The present invention relates to the field of labels, specifically labels comprising an embossed substrate and a wet glue.

Wet glue labels are well known in the art, particularly in fields such as food and beverage container labelling. This type of label generally comprises a substrate, which is often paper, to which a water-based adhesive has to be applied before the label can be applied to an article. Once the water-based adhesive, i.e. the wet glue, has been applied to the substrate, it is put in contact with an article. The substrate generally absorbs the water from the wet glue, which gives the first tack in sticking of the glue and which can cause expanding of the fibres in the substrate. The water may then be allowed to evaporate, thereby adhering the substrate to the article. Generally, evaporation takes place at least partly through the substrate, which is a water-permeable substrate, such as paper. However, not all substrates (including paper labels) have good water evaporation through the substrate. For example, many labels for mainly one way bottles (for example wine or spirits) include varnishes, which are not so penetrable.

This method of labelling provides a quick and easy way in which to adhere labels to an article. In a production line, the rate of labelling can reach up to 80,000 articles per hour.

Various techniques are being used with wet glue labels to affect the appearance of the labels, in order to capture the attention of the intended audience. This is particularly important in the alcoholic beverages industries, such as that for beer, wine or spirits, which are highly competitive. One such technique is embossing, which involves creating a raised pattern on the substrate.

Embossing a substrate and methods for doing so are well known in the art. For example, AU2010257300 discloses the application of glue to an embossed region of a web product, as the embossing is used to create a surface to which glue can be applied without coating the entire surface. US2009226670 also discloses the application of glue to the peaks of the embossed areas in a product such as toilet paper.

However, it has been found that the application of a wet glue to an embossed label, particularly those including cellulose fibre based substrates such as paper, in an amount sufficient to adhere the label to an article can cause the embossed structure to be broken down. This may be due to the change in shape and resulting distortion within the substrate that occurs as the substrate, particularly the fibres, absorbs the moisture from the wet glue. Labels that can be used with a wet glue and that can have an embossed structure are therefore required.

JP1 1241299 is in the neighbouring field of wallpapers used with a wet glue and discusses the application of a wet glue to an embossed wallpaper sheet substrate. In order to protect the embossed substrate, a waterproof adhesive is applied to the substrate and a backing layer is then applied to the waterproof adhesive. The wet glue is coated on the backing layer and the waterproof adhesive layer prevents the moisture reaching the embossed substrate. This therefore maintains the embossed region of the substrate as the moisture in the wet glue cannot reach the substrate and thereby cause any change of shape.

FR2787062 also discusses the problem of maintaining an embossed structure in a substrate of a decorative article. In order to maintain the embossed structure, the embossed area is filled with a thick, hard glue to maintain its shape. The glue may include fillers to ensure it hardens sufficiently.

Both of these methods increase the time and cost involved in producing a label before it is adhered to an article. For high-throughput processes such as bottle labelling, this can make a huge difference and can significantly reduce the number of finished articles created, as well as increasing the cost of each article. A cheap and fast alternative is therefore required.

According to a first aspect of the present invention, there is provided a label comprising an embossed substrate and a wet glue, wherein the wet glue is applied directly onto the back of the substrate and wherein the wet glue is prevented from contacting the embossed regions of the substrate.

It has surprisingly been found that preventing the wet glue from contacting the embossed regions of the substrate, even though the wet glue is in contact with the rest of the substrate, helps to maintain the embossed structure. This is thought to be because the moisture present in the wet glue has sufficiently less of an effect on the shape of the substrate in the embossed region to allow it to maintain its shape.

As used herein, "directly" applying the wet glue to the substrate means that there are no intermediate layers between the wet glue and at least part of the substrate. As used herein, an "embossed" substrate is one on which a raised pattern or region has been formed by deforming the substrate itself. Methods of embossing a substrate are well known in the art and are used to create a substrate with a raised pattern on one face and a corresponding pattern of indentations on the opposite face. In one embodiment, the raised pattern is on the front of the substrate and so the back of the substrate therefore comprises corresponding indentations. Alternatively, the embossed substrate may comprise a raised pattern on its back and corresponding indentations on its front.

As used herein, the "front" of the substrate means the face that is not in contact with the wet glue. The "front" of the label or the substrate is therefore the face that faces away from the article. Accordingly, the "back" of the substrate is the face to which the wet glue is applied. The "back" of the label or the substrate is therefore the face that faces towards the article.

The "embossed region" is the part of the substrate that is either raised or indented (depending on the side of the substrate) relative to the rest of the substrate. There must necessarily be regions of the substrate that are not embossed, i.e. regions other than the embossed regions, so that the embossed pattern can be raised or indented relative to these regions. "Embossed" in this specification also, or alternatively, means "debossed".

It is to be understood that in labels according to the present invention, the region of the substrate that is not embossed is large enough to allow sufficient water evaporation and adhesion of the label to an article on the application of a wet glue.

Avoiding contact between the wet glue and the embossed regions of the substrate can be done in a number of ways. In one embodiment, the wet glue is only applied to the regions of the substrate that are not embossed and so is not applied to the embossed regions of the substrate. A label in accordance with this embodiment is cheap to produce as no additional components are required.

Additionally or alternatively, the label may further comprise a water impermeable layer that covers the back of the embossed regions of the substrate, wherein the water impermeable layer acts to prevent the wet glue from contacting the embossed regions of the substrate.

As used herein, a "water impermeable" layer means a layer having a low WVTR. Preferably, the water impermeable layer has a WVTR of less than 10 g/m ² /day, more preferably less than 5 g/m ² /day. Wet glue for paper labels is applied normally with between 15 and 20 gsm. The glue may comprise approximately 50% water.

This water impermeable layer reliably prevents the wet glue, and specifically the moisture present in the wet glue which can affect the structure of the substrate, from contacting the embossed regions of the substrate. This provides a simple, easy and reliable way in which to prevent the wet glue from contacting the embossed regions of the substrate.

The water impermeable layer may cover an area encompassing the embossed regions and part of the surrounding non-embossed regions. Alternatively, the water impermeable layer may cover only the embossed regions, or substantially only the embossed regions. In this embodiment, the water impermeable layer will therefore have substantially the same shape as the embossed pattern.

In one embodiment in which the substrate comprises a raised pattern on its front and corresponding indentations on its back, the water impermeable layer does not completely fill the indentations on the back of the embossed regions of the substrate. The water impermeable layer is not intended to fill the indentations on the back of the embossed regions of the substrate in order to maintain the embossed structure. As such, the water impermeable layer may only be a thin layer with little structural strength, as long as it has sufficient water impermeable properties.

The water impermeable layer may comprise a varnish, which may comprise a varnish that contains a wax or a varnish that comprises no wax. Such varnishes are cheap, readily available and provide sufficient water-impermeable characteristics. It may be advantageous to use a varnish which is to some extent temperature sensitive. The process of embossing of the label may be performed with warm embossing tools (at elevated temperatures of for example 80 °C) and use of a varnish which softens at such elevated temperatures may assist the embossing process. Furthermore, once the embossing has been completed and the temperature of the label cools, the use of a varnish which hardens on cooling may stabilise the label structure.

Consequently, the invention contemplates a water impermeable layer comprising a varnish which is a temperature sensitive material which softens at elevated temperature (of above 40°C or 50°C or 60°C or 70°C or 80°C, for example) and hardens as the temperature falls. Temperature sensitive varnishes are well known in the art. Thermoplastic lacquers often contain PVC polymers. Resins with a low temperature melting point may also be mentioned amongst such lacquer systems and are suitable for use in the invention.

The substrate may further be coated or otherwise provided on some or all of its front with a water impermeable layer. The layer may cover some or all of the embossed region of the substrate and may further cover some or all of the non-embossed region of the substrate. Preferably, all of the front of the substrate is covered by the water impermeable layer.

The water impermeable layer may comprise a varnish or a lacquer, which may be the same as or different to a varnish applied to the back of the substrate. Additionally or alternatively, the ink used on the front of the substrate may comprise compounds that provide water impermeability. In this case, the ink provides the water impermeable layer. Additionally or alternatively, the water impermeable layer may be provided on all of the front of the substrate by means of a water barrier filmic layer applied to the front face of the substrate by co-extrusion or by extrusion coating.

Applying a water impermeable layer to the front face of the substrate may be particularly advantageous when the labelled container is filled with a low temperature liquid, which may in that case cause moisture from the atmosphere to condense on the front face of the label and prolong its drying time in the absence of the water impermeable layer on the front face. The impermeable layer on the front side protects the substrate against penetrating water and so helps to remain the relief created by the embossing. A water impermeable layer on the front face of the label may in any event help protect the label during the course of its commercial life, assisting it to withstand ice-bucket conditions for example.

It has surprisingly been found that including a water impermeable layer on the front of the label, preferably in addition to the layer on the back of the label, further helps to maintain the structure of the embossed region, particularly during stacking, storage and further processing of the labels.

The substrate may comprise paper and/or cellulose fibres and/or a water permeable filmic material. Such substrates are well known in the art, as are methods of embossing such substrates. These substrates are generally cheap and readily available. However, they are also particularly prone to destruction of an embossed pattern on the application of a wet glue to the substrate, which may be due to the water from the wet glue being absorbed into the substrate and causing distortion by causing expansion of the fibres within the substrate.

If paper is used, the paper substrate is generally relatively thin, which can make maintaining the embossed shape on the substrate even more difficult. The paper substrate can be between 50 gsm and 300 gsm, preferably between 60 gsm and 120 gsm and more preferably between 60 gsm and 90 gsm.

The wet glue may comprise any water based labelling adhesive, including vegetable glue, resin cement, animal glue, protein glue, latex cement, suitable combinations thereof and/or suitable mixtures thereof. Particularly, the wet glue may comprise starch glue, dextrin glue, casein glue, EVA, PVA and/or non-casein based polymeric glue such as synthetic glues or adhesives, including those with acrylates as the binder. Such glues are well known in the art and are commonly used in wet glue labelling applications.

According to a second aspect of the present invention, there is provided an article labelled with the label discussed above.

An article according to this aspect of the present invention will comprise a label that maintains its embossed structure once it has been applied to the article using a wet glue.

The article may be made of any suitable material. In one embodiment, the article is glass, metal or plastic, such as PET or HDPE. The article may be a bottle, jar or other type of container.

According to a third aspect of the present invention, there is provided a method of applying a label comprising an embossed substrate to an article using a wet glue, comprising the step of applying the wet glue directly to the back of the substrate before the label is applied to the article, wherein the wet glue is prevented from contacting the embossed regions of the substrate.

As discussed above, this method provides a quick and easy method of applying an embossed label to an article using wet glue, which helps to maintain the embossed regions on the substrate. The method can also be used with currently commonly used machinery. The embossed substrate may comprise a raised pattern on its front and corresponding indentations on its back. Alternatively, the embossed substrate may comprise a raised pattern on its back and corresponding indentations on its front.

The step of applying the wet glue such that it does not contact the embossed regions of the substrate can be achieved in a variety of ways. In one embodiment, the wet glue is only applied to the regions of the substrate that are not embossed and so is not applied to the embossed regions of the substrate. This is a cheap method of applying the glue, as no additional components are required. It also means that this method can be used with machinery that is currently commonly used in similar methods.

For example, the wet glue may be applied using a glue palette from which a region corresponding to the embossed regions of the substrate has been removed. Glue palettes are well known in the art to apply wet glues to labels. By removing a section of such a palette, a cheap and easy method of avoiding applying glue to the embossed regions of a label is provided, which can be incorporated into machinery currently commonly used.

Additionally or alternatively, the label may further comprise a water impermeable layer covering the back of the embossed regions of the substrate, which acts to prevent the wet glue from contacting the embossed regions of the substrate. In this embodiment, the wet glue can be applied over the entirety of the back of the substrate, as the water impermeable layer prevents it from contacting the embossed regions. However, the wet glue may also only be applied to the regions of the substrate that are not embossed and so is not applied to the embossed regions, which are covered by the water impermeable layer.

This water impermeable layer reliably prevents the wet glue, particularly the moisture present in the wet glue which can affect the substrate, from contacting the embossed regions of the substrate. This provides a simple, easy and reliable way in which to prevent moisture from reaching the substrate.

In one embodiment in which the substrate comprises a raised pattern on its front and corresponding indentations on its back, the water impermeable layer does not completely fill the indentations on the back of the embossed regions of the substrate. The water impermeable layer is not intended to fill the indentations on the back of the embossed regions of the substrate in order to maintain the embossed structure. As such, the water impermeable layer may only be a thin layer with little structural strength, as long as it has sufficient water impermeable properties.

The water impermeable layer may comprise a varnish, which may comprise a varnish that contains a wax. Such varnishes are cheap, readily available and provide sufficient water impermeable characteristics.

The substrate may comprise paper and/or cellulose fibres and/or a water permeable filmic material. Such substrates are well known in the art, as are methods of embossing such substrates. These substrates are generally cheap and readily available. However, they are also particularly prone to destruction of an embossed pattern on the application of a wet glue to the substrate, which may be due to the water from the wet glue being absorbed into the substrate and causing distortion by causing expansion of the fibres within the substrate.

If paper is used, the paper substrate is generally relatively thin, which can make maintaining the embossed shape on the substrate even more difficult. The paper substrate can be between 50 gsm and 300 gsm, preferably between 60 gsm and 120 gsm and more preferably between 60 gsm and 90 gsm.

The wet glue may comprise any water based labelling adhesive, including vegetable glue, resin cement, animal glue, protein glue, latex cement, suitable combinations thereof and/or suitable mixtures thereof. Particularly, the wet glue may comprise starch glue, dextrin glue, casein glue, EVA, PVA and/or non-casein based polymeric glue such as synthetic glues or adhesives, including those with acrylates as the binder. Such glues are well known in the art and are commonly used in wet glue labelling applications.

The article may be made of any suitable material. In one embodiment, the article is plastic, such as PET or HDPE, metal or glass. The article may be a bottle, jar or other type of container.

According to a fourth aspect of the present invention, there is provided a labelled article produced by the method discussed above. An article according to this aspect of the present invention will comprise a label that maintains its embossed structure once it has been applied to the article using a wet glue. Example 1

A sheet of paper of weight 70 gsm has a number of identical images printed on one of its faces. A pattern is then embossed onto each of the images, with the raised pattern on the printed face of the paper. The printed and embossed sheet is then cut into individual labels, which are stacked with the embossed patterns in register.

When the labels are to be applied to a glass bottle, each label is removed individually from the label stack and a wet glue is applied to the back of the labels, i.e. to the side that is not printed and that has the indentation pattern. The wet glue is specifically applied to the regions of the label that are not embossed, so that the embossed regions are not in contact with the wet glue.

The label is then brushed and pressed against a glass bottle so that the wet glue is in direct contact with the glass. The label is left for some time so that the moisture within the wet glue can evaporate, thereby adhering the label to the glass bottle.

Example 2

A sheet of paper of weight 70 gsm has a number of identical images printed on one of its faces. A pattern is then embossed onto each of the images, with the raised pattern on the printed face of the paper. A varnish that contains a wax is applied to the back of the label (i.e. the face that is not printed), which covers the indentations corresponding to the embossed pattern and a small part of the region of the paper surrounding the indentations. The printed and embossed sheet is then cut into individual labels, which are stacked with the embossed patterns in register.

When the labels are to be applied to a glass bottle, each label is then removed individually from the label stack and a wet glue is applied to the entirety of the back of the labels, i.e. to the side that is not printed and that has the indentation pattern.

The label is then pressed against a glass bottle so that the wet glue is in direct contact with the glass. The label is left for some time so that the moisture within the wet glue can evaporate, thereby adhering the label to the glass bottle.