CN113614190A - In-line production of linerless labels - Google Patents

Abstract

A label laminate comprising: a film or paper substrate having a first surface and a second surface; a Pressure Sensitive Adhesive (PSA) layer having an adhesive property and having a first surface and a second surface, the first surface of the PSA being in contact with the second surface of the substrate; and a debonding layer on top of the second surface of the PSA layer, the debonding layer having a melting point greater than about 50 ℃, wherein the surface coverage of the debonding layer is less than 100% of the second surface of the PSA layer.

Description

In-line production of linerless labels

Cross reference to related applications

This application claims priority to U.S. provisional patent application No. 62/806,812 filed on day 16, 2/2019 and is a co-pending partial continuation of U.S. patent application No. 16/253,145 filed on day 21, 1/2019, 16/253,145 is a partial continuation of and claims priority to U.S. patent application No. 16/104,112 filed on day 16, 8/2018, 16/104,112 is now U.S. patent 10325526 granted on day 18, 6/2019 and is a continuation of and claims priority to U.S. patent application No. 15/687,429 filed on day 25, 8/2017, 15/687,429 is now U.S. patent 10083635 granted on day 9, 2018 and is claimed priority to U.S. provisional patent application No. 62/460,873 filed on day 20, 2/2017, the entire contents of which are incorporated herein by reference.

Technical Field

The following description generally relates to linerless pressure sensitive adhesive labels and methods and systems for making the same.

Background

The related art Pressure Sensitive Adhesive (PSA) label paper (label stock) has a multilayer laminate structure including four essential elements: face or face stock, adhesive layer, release system, and backing layer. Such label paper is usually produced in the form of a roll comprising a plurality of individual labels, usually converted into individual labels after printing of the indicia. The end user may then apply the individual labels to the product. The remaining liner, coated with an anti-sticking system, becomes a waste stream. This waste stream is collected on a rewiring stand after distribution (i.e., labeling) and may subsequently be landfilled or sold for low value reprocessing.

To reduce the waste generated during the labeling process, the labeling industry has been seeking ways to affect the labeling of PSA-like materials without the use of liners and related anti-tack systems, thereby significantly increasing the efficiency of the materials and supply chain, reducing costs and eliminating the increasingly problematic waste streams. Only limited progress has been made in achieving this goal, usually in the form of so-called "linerless" labels and "activatable" labels.

Linerless labels are typically manufactured by: the indicia is first printed on one side of the facestock, then the anti-tack system is applied on the same side as the facestock is printed, and then the back of the facestock is coated with an adhesive to form a self-wound label paper that does not include a liner. Although the liner is eliminated, the anti-tack system is still coated on the facestock and thus the full cost potential of a truly liner-free solution is not realized.

There remains a need for a truly linerless solution that eliminates the liner and anti-stick system and does not replace either with another component.

Summary of The Invention

An aspect of one or more embodiments of the present invention relates to a method of labeling a plurality of products, the label being free of any liner and any anti-tack system, and not being replaced by any other material.

Another aspect of one or more embodiments of the present invention relates to a system for labeling a plurality of products, the label being free of any liner and any anti-tack system, and not being replaced by any other material.

Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments.

In accordance with an embodiment of the present disclosure, a method of labeling a plurality of products is provided. The method includes applying a pressure sensitive adhesive on a roll of facestock configured to be converted into a plurality of individual labels aligned in a single lane; separating individual labels from the roll of facestock; and applying the individual labels to the products of the plurality of products, wherein the coating, dividing and applying occur sequentially in a single continuous operation of a single continuous web of material.

In one embodiment, no winding or rewinding of the web is performed between application of the pressure sensitive adhesive, separation and application of the individual labels.

In one embodiment, the method may further comprise weakening the web roll to enable separation of the individual labels. Weakening of the web roll may be performed prior to application of the pressure sensitive adhesive, including perforation or weakening of the boundary lines of the individual labels.

In one embodiment, weakening of the roll of facestock may be performed after application of the pressure sensitive adhesive and prior to singulation of the individual labels, and includes cutting along the boundary lines of the individual labels using a laser, cutting die, and/or knife.

In one embodiment, the method may further comprise printing indicia on the facestock. Printing may be performed at a position different from the position where the pressure-sensitive adhesive is applied, before the pressure-sensitive adhesive is applied.

In one embodiment, printing may be performed at the same position as the position where the pressure-sensitive adhesive is coated before coating the pressure-sensitive adhesive coating, and printing may be performed sequentially with coating, dividing, and applying.

The facestock roll may have a first indicia prior to printing, and printing may provide the facestock roll with a second indicia.

The coat weight of the pressure sensitive adhesive may be from about 3gsm to about 20 gsm.

The 180 ° peel of the pressure sensitive adhesive may be from about 1N/inch to about 20N/inch.

In one embodiment, the method may further comprise unrolling the roll of facestock prior to applying the pressure sensitive adhesive, wherein the total time required from unrolling the portion of the facestock corresponding to an individual label to completion of application of the individual label to the product is about 60 seconds or less.

In one embodiment, the method may further comprise curing the pressure sensitive adhesive after coating the pressure sensitive adhesive and before singulating the individual labels.

Can be administered at a dose of about 2mJ/cm²To about 50mJ/cm²Curing by the radiation source of (a).

The coating may be performed at a temperature of about 60 ℃ to about 170 ℃.

In one embodiment, the individual labels may be applied about 10 seconds or less after the pressure sensitive adhesive is applied.

The application of the pressure sensitive adhesive may be by die coating, screen coating and/or spray coating.

According to an embodiment of the present disclosure, a system for labeling a plurality of products is provided. The system includes a coating station (coating station) that coats a pressure sensitive adhesive on a roll of facestock configured to be converted into a plurality of individual labels aligned in a single lane; a dividing station (dividing station) for dividing the individual labels from the roll of facestock; and a dispensing station (dispensing station) for applying individual labels to products of the plurality of products, wherein the coating station, the singulating station and the dispensing station are located at the same location to provide, in succession, the coating of the pressure sensitive adhesive, the singulating of the individual labels and the applying of the individual labels.

In one embodiment, the system may further comprise a transport station (transport station) that moves the facestock from the unwinding station (unwinding station) to the coating station, the slitting station, and the dispensing station sequentially.

The transport station may comprise a belt (belt).

In one embodiment, the system may further include a weakening station (Weakening station) that creates separation between adjacent individual tags.

In one embodiment, the system may further comprise an accumulation station (accumulation station) located between the coating station and the dividing station to accumulate the coated facestock when the speed of the facestock at the coating station is faster than the speed of the facestock at the dividing station.

In one embodiment, the system may further comprise an (intermediate) transport system and an accumulation station between the coating station and the singulation station to accumulate the coated facestock when the speed of the facestock at the coating station is faster than the speed of the facestock at the singulation station.

In one embodiment, the system may further include a printing station (printing station) that prints indicia on the facestock.

According to embodiments of the present disclosure, a pressure sensitive adhesive label consists of: a facestock, indicia on the facestock, and a pressure sensitive adhesive on the facestock, wherein the pressure sensitive adhesive has a coat weight of from about 3gsm to about 20gsm and a 180 ° peel of from about 1N/inch to about 20N/inch.

An embodiment of the invention consists of a process which: a plurality of products are labeled using a roll of pre-weakened facestock coated with a Pressure Sensitive Adhesive (PSA), and the surface of the PSA has been detackified with material that is coated, sprayed, printed, dusted, and/or otherwise applied. The roll is configured to be converted into a plurality of individual labels aligned in a single lane; singulating individual labels from a roll of facestock; and applying the individual labels to the plurality of products, wherein the debonded pressure sensitive adhesive layer is liquefied and rendered tacky by heat and/or Infrared (IR) radiation prior to application of the labels. The web roll may be weakened i) prior to application of the PSA and release layer (detack layer), or ii) after application of the PSA and release layer, or iii) after application of the PSA layer but before application of the release layer, or iv) in a separate process step at a converter (which also typically prints the roll to place indicia on individual labels, which are then cut to form individual channel label material). Embodiments of the present invention relate to the manufacture and application of linerless labels without the use of any kind of release layer or coating or release coated liner.

Another embodiment of the invention provides a web (web) coated with PSA on a high speed coater and the PSA surface is covered with a release layer (by coating, spraying, printing or dusting the material) at high speed and the web is pre-weakened and printed with graphics and wound up without the use or need of a release liner or release coating. Alternatively, the roll of film may be printed by the processor, then coated with a UV curable PSA, applied with a release material on top of the PSA, and pre-weakened for convenient dispensing. The pre-weakening can be performed before printing, after printing, or after application of an adhesive, or after application of a release layer. Such pre-weakened rolls are prepared for use at a product labeling site by imparting tackiness to the label using Near Infrared (NIR) or thermal means (thermal unit) and then applied to the product. Upon exposure to NIR or heat, the protective layer of release material melts, becomes tacky to the touch, and migrates into the PSA layer, making the PSA also tacky to the touch. Due to compatibility with the PSA, the entire laminate remains transparent and strongly tacky, forming a label that provides the product with a no-label appearance. This provides a new linerless solution without the need for an anti-stick coating or anti-stick liner.

Since PSA coating is performed on an adhesive coating line or by the processor coating and converting the PSA coated product, conventional PSAs such as emulsion PSAs, hot melt PSAs, solution PSAs, or radiation curable PSAs may be used. The PSA is coated by any coating method, such as roll coating, die coating, meyer rod coating, curtain coating, comma coating (comma coating), and the like. The PSA may also be deposited on the web by printing or spraying, resulting in a discontinuous layer. The adhesive deposited on the web may be dried using conventional ovens, or drying in the case of hot melt, warm melt or radiation curable adhesives is not necessary and, if desired, cured with radiation.

To avoid the use of a liner or release coating, the layers are rendered non-tacky by the use of a release layer so that the roll can be wound up automatically without adjacent layers adhering to each other in storage or unwinding conditions. Under high speed labeling conditions of about 600 bottles/minute, i.e., at web speeds in excess of 150 feet/minute, the debonding layer may liquefy and mix with the underlying adhesive. The detackifying layer is selected so that upon exposure to thermal or IR or NIR radiation it is converted to a liquid which does not affect and which enhances the performance of the underlying adhesive. A release layer may also be selected, wherein the release layer sublimes upon exposure to radiation, rendering the PSA tacky. It may also be such that upon exposure to radiation it breaks down into smaller components and becomes sticky to the touch. The detackifying layer may be i) melted and coated onto the surface of the PSA using conventional coating techniques, such as roll or die coating, or ii) sprayed onto the surface of the PSA using a Nordson spray device, wherein the material is fully or partially cured before landing on the PSA surface, or iii) applied to the PSA surface in the form of a powder which may be deposited uniformly or in a specific pattern as desired, or iv) printed onto the PSA surface using any of a variety of printing techniques, such as screen printing, ink jet printing, and the like.

In one embodiment, the detackifying material is added in a continuous process by spraying the detackifying material onto an adhesive coated web that is conveyed at a speed lower than the spray outlet. In one embodiment, the web speed is 150-3000 ft/min. In another embodiment, the spraying is performed using a powder spraying process in which a powder is fluidized and pumped through a nozzle to produce a powder spray that falls onto and is retained by an adhesive web (adhesive web) as it passes under a spray head. In one embodiment, the spraying operation is performed in a closed "booth" for control, recovery and reuse of overspray (overspray). The amount of powder retained by the web is determined by the speed at which the spray is emitted from the nozzle and the speed at which the web travels. In another embodiment, for a wide adhesive roll, an array of spray heads may be used. In one embodiment, the powder may be sprayed shortly after the adhesive coating of the coil. In another embodiment, the coil may be rewound immediately after spraying the powder. In another embodiment, the powder is sprayed at a suitable point between adhesive application of the coil and rewinding of the coil.

Some embodiments include cooling the web, or cooling the spray as it exits the spray orifice, or adding a nucleating agent to rapidly crystallize the detackifying material before it is deposited on the PSA surface. The release material is selected and applied at a rate such that under labeling conditions of about 150 to 600 bottles/minute the release material transitions to a PSA layer that is tacky to the touch and adheres with sufficient adhesion to the container being labeled or decorated (bottle, package, box or anything requiring labeling, hereinafter referred to as container). The tack-up time under these conditions is preferably less than about 4 seconds in order to label about 150 bottles with an activation module about 2.5ft long in the machine direction at a label width of about 4 inches. And most preferably less than about 1 second to allow a labeling speed of about 600 bottles/minute. Higher speed and therefore lower tack-up time can be achieved using a greater number of IR emitters, increasing the length of the active NIR module, higher power (watts), or a combination of these.

Brief Description of Drawings

These and other features and advantages of the present invention will be better understood by reference to the following detailed description when considered in connection with the accompanying drawings. It should be understood that selected structures and features are not shown in some of the figures in order to provide a better view of the remaining structures and features.

FIG. 1 is a schematic illustration of a method of labeling a plurality of products.

Figure 2 is a schematic representation of a cross-section of a roll of facestock material.

Fig. 3 is a schematic diagram of a process for labeling a plurality of products according to an embodiment of the present disclosure.

Fig. 4 is a schematic of a facestock coated with an adhesive in a channel.

Fig. 5A and 5B are schematic views of a label facestock with a matrix.

Fig. 6 is a schematic diagram of a labeling process of an embodiment of the present disclosure.

Fig. 7 is a schematic diagram of an exemplary labeling process at a customer.

FIG. 8 is a schematic diagram of a process including flow line printing.

Fig. 9 is a schematic diagram of a labeling process.

Fig. 10 is a schematic view of a labeling process.

Detailed Description

The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Expressions such as "at least one of" or "at least one selected from" or the like, when preceded by a list of elements, modify the entire list of elements without modifying individual elements in the list. Furthermore, the use of "may" in describing embodiments of the invention means "one or more embodiments of the invention.

It will be understood that when an element or layer is referred to as being "on," "connected to," "coupled to" or "adjacent to" another element or layer, it can be directly on, connected to, coupled to, or adjacent to the other element or layer, or one or more intervening elements or layers may be present. In contrast, when an element or layer is referred to as being "directly on," "directly connected to," "directly coupled to" or "directly adjacent to" another element or layer, there are no intervening elements or layers present.

As used herein, the terms "substantially," "about," and the like are used as approximate terms and not as degree terms, and are intended to account for inherent deviations in measured or calculated values that are recognized by those of ordinary skill in the art. Moreover, any numerical range recited herein is intended to include all sub-ranges subsumed within that range with the same numerical precision. For example, a range of "1.0 to 10.0" is intended to include all sub-ranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, i.e., having a minimum value equal to or greater than 1.0 and a maximum value of equal to or less than 10.0, e.g., 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein, and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, applicants reserve the right to modify the specification, including the claims, to specifically recite any sub-ranges subsumed within the ranges explicitly recited herein.

In accordance with an embodiment of the present disclosure, a method of labeling a plurality of products is provided. The method includes applying a pressure sensitive adhesive to a roll of facestock configured to be converted into a plurality of individual labels aligned in a single lane; singulating individual labels from a roll of facestock; and applying the individual labels to the products of the plurality of products, wherein the coating, dividing and applying occur sequentially in a single continuous operation of a single continuous web of material. Here, "single continuous operation" refers to a process in which coating, division and application to a product are sequentially performed on a given portion of the roll of facestock material (i.e., a given portion of the roll of material) in the same production line (i.e., the patch line). The web roll is continuously unwound at the beginning of the production line from an unwinding station, transported, if applicable, by a coating station and other stations (e.g. curing stations), continuously divided into individual labels, and applied to the products at the end of the production line. The process may include variable speeds (e.g., different speeds at different stations), but should not include rolling up the entire web and unrolling it again at different times and/or different locations between the coating station, the splitting station, and the applying.

According to embodiments of the present disclosure, no winding or rewinding of the web is performed between application of the pressure sensitive adhesive, splitting and application of the individual labels. For example, coating, dividing and applying can be performed sequentially and continuously in time in the same process. Here, the adhesive-coated facestock with printed labels forms a label, and the roll of adhesive-coated facestock with printed labels becomes a roll of label paper, which may include a plurality of individual labels.

FIG. 1 is a schematic illustration of a method of labeling a plurality of products. Referring to fig. 1, a roll of facestock 101 is unwound at station 110. The facestock 101 passes through a coating station 120 and a layer of pressure sensitive adhesive 103 is coated on the facestock 101. In one embodiment, the facestock 101 passes through a curing station 130, producing a cured pressure sensitive adhesive 105. In another embodiment, the curing station 130 is not included in the labeling process and the pressure sensitive adhesive is not cured.

The facestock 101 then passes through a singulation station 140 and the individual labels 107 at the leading edge of the facestock 101 are singulated (i.e., picked) from the roll of facestock 101. Next, at the dispensing station 150, individual labels 107 are applied to the products 109 of the plurality of products. Although the singulation and application of individual labels is described as being performed at the singulation station 140 and the dispensing station 150, respectively, embodiments of the present disclosure are not so limited and both the singulation and application of individual labels may be performed at the dispensing station, e.g., by the same tool picking out an individual label and applying the label to a product and/or as part of a single process.

As the labeled product 109 is removed from the dispensing station, the next individual label is applied to the next product and the labeling process continues. In one embodiment, the time span from the start of coating the PSA to the completion of individual label dispensing is 60 seconds or less for each individual label. Fig. 9 is a schematic diagram of a labeling process. Referring to fig. 9, according to an embodiment, the time required for an individual label of a web roll (e.g., a roll of printed film or paper) to travel from an unwind station to complete label application is less than 60 seconds. In another embodiment, the time required for an individual label of a roll of facestock (e.g., a roll of printed film or paper) to travel from the unwind station to complete label application is less than 30 seconds.

The facestock may be made of any suitable material. For example, the facestock may be paper-based or film-based (e.g., made from a transparent plastic material, an opaque plastic material, a foil, metallized paper, a metallized film, a laminate, etc.). In one embodiment, the facestock may have a thickness of about 20 microns or less, for example about 10 microns or less, or about 8 microns.

The web roll may be converted into a plurality of individual labels, for example 500, 1000, 2000, 10000 or more. Thus, the web roll may be weakened to create separation between adjacent individual labels. Weakening of the web roll may be performed prior to application of the pressure sensitive adhesive and may include perforating or weakening the boundary line of each individual label.

In one embodiment, the weakening of the web roll may be performed at a location different from the location where the labeling is performed. For example, weakening of the web may be performed at the manufacturing location of the printed web, for example. When the web roll reaches the unwinding station 110, the weakening has been completed and a perforation line or weakening line has been created between adjacent individual labels to define each individual label while the labels are still connected to each other. In the following, the term "weakened" refers to the state of a label web (e.g., a web roll) in which individual labels can be easily separated from the web, but still attached to the web. The line of weakness may be a perforation line or a cut line cut through only a portion of the web in the thickness direction. In this specification, the terms "web" and "roll" are used interchangeably.

In one embodiment, weakening of the roll of facestock may be performed after application of the pressure sensitive adhesive and prior to singulating the individual labels, and may include cutting along the boundary lines of the individual labels with a laser beam, cutting die, or knife. Although an exemplary weakening method has been described, embodiments of the present disclosure are not limited thereto and any suitable weakening method may be utilized.

Figure 2 is a schematic representation of a cross-section of a roll of facestock material. Referring to fig. 2, the roll of facestock 101 includes a plurality of individual labels 101a aligned in a single lane. Individual labels may have a perforation line or line of weakness 101b around their circumference, although embodiments of the present disclosure are not so limited and rolls of facestock material may not include a perforation line or line of weakness 101 b.

The facestock 101 may include indicia printed on a surface thereof. In one embodiment, printing may be performed at a location different from the location where the pressure sensitive adhesive is coated, before the pressure sensitive adhesive is coated. The printing process may not be part of the same continuous labeling process described in connection with fig. 1.

Printing may be performed at a label manufacturing location where the label facestock is printed and wound into a roll. The indicia may describe and advertise the product to be labeled. For example, the indicia may be a product name, product information, a logo associated with the product, and the like. This printing may be performed on a continuous (roll-to-roll) printing press, thereby producing a plurality of labels on and along a label paper web. Prior to the labeling process described in connection with fig. 1, the label paper web may be cut into single lane labels.

In one embodiment, printing may be performed at the same location as the location where the pressure sensitive adhesive is applied, before the pressure sensitive adhesive is applied, and printing and coating, dividing and applying may be performed in the same process, for example, sequentially and/or continuously in time. Fig. 3 is a schematic diagram of a process for labeling a plurality of products according to an embodiment of the present disclosure. In fig. 3, the same reference numerals as in fig. 1 are used to denote similar processes and materials, and the description thereof will not be repeated.

Referring to fig. 3, a roll of facestock 101, including a plurality of labels 101a, is unwound at an unwind station 110. The facestock 101 first passes through the printing station 170 and the second indicia is printed on the facestock 101. Here, the roll of facestock 101 may have first indicia printed at the manufacturing location, and the second indicia may add, for example, customized information to the label 101 a. In one embodiment, the roll of facestock 101 may not include the first indicia, and the entire printing is performed in-line at the printing station 170. Printing can be done on either side of the facestock or on both sides (using two printing stations).

The pressure sensitive adhesive may be a hot melt PSA or a warm melt PSA. Any suitable pressure sensitive adhesive formulation may be used that satisfies the following conditions: a clear pressure sensitive adhesive layer is formed, flows well at low coat weights to form a high quality coating (e.g., a uniform coating without significant defects), can be coated at temperatures of about 60 ℃ to 170 ℃, and requires limited or no post-coating treatment. For the purposes of the present description, the term "hot melt adhesive" or "hot melt pressure sensitive adhesive" refers to a pressure sensitive material that flows at temperatures of about 110 ℃ and above and can be coated to provide a high quality coating. The term "warm melt" or "warm melt pressure sensitive adhesive" refers to a pressure sensitive material that flows at a temperature of about 60 ℃ to about 110 ℃ and that can be coated to provide a high quality coating. The coating may be performed at a temperature of about 60 ℃ to about 170 ℃.

Suitable pressure sensitive adhesives may be based on acrylic polymers; acrylic copolymers such as vinyl acrylic acid; and acrylic polymers with other comonomers such as dioctyl maleate and/or dibutyl fumarate; rubber-based polymers such as block, tapered or random copolymers of styrene, butadiene, isoprene or ethylene butylene; a polyurethane; silicone polymers or hybrids (graft or block or random copolymers of the above polymers); or combinations or blends of the above polymers with or without other additives. These polymers or copolymers may be random, block or graft copolymers. PSAs can be deposited onto rolls from water-based systems (e.g., emulsion polymers or copolymers), from solvents or as hot melts (melting and coating well above 100 ℃) or warm melts (melting and coating below about 100 ℃) or as viscous syrups. The PSA may be further crosslinked using thermal means or using any kind of radiation (e.g., ultraviolet, electron beam, etc.).

The polymer may be modified with a variety of additives. Non-limiting exemplary additives include tackifiers, plasticizers, fillers, crosslinkers, viscosity modifiers, and the like, which may be commercially available or custom-synthesized. The additives may have very low vapor pressure at the coating temperature and may not emit harmful or odorous components. Other suitable additives that may be used are additives that enhance adhesion to wet bottles, or additives that enhance adhesion under humid conditions.

Suitable pressure sensitive adhesives typically have a glass transition temperature (Tg) that is about 20 to 25 ℃ lower than the application/application temperature. For example, for room temperature applications, the Tg of the PSA may be less than about 0 ℃.

Suitable pressure sensitive adhesives can be readily applied using die coating, screen coating, spray coating, or other suitable application techniques at temperatures that do not distort or otherwise affect the aesthetics of the facestock material on which the pressure sensitive adhesive is applied. The viscosity of the adhesive at the coating temperature should be suitable for forming a high quality coating on a coil. For example, the viscosity of the adhesive can range from about 100 centipoise to about 15,000 centipoise, and even higher, at the coating temperature.

The molecular weight of the polymer can be any suitable value so long as, once formulated with the additives, the viscosity of the adhesive composition falls within the intended range to form a high quality coating at the coating temperature. For example, the weight average molecular weight can be from about 20,000 daltons to about 300,000 daltons.

When a film facestock or substrate (e.g., a facestock made from a polymeric material) is used for a label, it is typically sensitive to high temperatures. For such facestocks, an Ultraviolet (UV) curable warm melt adhesive may be used or a warm melt adhesive that does not require any curing. The warm melt adhesive may be applied to a film web (i.e., a film facestock roll) at a relatively low temperature (e.g., less than about 130 c) without deforming the web.

The coating temperature can be further reduced by dissolving the hot or warm melt adhesive in a low vapor pressure, high boiling point, benign comonomer or low molecular weight polymer additive to make a slurry (syrup), coating the slurry on a coil and allowing it to cure. The use of a slurry further improves coating quality and also allows the use of a more heat sensitive film label facestock, such as Polyethylene (PE).

For example, UV curable adhesive systems (adhesive formulations) may be based on acrylic or rubber based chemicals. Non-limiting examples of suitable UV curable adhesives include those from suppliers such as BASF, Henkel, and the like. The hot melt adhesive can be easily and firmly coated at a low coating weight. In one embodiment, the coat weight is from about 3gsm to about 20gsm, or from about 3gsm to about 12gsm, depending on the facestock. The adhesive may be applied using any suitable coating technique.

In one embodiment, the hot melt adhesive is metered by pumping from a standard tank to a small slot die coater. Slot jet coaters are available from any of a number of companies, such as Acumeter, ITW, Nordson, and the like. Slit die (slot die) with flat slide bar ensures high quality coating at low coating weight. At the coating head, adhesive is applied to the reverse side of the printed and weakened facestock continuously fed into the die (i.e., adhesive is applied to the side opposite the side on which the indicia are printed on the facestock). The width of the coating can be easily adjusted to match the width of the facestock web using shims on the die.

In one embodiment, the method may further comprise curing the pressure sensitive adhesive after coating the pressure sensitive adhesive and before singulating the individual labels. Curing may be carried out at a dose of about 2mJ/cm²To about 50mJ/cm²Is performed by the radiation source of (1).

For example, after applying a hot melt adhesive or a warm melt adhesive to the label facestock, the facestock exits the mold. Optionally, at the curing station, the adhesive is exposed to short pulses of UV radiation (e.g., in a dose range of about 5 mJ/cm)²To about 50mJ/cm²) This partially cures the adhesive and prepares it for direct application to the product at the splitting station.

In one embodiment, the post-coating unit (e.g., at the curing station) is compact and robust. Curing apparatus from companies such as Nordson, Dymax, Fusion, etc. may be used for curing. The radiation required for curing may depend on the adhesive used, and for these labels, generally a low dose is sufficient. For example, curing can be achieved at high speed and in a short time using a lamp (e.g., a D-bulb from Fusion) with an output of 500 watts per inch (watt/in) or less.

The type of lamp used determines the wavelength of the radiation and can be selected according to the adhesive used. For example, BASF with the low coating weights described above

A250 adhesive with a wavelength of 250-290 nm and a thickness of about 2-50mJ/cm can be used²A dose of UV-C radiation lamp. After the web exited the die, a lamp in a 6 inch wide and 8 inch long apparatus was used. The adhesive was passed under a lamp and exposed to successive pulses of UV for a short period of time.

For transparent film label facestock materials for clear-on-clear applications, where the appearance of the final label on the product requires that the adhesive be uniform, transparent and defect free, continuous coating using a UV curable hot melt adhesive or warm adhesive has been found to be effective.

For paper-based labels and opaque film labels, where the adhesive is not visible after the label is applied to the product, the coating method can be chosen to further provide a cost advantage. In one embodiment, the hot melt adhesive is sprayed onto the printed web using a standard hot melt nozzle. Applying the adhesive by a spray method can reduce the total amount of adhesive needed because it is not a continuous covering and it is not necessary to bring the coating system into contact with the web (thus reducing the web tension required to pull the web through the coating system to the slitting station). After spraying, the adhesive can be cured by UV radiation, if desired, as it passes under a lamp in a curing apparatus. Universal such as Nordson may be used^TMSpraying by a Spray Nozzle system and the like.

In another embodiment, a standard mold is sized to coat the hot melt adhesive in the channels. This provides a discontinuous coating, thereby reducing the amount of adhesive used. Fig. 4 is a schematic of a facestock with adhesive coated in channels. Referring to fig. 4, the adhesive 103 is applied to the facestock 101 in stripes, each stripe being spaced from an adjacent stripe.

In another embodiment, the adhesive may be printed (e.g., in a discontinuous pattern) onto the web using, for example, a Stork screen printer. In another embodiment, the adhesive may be coated, printed or sprayed onto only certain areas of the label, such as, for example, the inner boundary of the label. In another embodiment, only certain areas of the label are coated, printed or sprayed to minimize the amount of adhesive used.

The Pressure Sensitive adhesives of embodiments of the present disclosure are selected to meet the Dahlquist criteria, and more details on the types of PSA materials that may be used can be found in a wide variety of patents and publications, one of which is the Handbook of Pressure Sensitive Adhesive Technology, Second Edition, ed.

The 180 ° peel of the pressure sensitive adhesive on the glass panel can be from about 1N/inch to about 20N/inch, for example from about 5N/inch to about 17N/inch.

In one embodiment, no curing or drying occurs after the adhesive is applied, i.e., the adhesive applied to the label facestock does not require any curing or drying.

After the label facestock is adhesively coated and optionally cured, it may be drawn to a singulation station 140. At the slitting station 140, labels are removed from the web, slit and continuously applied to products provided to the dispensing station for continuous application to the products. The separation may be performed by effective tearing of the label from the pre-weakened web or via die cutting using, for example, a knife or die cutting tool.

The web may be pulled to a slitting station (from the initial unwind station 110, through the coating station 120) using, for example, a low surface energy tape (which contacts the adhesive side of the web), a friction tape (which contacts the printed side of the web), or a winder (winder) that collects any substrate (matrix) remaining after the labels are removed from the web.

Leaving a small (e.g., about 1/8 ") lane on either side of the label can provide enough substrate to allow a rewind station to pull the label paper through the process when the web is pulled using a winder. Fig. 5A and 5B are schematic illustrations of a label facestock with a matrix. Referring to fig. 5A, the label facestock 101 includes a label 101a and a matrix 101c on both sides of the label 101 a. The width of the substrate 101c (from the edge of the label 101a to the corresponding edge of the facestock 101) may be from about 1/10 "to about 1/2" (and for labels without square corners, the width may vary). Referring to fig. 5B, after the label 101a is picked from the web and applied to a product, only the substrate 101c remains and it is rewound at the rewind station.

Winders are common in related art labeling processes (for collecting the substrate and pulling the label paper through a dispensing system), and the use of a winder after the dispensing station is suitable for applying non-rectangular or square labels. For irregularly shaped labels, material is typically left in the web (referred to herein as the substrate) after label separation and the substrate can be easily collected on a winder. The winder may be used with or without a belt.

Fig. 6 is a schematic diagram of a labeling process of an embodiment of the present disclosure. In fig. 6, the same reference numerals as in fig. 1 are used to denote similar processes and materials, and the description thereof will not be repeated.

Referring to fig. 6, a roll of facestock 101, including a plurality of labels 101a, is unwound at an unwind station 110. The facestock 101 passes through the coating station 120 and the adhesive layer 103 is coated on the facestock 101. The adhesive may optionally be cured. The web may optionally be rotated 90 and arrive at the slitting station 140. After the individual labels 107 are singulated (i.e., picked from the web) and applied to the products 109, the remainder of the substrate 111 is rolled up at a winding station 160.

In one embodiment, the individual labels may be applied about 10 seconds or less, for example about 6 seconds or less, after the pressure sensitive adhesive is applied. In one embodiment, the labeling process may be performed at a rate of about 50 labels per minute to about 1000 labels per minute.

According to an embodiment of the present disclosure, a system for labeling a plurality of products is provided. The system includes a coating station that coats a pressure sensitive adhesive onto a roll of facestock, the facestock including a plurality of individual labels aligned in a single lane; a singulation station that singulates individual labels from the roll of facestock; and a dispensing station for applying the individual labels to the products of the plurality of products, wherein the coating station, the singulation station, and the dispensing station are co-located to provide continuous application of the pressure sensitive adhesive, singulation of the individual labels, and application of the individual labels.

In one embodiment, the system may further comprise a transport station for moving the facestock from the unwind station to the coating station, the singulation station, and the dispensing station in succession. The transport station may comprise a belt, such as a conveyor belt.

When singulation is achieved by streamlining cutting of individual labels at the singulation station (or dispensing station if a separate singulation station is not used), the web speed at the dispensing point may be varied. For example, the web may be decelerated or stopped briefly to complete the cut. This results in different web speeds at the slitting station and the coating station. To reduce or eliminate any coating defects that may be caused by web speed variations, an accumulator (accumulator) may be used after the coating station, which may provide a means to maintain a constant web speed through the coating station while eliminating web slack in the downstream web caused by speed variations. In another embodiment, a driven roller (or belt) may be included between the coating station and the accumulator, which may ensure that the web speed through the coating station remains constant. Similarly, in some embodiments, variable speeds may be required to apply the singulated labels to the products, and the accumulator may be reused to ensure constant web speed at the coating station.

In one embodiment, the system may further comprise an accumulation station located between the coating station and the singulation station to accumulate the facestock when the speed of the facestock at the coating station is faster than the speed of the facestock at the singulation station. For example, the system may include two transport stations. A first transport station (e.g., a belt driven by a first roller) moves the facestock through the coating station at a first constant speed, and then a second transport station (or system) (e.g., a belt driven by a second roller) moves the coated facestock through the dividing station and the dispensing station at a second constant or variable speed. At any instant, the first and second constant velocities may have different values (although the time-averaged velocities may be the same). The two transport stations provide continuous web speed through the coating station and allow variable web speed through the slitting station and the dispensing station. Accumulation may also be in the form of larger rolls or ribbons from which the singulated labels are dispensed, and from which the target (container) may be further labeled or decorated. This enables the coating to be carried out in a continuous manner.

In one embodiment, the system may further include a weakening station that creates a separation between adjacent individual labels. In one embodiment, the system may further comprise a printing station that prints indicia on the facestock.

The labeling system of the disclosed embodiments is capable of eliminating the liner and the anti-tack layer and is not replaced with another component. Thus, it achieves the real cost and environmental commitment of a linerless solution. There is additional complexity at the distribution point, but this complexity is readily justified by the large savings, environmental benefits and supply chain efficiencies provided by the present invention. Further, according to embodiments of the present disclosure, the facestock may have a thickness of about 20 microns or less. In related art labeling processes, less than 25 microns of facestock is rarely used because die cutting only the release system and the facestock and adhesive layer on the liner becomes difficult at low thicknesses without compromising the liner and thus the overall roll integrity. The adhesive coat weight may be from about 3gsm to about 20gsm, for example less than 10gsm, which is much lower than the weight used in related art labels and related art labeling systems (typically greater than 15 gsm).

In accordance with an embodiment of the present disclosure, an exemplary label manufacturing process begins at a label manufacturing location where information and advertising to be placed on a product to be labeled is first printed on a roll of facestock material (paper or film) as is currently done with related art labeling. In the same process, but after printing, the facestock is perforated or weakened, for example using a rotary die, to make a roll of printed material, with individual labels defined by weakened areas at the end of each label. The roll of printed web carrying the "weakened" label is then slit to provide a single pass label. The printing and slitting process is essentially the same as the corresponding related art except that the label facestock is only weakened rather than die cut through the entire label facestock.

The slit roll is then transported away from the manufacturing location and presented to the end user at a labeling location. In the subsequent labeling process, the roll is fed to a coating station that applies a thin coat (3gsm to 15gsm) of hot or warm melt PSA (optionally UV curable) onto the facestock material. If it is a UV curable adhesive, it can be rapidly partially (or fully) cured by low doses of UV as it leaves the coating station and is then fed directly to the singulation station. However, curing is not required with the selection of an appropriate hot or warm melt adhesive (having the desired adhesive properties). In one embodiment, drying is not required after the adhesive is applied. The adhesive coated facestock can be conveyed directly to the cutting station without any drying process. In another embodiment, drying and curing are not performed after the adhesive is applied. The adhesive coated facestock can be directly transferred to the cutting station without any drying or curing process.

At the dividing station and the dispensing station (or a combined dispensing station without a separate dividing station), the labels are divided by breaking the weakening lines which are created during the printing process at the manufacturing location and are then applied to the products in a continuous manner.

Although specific process steps are described above in connection with an exemplary process, embodiments of the disclosure are not so limited. For example, the web material may not be perforated at the manufacturing site, adhesives other than UV curable hot melt or warm melt adhesives may be used, other suitable energy activated, fast curing adhesives or non-curable adhesives may be used, and/or printing may be performed partially or fully during the labeling process. While label facestocks having multiple individual labels aligned in a single lane have been described, embodiments of the present disclosure are not so limited. For example, the facestock may include multiple lanes of labels, such as 2 lanes of labels. At the singulation station, the labels for each lane may be singulated by a separate tool and applied to a separate product line (e.g., each product line is transported by a separate conveyor system), or a single tool may be used to singulate labels for multiple lanes and apply them to the same product line (e.g., all products are transported by the same conveyor system).

According to embodiments of the present disclosure, the label is coated with the adhesive as part of the same process of dispensing and applying the label to the product. This process is continuous and can be easily incorporated into existing (related art) distribution schemes. In principle, any adhesive can be used which (a) can be applied at a temperature of about 60-170 ℃ and (b) does not require further conditioning or requires very little energy to cure. These adhesives may be thermoplastic elastomer-based or acrylic-based adhesives or blends or hybrids of the two that do not require curing or self-curing or that can be cured using an external energy source such as UV. The coating temperature range can be wide but is limited by the ability of the coated substrate to withstand temperatures without deforming.

In one embodiment, adhesives that require energy to cure, but can be cured with very little energy to provide suitable adhesion properties at very low coat weights, can be used. In one embodiment, the adhesive is formulated without any photoinitiator, thereby reducing cost, and does not cure after coating, such adhesives performing well in a range of applications.

According to embodiments of the present disclosure, adhesive is applied to a continuous roll of label paper, or a coating that becomes adhesive, in the same continuous process, wherein labels are dispensed and applied to containers. Thus, during the labeling process (e.g., dispensing point), the label material (typically printed) is unwound, moved through the coating head, cured (cross-linked) by a simple UV system if necessary, and then advanced to a singulation station where the web is separated into individual labels (singulation) and the individual labels are then applied to the product. A key requirement in this process is that after coating, the adhesive must be ready for use in a short time (e.g., less than 10 seconds or less than 3 seconds) and during this time little or no treatment (curing) is required so that the process remains compact and running cost is low.

In one embodiment, the relatively low molecular weight adhesive may be selected so that it is uniformly coated at a low coat weight. The adhesive can be directly used as a label adhesive without any curing. Unlike the related art PSA labels, the adhesive coated roll is not rolled up (because the coated web is used directly). Thus, in the labeling process of embodiments of the present disclosure, there are no problems associated with related art label rolls in which the adhesive must have a sufficiently high molecular weight to resist the forces experienced by the adhesive layer in the roll form, which causes it to flow and cause edge bleed and blocking (blocking). The related art processes require significant curing (crosslinking) in order to achieve the desired molecular weight. Little or no curing is required during the course of the disclosed embodiments. In one embodiment, the label has been perforated and is therefore segmented by effectively tearing the perforation at the point of dispensing. However, the separation can be performed by using various separation methods such as laser or fly knife (with and without pre-perforation) at the dispensing point. Another label separation method is to film or laser cut the label on a moving vacuum anvil (usually a roller) which, after cutting, carries the label to the application point.

In accordance with embodiments of the present disclosure, an exemplary label manufacturing process for providing transparent film labels on products may be initiated at a manufacturing location by printing on a roll of facestock material (paper or film) information and advertising that may be placed on the product to be labeled, as is currently done with related art labeling. In the same process (in the same position), but after printing, each label is weakened at its periphery by rotating the die. The roll of printing material carrying the weakened label is then cut to provide a single pass label. This slit roll is then shipped from the manufacturing site and provided to the end user for use at the customer location (i.e., labeling location).

Fig. 7 is a schematic illustration of another labeling process of an embodiment of the present disclosure. In fig. 7, the same reference numerals as in fig. 1 are used to denote similar processes and materials, and the description thereof will not be repeated. Referring to fig. 7, a roll of facestock 101, including a plurality of labels 101a, is unwound at an unwind station 110. The facestock 101 passes through the coating station 120 and the adhesive layer 103 is coated on the facestock 101. The adhesive may optionally be cured at a curing station 130. Driven rollers or belts 136 at transfer station 135 pull the web through coating station 120 at a constant speed. In the case of tape 136, the tape has a low surface energy and is in contact with the adhesive. The web then passes through an accumulator 138 which takes up any slack in the web, causing a disturbance in the web speed downstream of the slitting and dispensing stations. The web may optionally be rotated 90 and arrive at the slitting station 140. After the individual labels 107 are singulated (i.e., picked from the web) and applied to the products 109, any remaining substrate 111 is rolled up at a winding station 160. In other embodiments, the strap 136 may be a friction strap that contacts the facestock 101.

Although die coating and continuous coating have been described in the above exemplary process, embodiments of the present disclosure are not limited thereto. For example, for applications where the final appearance of the adhesive is not important, spray or screen printing of the adhesive may be used instead of continuous coating. In another embodiment, for applications where the final appearance of the adhesive is not important, the adhesive may be pattern coated using a suitable coating die. In both cases, the amount of adhesive required to produce the finished label is reduced. For example, the adhesive may cover from about 30% to about 90% of the surface area of the label. Removal of the label from the pre-weakened web may affect the slitting, but cutting with a laser, knife or die may also affect the slitting. It should also be noted that if one or more transport stations (transport systems) are used immediately after the coating station, the transport system (e.g., tape) may be in contact with the web from the adhesive side or from the non-coated side as opposed to the adhesive side.

According to another embodiment, the printed and cut web of facestock material provided to the end user is coated with adhesive, cut or perforated in order to achieve singulation (singulation of individual labels from a web) and application in a continuous manner onto the product to be labeled. The coil may be perforated prior to adhesive coating, followed by adhesive coating, slitting and application. The corners of the label may be rounded during the singulation action, which may be performed using a die or laser beam, to enhance the aesthetic appearance of the label. When the web speed of the slitting or application station is variable (i.e. the web changes speed at different stations), an accumulator located after the coating station may be used to eliminate any variation in web speed due to the slitting action or the application action to ensure that the coating speed is constant.

A flow line indicia printing station on the roll after unwinding and prior to adhesive application may be included in the label printing process. In early deployments, the end user may also wish, for example, to be able to add some simple variable printing to each label, such as name tags or custom tags, in addition to early printing at the manufacturing location.

In one embodiment, the entire label may be printed in a manner consistent with the coating and singulation stations. This would allow the end user to create labels from a roll of starting material, or from a perforated roll with weakened areas around the label area, or from a simple (e.g. blank) roll of film or paper if die cut is done completely at the slitting station. Full flow-line printing allows the end-user to fully customize each label and eliminate expensive inventory.

FIG. 8 is a schematic diagram of a process including flow-line printing. Referring to fig. 8, a roll of blank (i.e., unprinted) facestock 101, unprinted with any indicia, is unwound at an unwind station 110 and pulled by a transport system 135 to a printing station 170. At the print station 170, the ink layer 117 represents indicia such as information and graphic presentations about the product, and the cover ink layer 117 is printed on the facestock 101 using, for example, a high speed digital printer. The printed facestock is then moved to the coating station 120 and optional curing station 130. The printed and coated web is then advanced through an accumulator 138 to a slitting station 140 before individual labels 107 are applied to products 109. In one embodiment, the labeling process may also include a rotating anvil 119, wherein individual labels are cut from the web using a cutting die.

While the printing station 170 is shown in a process that includes the curing station 130 and the rotary anvil 119, embodiments of the present disclosure are not so limited, and various suitable combinations of process stations may be utilized, and some process stations, such as the curing station 130 and/or the rotary anvil 119, may not be included. Further, while the ink layer 117 and the adhesive layer 103 have been shown to be on the same side of the facestock 101, embodiments of the present disclosure are not so limited and the ink layer 117 and the adhesive 103 may be on opposite sides of the facestock 101. For example, the ink layer 117 may be applied to the top side of the facestock 101 and the adhesive layer 103 may be applied to the bottom side of the facestock 101.

Fig. 10 is a schematic view of a labeling process. Referring to fig. 10, according to an embodiment, individual labels from a web roll (e.g., a roll of printed or unprinted film or paper) travel through an unwind station, a print station (optionally, may or may not be included), a coating station, a curing station (optionally, may or may not be included), an accumulation station (optionally, may or may not be included), a splitting station, and the time required to complete the application of the labels is less than 60 seconds. In another embodiment, the time required for an individual label from a web roll (e.g., a roll of printed or unprinted film or paper) to travel through the unwind station to complete application of the label is less than 30 seconds.

In related art labeling processes, the label includes a facestock, an adhesive layer beneath the facestock, an anti-tack system in contact with the adhesive, and a liner beneath the anti-tack system. The facestock is printed with indicia (typically describing and advertising the product to be labeled). This printing is typically done on continuous (roll-to-roll) printing machines, producing a number of labels on and under a web of label paper. The upper portion of the label paper (facestock and adhesive layer) is then film cut to produce individual labels, which are still carried in roll form and supported by a liner. Typically, but not necessarily, the die-cut is performed on the same asset as the asset used for the printed label (asset).

The printed die cut label paper is then cut to provide single pass labels, and these cut rolls are then fed to the end user who will apply the labels to the products through a dispensing process. The end user applies the labels by feeding the die cut label paper to a dispensing machine wherein one label at a time is removed from the liner and applied to the product to be labeled. The anti-stick system allows easy removal of the adhesive-backed label from the liner. This is usually a continuous operation running at high speed (30-600+ labels/min), where the product to be labelled is presented continuously to the dispensing point for its labelling.

The residual liner, coated with an anti-sticking system, becomes a waste stream. These waste streams are collected on rewinders after distribution and can subsequently be landfilled or sold for low value reprocessing.

The above-described related art process has existed for over 50 years and the basic construction remains unchanged despite continuing efforts to improve the process (e.g., attempts to use thinner surfaces and thinner liner materials, and lower coat weights for adhesives and anti-tack systems, etc.). During this time, the industry has developed a huge scale, usually applying adhesives at very high speed (usually over 1000m/min) onto wide rolls (usually 2-3 meters wide) of anti-stick coated backing layers (films or papers). The adhesive coated on this release coating liner is laminated to a face (film or paper) web in the same process to form a label paper. Most labels are manufactured in this manner by a process commonly referred to as transfer coating. The adhesive may also be coated directly onto the facestock and then laminated with an anti-tack coated liner, which is commonly referred to as a direct coating process. For the majority of this time, the industry has sought to implement labeling methods for PSA-type materials without the use of liners and associated anti-stick systems, thereby significantly increasing the efficiency of the materials and supply chain, reducing costs, and eliminating the increasingly problematic waste streams.

In general, the methods of linerless solutions fall into one of two broad categories: a "linerless label" and an "activatable label".

Linerless labels, while eliminating the backing layer, retain the anti-tack system and thus do not realize the full cost potential of a truly linerless solution. This process typically starts with printing the facestock, followed by applying an anti-tack system to the printed facestock, and then coating the adhesive on the back side to produce a self-wound label paper without a liner. Typically, self-wound paper is produced on narrow web presses (narrow web presses) using expensive adhesives, typically UV curable hot melt adhesives, at much lower speeds (<1000m/min) than the speeds used for adhesive coating in the related art. The cost accumulation of smaller scale, higher cost adhesives, and the continued use of anti-stick systems means that part of the cost-effectiveness of eliminating the backing layer relative to conventional processes is lost, often the full cost-effectiveness. It should be noted that as the label paper passes through the supply chain and subsequent dispensing process, the adhesive needs to have a modulus high enough to reduce or prevent it from flowing under the pressure experienced in the roll. To achieve this modulus, the adhesive must be cured (i.e., crosslinked). If the adhesive is uncured it can flow under the pressure of the roll, causing contamination of the label edges (due to edge bleed), aesthetic concerns, and problems with high speed unwinding of the roll (during dispensing) because such bleed tends to cause the roll to become lumpy. This need for higher crosslinking (via curing) necessitates the use of higher adhesive coat weights to achieve the desired tack and adhesion to the target surface, further driving costs.

Another challenge faced by this approach is that at the point of dispensing, individual labels (also referred to as "splits" in this description) are produced from the label paper by the end user. The division can only be made at the dispensing point, since no backing layer carries the pre-die cut label to the dispensing point. One way to address this challenge is to use a reusable liner at the point of dispensing. This allows the label to be cut, slit from the web and then carried by the temporary liner to the dispensing head. The reusable liner reduces the cost effectiveness of this solution (because the liner is reintroduced) and increases the complexity of the process. Another approach to the problem of dispensing linerless adhesive systems is to utilize labels that are "weakened" within the web prior to dispensing. In this solution the circumference of the label in the web is weakened by slits or perforations. This "weakening" is typically done on-press (and would replace conventional die cutting) so that the weakened self-wound material can be provided to the end user in a ready-to-use state. The line of weakness of each label includes at least one aperture which provides engagement by a tool which can be used to break the weakened region upon dispensing, thereby separating the leading label in the web and allowing it to be applied to the product. In this solution, the labels are carried from the roll to the dispensing point, but are easily removed from the roll. While such solutions address the distribution challenge, it is observed that their adoption is limited, as the limited cost advantages of the overall solution do not justify the additional complexity of distribution.

Activatable labels involve the application of a special coating or overlay to the adhesive system (essentially replacing the liner and release system) or to have an adhesive system that is non-tacky at room temperature. In these solutions, a separate process, just before the labelling, either removes the coating/covering to "uncover" the veil of adhesive or activates the adhesive by an external stimulus such as heat or liquid. The activatable label is provided to the end user in a non-tacky state and then the label is activated, i.e., the adhesive of the label is exposed (activated) to a tacky state prior to application to the intended product. Obviously, the activatable label is printed prior to activation. The detailed scheme comprises the following steps: heating the adhesive using ultraviolet ("UV") energy; corona treating the activated surface; heating the adhesive by radiant heat; moisture-activated rewettable adhesive; microencapsulating the activator material, which can then be crushed to allow the activator to mix with the rest of the formulation and activate the adhesive; covering a debonding agent layer on the adhesive, and then removing the debonding agent layer by heating or mechanical means; and activating the adhesive by ultrasonic energy.

To date, the most common activation schemes have utilized heat activation, including schemes that remove protective coatings or utilize heat activated label adhesives. Various techniques have been proposed for thermally activating adhesives. The adhesive remains tacky for a short period of time, defined as an open time between 0.2 and 10 seconds, during which time the adhesive must be applied to the container. In addition, general methods of heating using radio frequency ("RF") energy, inductive heat, radiant heat, and visible light are also well known and can be applied to this list of activation methods. These techniques may have some utility for low speed operations, but as the application speed of high speed labeling increases, these methods all deteriorate because the time the label must be exposed to the heating element must somehow be increased in order to obtain sufficient heating. The size of the device capable of providing sufficient heating and the costs incurred at the same time prevent high speed application.

While all of the above-described prior art activatable label solutions do eliminate the liner and anti-tack system, and thus the waste stream, they replace them with another, often relatively expensive, material, adding complexity, and again not meaningfully improving cost. Cost issues arise from the use of generally expensive components or expensive additives/processes to produce non-tacky adhesives in specialty coatings that mask the adhesive. Furthermore, additional process assets are required to remove coatings or activate adhesives, which also increases the cost of the overall solution. Finally, it remains challenging to cut labels at the point of dispensing (without a carrier web as previously described). As discussed, there are related art methods of partitioning at distribution points, but these methods add complexity, and the cost of the proposed activatable label solution does not justify the involvement of the end user in this additional complexity.

Finally, it should be noted that the final adhesive after activation is typically atomized (hazy) due to the generally complex formulation required to render the activatable adhesive non-tacky. If the adhesive is atomized, a significant portion of the label market, the so-called "clear on clear" labels, cannot be addressed. For transparent on, a transparent printed film with a transparent adhesive is applied to the product and only the printing is apparent, allowing the consumer to see the product under the label. If the adhesive is misted, the appearance is unacceptable.

The labeling process of the disclosed embodiments provides a number of improvements over related art PSA labeling. First, it does not require a liner and an anti-stick system. This has significant cost and environmental benefits. Unlike other methods, the excluded material is not replaced by another material. The use of hot or warm melt adhesives, for example, at low coating weights, saves material costs while providing the desired adhesive properties. Small adhesive application devices (e.g., for coating on a roll comprising only a single label web, rather than a wide roll comprising multiple labels) are included in labeling systems (i.e., new coating and dispensing systems). The cost of the coating device can amortize over years of operation and thousands of labels, and does not substantially increase the overall cost of the solution. In addition, the coating apparatus replaces the large coating assets used in traditional PSA labeling processes.

The labeling process and system of the disclosed embodiments also provide the ability to significantly simplify the supply chain. In deployments where printing is done at the end user location, the need for adhesive coaters and liner manufacturers is eliminated (essentially two steps taken from the value chain). In deployments where printing and dispensing is entirely streamlined by the end user, printers are excluded from the supply chain. These improvements provide efficiency and cost advantages, and in addition, provide great flexibility to the end user's supply chain and the ability to customize tags.

Another method of high speed labeling without the use of PSA is the system known as "Cut and Stack". The labeling system is primarily for paper labels, and comprises the following typical steps: first, labels are printed on the paper facestock, typically on a roll-to-roll printer. Labels are die cut from the printed facestock and then stacked into a carton (magazine). It should be noted that the shape of the tag is generally limited to a square or rectangle. Typically, this die cutting and stacking occurs at the end of the printer. The stacked labels are then delivered to the end user who loads the cassette into a feeding system, removes individual labels from the system and wipes them with a water-based adhesive. The wiped labels are then transported to a dispensing point where they are applied to a product.

The cutting and stacking process is typically used for high volume applications and provides an inexpensive paper label form. However, this system is only useful for paper labels. For film labels, the quality is insufficient, especially when a transparent label appearance is required, i.e. transparent on clear applications. In addition, it is difficult to effectively dry water-based adhesives with film facestocks.

The labeling system of the disclosed embodiments provides a cost-effective alternative to cutting and stacking, and enables the use of film facestocks. Similar to cutting and stacking, the labeling system of embodiments of the present disclosure uses only printed facestock and adhesive. However, the system of the disclosed embodiments utilizes a high performance, transparent and non-aqueous based adhesive (which does not require drying). Such adhesives are suitable for labeling paper and film facestocks and provide a very high quality final appearance. Warm melt/hot melt adhesives also provide water resistance, water whitening resistance and water bath immersion resistance, which are critical for transparent labels on bottles immersed in ice chests. In some embodiments, the substrate is a plastic film and the entire laminate remains transparent after exposure to heat to tackify the release layer, thereby forming a transparent label that provides a no-label appearance to the product to which the transparent label is applied. These square or rectangular film labels may be die cut and stacked in a box. In one embodiment, the cutting and stacking is performed in a manner similar to conventional cutting and stacking of labels. In another embodiment, the labeling system has a debonding PSA that is activated only prior to application to the bottle, rather than a wet glue. In another embodiment, the film need not be perforated because the die cutting is performed after coating the PSA and applying the release layer on the PSA. In another embodiment, the facestock may be paper with a debonding adhesive on one side and a print layer on the other side. Just as with cutting and stacking of the debonded labels, these paper labels may be die cut, stacked and activated prior to application.

According to embodiments of the present disclosure, a pressure sensitive adhesive label is comprised of a facestock, indicia on the facestock, and a pressure sensitive adhesive on the facestock, wherein the coating weight of the pressure sensitive adhesive is from about 3gsm to about 20gsm and the 180 ° peel is from about 1N/inch to about 20N/inch.

Any PSA that does not exhibit edge bleed and is used to make coated film or paper roll label stock can be used. In an embodiment of the invention, the debonding layer has the following properties: (i) it covers the PSA layer and renders the face film non-tacky, (ii) it does not migrate or push completely into the PSA layer under roll storage and transport conditions at a pressure of about 15-50psi and a temperature of about 50 ℃, (iii) it allows the roll to be wound and unwound without sticking, (iv) it converts readily into a tacky material under the influence of an external heat source in less than 4 seconds, preferably less than 1 second, to adhere to the product at high web speeds, i.e. a dispensing web speed of about 150fpm, (v) it does not alter the clarity or aesthetic appearance of the label, (vi) it forms a strong bond with the product, i.e. does not significantly reduce the adhesion of the PSA to the product, (vii) it is compatible with the PSA, and (viii) it does not alter the aesthetic appearance and clarity of the label after long term aging of the product by crystallization or incompatibility or other means.

In another embodiment, the debonding layer does not have all of those properties listed in (i) to (viii) above. Having some of the properties listed in (i) to (viii) above may be sufficient to act as a debonding layer. No external stimulus or process is required to remove or sublimate such debonding layers. In the case of thermal radiation or NIR, such detackifying materials of embodiments of the present invention become tacky and mix with the PSA without substantially changing the PSA properties or transparency. For paper labels or opaque or translucent film labels, properties (v) and (vii) are not necessary because the adhesive is not visible through the label paper by the consumer. Any material having all or some of the above properties may be used as the debonding material. Examples of such debonding materials include commercially available or laboratory synthesized tackifiers, plasticizers, tackifiers or plasticizers with or without other materials, combinations of tackifiers with plasticizers with or without other materials, combinations of several tackifiers by themselves or with other materials, combinations of several plasticizers by themselves or with other materials, or combinations of several tackifiers with several plasticizers by themselves or with other materials, other materials in addition to tackifiers or plasticizers having some of the characteristics listed above, and combinations thereof.

In one embodiment, a blend of solid plasticizer and solid tackifier in a weight ratio of 75:25 to 25:75 is used as a debonding layer on a PSA surface that becomes tacky when exposed to heat. The materials and blend ratios are selected to be compatible with the PSA. Accordingly, the clarity and adhesive properties of the resulting PSA with the blend of plasticizer/tackifier combination are defined as an indication of compatibility. For clear film label applications, the compatibility needs to be high enough so that the label retains a clear and label-free appearance both initially and after extended periods of time on the container. For paper label and non-transparent film label applications, limited compatibility noted by slight fogging or blushing is acceptable since the adhesive is not visible to the consumer. However, in the case of both clear and paper labels, compatibility must be good enough not to compromise adhesive properties. Further definitions of the compatibility of polymer blends, defined by the solubility parameters of the individual components, can be found in the literature, for example, Handbook of Pressure Sensitive Adhesive Technology, Second Edition, Edited by Donatas stands, Van Nostrand Reinhold, NY, 1989.

Plasticizers that are compatible with PSAs function to lower the glass transition temperature (Tg) and lower the modulus of the PSA. Tackifiers compatible with PSAs function to raise the Tg of the PSA and lower the modulus. By using such blends of solid tackifiers and solid plasticizers as debonding layers, the Tg of the PSA is not substantially increased or decreased when melted and compatible with the PSA, and thus the adhesive properties are not substantially changed and remain virtually unchanged or slightly improved. In one embodiment, the Tg of the PSA blend is within. + -. 10% of the Tg of the PSA. In another embodiment, the Tg of the PSA blend is within. + -. 25% of the Tg of the PSA. Furthermore, as both the tackifier and the plasticizer reduce the modulus, the wet through behavior of the PSA on the container (e.g., glass or plastic or any other substrate) is maintained and/or improved, and the PSA properties are also maintained and/or improved. In yet another embodiment, a blend of solid plasticizer and solid tackifier in a weight ratio of 98:2 to 2:98 is used as a debonding layer on a PSA surface, wherein the debonding layer becomes tacky when exposed to heat. In some embodiments, the compatibility of the debonding layer with the PSA may be limited, as evidenced by a slightly hazy or opaque film of the blend for applications where the clarity of the label is not important or for use in an opaque or translucent paper label or film label. In some embodiments, the Tg of the PSA blend may be substantially higher or lower than the Tg of the PSA.

Any material or combination of materials meeting the above requirements is suitable as the debonding material. In some embodiments, the material is a solid plasticizer, such as Uniplex 260, 512, 552, 280CG manufactured and supplied by Lanxess Corporation. These are benzoates with relatively sharp melting points and can be easily melted by IR or thermal radiation. The Melting Point (MP) of Uniplex 260 (glycerol benzoate) was 70-73 deg.C, the MP of Uniplex 512 (neopentyl glycol dibenzoate) was 49 deg.C, the MP of Uniplex552 (pentaerythritol tetrabenzoate) was 100 deg.C, and the MP of Uniplex 280CG (sucrose benzoate) was 93 deg.C. These materials are also relatively compatible with several acrylic PSA compositions. These plasticizers may be further mixed with components such as carbon black to improve IR sensitivity, additives such as fumed silica (Evonik) to increase modulus and antiblock (resistance to blocking) and modify rheology

200, R202 or R805), components which prevent crystallization of the plasticizer and which influence the transparency, for example solid tackifiers (Eastman Foral)^TM85E) Other additives that alter viscosity, increase activated viscosity, and the like. These materials may be used alone with the plasticizer, or in combination, or with other ingredients. In one embodiment, the debonding layer may be made of only the adhesion promoter. In another embodiment, the debonding layer may be made from only the plasticizer. In yet another embodiment, the debonding layer may be made from a combination of plasticizers and tackifiers in proportions such that the composition is transparent and tacky after exposure to heat or NIR radiation. In another embodiment, the tackifier or plasticizer, alone or in combination, may be combined with other ingredients to form a mixture comprising the detackifying material which retains its transparency and tackiness after being subjected to heat or NIR radiation. In addition to enhancing compatibility, these other ingredients may further add other features, such as NIR sensitivity.

The release layer can be applied to the adhesive surface in a variety of ways. In some embodiments, the detackifying layer can be a continuous layer or a discontinuous layer on the surface of the PSA layer. In some embodiments, when discontinuous, the release layer covers at least 60% of the PSA surface. In other embodiments, the debonding layer is discontinuous and covers at least 50% of the PSA layer surface. In some other embodiments, the debonding layer is discontinuous and covers at least 40% of the PSA layer surface. In some embodiments, the detackifying layer is discontinuous and covers at least 30% of the surface of the PSA layer. In some embodiments, the detackifying layer is discontinuous and has a surface coverage of less than 100% of the surface of the PSA layer. In one embodiment, the release layer may be coated onto the PSA surface by using conventional coating techniques such as roll coating, die coating, and the like. Coat weights of from about 3gsm up to about 25gsm may be used.

In another embodiment, the release material may be sprayed onto the PSA surface by: blends of plasticizers/tackifiers/rheology modifiers and/or other ingredients or additives are melted and then used such as Nordson Universal^TMSprayer such as nozzle systemIt was sprayed onto the PSA surface. The spraying may be done in such a way that the detackifying material is not cured or is partially cured or is fully cured before reaching the PSA surface. The melt rheology and surface tension of the detackifying material may be adjusted and the spraying conditions selected to obtain a continuous thin layer of detackifying material on the surface of the adhesive or a discontinuous layer may be obtained. In yet another embodiment, the release layer may be deposited on the PSA surface by a contact printing technique, such as screen printing, or a non-contact technique, such as inkjet printing. The detackifying material may also be deposited on the PSA surface by spraying or dusting or depositing a layer of powder on the PSA surface in a variety of ways, such as spraying, sprinkling, electrostatic deposition, and the like.

In one embodiment, the detackifying material is added in a continuous process by spraying the detackifying material onto an adhesive coated web being transported at a speed lower than the spray outlet. In one embodiment, the spraying is performed using standard powder spraying methods, wherein the powder is fluidized and pumped through a nozzle to produce a powder spray that is deposited on a roll of adhesive as it passes under a spray head. The operation is carried out in a closed "compartment" in order to control the overspray. In one embodiment, the overspray is recovered and may be reused. The amount of powder deposited on the web is controlled by the speed at which the spray is emitted from the nozzle and the speed at which the web travels. In one embodiment, the amount of powder deposited on the web and measured in grams per square meter (gsm) is from 2gsm to 40 gsm. In another embodiment, the amount of powder deposited is greater than 40 gsm. In one embodiment, the detackifying magic powder has a particle size distribution of 0.01 μ to 500 μ. In another embodiment, the detackifying powder has a particle size distribution of from 1 μ to 200 μ. In yet another embodiment, the detackifying powder has a particle size distribution of from 1 μ to 100 μ. In one embodiment, for a wide adhesive roll, an array of spray heads may be used. In another embodiment, the powder may be sprayed shortly after the adhesive coats the web. In another embodiment, the coil may be rewound immediately after spraying the powder. In another embodiment, the powder is sprayed at a suitable point between the adhesive coated web and the web rewind.

In one embodiment, the release layer and PSA layer may be coated as a bilayer in a single coating step. In another embodiment, a release layer is deposited on the PSA surface before or after the PSA is cured or crosslinked. In one embodiment, graphics and/or product information may be printed on the film facestock, the PSA is coated or sprayed on the non-printed side of the facestock, then the PSA is cured and a release layer is deposited (sprayed, sprinkled, dusted, screened, or coated) on top of the PSA. In another embodiment, the release layer may be placed on the PSA using transfer lamination or printing. In another embodiment, graphics and/or product information may be printed on the film facestock, the PSA is coated or sprayed on the non-printed side of the facestock, and then a release layer is deposited (sprayed, sprinkled, dusted, screened, or coated) on top of the PSA. The coating of the PSA and the deposition of the detackifying layer can also be done in one step using a two-layer coating technique. In one embodiment, the rolls of facestock as coated above are weakened at the beginning of any of the above steps, or after any of the above steps, or at the end of all of the steps. In another embodiment, the facestock is then cut to the desired width and then rolled for shipment to a consumer who will label the container.

In some embodiments, the pressure sensitive label laminate comprises a facestock, a PSA, and a release layer (DL), wherein the DL is applied to the PSA in a flow-line manner or by a secondary process whereby the DL forms a continuous solid layer. In another embodiment, the DL forms a discontinuous layer. The DL allows the resulting laminate to be rolled up and unrolled freely. Upon application of heat, the DL will melt in less than 2 seconds. In one embodiment, the DL melts in less than 1 second. PSA labels with melted DL on their surface have a tacky nature and can be immediately applied to a container. The molten DL forms an adhesive layer compatible with the PSA, allowing the adhesive to develop further rapidly, the adhesive being sufficient to apply the laminate to moving objects. In one embodiment, the DL layer does not have a deleterious effect on the tack and/or clarity of the PSA when mixed with the PSA over time. The PSA may have a coat weight of from about 5gsm to about 25gsm, most preferably from about 8gsm to about 15 gsm. In some cases, the PSA coat weight may be as high as 50 gsm.

In another embodiment, the printing and application is performed wherein the roll of release label laminate is passed through a heat source after printing. The roll is then cut to separate and the labels are applied with light pressure. In one embodiment, the label is applied using a vacuum tape. In another embodiment, the label is first segmented and then heat activated, followed by application of the label.

In some embodiments, a blend of plasticizer and tackifier is used, with the weight ratio of plasticizer to tackifier being from 75:25 to 25: 75. This ratio of materials becomes tacky and transparent when exposed to heat. In one embodiment, the heat exposure is at a temperature greater than about 85 ℃. In another embodiment, the heat exposure is at a temperature greater than about 50 ℃. Blends of plasticizers and tackifiers, as well as other additives such as rheology modifiers, IR susceptors, etc., are selected to be compatible with the PSA. DL comprises a blend of plasticizers and tackifiers, as well as other additives, if used. Having a PSA and DL (herein, "PSA blend") formed by migration of plasticizers and tackifiers and additives into the PSA, wherein the ratio of plasticizer to tackifier composition is from 75:25 to 25:75, prevents crystallization of the plasticizer and affects the clarity of the final PSA blend. If a plasticizer or tackifier is used alone, the final PSA/plasticizer or PSA/tackifier blend will over time cause whitening, thereby affecting the clarity of the label. Transparency is important for transparent labels applied to containers to achieve a label-free appearance. However, for paper labels or opaque film labels, transparency is not a critical feature.

The function of the plasticizer is to lower the Tg and lower the modulus of the PSA. The effect of the tackifier is to increase the Tg and decrease the modulus of the PSA. By using a PSA blend of plasticizer and tackifier, the Tg is not greatly increased or decreased. Any increase or decrease in Tg depends on the blend ratio. In some embodiments, the adhesive properties of the PSA blend are unchanged and remain at about the adhesive properties of the pre-blended PSA. In another embodiment, the adhesive properties of the PSA blend are enhanced compared to PSA properties, resulting in stronger and longer lasting adhesive bonds. Moreover, the modulus of the PSA blend is not greatly increased, thereby maintaining PSA properties and providing a wet through on the container similar to PSA over time. In one embodiment, the adhesive properties of the PSA are enhanced. The coating weight of the debonding layer may be from about 2gsm to about 20gsm, most preferably from about 6gsm to about 13 gsm. In some embodiments, the weight ratio of DL to PSA layer may be from about 9 DL% to 91% PSA layer (DLcwt of 3gsm and PSA coat weight of 30gsm) to about 67% DL to 33% PSA layer (DL cwt of 20gsm, PSA cwt of 10 gsm). Thus, the weight percent of DL in the PSA blend may be from about 9% to about 67%. If the coating weight of the PSA is lower or higher, the range of the DL percentage may be higher or lower.

In some embodiments, the weight ratio of PSA layer to debonding layer is from about 2:1 to about 10: 1. In some embodiments, the weight ratio of PSA to debonding layer may be from 1:5 to about 10: 1. In other embodiments, the weight ratio of PSA to debonding layer may be from 1:2 to 10: 1. In yet another embodiment, a detackifying layer is on top of an adhesive layer that is not a PSA, and such non-PSA layer becomes a PSA when one or more components of the detackifying layer migrate from the detackifying layer into such non-PSA layer.

In one embodiment, the laminate of the present invention comprises a non-PSA adhesive. In another embodiment, the debonding layer is not removed by sublimation or dissolution using heat, solvents, or other processes. In yet another embodiment, the debonding layer does not comprise a material that does not become tacky when exposed to heat. In another embodiment, the function of the debonding layer is to blend with the PSA upon exposure to heat to provide an adhesive surface having at least the same or better adhesion properties as the PSA, and the function of the debonding layer is not to expose the underlying PSA surface simply by migrating into the PSA upon application. The debonding layer becomes tacky upon exposure to heat or radiation, and the tacky debonding layer begins to blend with the base PSA layer to form a PSA blend. The process of blending the tacky release layer with the base PSA layer begins shortly after the release layer is tackified, and it takes more than one hour to blend a majority of the release layer with the PSA layer to form the PSA blend. In another embodiment, it takes about one hour to blend the majority of the debonding layer with the PSA layer to form the PSA blend.

In some embodiments, the film or paper substrate is coated with a conventional PSA that is inherently tacky. In another embodiment, the surface of the PSA is covered with a debonding layer comprising (i) at least one tackifier or (ii) at least one plasticizer. In one embodiment, the surface of the PSA is covered with a debonding layer comprising a mixture of at least one tackifier and a plasticizer in a tackifier/plasticizer weight ratio of from about 25:75 to about 75: 25. In another embodiment, the debonding layer mixture has a melting point of at least 85 ℃ or more. In another embodiment, the debonding layer has a melting point greater than about 50 ℃. In one embodiment, the coverage of the debonding layer on the PSA surface is at least 60% of the PSA surface. In another embodiment, the coverage of the debonding layer on the PSA surface is at least 30% of the PSA surface. In another embodiment, the debonding layer is a discrete solid form in the shape of a sphere, ellipsoid, silk, or the like. In some embodiments, the covering is achieved by spraying, sprinkling, sieving, dusting, printing, or coating the release layer onto the PSA surface. In one embodiment, the release layer coating on the PSA comprises a powder coating. The surface of the paper or film without the PSA is free of any anti-tack material so as to be capable of being printed by indicia at any stage of the label making or dispensing process in which flow lines pre-weaken or weaken the film or paper substrate to effect label splitting and dispensing without the need for a carrier anti-tack liner. In one embodiment, the detackifying layer is tackified using thermal or IR radiation with an exposure time of less than 3 seconds. In another embodiment, the PSA blend becomes tacky after exposure to heat and/or radiation and retains the tackiness for at least one hour or more.

The DL layer remains tacky for a long period of time after heat (or IR or NIR) exposure, allowing the DL layer and PSA blend to flow into the roughness and contours present on the surface of the container to which the label is applied, thereby displacing air in these rough, well-defined areas. This air venting from the roughness and contours allows the label to take on a "no label" appearance, which is aesthetically desirable for many applications where it is desirable that the label appear not to be a label but rather a portion of the container. In one embodiment, the DL layer remains tacky for more than 30 minutes. In another embodiment, the DL layer remains tacky for about one hour. In another embodiment, the DL layer remains tacky for more than one hour. In some embodiments, the release layer can be tackified in less than 3 seconds when exposed to a source of heat or infrared radiation, and after tackification, the release layer becomes permanently tacky and remains tacky, beginning to blend with the PSA layer to form a PSA blend that is also permanently tacky.

In one embodiment, the laminate comprises a facestock and a PSA, wherein the facestock is in contact with the first or lower surface of the PSA. The second or upper surface of the PSA includes a plurality of filaments and/or ellipsoids sprayed on the upper surface of the PSA. The filaments and/or ellipsoids have different shapes, lengths and/or thicknesses disposed in a random distribution on top of the upper surface of the adhesive, and at least two of the plurality of filaments and/or ellipsoids partially overlap each other. In some embodiments, the filaments and/or ellipsoids are random and comprise a sprayed, printed, sprinkled, dusted, and/or brushed material applied to the upper adhesive surface to provide a random distribution of filaments and/or ellipsoids on the upper adhesive surface.

Friction test

A one inch wide sample of the laminate prepared in example 3, consisting of a PSA film coated with or without a release layer, was placed on a stationary stainless steel panel. When a debonding layer is present, the debonding layer contacts the stainless steel panel. A 200 gram weight was placed on top of the laminate and the end of the laminate was attached to a Fish Scale AdiyZ portable electronic Scale. The digital scale was pulled at a constant speed of 3.85 feet/minute while the laminate was threaded through the stainless steel panel with a weight of 200g on top of the tape. The frictional force of the debonding/pressure sensitive adhesive layer through the stainless steel panel with a weight of 200 grams on the laminate was recorded in pounds (lb).

Detackifying coating weight measurement

The coat weight of the debonding layer on the pressure sensitive adhesives of examples 3-5 was gravimetrically measured by first measuring the weight of the 2 inch x 2 inch area of the pressure sensitive adhesive with the film and then subtracting it from the total weight of the debonding layer/pressure sensitive adhesive/film.

Detackifying surface coverage measurement

Digital photographs of the debonded pressure sensitive adhesive surface of example 3 were taken using an Ablegrid 2Megapixel USB digital microscope. Images were analyzed using an ImageJ analyzer, which is NIH freeware. Surface coverage was recorded as a percentage of the total area covered by the release layer.

Adhesion test (blocking test)

The PSA covered with the detackifying powder of examples 3-5 was cut to the desired size (0.3 "x 0.3" or 0.42 "x 0.42" square) and this covered surface was covered with a PET film and the sandwich (sandwich) was placed in an oven at 50 ℃ with a 2kg weight placed directly on top. This corresponds to 48.9psi pressure in the case of a 0.3x0.3 square, or 25psi pressure in the case of a 0.42x0.42 "square. Samples were removed after 7 days and checked for adhesion between PSA and PET films.

180 degree peel test

A half inch or 1 inch strip of the PSA laminate prepared in example 3 was adhered to the glass panel with the tacky surface next to the panel and adhered to the panel by rolling back and forth with a 2kg rubber roller. After the laminate had been left on the panel for a fixed time (0, 30 minutes or 1 hour), 180 ° peel was measured using a Labthink XLB (B) automatic tensile tester (Labthink Instruments co. ltd.) with a separation speed of 300 mm/min. Unless otherwise indicated by the examples, the residence time after lamination to the glass panel is typically 30 minutes. An average of 3-5 samples was tested and the average 180 ° peel data was expressed as N/inch laminate width (N/in).

The following tables and examples illustrate the performance of the adhesive on various surfaces.

Example 1:

hot melt adhesive from BASF using a slit die

A250UV was coated on an anti-tack liner at 0, 15 and 30mJ/cm²UV curing is carried out. After curing, it was laminated to 1mil or 2mil polyester film to test adhesion to glass, HOPE, and Stainless Steel (SS) panels. The adhesive on the 1mil or 2mil PET film was laminated to the respective panels, wound up and down with a 2kg rubber roller, and allowed to stand on the panels for various periods of time as listed in table 1. 180 ° peel adhesion was measured using a Lab Think XLB (B) automatic tensile tester (Lab Think Instruments co. ltd.) at a speed of 300mm/min, with the reported peel value being the average of 3-5 measurements.

Example 2

Except that Henkel UV curable adhesive UV 5321 was used instead of

Except for a250UV, the sample was prepared substantially similarly to the sample of example 1. The test data are shown in table 2.

TABLE 1

Foral^TM85E from Eastman, was used as a tackifier.

TABLE 2

A truly linerless labeling process and system has been described that eliminates the liner and anti-stick system. The labeling process applies the pressure sensitive adhesive in-line while dispensing the labels. Further, printing of all or part of the label graphics may be performed on the label paper along with dispensing. A hot melt or warm melt adhesive or UV curable syrup (or other suitable energy activated adhesive) is applied to the label facestock in a single continuous process, optionally rapidly cured, and then the singulated labels are dispensed onto a product (e.g., bottles or containers) to achieve a low cost waste-free system. This system eliminates the liner and anti-stick system and provides significant supply chain advantages (since the label is produced at the point of use). The invention described herein provides a meaningful reduction in the amount of adhesive needed (in some cases reducing the adhesive by more than 50%). In addition, the present invention also allows for a meaningful reduction in the thickness of the facestock. In addition, each layer of material used in the label manufacturing and application process remains on the final applied label and there are never other layers (such as liners and/or anti-tack systems) in the label and in the manufacturing or application process that need to be removed when the label is dispensed. In summary, the present invention significantly reduces the overall material usage and the attendant environmental footprint of PSA labeling.

Examples 3.1 and 3.2:

mixing BASF

A-250 was coated on a 1mil PET pre-perforated facestock at a coat weight of 10gsm and at 30mJ/cm²UV curing is carried out. The PSA surface was sprayed with the Uniplex plasticizers listed in tables 3.1 and 3.2. Spraying/sprinkling/depositing/sieving was performed using a 75 μm sieve to obtain uniform powder surface coverage. The coating weight of the plasticizer was measured gravimetrically. The labels detackified with plasticizer are heated on a hot plate or using an infrared lamp. The surface temperature of the PSA was measured using an IR thermometer. The label after exposure to thermal radiation is applied to the glass panel. 180 ° peel was measured as in example 1. The friction, surface coverage and debond coat weight of the labels prior to heat activated exposure were measured according to the test methods described in the specification. The transparency was measured visually. While labels with some plasticizers show clear coatings at lower coating weights, at higher coating weights crystallization leading to haze is noted, making them unsuitable for clear label applications.

Tables 3.1 and 3.2

TABLE 3.1

TABLE 3.2

PSA-1mil PET coating with BASF

A-250 at 30mJ/cm²UV cure dose and 10gsm coat weight cure

x-tal ═ crystal

Adhesive, 0.3"x 0.3" sample, 4.4 pounds weight, in a 50 ℃ oven

552-Uniplex 552 plasticizer

F85＝Foral^TM85E tackifier

Example 4:

combining Uniplex552 with Foral^TM85E tackifier is blended at a weight ratio of 25:75, 50:50 and 75: 25. The blend was melted at 100 ℃ and then coated on a transparent polyester film to visually evaluate the transparency. Also separately coated with Uniplex552 and Foral^TM85E, and evaluating the transparency. Initially, all of these coatings were transparent. After 2 days, the initially transparent Uniplex552 coating turned white, Uniplex 525 and Foral^TMThe 75:25 blend of 85E became cloudy. Oral^TM85E is transparent, and Uniplex552 and Foral in the ratios 50:50 and 25:75^TM85E is also transparent. All three blends of plasticizer and tackifier in ratios of 75:25, 50:50 and 25:75 were tacky when exposed to heat and exhibited rapid adhesion to the glass panel. The blocking test showed that the ratios of 50:50 and 25:75 were sprayed on BASF at a coat weight of 13gsm

A-250 (coated on 1mil PET at 10gsm and at 30 mJ/cm)²Cured) does not stick. Uniplex552 and Foral at a ratio of 65:35^TM85E at 13gsm sprinkled in BASF

A-250PSA surface and heated to 110 ℃ on a hot plate. The PSA surfaces were tested for tack after 1, 10, 30 minutes and 1 hour. In all of these cases, the surface had tack immediately after heating and remained tacky after 1 hour, indicating that the open time of this PSA was at least one hour. Peel of the 50:50, 65:35 and 25:75 blends was measured by: these radiation exposed surfaces were left open for various periods of time after which an open, tacky PSA surface was applied to the glass panel, then left on the glass panel for 30 minutes, followed by measurement of peel. After exposure to heat to melt the debonding layer, the 65:35 blend peeled 9.6, and 8.5N/inch on glass (after 30 minutes dwell on the glass panel) after 0, 30, and 60 minutes open time. After exposure to heat, the 50:50 blends exhibited peels of 10, 12 and 11N/inch after 0, 30 and 60 minutes open time. These long open times are particularly useful because they allow the label to wet out on the surface of the container being labeled and provide a no-label appearance.

Example 5:

mixing BASF

A-250 was coated on a 1mil PET pre-perforated facestock at 10gsm and at 30mJ/cm²UV cure was performed followed by spraying 6.1gsm of Uniplex552 plasticizer. The coated surface was exposed to a 7200watt/208volt/35amp Heraeus carbon infrared emitter (Trinity module) for 1 second using an automated shutter. The power level was 100 watts per square inch. The distance between the sample and the emitter was 3 inches. After exposure, the heated label was applied to the glass panel and after about one week the peel was measured to be 6.4N/inch. This example shows for 2.5 inches installed in the web path in the machine directionThe foot print of the IR apparatus, the web, can be run at a speed of 150 feet/minute to achieve an exposure time of 1 second to tack the release layer. Under these conditions, the adhesive becomes tacky to apply it to the product. By making the IR device longer or increasing the power, even shorter dwell times and thus higher web speeds can be achieved.

Example 6:

mixing BASF

A-250 was coated on a 1mil PET pre-perforated facestock at 10gsm and at 30mJ/cm²UV cure was carried out followed by spraying 6.1gsm and 13gsm of Foral 85E tackifier. The two atomized release layer spray surfaces were contacted with a hot surface maintained at 140 ℃ for about 2 seconds. Under these conditions, complete melting of the debonding layer was observed. These activated films were applied to a glass panel and very slight fogging of the coated laminate on the glass was observed, but exhibited transient adhesion to the glass. Within 2 hours, a slightly higher haze (haziness) was observed, but the adhesion to the glass substrate was good.

Typical examples of the use of the embodiments of the present invention for illustrative purposes are as follows.

The label paper manufacturer coats the PSA on a conventional film or paper roll, applies a release layer to the adhesive surface, rolls it, and then ships the master roll or converting (slitting) roll to the processor.

The fabricator takes the parent roll, cuts it as needed, prints it on the other side of the adhesive coated side, and then forms a smaller roll (single lane label roll) for shipment to the consumer. The perforation in this step can be performed before or after printing. In this example, in some cases, the processor may pass the parent roll through a cleaning station (e.g., by using a tacky roller or air flow or otherwise) prior to printing to remove any detackifying material that may have been transferred to the printing surface during transport and/or storage.

The adhesive coater can be bypassed by applying the adhesive at the processor. One advantage of this approach is that it eliminates the creation of large parent rolls that must be shipped to the processor. In large parent rolls, high pressure at the parent roll core may cause stiction (i.e., the debonding layer may not prevent the PSA from sticking to the back of the face material or facestock). The steps followed here are as follows:

pre-slit film roll or web printing, adhesive application, and application of a detackifying layer on the adhesive surface are all performed in a single operation on a printing press. Pre-weakening of the web may be performed at any stage of the process, i.e. before or after printing, or before or after adhesive coating, or before applying a release layer, or at the end of all these steps. In the process the roll is slit to form a single-pass roll.

This cut material is then sent to a labeling station where it is unrolled and the adhesive/debonding layer is converted to an effective PSA using NIR or heat. The now adhesive label is then cut from the pre-weakened roll and applied to the product. The process (spreading, detackifying of the detackifying layer and application onto the containers) is then continuous, incorporation being possible, if desired, at high labeling speeds (for example 600 labels/min).

The above steps can be performed in a variety of ways. In embodiments of the present invention, thermal radiation exposure using pre-weakened webs and release layers at the labeling system, as well as the elimination of all anti-tack material, are important features.

In some embodiments, the anti-stick system and associated liner that becomes a waste stream in a standard label supply chain is eliminated. In another embodiment, an anti-adhesive liner is used and the waste stream is reduced by allowing multiple uses of the liner composed of a low surface energy substrate. In one embodiment, after the release layer is applied, at the end of the coating process, the low surface substrate or release liner is rolled up with the roll so that it is between the release layer and the bottom surface of the substrate. A reusable liner material (interleaf material) is introduced into the label laminate before it is rolled up for storage and shipping. The low surface energy material forms a liner and helps prevent any potential blocking due to migration of the PSA through the release layer and into contact with the substrate, especially when the coverage level of the release system is low. When the roll is unwound for converting (weakening and/or printing), the linered material is removed and rewound to return it to the coating operation for reuse. The use of a linerboard material may allow for the use of a lower level of release material, whereby the release system may be converted to a tacky material more quickly during label application. This may be advantageous for labeling at very high speeds. The backing layer is paper or film based, coated on one or both sides with a low energy release composition. The anti-tack composition is based on a material that provides a low energy surface. Some examples are commercially conventional silicon-based anti-stick systems from suppliers such as Wacker, Momentive, Dow Chemical, and non-silicon-based compositions such as C14-Cl 8-based fatty acids, e.g., Quilon supplied by Zaclon, polyvinyl stearyl urethane supplied by Mayzo. In some embodiments, the release value is adjusted according to the PSA used and the surface coverage of the release layer.

In yet another embodiment, the release layer may be activated at the processor to form the PSA, and the release layer may be printed on top of the printed facestock to form a self-wound PSA construction. In this solution, the anti-stick layer is added at the processor site, but this means that no activation is required during the labelling process. In another embodiment, a label laminate is printed to form a label, which is cut, activated and applied to a container.

As discussed above, the key function of the release layer is to prevent the PSA from adhering to the facestock to be printed, thereby preventing blocking when the material is in roll form. In one embodiment, a release layer replaces the use of a liner and an anti-tack system. In industrial processes using liners, the pressure in large rolls can be very high (>50psi) at the core. In the system of the present invention, because a liner may not be used, the overall thickness of the laminate is lower, allowing the roll to be made smaller, which reduces the pressure at the core. In some cases, where the temperature may be higher, for example, during transport, thereby promoting adhesion, the incidence of adhesion and/or transfer of the debonding layer to the facing material may be mitigated by using much smaller (smaller diameter) rolls in each step of the process.

In one embodiment, spacers having a size greater than the size of the release layer may be sprayed on the PSA along with the sprayed release layer. In yet another embodiment, spacers having a size larger than the size of the debonding layer may be sprayed in a separate process than spraying the debonding layer. The spacers may be located on the PSA in a random or regular manner. Spacers may also be printed at regular intervals or randomly across the web, or at specific regular intervals, to further minimize the tendency of the web to stick under the high pressure conditions of manufacture and/or storage. In one embodiment, the size (diameter or height) of the spacers is at least 1.5 times or more (2, 3, or even 5 times the diameter of the debonding particles) the size (diameter or height) of the debonding particles of the debonding layer to relieve pressure exerted on the debonding particles in the roll. In another embodiment, the spacer is two times or more in diameter or height than the detackifying particles. In one embodiment, the spacer has a composition of detackifying material. In another embodiment, the spacers may be distinct, such as glass, ceramic, polymeric elastic particles, or other such microspheroidal particles or fibers or filaments. In some embodiments, the spacer particles may be hard, such as hollow or solid glass beads or particles, hard pigment particles, such as calcium carbonate, or rubber particles, such as highly crosslinked elastomeric particles. In another embodiment, the spacers are printed or sprayed or deposited by other means such as screening or dusting, before or just after application of the adhesive and before spraying, dusting, etc. of the detackifying layer. These spacers can be introduced in-line or in an off-line step. In one embodiment, the spacers are introduced prior to introducing the debonding layer on the PSA. In yet another embodiment, spacers may be printed on the printed side of the facestock to again minimize and/or eliminate the tendency to stick during manufacturing and/or storage by reducing the pressure on the detackifying particles.

In yet another embodiment, the detackifying layer may have particles, such as hollow glass microspheres or silica beads, that impart slipperiness to the label. These particles are selected to provide slip so that they stand or extend slightly higher than the detackified particles. With such slidable particles, the label can be moved around on the surface and then activated using heat or near infrared. In another embodiment, the label may be activated and still have slip properties due to the glass particles extending from the surface to provide the ability to move it around. In addition to PSA labels, this aspect of the release PSA layer is also suitable for other PSA applications. This aspect of slidability is also applicable to any application where a PSA is used, such as conventional PSA labels for envelope labeling, PSA tape for a variety of different applications, graphic applications where a PSA is used, such as promotional graphics, price marking graphics, fleet marking graphics for use on the side of trucks, and the like.

Although one or more embodiments of the present invention have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents.

It will be appreciated that several of the above-disclosed and other features and functions, or alternatives or variations thereof, may be desirably combined into many other different methods, systems, or applications. Also that various substitutions, modifications, changes or improvements may subsequently be made by those skilled in the art, which are also intended to be covered by the following claims.

In the description above, for purposes of explanation, numerous specific requirements and several specific details have been set forth in order to provide an understanding of certain embodiments. It will be apparent, however, to one skilled in the art, that one or more other embodiments may be practiced without one or more of these specific details. The described embodiments are not provided to limit the invention but to illustrate it. The scope of the invention is not to be determined by the specific embodiments provided above. In other instances, well-known structures, devices, and operations have been shown in block diagram form or without detail in order to avoid obscuring the understanding of the description. Where considered appropriate, reference numerals or terminal portions of reference numerals have been repeated among the figures to indicate corresponding or analogous elements, which may optionally have similar characteristics.

It should also be understood that, for example, reference in the specification to "one embodiment," "an embodiment," "one or more embodiments," or "different embodiments" means that a particular feature may be included in the practice of the specification. Also, it should be understood that in the description, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects. This method of disclosure, however, is not to be interpreted, or otherwise construed, as reflecting an intention that the invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects may lie in less than all features of a single disclosed embodiment. In another case, an inventive aspect may include a combination of the embodiments described herein or a combination of less than all aspects described in a combination of the embodiments.

Claims (22)

1. A label laminate comprising:

a film or paper substrate having a first surface and a second surface;

a layer of Pressure Sensitive Adhesive (PSA) having tack and having a first surface and a second surface, the first surface of the PSA being in contact with the second surface of the substrate; and

a debonding layer located on top of the second surface of the PSA layer, the debonding layer having a melting point greater than about 50 ℃, wherein the debonding layer has a surface coverage of less than 100% of the second surface of the PSA layer.

2. The label laminate of claim 1, wherein the weight ratio of the PSA layer to the debonding layer is from about 1:2 to about 10: 1.

3. The label laminate of claim 1, wherein the debonding layer comprises at least one plasticizer or at least one tackifier.

4. The label laminate of claim 1, further comprising a spacer on top of the second surface of the PSA layer and/or on top of the release layer to minimize blocking.

5. The label laminate according to claim 1, wherein the detackifying layer is provided in the form of a plurality of filaments and/or ellipsoids sprayed on the second surface of the PSA, having different shapes, lengths and/or thicknesses arranged in a random distribution on top of the second surface of the PSA, to form the detackified layer.

6. The label laminate of claim 1, wherein the debonding layer is provided in powder form.

7. The label laminate of claim 6, wherein said powder is sprayed on said PSA layer.

8. The label laminate of claim 1, wherein the surface coverage is obtained by spray, printing, spraying, sieving, transfer laminating, dusting, or powder coating the debonding layer on top of the second surface of the PSA.

9. The label laminate of claim 1, wherein said debonding layer is detackable in less than 3 seconds when exposed to a source of heat or infrared radiation, and after tackification said debonding layer begins to blend with said PSA layer to form a PSA blend, said debonding layer and said PSA blend having tack, and said debonding layer and said PSA blend remaining tacky for a period of at least 30 minutes.

10. The label laminate of claim 9, wherein the PSA blend has a glass transition temperature within ± 25% of the glass transition temperature of the PSA.

11. The label laminate of claim 1, wherein the substrate comprises at least a perforation line or a line of weakness configured to convert the label laminate into a plurality of individual labels.

12. The label laminate of claim 1, wherein the PSA is selected from acrylic polymers; acrylic copolymers such as vinyl acrylic acid; acrylic acid polymers with other comonomers such as dioctyl maleate and/or dibutyl fumarate; a polyurethane; a silicone polymer; copolymers of styrene and butadiene, styrene and isoprene, styrene and ethylenebutylene; and combinations thereof, with or without additives.

13. The label laminate of claim 1, wherein the PSA has a coat weight of from about 3gsm to about 50 gsm.

14. The label laminate of claim 1, wherein the first surface of the substrate is free of any anti-tack material, thereby enabling printing of indicia on the first surface of the label laminate.

15. The label laminate of claim 1, wherein the PSA is a hot melt pressure sensitive adhesive.

16. The label laminate of claim 1, wherein the pressure sensitive adhesive is an acrylic pressure sensitive adhesive comprising a tackifier.

17. The label laminate of claim 1, wherein said substrate is a plastic film and said label laminate remains transparent after exposure to heat to tackify said debonding layer, thereby forming a transparent label providing a no-label appearance to a product to which said transparent label is applied.

18. The label laminate of claim 1, wherein the label can be separated prior to tacking the anti-tack layer by an external heat source.

19. The label laminate of claim 1, further comprising a reusable liner material introduced into the label laminate prior to rolling the label laminate for storage and shipping.

20. The label laminate of claim 1, wherein said label laminate is die cut to provide labels, said labels being stacked to form a box for dispensing labels.

21. The label laminate of claim 1, wherein said label laminate is printed to form a label, which is cut, activated and applied to a container.

22. The label laminate according to claim 1, wherein the PSA is deposited on the film substrate or the paper substrate using a water-based system, such as an emulsion polymer or copolymer, or as a viscous slurry, or using a solvent, or as a hot melt that melts and coats above 100 ℃, or a warm melt that melts and coats below about 100 ℃.

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