METHOD OF MAKING A DUAL LABEL WEB This invention relates to a method for making a dual image web and related products. In this specification and the claims references to"web"are to be interpreted as covering not only relatively long lengths of web-like material but also web portions in the sense of discrete lengths of sheet material, such as may be produced by cutting a web into desired lengths.

An example of a dual image web is a label web which is intended for use in relation to products having a transparent or translucent surface whereby, when the label is in-place, not only the image on the usual outer label surface can be observed, but also a second image which is provided on the adhesive surface can be observed on the reverse side through the transparent or translucent material of the product. Examples of the use of such dual image webs include webs for use in relation to bottled products, together with window stickers and the like.

Problems which arise in relation to the presently available method for manufacturing dual image labels include the following. Firstly, the method is complex. It involves the delamination of the basic label web material which is used as a basis for all normal label production. Such basic label stock comprises a backing web coated on at least one surface with a release material such as silicone, and a label web having adhesive on one face and that adhesive face is releasably secured to the backing web. Versatile in-line web-making and printing presses of the kind available from the present applicants are capable of fabricating and printing a wide variety of multi-element web constructions if so wished. However, regardless of such versatility, many users of such presses have available to them an economical supply of basic label stock and thus may well wish to use same.

In order to print the two images on the label web, currently available methods adopt the inevitable approach of delaminating the siliconised backing web from the face label web and printing the first image on the upper (outer face) surface of the label web and then the second image on the adhesive (reverse) surface itself, and then relaminating the two webs together again. Alternatively, these printing steps can be in the reverse order.

Thus, not only is there the need for delaminating/relaminating steps but also the need to make the necessary technical arrangements whereby satisfactory printing is effected on the adhesive surface itself.

A further factor which makes the existing technique relatively unsatisfactory concerns the dynamic factors arising from web delamination. These concern maintenance of consistent and constant and equal dynamic factors in both portions of the delaminated web since otherwise the maintenance of the proper relationship between the two web portions (which has hitherto been ensured by their adhesive contact) is not assured. In such circumstances when the web is re-laminated there can be difficulties arising from the effect of the differences in the dynamic factors.

A still further factor relating to the existing known technique for producing dual image labels relates to the lack of clarity of the image which has to be printed on the adhesive, due to the effect of the adhesive itself on the image which is printed onto it. Clearly some improvement in this regard is needed and yet unless the image is printed before the adhesive is applied (which is out of the question where a production facility uses standard adhesive label stock for reasons of economy) it is difficult to see how this negative effect of the presence of the adhesive can be eliminated.

Accordingly, an object of the present invention is to provide a means whereby improvements in relation to one or more of the above shortcomings of previous methods are provided, or improvements generally.

According to the invention there is provided a method as defined in the accompanying claims.

In an embodiment, there is provided a method of making a dual image web for adhesive application to a product or article. Typically, such a product will comprise a bottle for a liquid material, but other products include windows and other transparent or translucent surfaces. The web is of the kind in which, in use, a first printed image is visible upon inspection of one face of the web (usually through a transparent or translucent portion of a product to which the web is applied), and a second of these partially different printed image is visible upon inspection of the other face of the web.

In the embodiment, the method comprises the steps of taking a web of transparent web material to carry the dual printed images. The web comprises a continuous length of transparent substrate laminated to a backing or carrier material which may be either siliconised paper or film.

The above-mentioned one face of the web material is coated with an adhesive for adhesive interaction with a product to which the web is to be applied. In this embodiment, this adhesively-coated face has adhesively secured thereto a backing web comprising a layer of release material which permits peelable removal of the backing web from the adhesive, ready for application of the label to a suitable product.

Turning to the steps of printing the first and second images on the face of the web, one of these images is printed on the above-mentioned"other"face of the web (which is the non-adhesively-coated face), and the second printed image is then printed on the same"other"face of

the web in at least partially overlapping positional. relationship with the first image, or indeed totally covering the first image. A barrier or blocking coating or layer may be printed on top of the first printing image and before the second image is printed. The web itself is at least partially transparent or translucent whereby the first of the images above-mentioned is visible through the web when the web is viewed from its adhesively-coated side (usually through a transparent or translucent product).

This first image is printed (on the non-adhesive surface of the web) in laterally-inverted format with respect to the image thereof to be viewed, due to the optical inversion effect of the printing of this image on the opposite surface of the web from that surface (which carries the adhesive) through which it is observed.

Thus, the embodiment of the invention provides a method whereby two simple printing steps on the same accessible and non-adhesively coated surface of the web enable a dual image effect to be created. The technical difficulties inherent in the method are relatively minor since all that is required is to print the two identical or differing images in generally superimposed relationship by printing steps carried out in sequence and with the first of the images being suitably laterally inverted.

In practice, optical image separation enhancement means may desirably be provided between the first and second printed images, and such means may be printed between the steps of printing the first and second images, such printing typically being of a blocking layer.

In a further embodiment described below a method of making a dual image web comprises printing the same side of the label web twice in such a way that the first image can be viewed on one side and the second image can be viewed on the other side. In this way, two (or three with the blocking layer) straightforward printing steps on the same

side of the web, which is the opposite side from the adhesive face, enable the production of a dual image web which has hitherto been the subject of all the disadvantages described in some detail above. It is noteworthy that the method of the embodiments can be carried out by relatively standard printing apparatus since none of the steps of the present invention is particularly difficult (to the technically competent person) to carry out. Indeed, it is illustrative of the unexpected nature of the technical advance provided by the embodiments of the invention that such an advance could have been achieved by the technically competent person using available materials and apparatus without significant difficulty if such a step could have been readily thought of.

In the embodiment, means is provided for separating the successively printed images, and such means is provided by an intermediate printing stage or step in which a blocking image or surface is printed between the images to be viewed on the opposite sides of the web. Usually such blocking image or surface is a uniform separating surface colour which forms a background for both of the images which are to be viewed from opposite sides of the web.

It will be understood that the web itself lies between the first printed image and the viewer, when that first printed image is viewed. Therefore, at that point, the web needs to be at least translucent and preferably transparent. Accordingly, in most cases, the method of the invention is carried out with a web comprising a transparent film substrate.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which.

Fig 1 shows a flow diagram illustrating the prior art method discussed above ; Fig 2 shows a flow diagram illustrating the method of

the invention; Fig 3 shows an elevation view of a printing press adapted to carry out the method of the invention; Fig 4 shows diagrammatically a section through a printed dual image web made in accordance with an embodiment of the method of the invention, with the web being shown adhered to a backing web which is to be peeled- away ; and Fig 5 shows a corresponding diagrammatic representation of the dual image web of Fig 4 subsequently adhered to a transparent or translucent product, and illustrating the positional relationships of the printed images with the web and the adhesive layer and the product to which the web is adhered.

As shown in Fig 1, the prior art method commences, as does the method of invention with the usual label stock material comprising a laminated assembly of a label web and a backing web. The label web is adhesively coated on one face and the backing web is release-material-coated (for example) on the corresponding surface at least. The laminar assembly is delaminated and then printed on the adhesive side of the label web. This is the first image.

Then, the label web is printed on its other face surface. This is the second image. The label web and the backing web are then relaminated.

In the method of the invention, the commencing label stock material comprises a transparent label web and the usual backing web.

As shown in Fig 2, the method comprises the three printing steps of producing the first image, the blocking image or surface, and the second image. These steps are carried out successively on the same web surface to produce the required dual image effect.

The press 10 employed for carrying out the method is illustrated at 10 in Fig 3 and comprises functional zones

identifiable as unwind zone 12, first printing zone 14, second printing zone 16, die-cutting zone 18, waste rewind zone 20 and product rewind zone 22.

As shown, the web 24 proceeds from unwind drum 26 through four banks each of three printing stations in printing zones 14 and 16 and onwards through die cutting zone 18 and waste rewind zone 20 to the product rewind roll 22.

Printing of the dual images on the same side of the label web is effected in multiple colours together with the intermediate blocking layer within first and second printing zones 14 and 16, in sequence.

Turning now to the structures shown in Figs 4 and 5, these show a dual image web 100 for adhesive application to a product 102. Web 100 is of the kind in which, in use, a first printed image 104 (identified in Figs 4 and 5 by the reference symbols 1) is visible upon inspection of one face 106 of the web (usually through a transparent or translucent portion of product 102), and a second different or identical printed image 108 (identified in Figs 4 and 5 by reference symbols 2) is visible upon inspection of the other face 110 of the web.

In the method of making the web 100 with its dual images 104 and 108, a web of transparent label material 112 carries the dual printed images 104 and 108 and provides the faces 106 and 110 of dual image web 100, for viewing of the dual images. The material of web 112, is transparent or translucent. The material of web or band 112 is transparent or translucent.

Face 106 of band 112 is coated with an adhesive layer 114 (identified by reference symbols X) for adhesive interaction with a surface of any suitable product to which the web is to be adhered. In the case of a label web, the product will be any product to which such a label may be applied such as glass and plastics made from transparent

and translucent materials. Adhesives for this purpose are well known in the art.

Secured to the face 106 of the web is a backing web 116 comprising a layer 118 of siliconised release material (identified by symbol R) permitting peelable removal of the backing web 116 from the adhesive 114 of the web for application of the web to any suitable product.

Turning now to the method of producing the dual image on the web 100, the images 104 and 108 are printed in sequence so as to be visible from opposite sides of the web. Thus, as the web 100 passes through the printing press, the first image 104 is printed on the surface face 100 of the web. This image may of course comprise a multi- colour image of which the colour components are printed at multiple printing stations in sequence. Then, when the first image 104 has been printed, there is next printed a blocking layer 122 (identified in Figs 4 and 5 by the reference symbol B). The blocking layer is printed, usually in either a single or double colour, at a further station in the printing press. The blocking layer 122 is the same size or large- than the first image 104. The blocking layer serves to optically separate the first 104 and second 108 printed images, as will be explained more fully below.

Then, the second printed image 108 is printed on top of the blocking layer 122 and thus on the same side of web 100 and on the same face 110 as the first image 104. The second image totally covers the first image in terms of the positional locations of these images. Moreover, not only do the images cover each other but the images are in a defined optical relationship to each other. This optical relationship -s given by the following statement. The first image 1C4 is printed in laterally-inverted form with respect to the image thereof to be viewed. Thus, in the case where the first and second images 104 and 108 are similar to each other (though often they will be totally

different), then in this case these images are in laterally-inverted optical relationship. This arises from the fact that image 104 is printed on the same face 110 of as second image 108, but is viewed from the opposite side ie through the transparent product 102.

It can now be seen that the above printing stages enable the dual image to be produced in a simple manner by three sequential printing steps carried on the same face of the web.

Blocking layer 122 provides optical image separation enhancement between the first and second images 104 and 108. As an alternative to a printed blocking layer it is also possible to apply a laminated coloured filmic substrate.

The method of the invention is applicable, in its principal commercial use to the printing of dual-sided labels, but the method of the invention is more generally applicable to other products in which a need for different images on opposite sides of a product to be viewed.

In a modification, the first and second printed images do not overlap. In this modification, the dual image label is intended for application to a product such as a transparent bottle. The outermost image 108 in the above embodiments is located so as to be at the front of the bottle to identify it, and the inner image 104 is located at the back of the bottle so as to be visible through the glass or plastic of the bottle and any liquid therein from above or below the front portion of the label. The non- overlapping relationship of the images (or there may be partial overlapping, depending on the actual lengths of the two images) does not detract from the advantages provided by this embodiment of the invention since the prior art approach to the production of such a lable would still involve printing on the adhesive portion of the label and delaminating it etc.