The invention relates to converted labelstock and to a method of converting labels, and in particular to two-sided labelstock in which adhesive labels are releasably attached to both sides of a release liner.

Background

Labels are applied to products to provide identification, product information and branding. Product owners seek efficient and effective ways to apply labels and to reduce material usage and waste. Pressure sensitive labels are an effective way to achieve these objectives and can be applied at high speed.

Traditional high speed labelling commonly known in the art, utilises machines to apply labels to articles advanced to the labelling station on a conveyor belt or other means of carriage. The pressure sensitive labels are pre-cut and adhesively attached to one or both sides of a roll of siliconised release liner.

The label separates from the release liner as the release liner moves over a return which has an acute angle commonly known in the art as a "beak". This separation occurs because the stiffness of the label is greater than the release force adhering the label to the release liner. In this way the label is presented to the article to be labelled with its adhesive surface exposed.

Converting labels (the process of printing, die cutting and matrix stripping the waste) from conventional labelstock which consists of a label adhesively adhered to the siliconised face of a one side siliconised release liner is known to those skilled in the art. Certain technical challenges remain for those wishing to convert labels on both sides of a two side siliconised release liner and ensure that they can be released at the correct time and presented in a suitable way for the product being labelled depending upon the process flow used. Statements of Invention

In accordance with a first aspect, the invention provides converted labelstock comprising a release liner and a plurality of adhesive labels releasably attached to both sides of the release liner, wherein the labels on opposite sides of the release liner are paired with each label in the pair having substantially the same outline shape, and wherein one label of the pair is smaller than the other label of the pair and lies wholly within the periphery of the larger label.

By ensuring that the outer edges of each label in the pair are not coterminous, when the individual labels are being cut into the labelstock (e.g. by die cutting or laser cutting), the chance of cutting into the release liner from both sides at the same point is avoided. This is referred to as die strike or laser burn-through. When die cutting is employed, the invention provides improved counter pressure compared to die cutting coterminous labels. In at least its preferred embodiments, the invention provides increased reliability of the labelstock since the release liner is less prone to failure. Label dispensing is also improved.

Preferably, the labels in each pair are centred on the same point of the release liner.

The difference in size between the labels is not critical other than the requirement to avoid die strike or burn-through. Preferably, the larger label of the pair is at least 0.7mm larger around its periphery than the smaller label of the pair. The larger label of the pair may be between 0.7mm and 10mm larger or between 0.7mm and 5mm larger around its periphery than the smaller label of the pair. A difference of about 3mm has provided good results. In preferred embodiments, the liner is a siliconised release liner. As mentioned above, the labels of the converted labelstock may be die cut or they may be are laser cut.

The larger and smaller labels may alternate on each side, which will provide the most efficient use of the space on the release liner, but such an arrangement could complicate the label application stage since label size will alternate. Preferably therefore the larger labels of each pair are on the same side of the release liner. The converted labelstock may be wound into a roll such that the larger labels are on the outside or the inside of the roll, depending on application requirements.

In accordance with a second aspect, the invention provides a method of applying labels to objects, comprising the steps of: supplying converted labelstock in accordance with the first aspect above to a first labelling station such that the larger labels are presented for application; applying the larger labels sequentially to objects; supplying the converted labelstock with the larger labels removed to a second labelling station such that the smaller labels are presented for application; and applying the smaller labels sequentially to objects. The method of the second aspect may further comprise the step of winding the converted labelstock with the larger labels removed into a roll prior to supplying the converted labelstock with the larger labels removed to a second labelling station.

Having labels of different sizes on each side creates a problem associated with the detection of the leading edge of the label. The detectors are optical or thickness detectors and if the smaller label is dispensed first, there is a danger that the detector will "see" the larger label and index the roll forward by the set amount based on that input. Therefore it is preferable that the larger label is dispensed first so that the detector and labeller always work to the same indexing position whether dispensing the larger or smaller label. The relationship of the leading edges of the labels on one side and the other should therefore always be based on the larger label being the first label to be dispensed.

In accordance with a third aspect, the invention provides a method of converting labels comprising the steps of: providing a release liner with adhesive labelstock releasably attached to both sides of the release liner, cutting labels into the adhesive labelstock on each side of the liner in pairs, with each label in the pair having substantially the same outline shape, wherein one label of the pair is smaller than the other label of the pair and lies wholly within the periphery of the larger label, and removing the waste adhesive labelstock matrix from each side of the liner to form converted labelstock.

In a preferred embodiment, the labels in each pair are centred on the same point of the release liner.

The difference in size between the labels is not critical other than the requirement to avoid die strike or burn-through. Preferably, the larger label of the pair is at least 0.7mm larger around its periphery than the smaller label of the pair. The larger label of the pair may be between 0.7mm and 10mm larger or between 0.7mm and 5mm larger around its periphery than the smaller label of the pair. A difference of about 3mm has provided good results.

In preferred embodiments, the liner is a siliconised release liner. The labels of the converted labelstock may be die cut or they may be are laser cut. The larger and smaller labels may alternate on each side, which will provide the most efficient use of the space on the release liner, but such an arrangement could complicate the label application stage since label size will alternate. Preferably therefore the larger labels of each pair are on the same side of the release liner. The converted labelstock may be wound into a roll such that the larger labels are on the outside or the inside of the roll, depending on application requirements.

In general, the methods of the invention may include the step of printing the surface or surfaces of the facestock or leaving them blank. If converting with multiple die cuts across the roll width, the method may include the step of slitting the roll into individual rolls.

The cutting of the two dies through the facestock on each side of a two side siliconised release line achieved by this invention produces a label on each side of a two side siliconised release liner which are centred on the same position but of marginally different sizes. By this means the labels are also more efficiently dispensed, causing less problems during labelling and any die strike or laser burn through is not in the same position on both sides and the release liner is less likely to be critically damaged.

At least in preferred embodiments, the invention provides a method of printing labels to each side of the release liner so they are presented in the correct manner for the application method used. When printing labels, the end customer, depending upon the setup of their labeller will specify to the converter one of the following winding patterns: head leading, bottom edge leading, right side leading or left side leading and whether they should be inside or outside wound. See Fig. 1.

When labels are on both sides of the release liner, then both sides have to be specified in relationship to each other. This will depend upon the setup of the labelling head or heads.

If the labels are dispensed from one side and then after rewinding, from the second and the first labelling head has labels specified as head leading inside wound, then the rewind will wind the roll in the reverse manner and mean that the rewound roll from the first labelling head, if transferred to the second will be bottom edge leading inside or outside wound (depending on rewind rotation direction). If the first labelling head requires head leading labels then the second will require head leading labels as well when labelling the same product, whether the labels on each side are the same design or different designs. It is therefore a requirement for the second side to be specified as bottom edge leading to be presented in the correct manner. Likewise if the first side is right edge leading then the second side needs to be left edge leading for a system where labels are dispensed from one side and then after rewinding, from the second and if they are to be used without rewinding the roll between the labelling heads. If the labelling heads are tandem and the roll is presented to the first labelling head and then turned and presented to the second labelling head in one pass then the labels should be printed on both sides with the same edge or side leading in a conventional manner.

Detailed Description Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Fig. 1 is a diagram illustrating head leading, bottom edge leading, right side leading and left side leading for both inside and outside wound labels;

Fig. 2 is a schematic diagram of the presentation and application of two side labels from a two side siliconised release liner using a standard beak in a double pass;

Fig. 3 is a schematic diagram of the presentation and application of two side labels from a two side siliconised release liner using a standard beak in a single pass;

Fig. 4 is a schematic diagram showing the positioning of a label on one side of the two side siliconised release liner relative to the position on the opposite side; and Fig. 5 is a schematic diagram showing sequential flat bed or rotary die cutting.

Various embodiments, versions and examples of a process of manufacturing and applying labels will be described. Definitions that are adopted herein for purposes of understanding the claimed invention are also provided.

"Labelstock" as a term used herein, is defined as a roll of material consisting of a multi-layer laminate suitable for self-adhesive labelling applications. The two-sided labelstock of the current invention consists of a release liner with a first side and a second side, a first pressure sensitive adhesive layer positioned adjacent to the first side of the release liner and a first facestock layer positioned adjacent to the first adhesive layer and a second pressure sensitive adhesive layer positioned adjacent to the second side of the release liner with a second facestock layer positioned adjacent to the second adhesive layer. "Facestock" as a term used herein, is defined as the printable layer located on each of the outward facing sides of the two-sided labelstock, defined above. According to the present invention, each facestock layer may itself comprise a single or multiple layers. The facestock is die-cut to a specified size and shape to form the labels. "Matrix waste" as a term used herein, is defined as the unprinted portion of the facestock and the pressure sensitive adhesive layer that does not form part of the labels following die-cutting, it is also known in the art as the "skeletal waste". The matrix waste is removed from both sides of the two- sided labelstock surfaces and discarded prior to rewind of the finished rolls and their subsequent application of the labels to the articles. "Corresponding" labels as a term used herein, are defined as the two opposing labels, one on the first side of the release liner and one on the opposite side of the release liner.

"Polymer" as a term used herein, can refer to homopolymers, copolymers, interpolymers, terpolymers, etc.

This application details a process for manufacturing and applying labels to articles utilising high speed labelling machines where those labels have been manufactured from a single side labelstock with pressure sensitive adhesive facestock releasably adhered to one side of a release liner or a two- sided labelstock comprising a release liner with pressure sensitive adhesive facestock releasably adhered to both sides.

Labelstock Labelstock comprises a web of siliconised release liner material upon which pressure sensitive adhesive coated facestock is releasably adhered. Converted labelstock with pressure sensitive adhesive labels releasably adhered to one side of the continuous siliconised web is commonly used in high speed labelling machine applications.

Two-sided labelstock comprises at least five distinct layers, including the release liner, a first pressure sensitive adhesive layer positioned adjacent to the first side of the release liner and a first facestock layer positioned adjacent to the first adhesive layer, a second pressure sensitive adhesive layer positioned adjacent to the second side of the release liner and a second facestock layer positioned adjacent to the second adhesive layer.

The release liner provides the medium for conveyance of the labels to the labelling machine. The release liner comprises a core layer with a coated layer on one side for standard labelstock and a coated layer on both sides for two-sided labelstock. The core may be any conventional flexible material known to those in the art and may be comprised of either single or multiple layers. The core may be a single-layer or multi-layer substrate selected from the following: glassine, paper, poly-coated paper, oriented or cast polymers of polypropylene, polyethylene, polyethylene terephthalate, polyamide, polystyrene and the like. The coating layers of the release liner are characterised by low tack and permit the easy release of pressure sensitive adhesive labels thereto applied. The release properties of the coating layers ensure that the adhesive remains with the facestock when it or the labels cut from the facestock are removed from it. The coating layers may include a release agent selected from the group consisting of silicone, polyethylene, polypropylene, fluorocarbons and blends thereof. This coating may be cured by a number of technologies such as thermal, UV, E beam or other methods known to those in the art.

The pressure sensitive adhesive bonds relatively weakly to the release liner and relatively strongly to the facestock. This allows removal of the pressure sensitive adhesive labels by a high speed labelling machine for application to the articles. The pressure sensitive adhesive may be selected from: hot melt adhesives, water-based adhesives, solvent-based adhesives and rubber-based adhesives in preferred embodiments of this invention.

The facestock layers may be single-layer or multi-layer products selected from: paper, metal foils, oriented or cast polymers of polypropylene, polyethylene, polyethylene terephthalate, polystyrene and the like. The two sided labelstock structure can be printed on both sides simultaneously in register using a suitable method for determining position and maintaining control of the image. A device for printing such a structure in such a manner is the Landa W50 Nanographic Printing Press.

The two-sided labelstock structure will typically be die-cut on both sides after printing with precision such that only the facestock layers and pressure sensitive adhesive layers are cut into a specified size and shape, to form pressure sensitive adhesive labels and without damaging the release liner. This may be achieved simultaneously with the dies on each side providing the anvil to each other. In alternative arrangements the labels are cut through with the use of a laser or lasers which cut through the facestock and adhesive layers but leave the release liner layer undamaged. In another arrangement, the facestock on each side may be die-cut sequentially, one side followed by the opposite side. After cutting, the redundant facestock material surrounding the pressure sensitive adhesive labels on both sides of the two-sided labelstock, commonly known in the art as matrix or skeletal waste, is stripped away leaving the pressure sensitive adhesive labels releasably adhered to both sides of the two side siliconised release liner. The skeletal waste is discarded after removal. The release liner with labels on both sides is then wound into a roll which can be mounted on a high speed labelling machine ready for application of said labels.

Articles to be Labelled

The invention can be used for the application of pressure sensitive adhesive labels from one or both sides of a siliconised release liner by a high speed labelling machine to a variety of articles including, but not limited to: bottles, jars, boxes, trays, cartons, books, magazines, food, electrical, mechanical, computer, gardening, sports and leisure equipment, building products, CDs, stationery, office products, furniture, furnishings, decorative products, plants, cleaning and washing products, health and beauty care products, clothing, automotive, aerospace and shipping parts and products, mechanical and machine parts, tools, toys, hobby products, and packaging materials. Double Pass Embodiment

A schematic view of a double pass embodiment of the method for labelling articles is shown in Fig 2. In this embodiment, the method comprises the use of a roll 200 of labels, comprising a plurality of labels 201, 202 adhesively adhered to both sides of a two side siliconised release liner 203, mounted on an offwind 10 which is able to rotate on a high speed labelling machine. The continuous release liner web 203 with labels 201, 202 adhesively applied to both sides is pulled through the high speed labelling machine by a powered rewind 20 and correct tension maintained through a braking device and dancing rollers 30. As the release liner moves over a beak 40 the stiffness of the label on the outside breaks adhesion with the release liner which is pulled away at an acute angle. The label 204 is presented to the articles A to be labelled which move in a direction D at an angle (e.g. tangentially, perpendicularly or at an angle between zero and 180 degrees) relative to the direction of travel of the presented label 204 before attachment. The label may be subsequently brushed down to ensure full adhesion and that there are no trapped air bubbles. The labels 202 which were on the inside remain adhered to the release liner 203 and move round the beak 40 and are rewound into a roll 205. In this embodiment the beak 40 should be sufficiently blunt so as to avoid damaging the second side pressure sensitive adhesive labels as they pass around the end of the beak.

Typically, the articles A to be labelled move past the applicator on some form of conveyor or other handling device (not shown), that moves them past the beak 40 and as in the standard system a control mechanism ensures one label is presented to each article, unless a double application is required. The roll 205 of rewound labels now adhesively adhered to only one side of the two side siliconised release liner 203 is removed from the rewind 20 of the label machine and mounted once again on the offwind 10 for the labels 202 on the second side to be applied to articles (i.e. the second pass).

The main advantage of the double pass embodiment is that existing high speed labelling machines can be adapted for use with two-sided labels on a two side siliconised release liner with little modification except to the tension control on the rewind side, to ensure the roll of labels will be wound properly (not shown) and an edge guide to ensure the roll is nicely presented to the second offwind when transferred. This could be achieved by pulling the release liner with labels still adhered to the second side through incident contra rotating rollers on each side of the release liner with a suitable tension control and a powered rewind working in unison. In this manner a well wound roll on the rewind may be achieved, which can then be reloaded for application of labels from the second side. As will be apparent to persons skilled in the art, the double pass embodiment could be used with other types of high speed labelling machines that utilize other label dispensing means (e.g. a lay-on roller).

Single Pass Embodiment A single pass embodiment for labelling articles is shown in FIG. 3. In this embodiment, the method comprises the use of a roll 300 of labels , comprising a plurality of labels 301, 302 adhesively adhered to both sides of a two-side-siliconised release liner 303 mounted on an offwind 10 which is able to rotate on a high speed labelling machine. The continuous release liner web 303 with labels 301,302 adhesively applied to both sides is pulled through the high speed labelling machine by a powered rewind 20 and correct tension maintained through a braking device and dancing rollers 30. As the release liner moves over the first beak 40 the stiffness of the label on the outside breaks adhesion with the release liner 303 which is pulled away at an acute angle. The label 304 is presented to the articles Al to be labelled which move in a direction Dl at an angle (e.g.

tangentially, perpendicularly or at an angle between zero and 180 degrees) relative to the direction of travel of the presented label 304 before attachment. The label may be subsequently brushed down to ensure full adhesion and that there are no trapped air bubbles. The labels 302 which were on the inside remain adhered to the release liner 303 and move round the beak 40. In this embodiment the first beak 40 should be sufficiently blunt so as to avoid damaging the second side pressure sensitive adhesive labels 302 as they pass around the end of the beak.

Typically, the articles to be labelled move past the applicator on some form of conveyor or other handling device (not shown), that moves them past the beak and as in the standard system, a control mechanism ensures one label is presented to each article, unless a double label application is required.

After passing around the first beak 40, the release liner 303 now with adhesive labels 302 adhered to only one side proceeds toward a second beak 41. As before, the stiffness of the label on the outside breaks adhesion with the release liner which is pulled away at an acute angle. The label 305 is presented to the articles A2 to be labelled which move in a direction D2 at an angle (e.g.

tangentially, perpendicularly or at an angle between zero and 180 degrees) relative to the direction of travel of the presented label 305 before attachment. These articles A2 may be the same articles as presented to the first labelling station or they may be different, and the label 305 may be the same type of label 304 as was presented at the first labelling station or it may be different. The label may be subsequently brushed down to ensure full adhesion and that there are no trapped air bubbles. As before the articles A2 are presented to the second labelling station by a conveyor or other handling device (not shown).

In a variation of this embodiment there may be a turning bar between the two labelling stations so that the labels are presented on the same side and a split conveyor or separate product streams are not required. In this variation each labelling head can label alternate bottles or label the front and the back sequentially with different labels if the bottles are also turned between the label heads.

At the end of the process the release liner 303 then moves towards a rewind 20 where it is rewound into a roll 306 for later disposal. Alternatively it may be shredded, spooled onto the floor or other surface, directed into a bin or other waste receptacle, or otherwise disposed without rewinding. Fig. 4 is a schematic diagram showing the positioning of labels on one side of the two side siliconised release liner relative to the position of labels on the opposite side. Larger labels 401 are shown on the front side and smaller labels 402 are shown in dashed outline on the reverse side of release liner 403. In this embodiment, the labels of each pair (401a and 402a, 401b and 402b, etc.) are centred on the same point of the release liner 403. Fig. 5 is a schematic diagram showing sequential flat bed or rotary die cutting. Die blade or laser cutter 510 cuts labels 501 into the facestock 504 on the top side of release liner 503 and die blade or laser cutter 511 cuts labels 502 into the facestock 505 on the underside of release liner 503. The die blades or laser cutters 510 and 511 are sequential and not located at the same point of the process. As can be seen from Fig. 5, the cut lines are offset from one another and do not coincide.

Throughout the specification, the term "having substantially the same shape" is intended to mean that the labels in each pair do not have different shapes completely, but, other than the relative difference in size, have the same outline shape. At least in preferred embodiments, the labels in each pair are uniformly smaller or larger around the periphery such that their outer edges are not coterminous at any point.

It will be clear to the skilled person reading the specification that the viewpoint when considering the labels in each pair is from a direction orthogonal to the plane of the release liner, as in Fig. 4.. Variations

In other embodiments of this invention, one pressure sensitive adhesive label from the first side of the release liner can be applied to an article at the first labelling station and one pressure sensitive adhesive label from the second side of the release liner can be applied to an article at the second labelling station. Utilising this invention the same roll of labels can have any variation of labels on each side of the two side siliconised release liner and these can be applied in any combination to articles and even on top of each other in a piggyback type arrangement where the surface of the label has been suitably treated or where the adhesive is of a non-permanent type to ensure one label can be peeled from the other. In this manner front and back and piggyback labels or combinations can applied from the same roll at one or other labelling station to the same or different articles.