the surface X) is twofold -stronger ink bonds and pre treatment of the film 20 so that the inks bond to the film 20 well. As mentioned above, after printing the OPENED message 30 on the film 20, there is a full coverage of corona or plasma treatment 35. The corona or plasma treatment can be though of as roughening a surface so the ink has something to key onto. Hence, any ink 40, 50. 60 applied to the corona treated film 20 will bond well, whereas the OPENED message 30 was applied before the corona treatment 35 and so the OPENED message 30 is sitting in a fragile state on the untreated film 20 under the characters "OPENED" such that they break apart as described above.

Dual layer label In another embodiment of the invention, a dual layer (high residue) label 100 is a composite product made of multiple layers, and comprises, a clear film 120, a clear fiexographic printing ink 130 of an "OPENED" message which denotes tampering (or message having equivalent effect), a corona treatment 135, an inkjet identifier such as a number 140, a first flexographic colour printing ink 150, a release layer 160, a dry peel layer 165, a hot melt adhesive 170, and a release liner 180.

S

Figure 1 shows the construction of a dual layer (high residue) label 100, and the physical colour (or appearance) of the dual layer (high residue) label 100.

The words "PARTIAL" or "FULL" denote the extent, or coverage, of the layer in question (as a proportion of the area of the abel).

The clear film 120 corresponds to clear film 20, and will not be described again for conciseness.

iS The clear flexographic printing ink of an "OPENED" message 130 corresponds to clear flexographic printing ink 30. and will not be described again for conciseness.

The corona treatment 135 corresponds to corona treatment 35. and will not be described again for conciseness.

The inkjet identifier such as a number 140 corresponds to identifier 40, and will not be described again for conciseness.

The first flexographic colour printing ink 150 corresponds to first flexographic colour printing ink 50, and will not be described again for conciseness.

The hot melt adhesive 170 corresponds to hot mcli adhesive 70, and will not be described again for conciseness.

The release liner 180 colTesponds to release liner 80, and will not be described again for conciseness.

The release layer 160 is a flexographically printed release layer, in which a standard high silicone release varnish is used.

The dry peel layer 165 is a flexographically printed dry peel layer that kaves the surface dry to the touch, a standard dry peel release varnish is used.

Referring to Figure 4, dear areas in the blue block 150 arc "knocked out" to make the "No." and "SECURITY SEAL" message. The "knock out" process involves printing the blue block "in register" with a printing plate so there is no blue ink printed in the area of the visible "No." and "SECURITY SEAL" message.

Prior to applying the dual layer label 100 to a surface X of an object to be secured, the rest of the dual layer label 100 (i.e. parts 120 to 170) is removed from the release liner 180. Like as described in relation to the low residue label 1, the rest of the dual layer label 100 keeps its integrity when the rest of the dual layer label 100 is removed from the release liner 180.

The rest of the dual layer label 100 (i.e. parts 120 to 170) is then applied to a sm-face X of an object to be secured.

The rest of the dual layer label 100 (i.e. pails 120 to 170) can be tampered with whilst it is applied to the surface X of an object to be secured.

Certain physical and/or chemical interactions occur between the dilerent layers of the dual layer label 100, and the surface X to which the dud layer label 100 is appfied, to cause the rcvcal of the "opcncd" mcssagc 130 when the film 120 of the dual layer label 100 is removed from the surface X. For the Dual byer label 100. certain physical and/or chemical interactions occur between the different layers of the Dual layer label, and the surface to which the Dual layer label is applied, to cause the reveal of the "opened" message when the Dual layer label is removed from the surface. The principles behind the low residue OPENED message creation are essentially the same for the dual layer label 100. The difference is, on removal from the surface X, 100% of the adhesive 170 remains on the application sm-face X, and the dry peel layer 165 covers 100% of the adhesive 170 and also remains on the surface X. The separation which causes the "tampered" message to show occurs in the release layer 160. In particular.

part of the label 100 shown in Figure 7 (including the plastic film label 120) is designed to come away from the residue shown in Figure 6 (including the dry peel byer 165). The OPENED letters 130 release from the underside of the film 120 as per the Low Residue label 1, but, in contrast to the Low Residue label 1, the OPENED letters 130 remain attached to the dry peel layer 165 so they are visible as blue letters. In fact, if you looked at the residue from a dual layer label 100, i.e. everything shown in Figure 6, from above you would encounter, in order, the clear OPENED message ink 130, the blue flexo ink 150, the clear release layer 160, the dry peel layer 165 and finally the adhesive 170, which together give the appearance of blue OPENED characters 168. The bond strength of the OPENED message 130 to the film is less than the bond strength of the blue flexo ink 150 to the rdease layer 160, which is why it stays in place on the dry peelladhesive layer.

Certain physicd and/or chemical characteristics of the Dud layer label mean that the other layers of the Dual layer label 100 do not delaminate when thc "opcncd" mcssagc is rcvcalcd when the film 120 of the Dual layer label is removed from the dry peel layer 165 which remains on the surface X. The only other relevant bond is the blue flexo ink 150 to the film 120, and again, as per the low residue label I, it is strongly bonded after it has been corona or plasma treated 135.

Given the label 100 has only one ayer 150 of blue ink, it will be appreciated that Hue ink 168 visible on the residue once removed, has been removed from the film 120, as shown by clear areas 171 of the film 120.

The dual layer (high residue) label 100 is designed so that the inkjet identifier 140 leaves a residue on both the clear film 120 and the dry peel layer 165.

Surface printed tape Figure 1 shows the construction of a surface printed tape 200, and the physical colour (or appearance) of the surface printed tape 200.

In another embodiment of the invention, a surface printed tape 200 is a composite product made of multiple layers, and comprises, a silicone layer 205, a first colour flexographic printing ink 210, a first corona treatment 215, a clear film 220, a clear flexographic printing ink 230 of an "OPENED" message which denotes tampering (or message having equivalent effect), a second corona treatment 235, an inkjet identifier such as a number 240, a second flexographic colour printing ink 250, a release layer 260, a dry peel layer 265, and a hot melt adhesive 270.

The words "PARTIAL" or "FULL" denote the extent, or coverage, of the layer in question (as a proportion of the area of the label).

The silicone layer 205 of the surface printed tape 200 has the same effect as the release liner of the low residue labd I, in that the other layers come away from it easily.

The clear film 220 corresponds to clear film 20, and will not be described again for conciseness.

The clear flexographic printing ink of an "OPENED" message 230 corresponds to clear flexographic printing ink 30. and will not be described again for conciseness.

The corona treatment 235 corresponds to corona treatment 35, and will not be described again for conciseness.

The inkjet identifier such as a number 240 corresponds to identifier 40, and will not be S described again for conciseness.

The first flexographic colour printing ink 250 corresponds to first flexographic colour printing ink 50, and will not be described again for conciseness.

The hot melt adhesive 270 corresponds to hot melt adhesive 70, and will not be described again for conciseness.

The release layer 260 is a flexographically printed release layer, in which a standard high silicone release varnish is used. The release layer 260 corresponds to the release layer 160.

The dry peel layer 265 is a flexographicafly printed dry peel layer that leaves the surface dry to the touch, a standard dry peel release varnish is used. The dry peel layer 265 corresponds to the dry peel layer 165.

The tape 200 is typically wound in a reel, such that prior to use, the adhesive 270 of a piece of tape 200 should be detached from the silicon layer 205, and then the piece of tape should be cut from the reel.

In use, the surface printed tape 200 (i.e. parts 210 to 270) is then applied to a surface X of an object to be secured.

The surface printed tape 200 can be tampered with whilst it is applied to the surface X of an object to be secured. Figure 9 shows attempted removal of the surface printed tape 200 from the surface X. The part of the surface printed tape 200 shown in Figure 11 (including the plastic film label 220) is designed to come away from the residue shown in Figure 10 (including the dry peel layer 265).

Certain physical and/or chemical characteristics between the different layers of the surface printed tape 200, and the surface X to which the surface printed tape is applied, cause the reveal of the "opened" message 230 when the surface printed tape is removed from the surface. Simply put, the tape 200 is exactly the same as the dual layer label 100 underneath, except the dual layer label 100 has a rdease liner 180. Mso, the surface printed tape 200 has two differences above the film 220 that differ from the dual layer label 100. The first difference is the surface white flexo printed partial image 210 onto the corona treated surface 215 of the film 220. This gives greater visual contrast to the OPENED message 230. The second difference is silicone layer 205 stops the adhesive 270 sticking to the upper surface of the tape 200, and performs the function of a glassine liner, but without the cost of the paper liner. In other words, the entire content of the surface printed tape 200 maintains its integrity when the surface printed tape is removed from the reel.

The physical andlor chemical characteristics of the surface printed tape 200 that mean that the other layers of the surface printed tape do not delaminate when the "opened" message is revealed when the surface printed tape is removed from the surface are the same as for dual layer label 100.

An advantage of the invention is that the UV resistant additive in the hot melt adhesive 70 reduces degradation of the hot melt applied UV adhesive in the translucent areas of the label or tape. Hence a label 1, 100 in accordance with the invention or a tape 200 in accordance with the invention can have a longer lifespan particularly in outside use.

It will be apparent to the reader from the description and drawthgs that certain parts shown in series in Figure 1 are in fact in parallel. e.g. the inkjet identifier 40 and the second flexographic colour printing ink 50.

Claims

CLAIMS1. A tamper evident label comprising a translucent film, the translucent film comprising an inked tampering message applied thereto, the translucent film and tampering message being corona treated, the tamper evident label comprising ink applied to the corona treated translucent film, the translucent film comprising a non inked trans'ucent area, the tamper evident label comprising a hot melt applied adhesive applied to the corona treated and inked translucent film, the tamper evident label being designed so that peeling of the film from a surface to which the adhesive of the label is applied causes the tampering message to be revealed, wherein the hot melt applied adhesive comprises a UV resistant additive which reduces degradation of the hot melt applied adhesive in the translucent areas of the label.
2. A tamper evident tape comprising a translucent film, the translucent film comprising an inked tampering message applied thereto, the translucent film and tampering message being corona treated, the tamper evident tape comprising ink applied to the corona treated translucent film, the trans'ucent film comprising a non inked translucent area, the tamper evident label comprising a hot melt applied adhesive applied to the corona treated and inked translucent film, the tamper evident label being designed so that peeling of the film from a surface to which the adhesive of the label is applied causes the tampering message to be revealed, wherein the hot melt applied adhesive comprises a UV resistant additive which reduces degradation of the hot melt applied adhesive in the translucent areas of the tape.
3. A tamper evident label substantially as described herein andlor with reference to the one or more of Figures Ito 3 of the accompanying drawings.
4. A tamper evident label substantially as described herein and/or with reference to the one or more of Figures 1 and 4 to 7 of the accompanying drawings.
5. A tamper evident tape substantially as described herein andlor with reference to the one or more of Figures I and S to II of the accompanying drawings.
6. A method of making a tamper evident label substantially as described herein and/or with reference to one or more of Figures 1 to 3 of the accompanying drawings.
7. A method of making a tamper evident label substantially as described herein and/or with reference to one or more of Figures 1 and 4 to 7 of the accompanying drawings.
8. A method of making a tamper evident tape substantially as described herein and/or with reference to one or more of Figures 1 and 8 to ii of the accompanying drawings.
9. A tamper evident label or tape comprising a translucent film, and a hot melt applied adhesive applied to the translucent film, the tamper evident label or tape comprises a UV resistant additive which reduces degradation of the hot mcli applied adhesive in the translucent areas of the label.