Unlined Label

Abstract

This invention relates to a method for manufacturing a direct thermal linerless label web (100), the direct thermal linerless label web (100) comprising a surface (110) having a multilayer structure, the multilayer structure comprising at least three layers, the surface comprising a base layer (113), a direct thermal printable coating (115), and an intermediate layer (114) disposed between the base layer and the direct thermal printable coating, wherein the basis weight of the intermediate layer is 0.9 g / m². 2 Up to 7g / m 2 Within the specified range, the total amount of mineral pigments in the intermediate layer is equal to or less than 4 g / m³. 2 Furthermore, based on the total dry weight of the intermediate layer, the mineral pigment content of the intermediate layer is less than 85% by weight, preferably equal to or less than 75% by weight. The method includes: providing a surface (110), applying a water-based acrylic adhesive coating (121), and thermally drying the adhesive coating (121) into a pressure-sensitive adhesive coating (120). The water-based acrylic adhesive coating (121) is applied to the surface or to a carrier material. The method also includes: transferring the pressure-sensitive adhesive coating from the carrier material to the surface. The invention also relates to a direct thermal liner label web (100) and its application in on-demand printing.

Description

TECHNICAL FIELD

[0001] The present specification relates to a method for manufacturing a direct thermal linerless label web. The present specification also relates to a direct thermal linerless label web. The present specification also relates to the use of a direct thermal linerless label web in on-demand printing. BACKGROUND

[0002] Linerless labels with direct thermal facestocks can be used for a variety of purposes, such as for on-demand printing. However, it is well known that conventional linerless labels cause problems over time, especially in simple and low-cost on-demand printers. These problems can be due to the pressure sensitive adhesive being exposed without a protective release liner, resulting in the tacky adhesive contaminating the internal mechanisms of the printer, causing paper jams and requiring additional maintenance.

[0003] Furthermore, some pressure sensitive adhesives have traditionally been difficult to use in linerless labels containing direct thermal facestocks. Therefore, there remains a need for an improved but simple direct thermal linerless label product, and an improved method for manufacturing a direct thermal linerless label product that provides consistent and trouble-free performance. SUMMARY

[0004] It is an object of the present specification to provide a method of manufacturing a direct thermal linerless label web containing a pressure sensitive adhesive. Furthermore, it is an object of the present specification to provide a direct thermal linerless label web containing a pressure sensitive adhesive.

[0005] The features of the various aspects of the present invention are set forth in the claims. Some preferred embodiments are disclosed in the dependent claims. These and other embodiments are disclosed and are disclosed in the specification and drawings.

[0006] A method for manufacturing a direct thermal linerless label web comprising a face, the face comprising:

[0007] - a base layer,

[0008] - a direct thermal printable coating, and

[0009] - an intermediate layer disposed between the base layer and the direct thermal printable coating,

[0010] wherein,

[0011] - the grammage of the intermediate layer is between 0.9 g / m 2 and 7 g / m 2 ,

[0012] - the total amount of mineral pigments in the intermediate layer is equal to or less than 4 g / m 2 , and

[0013] - the mineral pigment content of the intermediate layer is less than 85 wt.%, preferably less than 75 wt.%, calculated on the total dry weight of the intermediate layer,

[0014] The method can comprise the steps of:

[0015] - providing a face,

[0016] - applying a water-based acrylic adhesive coating, and

[0017] - heat drying the adhesive coating into a pressure sensitive adhesive coating,

[0018] wherein,

[0019] i) applying the adhesive coating on the face,

[0020] or

[0021] ii) applying the adhesive coating to a carrier material, and the method further comprises:

[0022] - transferring the pressure sensitive adhesive coating from the carrier material to the face.

[0023] The speed of the adhesive layer during drying can for example be in the range of 100 m / min to 600 m / min.

[0024] Due to the novel solution employed, the problem of dusting of direct thermal linerless label webs in on-demand printers can be greatly reduced.

[0025] According to one embodiment, there is provided a method for manufacturing a direct thermal linerless label web comprising an adhesive coating, the adhesive coating comprising an emulsified silicone additive.

[0026] According to one embodiment, there is provided a method for manufacturing a direct thermal linerless label web comprising a patterned adhesive coating.

[0027] The direct thermal linerless label web comprises a face having a first side and a second side. The first side of the face can be the top side of the face, and the second side of the face can be the bottom side of the face. Further, the first side of the direct thermal linerless label web can be the top side of the linerless label web, and the second side of the direct thermal linerless label web can be the bottom side of the linerless label web.

[0028] The face can comprise:

[0029] - a base layer which is an uncoated base paper or film material,

[0030] - a directly thermal printable coating, and

[0031] - an intermediate layer between the base layer and the directly thermal printable coating.

[0032] Advantageously, for cost and environmental reasons, the base layer is an uncoated base paper having a grammage comprised between 38 g / m 2 and 82 g / m 2 The mineral pigment content of the uncoated base paper is preferably equal to or less than 18 wt.%, more preferably equal to or less than 16 wt.% to reduce the tendency of the product to dust.

[0033] The fiber content of the uncoated base paper can be equal to or greater than 50 wt.%, preferably at least 60 wt.% to increase the strength of the linerless label web and reduce the tendency of the product to dust.

[0034] The directly heat-sensitive printable coating of said face can have a grammage comprised between 1 g / m 2 and 5 g / m 2 .

[0035] The intermediate layer can have the following characteristics:

[0036] - a grammage comprised between 0.9 g / m 2 and 7 g / m 2 , preferably comprised between 1 g / m 2 and 5 g / m 2 ,

[0037] - a mineral pigment content less than 85 wt.%, preferably equal to or less than 75 wt.% calculated on the total dry weight of the intermediate layer, and

[0038] - a total amount of mineral pigments in the intermediate layer equal to or less than 4 g / m 2 , preferably equal to or less than 3 g / m 2 .

[0039] The face can further comprise a top coating on top of the directly heat-sensitive printable coating. The top coating can protect the directly heat-sensitive printable coating. The top coating can have a grammage comprised between 0.5 g / m 2 and 3 g / m 2 .

[0040] The top coating can comprise at least one of the following: starch, polyvinyl alcohol (PVA), latex and wax. Preferably, the top coating comprises polyvinyl alcohol (PVA) and / or wax. These polymers can be used to protect the directly heat-sensitive printable coating. Furthermore, the wax can improve the friction properties of the linerless label web. The top coating can further help to reduce the dusting of the linerless label web.

[0041] In addition to said face, the directly heat-sensitive linerless label web can comprise an adhesive coating. The adhesive coating is preferably a water-based acrylic adhesive. In one embodiment, the adhesive comprises a silicone additive.

[0042] Thus, in one embodiment, the direct thermal linerless label web can consist of the following listed parts:

[0043] - a face comprising at least:

[0044] - a base layer, preferably paper,

[0045] - a direct thermal printable coating, and

[0046] - an intermediate layer arranged between the base layer and the direct thermal printable coating,

[0047] - optionally, a release coating on said face, and

[0048] - an adhesive coating.

[0049] For environmental reasons, the linerless label web can be a paper-based direct thermal linerless label web. However, dust caused at least partly by the paper and the mineral particles in the intermediate layer can interfere with the labelling process and reduce the quality of the direct thermal printing, and eventually can cause damage to the print head. Thus, by minimizing the dusting of the paper-based direct thermal linerless label, long-term trouble-free printing of the paper-based direct thermal linerless label can be achieved. Due to the advantageous embodiments, the dusting of the paper-based direct thermal linerless label in the direct thermal printer can be reduced.

[0050] Depending on the printer model in question, dust and other contaminant residues in the label material can have a number of different adverse effects on the printer mechanism. Some of these effects are also interrelated, possibly reinforcing the overall negative outcome together. For example, the dust released by the thermal linerless label can wear out and shorten the service life of the thermal print head itself. But if the dust further accumulates on or around the print head due to some adhesive residue, it can also reduce the thermal contact of the print head with the label material, thus reducing the print quality. This can cause hot spots to appear in the printer head and / or require compensation by using higher print head energy, which in turn shortens the service life of the printer. Adhesive residue is often produced, especially when cutting the label material against a manual or motorized cutting mechanism to separate the printed individual labels. These residues can then either weaken the action of the cutting mechanism itself, or be slowly conveyed and built up on other internal components of the printer. Thus, the cutting performance of the adhesive layer itself plays an important role in how much adhesive residue is produced. The cutting phase is also the main dust source for the release of dust from the inner layers of the label material. Therefore, the present invention aims to particularly optimize the cutting phase by optimizing the properties of the thermal face substrate as well as the adhesive layer. This minimizes the negative effects associated with each of these layers / components individually, but also minimizes the further effects explained above that are interrelated.

[0051] The adhesive coating can comprise a water-based acrylic adhesive coating. The adhesive coating can further comprise an emulsified silicone additive. If used, the amount of emulsified silicone additive can range from 1 wt.% to 6 wt.%, preferably from 2 wt.% to 4 wt.%, calculated on the total dry weight of the adhesive coating. Thus, an improved usability of the linerless label for the printer can be provided by a cost-effective solution. Moreover, such an adhesive coating can still have good adhesive properties.

[0052] The adhesive coating can further comprise one or more than one wetting agent. If used, the total amount of wetting agent can range from 0.3 wt.% to 5 wt.%, calculated on the total dry weight of the adhesive coating.

[0053] The coating weight of the adhesive coating can range from 10 g / m 2 to 30 g / m 2 , preferably from 10 g / m 2 to 25 g / m 2 , calculated on the total dry weight of the adhesive coating.

[0054] The total coverage of the adhesive coating can be up to 100%, calculated on the total area of the second side. In one embodiment, the total coverage of the adhesive coating ranges from 10% to 90%, calculated on the total area of the second side. A reduced coverage can help to reduce dust and adhesive build-up on the cutting blade of the drop-on-demand printer.

[0055] The grammage of the intermediate layer ranges from 0.9 g / m 2 to 7 g / m 2 . In an advantageous embodiment, the grammage of the intermediate layer ranges from 0.9 g / m 2 to 5 g / m 2 , more preferably from 1 g / m 2 to 4 g / m 2 , most preferably from 1 g / m 2 to 3 g / m 2 . Thanks to the intermediate layer, the quality of the direct thermal coating can be improved. Moreover, the amount of expensive direct thermal coating needed to obtain good printability properties can be reduced.

[0056] The total amount of mineral pigments in the intermediate layer can be equal to or less than 4 g / m 2 . In an advantageous embodiment, the total amount of mineral pigments in the intermediate layer is equal to or less than 3 g / m 2 , more preferably equal to or less than 2.5 g / m 2 , most preferably equal to or less than 2 g / m 2The mineral filler can increase dusting of the face, which can cause clogging and other problems in a drop-on-demand printer. Therefore, preferably the total amount of mineral pigments in the intermediate layer is very low.

[0057] Furthermore, the mineral pigment content of the intermediate layer can be less than 85 wt.%. In one embodiment, the mineral pigment content of the intermediate layer is equal to or less than 80 wt.%, preferably less than 70 wt.%, more preferably less than 60 wt.%, most preferably less than 50 wt.%, calculated on the total dry weight of the intermediate layer. The mineral filler can increase dusting of the face, which can cause clogging and other problems in a drop-on-demand printer. A higher mineral pigment content of the intermediate layer increases the dusting tendency of the product. Therefore, preferably the content of mineral pigments in the intermediate layer is very low.

[0058] The binder content of the intermediate layer can be equal to or more than 15 wt.%, preferably equal to or more than 25 wt.%, more preferably equal to or more than 35 wt.%, most preferably equal to or more than 45 wt.%, calculated on the total dry weight of the intermediate layer. Increasing the binder content of the intermediate layer can help to reduce dusting, which can cause clogging and other problems in a drop-on-demand printer.

[0059] The total mineral content of the direct thermal, linerless label web can be in the range of 0 to 20 wt.%, preferably in the range of 0 to 10 wt.%, calculated on the total dry weight of the direct thermal, linerless label web. Therefore, problems related to dusting can be avoided or at least reduced.

[0060] In one embodiment, a method for manufacturing a direct thermal, linerless label web for drop-on-demand printing can comprise the following steps:

[0061] - providing a face comprising a directly thermal printable coating,

[0062] - applying an adhesive coating to the substrate, the adhesive coating comprising:

[0063] a) a water-based acrylic adhesive,

[0064] b) optionally, an emulsified silicone additive, the amount of emulsified silicone additive being in the range of 1 to 6 wt.%, and

[0065] c) optionally, at least one wetting agent,

[0066] and

[0067] - heat drying the adhesive coating on the substrate into a pressure sensitive adhesive coating,

[0068] wherein,

[0069] 1 ) applying the adhesive coating on the face,

[0070] or

[0071] 2) Applying an adhesive coating to a carrier material, and the method further includes:

[0072] - Transfer the pressure-sensitive adhesive coating from the carrier material to the surface.

[0073] In this embodiment, the substrate can be either the first side or the second side of the face. Alternatively, the substrate can be a carrier material from which the pressure-sensitive adhesive coating can be transferred from the carrier material to either the first or second side of the face. After the linerless label web is wound into a roll, the PSA coating will be anchored to the second side (i.e., the bottom side) of the face, regardless of whether the adhesive coating is applied to or transferred to the first or second side of the face.

[0074] In one embodiment, the adhesive coating is first applied to a substrate (which is the surface) and then heat-dried to form a pressure-sensitive adhesive coating on the surface.

[0075] In another embodiment, the adhesive coating is applied to a substrate serving as a carrier material, and then thermally dried to form a pressure-sensitive adhesive coating on the carrier material, after which the pressure-sensitive adhesive is transferred from the carrier material to the surface.

[0076] Therefore, the adhesive coating can be applied to the second side of the surface, or the pressure-sensitive adhesive coating can be transferred from the carrier material to the second side of the surface.

[0077] Alternatively, the linerless label web may include a release coating on a first side of the face, and the adhesive coating may be applied to the release coating, or the pressure-sensitive adhesive coating may be transferred from the carrier material to the release coating. After the direct thermal face is rolled up, the pressure-sensitive adhesive will be anchored to a second side of the face, i.e., the bottom side. This embodiment may be a particularly efficient manufacturing method, and the resulting product may have good on-demand printing performance.

[0078] Water-based acrylic adhesives can be tackified acrylic adhesives. Tackified acrylic adhesives can be used to provide strong adhesion to surfaces.

[0079] The preferred adhesive is a water-based acrylic adhesive.

[0080] The adhesive coating may contain at least one surfactant. Surfactants are typically compounds that reduce the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid. At least one surfactant may be an emulsifier to obtain an emulsified silicone additive.

[0081] Therefore, in one embodiment, the adhesive coating comprises an emulsified silicone additive. The emulsifier allows the silicone additive to remain a stable aqueous dispersion. The emulsified silicone additive may comprise:

[0082] - Silicone components, such as silicone oil (polydimethylsiloxane),

[0083] - at least one emulsifier, and

[0084] -water.

[0085] Therefore, if used, silicone additives can be added in the form of an aqueous emulsion containing an emulsifier. In one embodiment, the emulsifier is nonionic or anionic, such as weakly anionic.

[0086] Based on the total dry weight of the adhesive coating, the amount of silicone additive can be equal to or greater than 1% by weight, more preferably equal to or greater than 1.5% by weight, and most preferably equal to or greater than 2% by weight. Furthermore, based on the total dry weight of the adhesive coating, the amount of silicone can be equal to or less than 6% by weight, more preferably equal to or less than 5% by weight, and most preferably equal to or less than 4% by weight. Traditionally, water-based acrylic adhesives and silicone additives are not easily mixed. Silicone additives can be mixed with water-based acrylic adhesives in the form of an emulsion to form an adhesive coating containing both silicone additives and adhesives. Therefore, silicone additives can be provided in the form of an aqueous emulsion.

[0087] In one embodiment, the adhesive coating comprises two surfactants: an emulsifier and a wetting agent. The wetting agent can be added to the adhesive coating to improve the coating process. The wetting agent can increase spreading and penetration properties by reducing surface tension.

[0088] In one embodiment, the adhesive coating may contain a wetting agent such that the total content of the wetting agent, calculated based on the total dry weight of the adhesive coating, can be in the range of 0 to 5% by weight, more preferably at least 0.3% by weight, and most preferably in the range of 0.4% to 3% by weight.

[0089] Those skilled in the art know about wetting agents. In one embodiment, the wetting agent may include at least one of the following:

[0090] -Surfynol 3120 from Evonik

[0091] -Hydropalat 3120 from BASF, and

[0092] - Lumiten ISC from BASF.

[0093] However, these are just some examples of suitable wetting agents.

[0094] The amount of adhesive in the pressure-sensitive adhesive coating can range from 90% to 100% by weight, calculated based on the total dry weight of the pressure-sensitive adhesive coating.

[0095] The adhesive coating may include adhesive areas and non-adhesive areas. The adhesive coating may include, for example, at least one of the following:

[0096] - Straight continuous strips,

[0097] - A continuous bar with alternating positions, and

[0098] - Small, patterned adhesive application.

[0099] Based on the total surface area of ​​the second side, the total coverage of the pressure-sensitive adhesive coating can be equal to or less than 100%, preferably equal to or less than 90%, and more preferably equal to or less than 80%. Furthermore, based on the total surface area of ​​the second side, the total coverage of the pressure-sensitive adhesive coating can be equal to or greater than 10%, more preferably equal to or greater than 20%, and most preferably equal to or greater than 30%.

[0100] The pressure-sensitive adhesive coating can be disposed on a second side of the surface, for example, as a continuous adhesive strip along the longitudinal direction of the web. The continuous adhesive strip can be a straight continuous adhesive strip. As an alternative or supplement to a straight continuous adhesive strip, the continuous adhesive strip can be a continuous adhesive strip with alternating positions.

[0101] In one embodiment, continuously alternating adhesive strips are arranged on the second side of a linerless label web, having a predetermined number of strips in the transverse direction, a predetermined strip width in the transverse direction, a predetermined strip position frequency in the longitudinal direction, and a predetermined strip position amplitude in the transverse direction. In this embodiment, the predetermined characteristics of the continuously alternating adhesive strips can be selected such that the number of strips in each individual customer roll is one or more, the width of each strip is less than the width of each individual customer roll, and the position frequency is selected such that one oscillation cycle covers 0.1-10 circumferences of the machine roll. Alternatively, one oscillation cycle can cover 1-100 circumferences of the customer roll, defined as the circumference of a complete roll.

[0102] Therefore, the method may also include the following steps:

[0103] - Provides alternating bonded and unbonded areas before the adhesive coating dries into a pressure-sensitive adhesive coating.

[0104] Unbonded areas reduce the buildup of adhesive coating on linerless label printers. This adhesive buildup can lead to more dust-related problems, as dust adheres to the printer along with the adhesive, resulting in shorter printer service cycles.

[0105] In one embodiment, an adhesive coating is applied locally to a surface or carrier to provide a surface with alternating adhesive and unadhesive areas.

[0106] In one embodiment, the adhesive coating may be applied to the surface, most preferably to a second side of the surface, and the method may further include:

[0107] - Provide moisture to the unbonded areas of the surface before the adhesive coating dries.

[0108] In this embodiment, moisture can be provided, for example, by spraying water onto the unbonded area on the second side of the surface. Alternatively or additionally, the method may include the following steps to provide the unbonded area:

[0109] - Apply an adhesive coating to the substrate (i.e., the surface or carrier material), and

[0110] - Remove at least 10% of the adhesive coating from the substrate (i.e., the face or carrier material) before drying to provide alternating adhesive and non-adhesive areas.

[0111] In this embodiment, the adhesive coating can be removed, for example, by wiping with a blade, preferably at a wiping angle of 75-85 degrees relative to the substrate surface. The dwell time between applying and removing the adhesive coating can be 0.05 to 3 seconds.

[0112] As discussed, the adhesive coating can be dried as a pressure-sensitive adhesive coating on the surface or on a carrier material. If the adhesive coating is dried on the carrier material, the adhesive is dried as a pressure-sensitive adhesive before being transferred to the surface. If used, the carrier material can be a reusable batch web or a ring-shaped tape.

[0113] The adhesive coating can be dried at temperatures ranging from 60°C to 100°C. If the adhesive coating is dried on the surface, the temperature of the linerless label web when exiting heat drying can be set 5 to 15 degrees Celsius lower than the activation temperature of the coating that can be directly thermally printed.

[0114] Based on the total dry weight of the pressure-sensitive adhesive coating on the second side, the coating weight of the pressure-sensitive adhesive coating can be equal to or greater than 5 g / m². 2 More preferably equal to or greater than 10 g / m 2 The optimal value is equal to or greater than 15 g / m 2 Furthermore, based on the total dry weight of the pressure-sensitive adhesive coating on the second side, the coating weight of the pressure-sensitive adhesive coating can be equal to or less than 25 g / m². 2 More preferably equal to or less than 21 g / m 2The optimal value is equal to or less than 16 g / m 2 .

[0115] Direct thermal unlined label webs can be used for on-demand printing.

[0116] Many advantages can be obtained due to the novel solution. For example, sans-free label webs for on-demand sans-free label printers can be obtained in a cost-effective manner, and the sans-free labels can have improved properties for on-demand printing as well as for labeling purposes.

[0117] Furthermore, solutions incorporating direct thermal liner label webs containing acrylic PSA and an intermediate layer can significantly reduce dust generation from direct thermal liner label webs in on-demand printers.

[0118] Furthermore, adhesive coatings, especially those containing PSA and silicone additives, can improve the functionality of motorized or manual cutters in linerless printers, together with the intermediate layer. Adhesives containing water-based acrylic PSAs with silicone additives are easier to mechanically cut in such devices and leave less adhesive residue on the cutting blades or edges. Additionally, the paper-based substrate implementation makes it easier to achieve high-quality, cost-effective, and environmentally friendly substrates for direct thermal printing layers, while reducing the dust generation tendency of paper-based direct thermal linerless label webs.

[0119] Furthermore, this method allows the adhesive to dry on the face or carrier material without causing unwanted and premature color changes to the thermal coating of the direct thermal liner label web. Attached Figure Description

[0120] Figure 1a An example is shown of an unlined label (web). x S y cross section,

[0121] Figure 1b An example is shown for surface S. x S y cross section,

[0122] Figure 2 An example illustration shows a label printer that can be used for linerless label webs according to this disclosure.

[0123] Figure 3 An example is shown illustrating method steps according to one embodiment.

[0124] Figure 4 An example is shown illustrating method steps according to one embodiment.

[0125] Figure 5 An example of one embodiment of the manufacturing method and apparatus is shown.

[0126] Figure 6 Details of a manufacturing method and apparatus according to one embodiment are illustrated by example.

[0127] Figure 7 Details of a manufacturing method and apparatus according to one embodiment are illustrated by example.

[0128] Figure 8 An example of one embodiment of the manufacturing method and apparatus is shown.

[0129] Figure 9 An example of one embodiment of the manufacturing method and apparatus is shown.

[0130] Figures 10a-10b Examples show adhesive strips with alternating positions on the surface of a linerless label, and

[0131] Figure 11a -b displays photos of the experimental tests, in which

[0132] Figure 11a This shows the dust generation of standard market materials, and

[0133] Figure 11b Dust generation is shown for the linerless label according to this instruction manual.

[0134] The accompanying drawings are schematic and intended to illustrate the general principles of the disclosed technical solutions. Therefore, the illustrations in the drawings are not necessarily to scale or suggest a precise layout of system components. Detailed Implementation

[0135] The technical solution will be described in more detail below with reference to some implementation methods, but it should not be regarded as a limitation.

[0136] In this specification, reference is made to the accompanying drawings, which have the following reference numerals and symbols:

[0137] Sx, Sy, Sz 3D coordinates

[0138] MD (Machine Design) direction, first direction.

[0139] CD horizontal, second direction

[0140] A1 position amplitude,

[0141] P1 One cycle

[0142] WL position wavelength,

[0143] The width of the WMR machine roll.

[0144] WCR customer volume width,

[0145] 100 Unsleeved Label Banners

[0146] 110 sides,

[0147] 111 The first side, i.e. the top side,

[0148] 112 The second side, i.e. the bottom side,

[0149] 113. Basic materials, such as paper.

[0150] 114 Intermediate layer,

[0151] 115 Coatings that can be directly printed using thermal printing

[0152] Top coating on surface 116

[0153] 120 Adhesive Coating (PSA),

[0154] 121 Adhesive coating,

[0155] 130 release coating,

[0156] 150 Unbonded areas

[0157] 200 Unlined Labels, Labels

[0158] 240 label printer,

[0159] 401 Setting surface,

[0160] 402 Apply water-based adhesive.

[0161] 403 Set up non-adhesive areas.

[0162] 404 Ensure the predetermined moisture level.

[0163] 405. Dry the adhesive coating.

[0164] 406 Transfer the adhesive to the surface material.

[0165] 407. Wind the material into a linerless roll.

[0166] 560 drying unit,

[0167] 561 Drying apparatus,

[0168] 570 rolls without labels

[0169] 580, a coating unit for applying adhesive.

[0170] 590 is a moisturizing unit used to ensure a predetermined moisture level.

[0171] 611 Carrier material,

[0172] 611b web material,

[0173] 612-sided uncoiler

[0174] 650 cooling cylinder,

[0175] 660 roll gap,

[0176] 690 Units without adhesive

[0177] 710 Carrier Unwinder

[0178] 770 linerless label web winding machine, and

[0179] 780 Carrier Rewinder.

[0180] In this specification, the term "including / comprises" may be used as an open-ended term, but also includes the closed-ended term "consisting of". Therefore, unless otherwise stated, the word "including / comprises" can be understood as "including / comprises or consists of".

[0181] For the purposes of this specification and claims, unless otherwise stated, all ranges include any combination of the disclosed highest and lowest points and any intermediate ranges therein, which may or may not be specifically enumerated herein.

[0182] Temperature is expressed in degrees Celsius, which is equivalent to °C.

[0183] Unless otherwise stated, percentage values ​​for the amount of material are weight percentages (wt%).

[0184] Unless otherwise stated, all percentage values ​​relating to material quantity refer to dry weight.

[0185] The term "web" refers to a continuous sheet of material. Webs are typically processed by moving them on rollers. Between two processing stages, webs can be stored and / or transported in rolls.

[0186] In this application, the term "sans-free label web" refers to a continuous direct thermal web comprising face 110 and pressure-sensitive adhesive 120 from which sans-free labels 200, i.e., individual labels, can be separated. Conventional sans-free label webs may not present the same challenges as direct thermal sans-free label webs due to their direct thermal coating and typical end-use in on-demand printing.

[0187] In this application, unless otherwise stated, the terms "label," "linerless label," and "adhesive label" refer to a single direct thermal label product 200 to be applied to an article, separated from the direct thermal linerless label web 100. The label 200 can be adhered to the article using an adhesive. Therefore, in this application, unless otherwise stated, the terms "label," "linerless label," and "adhesive label" refer to a product comprising a direct thermal surface 110 and a pressure-sensitive adhesive coating 120.

[0188] The terms “unlined label (web)” and “label 100, 200” refer to label 200 and / or unlined label web 100.

[0189] The term "machine orientation" refers to the manufacturing direction of the web. Machine orientation can also refer to the circumferential direction of the roller. Furthermore, the longitudinal direction of the web refers to the machine orientation. In this application, the term "first orientation" refers to the machine orientation.

[0190] The terms "section direction," "transverse machine direction," and "lateral" refer to directions transverse to the machine direction. In this application, the term "second direction" refers to the transverse direction.

[0191] The term "face" refers to the substrate of the label, also known as the face stock or face material. In this application, the face includes a base layer, a coating that can be directly thermally printed, and an intermediate layer between the base layer and the coating that can be directly thermally printed. In an advantageous embodiment, the base layer is uncoated paper.

[0192] In this application, the term "adhesive coating" refers to a coating containing an adhesive. Preferably, the adhesive coating contains a water-based acrylic adhesive. The adhesive coating may also contain, for example, silicone additives.

[0193] The terms "adhesive layer" and "adhesive coating" refer to a layer of adhesive, which may be continuous or discontinuous. An adhesive layer may include adhesive areas, such as adhesive strips and / or adhesive dots.

[0194] The term "PSA" refers to pressure-sensitive adhesive.

[0195] noodle

[0196] Figure 1b The example illustrates the surface S. x S y Cross-section. Surface 110 is the layer that is adhered to the surface of the product by an adhesive coating during labeling.

[0197] Surface 110 includes a first side 111 and a second side 112 (e.g.) Figure 1a (As shown). The top side (first side 111) of the linerless label (web) can be printed using heat. The second side 112 is the adhesive side.

[0198] The surface 110 of the direct thermal linerless label web has a multilayer structure comprising at least three layers. The surface includes at least:

[0199] -Base layer 113, which can be a paper or film material.

[0200] - Direct thermal coating 115, and

[0201] - Intermediate layer 114, which remains between the direct heat-sensitive coating 115 and the base layer.

[0202] Furthermore, surface 110 may include an additional layer. This surface may include, for example, one or more topcoats 116 on the direct thermal coating 115 to protect the thermal coating. The topcoat 116 may contain, for example, polyvinyl alcohol or be based on, for example, polyvinyl alcohol. At least during the manufacturing process of the direct thermal liner label web, the topcoat can protect the direct thermal coating. The topcoat can protect the top surface of the surface and / or the printed material from friction or other external stresses.

[0203] As a supplement to or alternative to the top coating 116, the surface may also include one or more back coatings, for example, on a second side 112 of the surface 110. The back coating may contain, for example, polyvinyl alcohol or be based on, polyvinyl alcohol. The back coating can improve the anchoring of the adhesives 120, 121 to the surface 110. In one embodiment, the surface does not have the back coating, and instead, the water-based pressure-sensitive adhesive 120 is in direct contact with the substrate, without any additional coating between the PSA and the substrate.

[0204] The linerless label (web) 100, 200 may also include one or more barrier layers to prevent chemical migration through the surface of the first side 111 or the surface of the second side 112 of the face, or other interfaces of the linerless label (web) 100, 200. In one embodiment, the linerless label web does not have any additional barrier layers.

[0205] The weight of surface 110 is preferably at least 45 g / m². 2 More preferably at least 50g / m 2 Furthermore, the surface weight is preferably less than 80g / m². 2 More preferably equal to or less than 75 g / m 2 For example, the weight can be 45g / m³. 2 Up to 80g / m 2 Within the range or at 50g / m 2 Up to 75g / m 2 The basis weight is within the specified range. This basis weight is particularly suitable for liner-less labels containing a coating that can be directly thermally printed, and for use with on-demand liner-less label printers. The basis weight can be measured according to standard ISO 536.

[0206] Surface 110 may have a static sensitivity below 100°C, preferably in the range of 75°C to 95°C. The static sensitivity needs to be high enough so that the product does not darken before printing (e.g., during transport). However, the liner labels (webbed) 100, 200 should be sensitive enough for thermal printing.

[0207] Surface 110 can have a caliper thickness in the range of 60μm to 85μm as measured according to ISO 534. If the surface is too thin, the sans-serif label (web) 100, 200 may be difficult to process. For example, if the surface is very thin, the stiffness of the sans-serif label web may be too low, resulting in the sans-serif label web being too loose. Therefore, when used with a sans-serif label printer, the sans-serif label (web) may be difficult to manufacture and / or the sans-serif label (web) may cause problems.

[0208] The PPS10 roughness of the liner label (web) can be in the range of 0.9 μm to 1.5 μm, preferably in the range of 0.9 μm to 1.3 μm, and most preferably in the range of 0.9 μm to 1.2 μm. This roughness is determined by the top surface of the liner label (web) according to ISO standard ISO 8791-4. For example, for surfaces using paper, if the paper is too rough, the printhead life may be excessively shortened.

[0209] When measured according to standard ISO 2469, the brightness of sans-serif labels (webbed material) can exceed 85% (R457). Therefore, sans-serif labels may appear quite good. Furthermore, the high brightness can create contrast between symbols / letters. Thus, if the lettering includes some machine-readable characters, these letters can be easily read due to the aforementioned brightness.

[0210] When measured according to standard ISO 2471, the opacity of sans-free labels (webbed sheets) can be higher than 80%, for example, in the range of 80 to 90. Due to this opacity, the surface of the sans-free label will not be so transparent that it becomes unreadable to machines or the human eye.

[0211] When measured according to standard ISO 1924 / 2, the tensile strength of the liner label (web) in the machine direction (i.e., the first direction) can be greater than 40 N / 15 mm, preferably greater than 45 N / 15 mm. Therefore, the dimensional stability of the liner label (web) can be improved, which can have a positive impact on the manufacturing and printing processes.

[0212] When measured according to standard ISO 1924 / 2, the tensile strength of linerless labels (webbed material) in the transverse direction (i.e., the second direction) can exceed 10 N / 15 mm. This strength improves the dimensional stability of linerless labels, which in turn affects the manufacturing and printing processes.

[0213] The stiffness of the linerless label web can range from 0.15 mNm to 0.30 mNm, determined in the machine orientation (MD) of the linerless label web. The stiffness of the linerless label web can be measured according to ISO standard ISO 2494. Due to this stiffness range, the stiffness of the linerless label web will not be too low, which could result in the linerless label web being too loose. Therefore, when used with a linerless label printer, the linerless label web may not cause too much trouble. Furthermore, due to this stiffness, the functionality of the cutter in the linerless printer and the ease of the cutting process therein can be improved, which can further reduce dust generated by the cutting process. Therefore, the combination of this stiffness, the intermediate layer, and the acrylic adhesive can significantly reduce dust and adhesive buildup on the cutter blade of the on-demand printer. In one embodiment, the stiffness of the linerless label web is in the range of 0.05 mNm to 0.20 mNm, determined in the transverse direction of the linerless label web.

[0214] Surface: grassroots

[0215] The base layer of surface 110 may include or be composed of paper. Alternatively, the base layer of surface 110 may include or be composed of a film material. The film material may be made of polyethylene (PE), polypropylene (PP), or biaxially oriented polypropylene (BOPP). Furthermore, other suitable materials, such as different types of polyesters, such as polyethylene terephthalate (PET) or polyethylene, are also feasible.

[0216] Regardless of whether the substrate is fiber-based or film-based, the composition of the intermediate layer 114, situated between the substrate and the directly thermally printable coating, is significant in influencing dust levels when linerless label material is cut and separated into labels in a thermal printer. The composition of the intermediate layer 114 appears to significantly affect how internal pressure diffuses into the label material layers during the cutting operation of the cutter. The composition of the intermediate layer appears to prevent dust generation not only within the intermediate layer itself but also from other layers of the label material. In the case of a film substrate, the structure of the intermediate layer 114 appears to minimize the diffusion of compressive stress generated in the cutter from the cut line into the label material, thus affecting only a smaller area around the cut line.

[0217] Preferably, the base layer comprises or is composed of paper. Advantageously, the base layer is composed of uncoated paper.

[0218] Surface 110 may include a base paper containing natural fibers as its primary raw material. Natural fibers refer to any plant material containing cellulose. Natural fibers may be wood-based. Wood-based natural fibers may be derived from softwood trees, such as spruce, pine, fir, larch, Douglas fir, or hemlock, and / or from hardwood trees, such as birch, poplar, aspen, alder, eucalyptus, or acacia, or from a mixture of softwood and hardwood.

[0219] If used, the base paper preferably contains wood-based natural fibers. Wood-based natural fibers are preferably the main fiber material of the base paper. The face 110 may include cellulose fibers from hardwood and / or softwood. A mixture of hardwood and softwood can be used to improve the internal bonding strength of the face 110.

[0220] The base layer can be so-called wood-free pulp paper. Wood-free pulp refers to chemical pulp, such as kraft pulp. According to one embodiment, due to the high quality requirements of the face, the pulp used to manufacture the face does not contain any kind of mechanical pulp. The base paper 113 of the face 110 can be wood-free pulp paper containing fibers (e.g., fibers from softwood and / or hardwood).

[0221] The substrate 113, such as uncoated base paper, may further include at least one mineral filler selected from the group consisting of clay, calcined clay, kaolin, natural heavy calcium carbonate, precipitated calcium carbonate, talc, calcium sulfate, and titanium dioxide. Based on the total weight of the substrate 113, the total amount of mineral filler in the substrate 113 may be less than 18% by weight, preferably less than 13% by weight, more preferably less than 8% by weight, and most preferably less than 5% by weight, for example, between 0% and 4% by weight. Mineral fillers can reduce the cost of manufacturing products. However, mineral fillers may also reduce the strength properties of the surface 110. Furthermore, if the substrate contains excessive filler, some properties of the surface 110 may be impaired. For example, mineral fillers may increase dust generation on the surface, which may cause clogging and other problems in on-demand printers. If the amount of mineral filler in the substrate is very low, the dust generation tendency of direct thermal liner label webs can be reduced.

[0222] Increasing the amount of natural fibers can reduce dust generation in the base layer of an on-demand printer. Therefore, the dust generation tendency of the base paper 113 can be reduced as the natural fiber content of the base paper increases. Thus, if natural fibers are used, the natural fiber content of the base paper 113 can be at least 75% by weight, preferably at least 80% by weight, more preferably at least 85% by weight, and most preferably at least 88% by weight, based on the total weight of the base paper 113.

[0223] In this specification, the term "base paper" refers to paper without a pigment coating. Base paper can be calendered using a calender or supercalender to obtain a high-density surface. The base paper can be coated to create an intermediate layer.

[0224] The base paper can be supplied by FSC. TM Certified (hybrid credit) paste manufacturing. Therefore, the face can include or be composed of environmentally friendly materials. Thus, new linerless labels (webbed sheets) may be more environmentally friendly than some other types of facebeds.

[0225] Surface: Middle layer

[0226] A coating can be applied to the substrate 113 to form an intermediate layer 114 located between the substrate 113 and the direct heat-sensitive coating 115. The coating weight of the intermediate layer 114 can be from 0.9 to 7 g / m² on each side. 2 Within the range, preferably within 1 g / m 2 Up to 5g / m 2 Within the range, more preferably within 1.3 g / m 2 Up to 4g / m 2 Within the range, the optimal value is 1.6 g / m³. 2 Up to 3g / m 2 Within a certain range. Due to the intermediate layer, the quality of the direct thermal coating can be improved. Furthermore, the amount of expensive direct thermal coating required to achieve good printability can be reduced. Moreover, because the intermediate layer coating is very lightweight, dust-related problems can be avoided or at least reduced.

[0227] The intermediate layer may contain at least one mineral pigment. The mineral pigment may be selected from the following group: clay, calcined clay, kaolin, natural heavy calcium carbonate, precipitated calcium carbonate, talc, calcium sulfate, and titanium dioxide.

[0228] The total amount of mineral pigment in the intermediate layer 114 can be less than 85% by weight, for example, in the range of 0% to 80% by weight. Preferably, based on the total weight of the intermediate layer 114, the total amount of mineral pigment is less than 75%, for example, in the range of 5% to 70% by weight, more preferably in the range of 10% to 65% by weight, and most preferably equal to or less than 60% by weight. Mineral pigment can be used to provide a smooth surface for the intermediate layer 114. Therefore, the quality of the direct thermal coating can be improved. In addition, the amount of expensive direct thermal coating required for this layer can be reduced. However, mineral fillers may increase surface dusting, which may cause clogging and other problems in on-demand printers. Dusting in the intermediate layer can be particularly problematic because the intermediate layer typically does not contain fibers that can partially bind mineral particles. Therefore, preferably, the amount of mineral pigment in the intermediate layer is very low.

[0229] As an alternative to or supplement to mineral pigments, the intermediate layer may contain non-mineral pigments to reduce the amount of mineral pigments in the intermediate layer. Non-mineral pigments may include, for example, polymeric materials. Polymeric materials may include, for example, thermoplastic polymers, such as thermoplastic biopolymers. Due to the use of non-mineral pigments, dust generation on direct heat-sensitive linerless label webs can be reduced.

[0230] Non-mineral pigments may include, for example, expandable plastics. The shape of non-mineral pigments may be, for example, balloon-shaped particles. The diameter of non-mineral pigment particles may be, for example, a few micrometers.

[0231] In addition, the intermediate layer may contain an adhesive. The adhesive may include one or more of starch, polyvinyl alcohol (PVA), and latex. The latex may contain styrene-butadiene latex (SB) and / or styrene-acrylic latex (SA). These adhesives can be used to reduce the dust-generating tendency of linerless label webs. If used, the latex is preferably styrene-butadiene latex (SB latex).

[0232] Based on the total weight of the intermediate layer 114, the amount of adhesive in the intermediate layer can be at least 15% by weight, for example, in the range of 20% to 50% by weight, preferably in the range of 25% to 45% by weight, more preferably in the range of 30% to 42% by weight, and most preferably in the range of 33% to 40% by weight. The adhesive can be used to bond pigment particles together to form a uniform coating. Due to the amount of adhesive, dust generation problems on direct thermal linerless label webs can be reduced.

[0233] Before applying a direct thermal coating to the intermediate layer, the combination of the base paper and the intermediate layer can be calendered or supercalendered to obtain a high-density surface. If the intermediate layer is calendered, its smoothness can be improved. Therefore, the quality of the direct thermal coating on the intermediate layer can be improved.

[0234] In one embodiment, the thickness of the interlayer of the produced linerless labels (webs) 100, 200 can range from 2 μm to 6 μm, preferably from 2.5 μm to 5.5 μm, and most preferably from 3 μm to 5 μm. The thickness of the interlayer needs to be sufficiently high to fill the pores on the surface of the base paper. Therefore, the thickness of the interlayer may depend on the smoothness of the surface. Furthermore, the thickness of the interlayer needs to be sufficiently high to form a smooth surface for direct thermal coating. Due to the presence of the interlayer, a smooth surface can be formed for direct thermal coating.

[0235] Therefore, surface 110 can have an intermediate layer 114. The intermediate layer 114 can reduce heat transfer from the thermal coating to the base paper 113. This allows for the formation of enhanced or high-resolution printed content. The intermediate layer 114 can also provide smoothness to the substrate (i.e., the top surface of surface 110). The smoothness of surface 110, including the paper, has a positive impact on printing, for example, by providing better resolution. Therefore, the intermediate layer can have a positive impact on print quality. Furthermore, the intermediate layer (if it has a sufficiently low basis weight and / or mineral pigment content) can reduce the dusting tendency of surface 110.

[0236] Surface: Examples of coatings that can be directly thermally printed

[0237] Surface 110 includes a coating 115 that can be directly thermally printed. Therefore, surface 110 can be referred to as a surface that can be directly thermally printed.

[0238] A directly thermally printable coating 115 is arranged such that surface 110 provides thermal printability. The directly thermally printable coating is arranged to form a thermally reactive layer that changes color during thermal printing. The thermal coating contains reactive components. The thermal coating may contain a matrix. The matrix may contain dyes and developers.

[0239] The solid thermal coating matrix is ​​heated by a thermal printhead to above its activation temperature and / or melting point. The dye in the thermal coating may include leuco dyes. Leuco dyes are arranged to react with acid and become colored. The thermal coating may contain dyes, developers, sensitizers, binders, and stabilizers.

[0240] The developer can be arranged to react with the dye during the thermal printing process at a temperature above the activation temperature. The reaction between the dye and the developer is configured to induce color formation. The developer may include sulfonylureas, zinc salts of substituted salicylic acids, or phenols, such as bisphenol A (BPA) or bisphenol S (BPS). The thermal coating is preferably BPA-free, bisphenol (BP)-free, or phenol-free to improve chemical safety.

[0241] Sensitizers can be used in thermosensitive coatings to lower the melting points of dyes and / or developers. The dyes and developers are configured to react when heated to a temperature above the melting point of the thermosensitive coating matrix. The melting point of the matrix can depend on the melting point values ​​of its components. The thermal threshold of the thermosensitive coating is the melting point of the component in the thermosensitive coating that has the lowest melting point. Sensitizers in thermosensitive coatings can be configured to lower the melting points of dyes and / or developers. This has the effect of demonstrating melting point accuracy and / or optimizing temperature for color changes and / or promoting the mixing of dyes and developers.

[0242] Optionally, the thermal coating may contain a stabilizer. The dyes in thermal paper may be unstable and tend to revert to their original colorless crystalline form. For example, thermal paper may be sensitive to external conditions of heat and humidity. To stabilize the metastable glass formed by the leuco dye, developer, and sensitizer, a stabilizer may be added to the mixture. The stabilizer has the function of inhibiting the recrystallization of the dye and developer and / or stabilizing the printed content.

[0243] The adhesive for the heat-sensitive coating can facilitate adhesion of the heat-sensitive coating to a substrate or pre-coating. The adhesive may contain double bonds. The adhesive may include polyvinyl alcohol (PVA) or latex, such as styrene-butadiene latex (SB) or styrene-acrylic (SA).

[0244] The sensitivity of a thermal coating refers to its degree of response to a given amount of heat or energy. Sensitivity is a decisive factor in selecting a suitable thermal coating or thermal paper. It can be described by plotting image density or optical density (OD) against the amount of heat or energy transferred. Optical density is a measure of the relationship between incident and reflected light. An optical density of approximately 1.1 is generally considered completely black to the human eye. Therefore, lower optical densities correspond to different shades of gray. Static and dynamic sensitivity are commonly used to characterize thermal coatings and thermal papers.

[0245] Static sensitivity refers to the temperature at which thermal paper begins to image (i.e., change color). Thermal paper with low static sensitivity only begins to image at high temperatures, such as above 90°C. On the other hand, thermal paper with medium static sensitivity begins to image at lower temperatures, such as between 80°C and 90°C. Thermal paper with high static sensitivity begins to react even at lower temperatures, such as 65-80°C or 70-80°C.

[0246] The dynamic sensitivity of thermal paper essentially indicates the printing speed that the thermal paper can achieve. This is especially important for selecting the right thermal paper for a specific thermal printer, because the higher the paper's dynamic sensitivity, the faster the printer can run without changing any settings. Dynamic sensitivity is usually expressed in mJ / mm². 2 Therefore, thermal paper with low dynamic sensitivity requires higher printhead temperatures and / or longer exposure times, i.e., slower printing speeds to achieve high optical density in the image. On the other hand, high dynamic sensitivity enables faster printing even at lower printhead temperatures.

[0247] Dynamic sensitivity is difficult to achieve by using a specific single value (e.g., in mJ / mm²). 2 The thermal capacity of thermal paper is categorized into low, medium, and high levels (in units of energy) because the total energy transferred to the paper does not directly correspond to a specific temperature reached in the thermal coating. The thermal capacity of thermal paper is related, for example, to the paper's thickness and the presence of different materials or layers. Therefore, different amounts of energy may be required to heat papers of different thicknesses to the same temperature. Different paper thicknesses or different layers of thermal conductivity can result in different temperature levels within the thermal coating.

[0248] For example, at an optical density of 1.1 (where the human eye perceives complete darkness), very different energy levels might be required to achieve this panchromatic change in a thermal coating. High dynamic sensitivity thermal paper might require energy levels below 15 mJ / mm². 2 Such optical density has already been achieved at energy levels; moderate dynamic sensitivity would likely require approximately 20 mJ / mm². 2 For example, 15-25 mJ / mm 2The energy required is within a certain range, and for the same print darkness, low dynamic sensitivity thermal paper may even require more than 25 mJ / mm². 2 The energy level. Each sheet of these papers may still be at a much lower energy level (e.g., below 10 mJ / mm). 2 Some color changes began to appear.

[0249] A combination of high static sensitivity and high dynamic sensitivity is likely preferred, allowing for rapid printing using an economical and simple linerless printer. The surface temperature of the labeled item is unlikely to exceed 65-70°C, allowing the use of thermal papers with medium static sensitivity, and more preferably, thermal papers with high static sensitivity close to the highest surface temperature of the labeled item. On the other hand, long-term stability is not an issue in these short-term applications, so more economical thermal papers not specifically designed for archiving or long-term stability can be used. This high static and dynamic sensitivity of the thermal coating / paper can pose challenges to the manufacture of linerless labels that can be directly thermally printed, as it limits the maximum temperature that the direct thermal face stock can be exposed during the manufacturing process of linerless labels to prevent unwanted and premature color changes in the thermal coating.

[0250] Adhesive coating

[0251] During the manufacturing process of the linerless labels (webs) 100 and 200, the adhesive coating 121 is dried to form a pressure-sensitive adhesive coating 120. The adhesive coatings 120 and 121 may contain a water-based acrylic adhesive.

[0252] The label 200 and linerless label web 100 disclosed herein include a pressure-sensitive adhesive coating 120 disposed on a second side 112 of the face 110. The pressure-sensitive adhesive coating 120 may also be referred to as a self-adhesive coating.

[0253] The pressure-sensitive adhesive coating 120 may include one or more water-based adhesive layers. If the PSA coating 120 includes more than one adhesive layer, the adhesive coating may have improved smoothness. For example, if the first adhesive coating includes any pores, these pores can be filled with a second adhesive coating.

[0254] PSA can be a permanent adhesive, or it can be removable or repositionable, or even ultra-removable. PSA can have an operating temperature range from ambient temperature to freezing temperature.

[0255] In one embodiment, the maximum tack value of the pressure-sensitive adhesive 120 measured on glass according to the FINAT test method FTM9 can be equal to or greater than 3N, more preferably equal to or greater than 4N. This value can be a suitable performance value for the pressure-sensitive adhesive coating 120 of the direct thermal liner label (webbed) 100, 200.

[0256] Pressure-sensitive adhesives can be used for permanent or removable linerless labels (webs). For removable linerless labels (webs), the maximum tack value measured on glass according to FINAT test method FTM9 can be between 3N and 6N. For permanent linerless labels (webs), the maximum tack value measured on glass according to FINAT test method FTM9 can be equal to or greater than 8N, more preferably equal to or greater than 10N, and most preferably equal to or greater than 17N.

[0257] In one embodiment, the maximum tack value of the pressure-sensitive adhesive 120, measured on glass according to the FINAT test method FTM9, is equal to or less than 12N, more preferably equal to or less than 6N, and most preferably between 3N and 6N. This value may be a particularly suitable performance value for the pressure-sensitive adhesive coating 120 used in direct thermal liner labels (webbed) 100, 200 for fast food restaurants.

[0258] In another embodiment, the maximum tack value of the pressure-sensitive adhesive 120, measured on glass according to the FINAT test method FTM9, is equal to or greater than 8 N, more preferably equal to or greater than 10 N. This value may be a particularly suitable performance value for the pressure-sensitive adhesive coating 120 of direct thermal linerless labels (webs) 100, 200 used for industrial food or retail labeling.

[0259] In another embodiment, the maximum tack value of the pressure-sensitive adhesive 120 measured on glass according to the FINAT test method FTM9 can be equal to or greater than 15N, more preferably equal to or greater than 17N. This value can be a particularly suitable performance value for the pressure-sensitive adhesive coating 120 of direct thermal linerless labels (webs) 100, 200 used in logistics and warehousing.

[0260] The properties and characteristics of PSA used herein may vary depending on the end use of the label discussed. Table 1 shows some exemplary properties and provides example values ​​and factors for adhesives used for different end uses.

[0261] Table 1.

[0262]

[0263]

[0264] In the context of this specification, PSA is preferably water-based PSA. Water-based binders offer better sustainability, involving less fossil raw materials and less volatiles in both manufacturing and end-use. These benefits can be seen, for example, through life-cycle analysis for cradle-to-gate or cradle-to-grave applications.

[0265] Furthermore, even without using any additional primer, it may be easier to achieve a good level of anchorage on the surface 110 disclosed herein using a water-based PSA. Therefore, in one embodiment, the water-based pressure-sensitive adhesive 120 is in direct contact with the surface 110, for example, with the substrate of the surface, without any other coating between the PSA and the surface.

[0266] Furthermore, water-based adhesives can be designed to obtain approval for direct or indirect food contact (food safety), which is a requirement in certain end-use areas of food-related labeling.

[0267] Pressure-sensitive adhesives are suitable for high coating speeds. Preferably, the adhesive is applied at a concentration of 10-30 g / m³. 2 The coating weight (dry coating weight) provides a non-mesh coating. The adhesive can be plasticizer-free and can be used on thermal paper (including economy grade) without problems such as premature image development or image fading.

[0268] In one embodiment, the adhesive exhibits sufficient anchoring to the surface 110 and resistance to surface penetration, making a primer unnecessary. A flat adhesive distribution with extended dwell time and / or sufficient cohesion may be preferred to resist wingspan on curved surfaces.

[0269] Preferably, the water-based PSA is acrylic-based. Water-based acrylic PSA may have many advantages over other types of PSA. Water-based acrylic PSA can be very environmentally friendly. Furthermore, the tackiness of the product can be improved due to the water-based acrylic adhesive. Additionally, hot melt adhesives may accumulate more easily in the cutting machine compared to water-based acrylic adhesives, further increasing the amount of dust in the machine. Moreover, acrylic adhesives may have a longer open time, so the linerless label (web) containing water-based acrylic PSA can be removed after seconds or minutes if needed. Conversely, hot melt adhesives are generally not removable from surfaces, even if adhered to the wrong surface. Therefore, the removability of water-based acrylic adhesives may be better than that of hot melt adhesives. Furthermore, the peel value of acrylic adhesives is generally different from that of hot melt adhesives.

[0270] Adhesives may contain silicone additives. Traditionally, silicones are not readily mixed with water-based acrylic PSAs to form stable adhesive emulsions. Therefore, water-based acrylic adhesives can be supplied as aqueous dispersions containing emulsifiers and silicone additives. The silicone additives themselves may also be in the form of silicone emulsions before being incorporated into the acrylic adhesive. Emulsifiers may be required to form stable adhesive emulsions when the water-based acrylic adhesive is applied to the surface of a face or carrier material.

[0271] In one embodiment, the adhesive in the form of an aqueous dispersion or emulsion may be further mixed with a wetting agent. In some embodiments, a wetting agent may be necessary to enable the adhesive dispersion / emulsion to be coated onto the siliconized surface when the adhesive coating is applied to a separate siliconized carrier substrate for adhesive drying and curing, or if it is applied directly to a siliconized thermal surface for drying and curing.

[0272] If used, the silicone component in the emulsified silicone additive may be polydimethylsiloxane. In this embodiment, the silicone additive is preferably mixed with the emulsifier and the water-based adhesive, so that a substantially uniform adhesive layer 120, 121 comprising the silicone additive can be formed.

[0273] The adhesive coatings 120 and 121 may comprise, or consist of, a mixture containing the water-based acrylic adhesive and optionally at least one emulsifier and silicone additive. In this embodiment, the silicone additive used for the adhesive layer is preferably recyclable. In one embodiment, the adhesive coating comprises at least one emulsifier and at least one wetting agent.

[0274] In one embodiment, a silicone additive is added to an acrylic water-based adhesive to form an adhesive coating 121. This combination can significantly reduce adhesive buildup on the cutting blade of the on-demand printer. Furthermore, dust buildup on the cutting blade of the on-demand printer can be reduced. Additionally, the acrylic water-based adhesive can be an environmentally friendly adhesive and can be used, for example, with food materials. Therefore, linerless labels (webs) 100, 200 can be used with food packaging.

[0275] Therefore, liner labels (webs) 100, 200 may include an intermediate layer 114 containing a reduced amount of mineral particles and an adhesive containing silicone additives. The combination of water-based acrylic adhesives and silicone additives in adhesive coatings 120, 121, together with the intermediate layer 114, can significantly reduce the accumulation of dust and adhesives on the rollers and other components of the web guide of the liner printer. This can be advantageous because it allows for the use of more aggressive adhesives without shortening the service life of the on-demand printer. Furthermore, this combination can extend the service life. Therefore, due to the implementation with water-based acrylic adhesives, silicone additives, and an intermediate layer, direct thermal liner labels (webs) 100, 200 can be used with liner label printers without shortening the printer's service life.

[0276] Pressure-sensitive adhesive layer 120 can have a strength of 10 to 30 g / m². 2 The coating weight (dry coating weight) is within the specified range. Preferably, the coating weight of the adhesive layer 120 is 15 g / m². 2 Up to 25g / m 2 Within the range (dry coating weight), the optimal value is 16 g / m³. 2 Up to 21g / m 2 Within a certain range. Preferably, in order to obtain a sufficiently good adhesive layer to adhere the liner label to the surface of the article without being too expensive, the adhesive is an acrylic-based water-based PSA.

[0277] As discussed above, the adhesive coating may contain emulsified silicone additives. The silicone additives in adhesive coatings 120 and 121 can improve the ease of cutting label material, especially for on-demand linerless label printers. Furthermore, the silicone additives in adhesive coatings 120 and 121 can reduce dust levels in on-demand printers. Additionally, the silicone additives in adhesive coatings 120 and 121 can improve the self-winding property of the linerless label web 100. Moreover, the silicone additives can facilitate the self-winding of the linerless label web 100 around itself without any tendency to cause adjacent layers of the linerless label web 100 to obstruct each other.

[0278] If the adhesive layer contains silicone, the amount of emulsified silicone additive in the adhesive layer, calculated based on the total dry weight of the adhesive coating, can be equal to or greater than 1% by weight, more preferably equal to or greater than 1.5% by weight, and most preferably equal to or greater than 2% by weight. This weight can provide improved usability for printers using liner-less labels. Furthermore, the amount of emulsified silicone additive can be equal to or less than 6% by weight, more preferably equal to or less than 5% by weight, and most preferably equal to or less than 4% by weight, thus achieving a cost-effective solution with good adhesive properties. The amount of emulsified silicone additive in the adhesive layer, calculated based on the total dry weight of the adhesive coating, can range from 1% by weight to 6% by weight, or from 2% by weight to 4% by weight.

[0279] In one embodiment, the amount of emulsified silicone additive in the adhesive layer can be equal to or greater than 0.1 g / m³. 2 In this embodiment, the amount of emulsified silicone additive in the adhesive layer can be at least 0.15 g / m³. 2 More preferably at least 0.2 g / m 2 (dry gram weight) to provide improved usability of liner-less labels for printers. Furthermore, the amount of emulsified silicone additive can be up to 1.7 g / m³. 2 More preferably, the maximum is 1.3 g / m 2 And the optimal value is equal to or less than 1.1 g / m 2 (dry gram weight) to provide a cost-effective solution. The amount of emulsified silicone additive on the adhesive layer can be, for example, 0.15 to 1.5 g / m³. 2 or 0.2 to 1.2 g / m 2 (Dry weight)

[0280] If silicone additives are used, they can be provided in the form of an aqueous emulsion. To form a substantially homogeneous mixture, the silicone additives are preferably added in the form of an aqueous emulsion containing an emulsifier. The emulsifier can reduce the surface tension between the water-based acrylic adhesive and the silicone. The emulsifier may contain both hydrophilic and hydrophobic groups. Therefore, in one embodiment, the emulsifier molecules may encapsulate the silicone, with its hydrophilic portion extending out.

[0281] If an emulsifier and / or wetting agent are used, the emulsifier and / or wetting agent is preferably anionic or nonionic. More preferably, the emulsifier and / or wetting agent can be anionic. Thanks to the emulsifier, the silicone additive will not float in water, but rather the silicone additive can be mixed (“dissolved”) in the aqueous solution. Furthermore, the use of a wetting agent can improve the ease of the adhesive coating process.

[0282] If silicone additives are used, they can be added to the adhesive coating by adding a silicone emulsion to an acrylic water-based adhesive, thereby forming adhesive coating 121. When the silicone emulsion is mixed into the water-based adhesive at 1% to 6% by weight, preferably 2% to 4% by weight, the adhesive properties can be altered, resulting in a significant reduction in the instantaneous adhesion of the rapidly moving metal blade during printing / labeling. Furthermore, the combination of the acrylic water-based adhesive containing silicone additives and the intermediate layer 114 with reduced mineral content can reduce the printer's dust generation tendency, thereby improving the lifespan of the thermal printer.

[0283] In one embodiment, the adhesive coating 121 comprises a silicone emulsion, wherein the average particle size of the silicone emulsion can be in the range of 0.1 micrometers to 1 micrometer. This can improve the performance of the emulsified silicone additive. Preferably, the average particle size is between 0.1 micrometers and 0.4 micrometers, and most preferably between 0.1 micrometers and 0.2 micrometers.

[0284] The pressure-sensitive adhesive coating 120 of the produced linerless labels (webs) 100, 200 can have a thickness of at least 10 μm, preferably at least 12 μm or at least 14 μm, and most preferably equal to or greater than 16 μm. The coating weight of PSA needs to be high enough to fill the pores of the surface. Therefore, the thickness of PSA can depend on the surface to be coated. In addition, the amount of PSA needs to be high enough to adhere the label to the surface of the object. Advantageously, the thickness of the pressure-sensitive additive coatings 120, 121 is equal to or less than 40 μm, preferably equal to or less than 30 μm, more preferably equal to or less than 25 μm, and most preferably equal to or less than 20 μm. The thickness of the adhesive layer can be, for example, between 12 and 25 micrometers. Therefore, an adhesive layer that is good enough to adhere the linerless label to the surface of the article can be obtained at a relatively low cost.

[0285] As discussed, the adhesive layer applied to the liner label may contain silicone additives, i.e., compounds based on silicone polymers. Silicone compounds can improve the ease of use of the liner labels (webs) 100, 200. The chemical properties of silicone affect the force required to peel the adhesive layer 120 (and thus the topcoat) from the substrate. The silicone additives in the adhesive coating can protect the adhesive coatings 120, 121 and allow for effective handling when the label adheres to the substrate. Furthermore, while protecting the adhesive layer, the silicone additives can further protect the liner label printer from the effects of the adhesive layer. The silicone additives protect the liner label printer because they reduce the surface energy of the adhesive layer. Therefore, the label can be easily cut so that the adhesive does not adhere to the printer. Thus, the liner label adhesive coating containing the adhesive and silicone additives can be used to minimize adhesive buildup on the cutting blades, rollers, and web paths in the liner printer. Furthermore, the silicone additives, together with a specific intermediate layer, can protect the liner label printer from dust.

[0286] The adhesive coating 120 may be plasticizer-free. This can have several advantages, as plasticizers can migrate into the product and cause problems. For example, food safety may be compromised.

[0287] Therefore, the novel sans-free labels (web sheets) 100, 200 may have several advantages. The sans-free labels (web sheets) can be completely removed from the printed / painted surface. Furthermore, the sans-free labels (web sheets) 100, 200 can have sufficient anchoring and resistance to paper penetration. In addition, the sans-free labels (web sheets) 100, 200 can have flat adhesion properties and sufficient cohesion to resist wing-like structures on curved surfaces during extended dwell times.

[0288] If the adhesive coating 120 contains a silicone additive, the silicone additive can help prevent adhesive buildup on the blades and rollers of the liner label printer 240, and also prevent or at least reduce some dust-related problems. The buildup of adhesive and dust can lead to a shortened printer service life. The silicone additive in the adhesive coating, especially in conjunction with a facet having a reduced mineral weight, can significantly reduce dust and the buildup of adhesive and dust in the liner label printer. Therefore, the printer service life can be significantly improved. An adhesive coating containing silicone additives and PSA can be used on thermal paper (including economy grade) without problems of premature image development or image fading.

[0289] In addition, using water-based acrylic PSA may make it easier to achieve good anchoring on the substrate, and in some cases, no additional primer may be needed.

[0290] Adhesive coating

[0291] The adhesive coating can be a continuous layer or a discontinuous layer.

[0292] Therefore, the adhesive coating of the linerless label web can be a continuous adhesive layer, wherein the adhesive coating does not have any unbonded areas.

[0293] Alternatively, the adhesive coating of the linerless label web can be a discontinuous adhesive layer. A discontinuous adhesive layer may include adhesive areas and unadhesive areas. Advantageously, the adhesive coating includes one or more adhesive areas and one or more unadhesive areas.

[0294] Adhesive coatings may include or consist of, for example, adhesive strips and / or adhesive dots and / or other shaped adhesive areas.

[0295] Adhesive coatings may include at least one of the following:

[0296] - Straight continuous strips,

[0297] - A continuous bar with alternating positions, and

[0298] - Small patterned adhesive application.

[0299] Adhesive strips

[0300] Adhesive coatings 120 and 121 can be, for example, Figure 6 and 7 The patterned coating is shown. By arranging the adhesive coatings 120, 121 in strips along the longitudinal direction (i.e., the first direction) of the label web 100, the performance of the linerless label web 100 in on-demand printers and the manual handling of the printed labels can be significantly improved. The adhesive strips can be in the form of straight continuous strips or in the form of alternating continuous strips.

[0301] In one embodiment, the total coverage of the adhesive coating, calculated based on the total area of ​​the second side of the surface, can be equal to or less than 90%, preferably equal to or less than 80%. Furthermore, the total coverage of the pressure-sensitive adhesive coating, calculated based on the total area of ​​the second side of the surface, can be equal to or greater than 10%, more preferably equal to or greater than 30%, and most preferably equal to or greater than 40%. This total coverage can prevent adhesive seepage from the label roll and helps keep the printer mechanism free of adhesive and dust.

[0302] For certain end uses, it may be necessary to leave a continuous unadhesive area / strip 150 near the longitudinal edges of the label web 100. These unadhesive areas / strips 150 near or on the longitudinal edges may correspond to a minimum of 10%, a minimum of 30%, or even more than 50% of the total width of the label web 100. A relatively wide unadhesive area on the outer edge of the label can prevent any seepage of adhesive from the label roll and help keep the printer mechanics clean. The unadhesive areas may be arranged symmetrically or nearly symmetrically on the two longitudinal edges of the label web 100. This simplifies label movement within the printer and / or helps allow the label to be gripped with fingers without contact with the adhesive PSA. If the width of the unadhesive area 150 is chosen to be asymmetrical, the narrower area in these regions on either longitudinal edge of the label web 100 may correspond to a minimum of 10%, 15%, 25%, or even more than 35% of the total width of the label web 100.

[0303] For example, the width of a single PSA strip in the middle of the linerless label 200 ranges from 10 to 25 mm, providing a good balance between adhesiveness and manual handling, and most importantly, good long-term performance in compact on-demand linerless printers. A fairly wide adhesive-free area 150 on the outer edge of the label prevents any adhesive seepage from the label roll and helps keep the printer mechanics clean. However, the PSA area is wide enough to provide sufficient traction in the printer rollers to pull the label through the printer. In one embodiment, to obtain at least some of the above advantages, the width of the adhesive-free area / strip 150 near (or above) the longitudinal edge of the label web 100 can be in the range of 10 to 25 mm.

[0304] Unbonded areas can include 0 g / m 2 Up to 5.0g / m 2 Within a range, for example, at 0.5 g / m 2 Up to 4.0g / m 2 The amount of adhesive coating residue within the specified range. In one embodiment, the unbonded areas do not contain any residual adhesive coating.

[0305] It should be noted that, generally, despite the alternating positions, the thickness of the adhesive coating and the width of the adhesive strip (and adjacent unadhesive or non-adhesive areas) remain substantially constant over the length of the web. This makes the coating process technically easier to implement and simplifies the curing / drying of the adhesive layer. For example, in customer rolls, a reduction in the adhesive coating can improve the functionality of the electric or manual cutter in a linerless printer. Furthermore, in such an apparatus, linerless labels including adhesive strips may be easier to mechanically cut, leaving less adhesive residue on the cutting blade or edges. Moreover, this implementation can reduce the accumulation of adhesive coating on the linerless label printer. Such adhesive accumulation can lead to more dust-related problems, as dust adheres to the printer along with the adhesive, thus resulting in shorter printer service cycles. Therefore, due to this implementation, dust-related problems can be avoided or at least reduced.

[0306] Therefore, this embodiment including the adhesive strip may have one or more of the following advantages:

[0307] - No adhesive leakage / seepage

[0308] - This can avoid or at least reduce problems related to dust generation.

[0309] - Reduced adhesive residue in any parts that come into contact with the web during manufacturing (coating, slitting) or final use (printing), and

[0310] - Acrylic water-based adhesives can be environmentally friendly and can be used on, for example, food materials. Furthermore, they may have longer open times, allowing liner-less labels (webs) containing water-based acrylic PSA to be removed after seconds or minutes if needed.

[0311] Adhesive strips with alternating positions

[0312] Unlined label webs may include straight adhesive strips and / or adhesive strips with alternating positions.

[0313] Each customer roll of unlined label web may include at least one adhesive strip with alternating positions. Therefore, for each customer roll to be obtained from the machine roll, the machine roll may include at least one adhesive strip with alternating positions. Figure 10a -b shows an example of an adhesive strip with alternating positions.

[0314] In this embodiment, the method for manufacturing continuous linerless label webs may include the following steps:

[0315] -Optionally, a release coating may be provided on the surface, provided on the first side.

[0316] - A continuous adhesive strip with alternating positions is provided on the second side of the web, and has

[0317] -The predetermined number (A) of strips in the transverse direction of the web,

[0318] - The predetermined width (B) of the strip in the transverse direction of the web,

[0319] - The predetermined position frequency (C) of the strip in the longitudinal direction of the web, and

[0320] - The predetermined position width (D) of the strip in the transverse direction of the web.

[0321] "Pre-order" should be understood as the adhesive strips with alternating positions being designed to provide benefits for both larger machine rolls and smaller customer rolls. Therefore, alternating positions are specifically designed to provide benefits for both machine rolls and customer rolls.

[0322] The “positional alternation” is further divided into two main parts: the frequency at which the adhesive strip changes its position in the longitudinal direction of the web and the magnitude of its position in the transverse direction. These parameters together define the speed and extent at which the adhesive strip changes its position along the length of the web.

[0323] The predetermined characteristics (A, B, C, D) of the continuous adhesive strip with alternating positions can be selected, such that...

[0324] - The number of rows in each customer volume can be one or more.

[0325] - Each strip is narrower than the width of a single customer volume, and

[0326] - Select a position frequency such that one oscillation cycle covers 0.1-10 times the outer perimeter length of the machine roll, where the outer perimeter length is defined as the length of the outer perimeter of the complete machine roll.

[0327] - Optionally, select a position frequency such that one oscillation cycle covers 1-100 perimeter lengths of the client volume, where the perimeter length is defined as the length of the perimeter of the complete client volume.

[0328] This implementation avoids telescoping problems that could challenge the manufacturing process and reduce its productivity. Furthermore, it reduces the buildup of adhesive coating on the linerless label printer. This adhesive buildup can lead to more dust-related problems, as dust adheres to the printer along with the adhesive, resulting in shorter printer service cycles. Therefore, this implementation avoids or at least reduces dust-related problems.

[0329] The number of adhesive strips with alternating positions in the customer roll can be one or more, preferably equal to or more than two, more preferably equal to or more than four, and most preferably equal to or more than six. The number of adhesive strips in the customer roll can be used to adjust the overall tackiness of the label and reduce adhesive contamination in linerless printers. Furthermore, a larger number of adhesive strips provides label removability and the ability to adhere to uneven surfaces. Additionally, the number of adhesive strips with alternating positions in the customer roll can be equal to or less than 15, more preferably equal to or less than 12, and most preferably equal to or less than 10. A larger number of strips generally does not provide any further benefits but does complicate the manufacture of the label web. Therefore, with an appropriate number of adhesive strips, caking problems can be avoided while ensuring good properties of the customer roll. Moreover, dust-related problems can be avoided or at least reduced.

[0330] In one embodiment, to avoid machine roll folding issues, the position frequency of the adhesive strip can be selected such that one oscillation cycle covers 0.1-10 times the outer circumference length of the machine roll, where the outer circumference length is defined as the length of the outer circumference of the complete roll. Furthermore, to avoid folding issues and improve the performance of the customer roll, the position frequency of the adhesive strip can be selected such that one oscillation cycle covers 1-100 times the outer circumference length of the customer roll, where the outer circumference length is defined as the length of the outer circumference of the complete roll.

[0331] Therefore, the position frequency of the adhesive strip can be selected such that one oscillation cycle covers an area equal to or greater than 0.1 outer circumference length of the machine roll, more preferably equal to or greater than 0.4 outer circumference length, and most preferably equal to or greater than 0.8 outer circumference length, where the outer circumference length is defined as the length of the outer circumference of the complete machine roll. Furthermore, the position frequency of the adhesive strip can be selected such that one oscillation cycle covers an area equal to or less than 10 outer circumference length of the machine roll, more preferably equal to or less than 6 outer circumference length, and most preferably equal to or less than 3 outer circumference length, where the outer circumference length is defined as the length of the outer circumference of the complete machine roll. Therefore, the problem of machine roll stacking can be avoided. Furthermore, the simplicity of the manufacturing process with this position frequency can be improved. Additionally, the accumulation of adhesive coating on linerless label printers and dust-related problems can be avoided or at least reduced.

[0332] Furthermore, the position frequency of the adhesive strip can be selected such that one oscillation cycle covers an area equal to or greater than one outer perimeter length of the customer roll, more preferably equal to or greater than 10 outer perimeter lengths, and most preferably equal to or greater than 30 outer perimeter lengths, where the outer perimeter length is defined as the length of the complete customer roll's outer perimeter. Additionally, the position frequency of the adhesive strip can be selected such that one oscillation cycle covers an area equal to or less than 100 outer perimeter lengths of the customer roll, more preferably equal to or less than 80 outer perimeter lengths, and most preferably equal to or less than 60 outer perimeter lengths, where the outer perimeter length is defined as the length of the complete customer roll's outer perimeter. Therefore, the problem of customer roll stacking can be avoided. Furthermore, some characteristics of the customer roll can be improved.

[0333] In one implementation, the step of providing one or more adhesive strips with alternating positions may include the following steps:

[0334] - Apply at least one continuous adhesive layer,

[0335] - Before drying, at least 50% of the applied adhesive coating is removed in an oscillating manner using an oscillating actuator to provide one or more alternating adhesive strips and unbonded areas.

[0336] The oscillating actuator may include a blade that can be used to remove at least some of the applied adhesive.

[0337] In one embodiment, the non-adhesive region may contain 0.5-5.0 g / m³. 2 The amount of adhesive coating residue within the specified range. Alternatively, the dry weight content of the adhesive coating removed from the substrate may be 0.1-5% lower than the dry weight content of the adhesive coating applied to the substrate. Alternatively, the dwell time between applying and removing the adhesive coating may be 0.05 to 3 seconds.

[0338] In one embodiment, the step of providing one or more adhesive strips with alternating positions includes:

[0339] - By using an oscillating actuator to locally apply an adhesive coating to provide an adhesive strip with one or more alternating positions.

[0340] In this embodiment, the oscillation actuator may include a nozzle for applying adhesive.

[0341] In one embodiment, the adhesive strip with alternating positions has a predetermined strip width, a predetermined position amplitude, and a predetermined position frequency. The predetermined position frequency defines the wavelength of the strip.

[0342] In one implementation, the width of each strip can be less than the width of each customer roll. The width of each strip can be less than 0.5 times the width of each customer roll. The width of the strip can be equal to or less than the width of adjacent unadhesive areas. Furthermore, the width of each strip can be less than the width of the smallest single customer roll obtained from the machine roll. Therefore, the problem of linerless label roll shrinkage can be avoided while providing a good level of adhesion for pressure-sensitive labels. A typical width of a linerless customer roll can be approximately 2 inches, for example, 58 mm. In this case, the adhesive strip can have a width of 5 mm, separated by 5 mm unadhesive areas. As explained further below, the positional amplitude of the strip can be, for example, 15 mm to 25 mm.

[0343] In addition, one or more adhesive strips with alternating positions may have positional amplitudes. Positional amplitudes are determined on the transverse CD of the linerless label web. Positional amplitude refers to the height of a wave (from the bottom to the top of the strip) determined on the transverse CD of the linerless label web. When measuring positional amplitude, each position of the alternating adhesive strip can be determined from the middle of the adhesive strip.

[0344] The positional amplitude can be selected such that it ranges from 0.1 to 1 times the width of each customer roll. Preferably, the positional amplitude is equal to or greater than 0.1 times the width of each customer roll, more preferably equal to or greater than 0.2 times the width of each customer roll, and most preferably equal to or greater than 0.3 times the width of each customer roll. Furthermore, the positional amplitude is preferably equal to or less than 1 times the width of each customer roll, more preferably equal to or less than 0.8 times the width of each customer roll, and most preferably equal to or less than 0.7 times the width of each customer roll, for example, in the range of 0.3 to 0.7 times the width of the customer roll. Therefore, each customer roll can have an adhesive coating over its entire length, i.e., the entire length of a customer roll has an adhesive coating on its surface. Furthermore, the positional amplitude helps prevent caking problems by preventing the edges of the adhesive strips from "piling up" at the same location on successive layers of the customer roll. An additional technical advantage is that, in a linerless printer, the accumulation of adhesive residue (which may be more noticeable at the edges of the adhesive strips) is distributed over a wider lateral area. Because the non-adhesive strips also have a high affinity for adhesive (to achieve good adhesive anchoring), these areas also tend to remove any loose adhesive residue inside the printer. Furthermore, this implementation method reduces dust-related problems.

[0345] In this embodiment, the total coverage of the adhesive coating can be equal to or less than 50% based on the total area of ​​the second side of the surface. Furthermore, the total coverage of the pressure-sensitive adhesive coating can be equal to or greater than 10%, more preferably equal to or greater than 30%, and most preferably equal to or greater than 40% based on the total area of ​​the second side of the surface. Therefore, by employing adhesive of the stated total area and adhesive strips with alternating positions, the problem of slack rolls collapsing can be prevented.

[0346] This embodiment provides a linerless label web comprising a pressure-sensitive adhesive coating on a second side of its surface. This adhesive coating includes one or more adhesive strips and unadhesive areas that are alternately positioned in a predetermined manner. This allows the linerless label web to self-wind into larger machine rolls without being affected by camber effects, which can cause significant complications or even prevent subsequent unwinding and longitudinal slitting into narrower customer rolls. The invention also offers significant benefits for smaller customer rolls, from avoiding camber to causing less adhesive contamination in linerless printers. Furthermore, this embodiment avoids or at least reduces dust-related problems.

[0347] Therefore, this implementation may have one or more of the following advantages:

[0348] - The rolls in the machine rolls or customer rolls have smooth outer surfaces.

[0349] - There is no stacking in the machine volume.

[0350] - There is no collapse in the customer's volume.

[0351] - No adhesive seepage / bleed, even if there is some adhesive at the edges of the customer's roll.

[0352] - This can avoid or at least reduce problems related to dust generation.

[0353] - Reduced adhesive residue in any parts that come into contact with the web during manufacturing (coating, slitting) or final use (printing).

[0354] - It can cut any width of fabric without special adjustments, and

[0355] - Water-based acrylic adhesives can be environmentally friendly and can be used on, for example, food materials. Furthermore, water-based acrylic adhesives may have longer open times, so liner-less labels (webs) containing water-based acrylic PSA can be removed after seconds or minutes if needed.

[0356] The range of waveforms generated by a predetermined selection of the position frequency and position amplitude of a bar can range from smoothly varying sinusoidal waveforms to more rapidly varying waveforms that are almost stepped or sharply stepped. However, all of these can be characterized by having specific position dominant frequency and dominant amplitude properties.

[0357] Release coating

[0358] The direct thermal liner label (webbed) may have a release coating 130 on the first side 111 of the face 110, i.e. the top of the face 110, as shown in Figure 1.

[0359] A linerless label web 100 having a pressure-sensitive adhesive 120 on one side (bottom side) and a release coating 130 on the other side (top side) can self-wrap around itself without the tendency for adjacent layers of the label web 100 to obstruct each other.

[0360] Release coating 130 can be applied directly to the direct heat-sensitive coating. Alternatively, the release coating can be applied to the top coating 116 on the surface.

[0361] There are several options on how and when the release coating 130 can be applied to the first side of the surface 110.

[0362] According to one embodiment, a release coating 130 is applied to and cured on the top of the surface 110 before the adhesive coatings 120, 121 on the bottom of the surface 110 are directly applied and dried, or before the separately dried adhesive coatings 120, 121 are transferred to the bottom of the surface 110. In other words, in these embodiments, an easily peelable coated surface 110 is provided for the process of adding adhesive coatings 120, 121 to the opposite sides of the surface 110. An advantage of these embodiments is that the release coating 130 can be provided as a completely independent step and may be provided in a completely separate facility.

[0363] According to another embodiment, face 110 is first directly coated and dried to have an adhesive coating 120 on the bottom of face 110, or alternatively, a separately dried adhesive coating 120 is first applied to the bottom of face 110. In other words, in these embodiments, face 110 is first provided with adhesive coatings 120, 121 on the bottom of face 110, and then a release coating 130 is applied to the opposite side of face 110. The advantage of these embodiments is that the release coating 130 does not undergo any prior processing steps, which helps to avoid release agent contamination during these steps. On the other hand, in this embodiment, it is preferable to add the release coating 130 in the same process, because otherwise, the adhesive-coated web may not be able to self-wind into a roll.

[0364] According to another embodiment, a release coating 130 is pre-coated on the thermally printable top side of face 110. Adhesive coatings 120, 121 are then directly applied and dried on the same side and top of the release coating 130, or separately dried adhesive coatings 120, 121 are transferred to the top of the release coating 130. In these embodiments, when the web is self-wound, the pressure-sensitive adhesive coating 120 is anchored to the bottom side of face 110, which currently lacks a release coating. When the roll is unwound, this linerless web adhesive coating 120 is now retained on the bottom of face 110, while the release coating 130 remains on the top of face 110. The advantage of this embodiment is that, particularly in direct adhesive coating methods, it allows the use of adhesive coating methods typically used in the label industry. This is because other methods of manufacturing unlined labels (webs) 100, 200 involve applying and drying pressure adhesive on a release-coated backing, and then using the same pressure-sensitive adhesive layer to press the backing onto the label facestock.

[0365] Thermal printing of unlined labels (webbed) 100 and 200 can be performed via release coating 130.

[0366] Release coating 130 may be a silicone-based or non-silicone-based release coating. Preferably, the release coating comprises or is composed of a silicone-based release coating.

[0367] Non-thermally curable release coatings are preferred, such as UV-curable silicone, because the curing of these layers does not heat the thermal material in the directly thermally printable surface 110.

[0368] The release coating can be a UV-curable silicone, which has the advantage of curing on top of a heat-sensitive surface without heating. The PA silicone-based release coating 130 may include a UV-curable silicone, such as a UV radical silicone or a cationic UV silicone.

[0369] Release coating 130 may comprise one or more layers of release coating 130. Due to the release coating, the adhesion can be low enough that the adhesive layer can be easily peeled off from the face stock when the roll of linerless label products is unrolled. This effect can be further improved if the adhesive coating has an adhesive-free area 150, and / or if the adhesive coating contains silicone additives.

[0370] Release coating 130 can also provide a lower level of friction to the printhead and / or other mechanical components of the on-demand printer, thereby minimizing wear on these components and minimizing the accumulation of adhesive residue. Therefore, in one example, release coating 130 is used to reduce friction on the printer's printhead.

[0371] Therefore, in an advantageous embodiment, surface 110 may include paper and a direct thermal coating, wherein the top side of surface 110 is coated with a silicone-based release coating 130, while the other side of surface 110 is coated with an adhesive layer.

[0372] Release coating 130 can be an optional feature. For example, when adhesive coatings 120, 121 contain silicone additives, if the adhesive strength of face 110 (without release coating 130) is low enough that the pressure-sensitive adhesive can be easily peeled off face 110 when unrolling the roll of linerless label products, then linerless labels (webs) 100, 200 may be without release coating 130. However, even if adhesive coatings 120, 121 contain silicone additives, release coating 130 can be used to further improve the self-winding properties of linerless labels.

[0373] Unlined Label

[0374] Label 200 (also known as a linerless label or label product) is a piece of material to be applied to an article. Articles of different shapes and materials can be used with label 200. The article can be packaging. The characteristics and requirements of label 200 may vary depending on the end use discussed, as described in Table 1.

[0375] Label 200 includes at least face 110. A typical way to adhere label 200 to an article is using a PSA coating 120. Therefore, the adhesive coating 120 contains a pressure-sensitive adhesive (PSA). Label 200 containing a pressure-sensitive adhesive may be referred to as a pressure-sensitive adhesive label. A pressure-sensitive adhesive label may also be referred to as a self-adhesive label.

[0376] Labels 200 containing PSA can adhere to most surfaces via an adhesive layer without the use of additives (such as solvents) or heat to enhance adhesion. In that case, the adhesive itself is pressure-sensitive. Alternatively, the adhesive can be activated to be pressure-sensitive. When pressure is applied to the label at ambient temperatures (e.g., between 15°C and 35°C) or, for cold applications, even at freezing temperatures below 0°C, the PSA forms an adhesive, adhering the label to the item to be labeled. Examples of pressure-sensitive adhesives include water-based (aqueous) PSA, solvent-based PSA, and hot-melt PSA. As an alternative or additional form, the label may contain other adhesives.

[0377] Different types of labels are available on the market. Labels can be so-called liner labels 200. A liner label includes a face 110 and an adhesive on the face 110. Alternatively, a label can be a so-called shrink label, in which a heat-shrinkable polymer face stock is sewn and wrapped around or fitted onto an item to which the label is affixed, and shrinks around the item. Shrink labels may additionally contain some pressure-sensitive adhesive, or may be produced without any pressure-sensitive adhesive or even seam adhesive. Furthermore, labels can be activated liner labels, in which the adhesive can be activated to be pressure-sensitive, for example, using additional heat, moisture, or other activation methods.

[0378] In this application, the pressure-sensitive adhesive is a water-based acrylic PSA. The PSA may have inherent pressure sensitivity and does not require separate activation before it can be applied to the article to be labeled. Furthermore, the label may be a liner-less label, which adheres to the article to be labeled primarily by the pressure-sensitive adhesive at least partially covering the bottom side of the label. The liner-less label (web) of this invention is strip-type; in other words, it can self-wind in a roll without additional release liner.

[0379] Labels can be used in a wide range of labeling applications and end-use areas, such as labeling food, home and personal care products, industrial products, pharmaceutical and health products, beverage and wine bottles, and other consumables. Labels can provide information about the product being labeled, such as product specifications. This information, such as the printed material of the label, can include human-readable information, such as images, logos, and text, and / or machine-readable information, such as barcodes and QR (Quick Response) codes. An important subcategory of labels using directly thermally printable face stock is the so-called Variable Information Print (VIP) label. These labels are at least partially printed before being applied to the items to be labeled, carrying product-specific information on the individual item being labeled. For example, VIP labels are used on retail weighing scales for fruits, vegetables, meat, and other items sold by weight. Other labels printed separately as needed are different types of logistics labels—containing shipping or product-specific information, bus or train tickets, or other tickets, etc.

[0380] Advantageously, the linerless labels (web sheets) 100, 200 include a face containing a base paper, an intermediate layer on the base paper, a direct thermal coating on the intermediate layer, a release coating 130 on the top side 111 of the face, and an adhesive layer on the bottom side 112 of the face. Therefore, an improved direct thermal linerless label can be formed, which can have improved properties.

[0381] In a favorable example, an unlined label (web) consists of the following:

[0382] -Based on the direct thermal surface of paper,

[0383] - Release coating on the first side 111 of the surface, and

[0384] - A water-based acrylic adhesive on the second side 112 of the face.

[0385] Natural fibers can reduce dust generation in products. Therefore, in one embodiment, based on the total weight of the liner label (web), the natural fiber content of the liner label (web) can be at least 65% by weight, preferably at least 70% by weight, more preferably at least 72% by weight, and most preferably at least 74% by weight.

[0386] Sans-free label webs and sans-free label rolls

[0387] Figure 1a The Sx and Sy cross sections of linerless label (web) 100 and 200 are shown by way of example. The web can be linerless label 100 or a single label 200.

[0388] As discussed herein, linerless label web 100 refers to a structure comprising a continuous surface 110 and an adhesive 120 disposed on one side of the surface 110. Linerless label web 100 is typically processed by moving it on a roller. Between processing stages, label web 100 can be stored and transported as a roll. Individual labels 200 can be cut from linerless label web 100.

[0389] The width of the linerless label web before it is cut into customer rolls is typically several times the width of the final customer roll. The width of the web can be, for example, 1 to 3 meters before it is cut into customer rolls.

[0390] The wider web width of the machine rolls produced in this manufacturing process can then be cut to a suitable customer roll width, for example, at least 10 mm, preferably 20 to 100 mm, or 40 to 100 mm. A fairly common width is between 40 and 60 mm.

[0391] After being rolled up, the linerless label web 100 may be referred to as a (linerless label) customer product roll, customer roll, or product roll. Depending on the diameter of the label roll and the thickness of the linerless label material, a single roll may contain, for example, 10-100 meters of label material (i.e., linerless label web 100).

[0392] Unlined labels (webbed) 100, 200 may include at least one characteristic selected from the group below, preferably including all characteristics of the group below:

[0393] The surface has at least three layers, including a base layer, an intermediate layer, and a direct thermal coating. The intermediate layer is located between the base layer and the direct thermal coating. The amount of mineral pigment in the intermediate layer is less than 4 gsm. Due to the intermediate layer, the quality of the direct thermal coating can be improved. Furthermore, the amount of expensive direct thermal coating can be reduced. The intermediate layer with the aforementioned mineral content reduces dust generation. This ensures an increased lifespan for the thermal printer.

[0394] The surface has a static sensitivity of below 100°C, preferably below 95°C but above 65°C. This ensures that thermal printing can be performed at relatively low energy levels and high speeds in thermal printers, while simultaneously preventing the thermal paper from undergoing unwanted activation during manufacturing and logistics.

[0395] - The coating weight of adhesive layer 120 is 15-30 g / m². 2 Within the range (dry coating weight) to ensure both: good anchoring to thermal paper and good adhesion to different types of surfaces.

[0396] - Adhesive layers 120 and 121 contain acrylic-based PSA and optional silicone additives. Acrylic adhesives are more environmentally friendly and offer more suitable time to build up final tack, helping to reduce printer contamination. Furthermore, acrylic adhesives may have longer open times, so liner-less labels (webs) containing water-based acrylic PSA can be removed after seconds or minutes if needed.

[0397] - This can avoid or at least reduce problems related to dust generation.

[0398] - Adhesive layers 120, 121 have at least one adhesive area, preferably at least one unadhesive area. This ensures suitable label properties for each given end use and also helps reduce printer contamination.

[0399] Linerless label printer

[0400] The general properties of on-demand compact printers are discussed to clarify the requirements for label products. During the labeling process, the linerless label web 100 is printed by a printer with variable information, and the printer's cutter cuts the label web 100 to the appropriate label length for affixing to the product.

[0401] Labeling can be done manually or automatically. A challenge for linerless label printers is the accumulation of adhesive and dust on things like the cutter blade, leading to shorter printer service cycles. In the worst case, the adhesive application may be perfect, but the printer becomes unusable due to the shortened service cycles.

[0402] Figure 2An example of a label printer 240 according to this disclosure, which can be used with liner label web 100, is shown. Label printer 240 may be referred to as a liner label printer or a liner printer. These terms refer to a printer designed to print liner labels. Label printer 240 may be referred to as an on-demand label printer to emphasize that the printer can be used to print labels individually as needed.

[0403] Business environments using this type of on-demand label printer typically require very compact size and easy-to-use printer equipment with minimal maintenance needs. Thanks to sans-free labels that can be directly thermally printed, the labels themselves have a thermally printable coating. This differs from other indirect thermal printing methods, such as those using separate thermal printing tapes that need to be loaded into the printer and replaced after each use.

[0404] Furthermore, the number of individual components is chosen to minimize complexity. Preferably, the printer is also manufactured to be very easy to use and requires minimal setup and adjustment, for example.

[0405] The main functional components inside this compact linerless label printer may include: a mechanism for conveying the label web 100 through the printer, a thermal printhead for printing individual labels onto the label web 100, and a mechanism for separating individual labels from the label web 100 and providing them for manual dispensing.

[0406] The mechanism used to feed the label web 100 from the unfolding of the label roll through all the different parts of the printer and ultimately output individual labels is typically a series of guide rollers and guide surfaces. To minimize the size and complexity of this device, most rollers are free-running, and perhaps only one or a few are motorized to pull the label web 100 forward during printing. These rollers or surfaces may not use any special friction-reducing coatings for a cost-effective construction. Traction rollers may also comprise simple plastic or rubber rollers with only a rough surface to ensure traction without any special coating. Typically, individual printer models are also designed to accept label rolls of varying widths, using simple adapters to center the rollers relative to the web track. This simple, efficient, and economical printer design places stringent requirements on the linerless label web 100 to ensure smooth customer service. Typical challenges involve the pressure-sensitive label web 100 adhering to its various components inside the printer and hindering the smooth forward traction of the label web 100, and / or adhesive residue accumulating on printer components over prolonged use, causing the aforementioned problems and requiring cleaning of the printer components.

[0407] The thermal printheads in this type of compact printer are typically selected to use lower printing energy, meaning less heat can be transferred to the thermal layer of the liner label web 100. This is preferred in applications where short-term labels are printed in a simple and economical manner. Even if the printheads can be tuned for higher energy levels or temperatures, it is best to operate them at lower settings to maximize the lifespan of the thermal printhead / printer. It may also be necessary to reduce printing speeds due to printer performance limitations if liner labels require higher activation.

[0408] For printing, the thermal liner label web 100 is drawn through the gap between the thermal head and the pressure roller. The printer sends an electric current to the heating element of the thermal head, generating heat. The heat activates the thermal coloring layer of the thermal paper, turning black where heated. This printing mechanism is called a thermal printing system or a direct thermal printing system. The heating elements are typically arranged in a row of closely spaced small dots. Printing energy (temperature and / or exposure time) can be adjusted, but such adjustments are often tedious. Preferably, label materials that can be directly thermally printed should be selected so that they can operate without requiring fine-tuning of printer characteristics. If more printing energy is required, this usually means a slower printing speed, resulting in a longer time for the printing temperature to affect the label, thus transferring more energy to the web. Therefore, the performance of the printhead influences the selection of the thermal face stock for liner label products to ensure good print quality even at lower printing energy / heat levels and higher printing speeds.

[0409] The mechanism located on the printer's output side for separating individual printed labels from the continuous linerless label web 100 can include various types of motorized cutting blades or cutters, or in many cases simply a non-movable serrated cutting blade. The latter requires the user to manually tear the label web 100 using the serrated or toothed blade. In any case, the user needs to manually grasp the printed label output by the printer. When using a non-motorized or non-assisted cutting mechanism, the user needs to hold the label fairly firmly to manually separate it from the continuous web. This again places demands on the label material so that it does not unnecessarily stick to the printer's cutting mechanism or the user's fingers, and the user needs to be able to easily position the label in its first labeling position.

[0410] For use with such printers, the linerless labels (webs) 100, 200 according to the invention use water-based acrylic adhesives. Water-based acrylic adhesives have lower initial tack, meaning that upon being unrolled from the label roll, the immediate tack of the PSA as it is guided through the printer is lower than that of, for example, a hot-melt PSA. This, along with other characteristics of the label, helps to minimize adhesive residue buildup inside the printer. Final tack only forms after the label has been applied and remained on the labeled item for an extended period. The label can even be removable for a period of time (minutes) before a more durable type of tack is established. The specific properties of the PSA naturally depend on the exact formulation of the adhesive and the surface material to which the label will be applied.

[0411] The linerless label products disclosed herein are intended for end-use applications with short label lifespans, requiring manual handling, and featuring repositionable and / or removable structures that are lean, sustainable, and economical.

[0412] For example, in a fast-food restaurant, as a specific end-use, orders can first be placed remotely via the internet or locally at the restaurant via self-service touchscreen kiosks or at the counter. After the order is confirmed and sold, one or more labels can be printed for the order. For example, at a beverage station, one or more labels can be printed for the beverages and affixed to the appropriate cups. In the kitchen, one or more labels can be printed for different parts of the meal, such as for different burgers and other dishes or side dishes. After the various dishes are prepared and individually boxed or packaged, appropriate labels can be affixed individually to each dish. If applicable, especially for larger orders, compilation or summary labels can also be printed to help summarize and check that all dishes included in the order are prepared and included before the order is delivered to the customer.

[0413] For example, a luggage tag can be a tag wrapped around the handle of a luggage bag, typically found on takeout or delivery bags. The luggage tag adheres to itself by wrapping around the handle with the adhesive side facing inwards and the printed side facing outwards. Therefore, in takeout or delivery bags, this luggage tag can serve as a sealing label or an identification tag for use during transport or by the end user.

[0414] The linerless labels according to this specification are particularly suitable for use with on-demand linerless label printers. Therefore, it reduces problems caused by the printer's cutting action, where the linerless label is cut by the printer's blades. The novel solution prevents the adhesive coating 120 from accumulating on the linerless label printer blades, which leads to shorter printer service cycles. Due to the novel solution incorporating silicone additives in the adhesive coating, adhesive accumulation on the printer blades is significantly reduced. Furthermore, adhesive accumulation on the pressure rollers and other components of the linerless label printer is significantly reduced.

[0415] Therefore, in order to provide cost-effective, efficient and trouble-free operation in a user-friendly and sustainable manner, various requirements are placed on liner-less label products.

[0416] Manufacturing method

[0417] A method for manufacturing a direct thermal liner label web 100, the direct thermal liner label web 100 including a multilayer structure of at least three layers, the method may include the following steps:

[0418] - Provides noodle 110,

[0419] - Apply a water-based acrylic adhesive coating 121, and

[0420] - Heat-dry the adhesive coating 121 to form a pressure-sensitive adhesive coating 120.

[0421] in,

[0422] 1) Apply the adhesive coating to the surface 110.

[0423] or

[0424] 2) Applying an adhesive coating to the carrier material 611, and the method further includes: transferring a pressure-sensitive adhesive coating 120 from the carrier material to the surface 110.

[0425] The surface includes:

[0426] -Uncoated substrate

[0427] - Coatings that can be directly thermally printed

[0428] - An intermediate layer, which remains between the base layer and the coating that can be directly thermally printed, and

[0429] -Optionally, a top coating on top of a coating that can be directly thermally printed.

[0430] in,

[0431] - The weight of the intermediate layer is 1 g / m³ 2 Up to 7g / m 2 Within the range,

[0432] - The total amount of mineral pigments in the intermediate layer is equal to or less than 4 g / m³ 2 Preferably equal to or less than 3g / m 2 ,as well as

[0433] -Based on the total dry weight of the intermediate layer, the mineral pigment content of the intermediate layer is equal to or less than 85% by weight, preferably equal to or less than 80% by weight, more preferably equal to or less than 75% by weight, and even more preferably equal to or less than 70% by weight.

[0434] The machine speed for this method can be, for example, 100-600 meters per minute.

[0435] Figure 3 A method according to one embodiment is shown. This method allows the application of PSA to a sensitive, unlined surface and the formation of an unlined label web 100 without exposing the surface 110 to temperatures exceeding the activation temperature of the direct heat-sensitive coating material. Steps 402, 405, 406, and 407 may also be referred to as stages or levels.

[0436] according to Figure 4 The illustrated embodiment provides a method for manufacturing a liner-less label web 100, the liner-less label web 100 comprising a coating suitable for direct thermal printing and a pressure-sensitive adhesive. The method may include:

[0437] - Set up a surface with a coating that can be directly thermally printed (step 401).

[0438] - Apply adhesive coating 121 to the surface (step 402),

[0439] Optionally, the surface is provided with alternating adhesive and non-adhesive areas (step 403); optionally, the non-adhesive area 150 is ensured to have a predetermined humidity level (step 404), and

[0440] - Heat-dry the adhesive coating 121 to form a pressure-sensitive adhesive 120 (step 405).

[0441] Steps 402-404 of this method can be performed simultaneously or sequentially. Step 404 may also refer to maintaining or arranging the non-adhesive area 150 with moisture.

[0442] Example of adhesive application steps

[0443] A coating unit 580 can be provided to apply the adhesive coating 121 onto the surface 110. The adhesive coating 121 can be applied to the surface 110 using contact coating methods, such as roller coating or curtain coating, foam coating or spray coating. The adhesive coating 121 can also be applied by direct gravure coating.

[0444] Alternatively, a coating unit 580 may be provided to apply the adhesive 121 to the carrier material. The coating step may include contact coating methods, such as roller coating or curtain coating, foam coating or spray coating.

[0445] As discussed, the adhesive coatings 120, 121 may or may not be patterned. Patterned adhesive refers to adhesive covering less than 100% of the second side 112 of the surface. For example, the adhesive may cover 10% to 90% of the total area of ​​surface 110. The adhesive may be arranged as strips, for example, along the longitudinal direction (i.e., the first direction) of the label web 100. Alternatively, the adhesive may be arranged as dots or other similar discontinuous areas, for example. Due to these solutions, contamination of the printer components by the adhesive can be avoided or at least reduced. Furthermore, from an economic and environmental perspective, it is advantageous to apply adhesive only to the label webs 100, 200 on the portions of the label necessary to provide the desired adhesion.

[0446] Therefore, the adhesive layer can be a continuous layer, or the adhesive layer can be a discontinuous layer having the following regions:

[0447] - Adhesive areas, such as adhesive dots and / or adhesive strips, and / or other types of adhesive areas, and

[0448] - Areas without adhesive.

[0449] In one embodiment, the patterned adhesive is provided by first applying an adhesive coating 121 to 100% of the area of ​​surface 110 via a coating unit 580. Subsequently, some of the adhesive coating 121 can be removed from surface 110, thus providing surface 110 with alternating bonded and unbonded areas 150 in the transverse direction of surface 110. Adhesive removal is performed before drying the adhesive in at least one drying unit 560. Adhesive removal can be performed by unit 590.

[0450] Applying adhesive coating 121 to 100% of the surface 110 provides the effect that areas where the adhesive is later removed will also be moistened by the water contained in the adhesive. Therefore, it may not be necessary to separately apply moisture to the unadhesive areas 150 of surface 110. When adhesive coating 121 is applied to the entire area of ​​surface 110, water is absorbed into surface 110, and after patterning, a small amount of adhesive remains on surface 110, as well as in areas where the adhesive has been removed. In any case, the amount of adhesive residue is minimal and does not provide significant adhesive properties after drying; hence, it is termed "unadhesive."

[0451] The adhesive can be removed from the surface using a blade, such as a nylon blade. The blade may be referred to as a patterning blade or a scraper. The blade can refer to any device suitable for removing adhesive from a web. The blade has the effect that, while removing the adhesive, it simultaneously applies pressure to the surface 110, thereby pushing moisture, i.e., water contained in the adhesive, into the surface 110.

[0452] It should be noted that a certain coating thickness (coating weight) is required to obtain a water-based PSA as a uniform, defect-free layer on surface 110. Simply reducing the adhesive coating thickness below a certain value in an effort to promote drying at a lower temperature without increasing the drying time may result in unsatisfactory PSA quality and performance. Therefore, this disclosure also aims to provide a method for obtaining good PSA quality and performance using a sufficiently high coating thickness (coating weight) along with a sufficiently high drying temperature while still preventing the heat-sensitive coating from overheating.

[0453] Figure 6 Detailed views of a method and apparatus according to one embodiment are provided. An adhesive coating 121 is applied to 100% of the area of ​​surface 110 via a coating unit 580. Subsequently, some of the adhesive coating 121 can be removed from surface 110, thus providing surface 110 with alternating adhesive and unadhesive areas 150 in the transverse direction of surface 110. A unit 690 is provided to remove the adhesive coating 121, thereby providing an adhesive strip to surface 110. Figure 6 It is shown as black block 121 in the magnified dashed line. Figure 6 The small gray droplets indicate the adhesive coating removed from surface 110. The adhesive removed from surface 110 can be collected and returned to the coating unit, as indicated by the curved arrow between unit 690 and coating unit 580.

[0454] Alternatively, if a patterned adhesive is used, it can be provided by applying the adhesive coating 121 only locally to the surface 110, thereby providing the surface 110 with alternating adhesive areas 121 and unadhesive areas 150 in the lateral direction of the surface 110. This is shown in Figure 7 In the middle. The adhesive area, i.e., the strip of adhesive 121, in Figure 7 The image is shown as a black block. To prevent the thermal paper from activating during adhesive drying, moisture can be supplied to the unbonded areas 150 of surface 110 before the adhesive coating 121 dries into pressure-sensitive adhesive 120. Moisture can be supplied by unit 590, in this case, unit 590 is, for example, a water sprayer. The water sprayer can be configured to spray water only onto the unbonded areas 150, such as... Figure 7 As shown by the gray wide arrow in the image.

[0455] Therefore, downstream of the coating unit 580, the device may include:

[0456] - Unit 590 for removing adhesive, and / or

[0457] -like Figure 5 The humidification unit 690 shown is shown.

[0458] Ensure there is no adhesive area of ​​150 (e.g.) Figure 7As shown, a predetermined level of moisture produces the following effect: the moisture evaporates as the adhesive dries, preventing the temperature of the thermal paper from rising to a value that would cause the thermal paper to activate.

[0459] Drying Steps Example

[0460] The adhesive coating 121 can be dried in at least one drying unit 560.

[0461] One issue with the thermal paper, including surface 110, stems from its thermal sensitivity. The thermal coating on the thermal paper is activated by heat. This can hinder the drying and / or heating of water-based adhesives on the thermal paper, as heating may cause activation and darkening of the thermal paper, or result in less severe but undesirable visual changes. A partially or fully activated brown or black surface of the thermal paper hinders the delivery of high-quality visible printing on it.

[0462] Other problems may arise when only a portion of the surface 110 containing the direct thermal paper is configured to contain adhesive, thus leaving certain areas of surface 110 without adhesive. Those areas without adhesive may be even more prone to activating the thermal paper when the adhesive is dried and / or heated. Some label applications require this patterned adhesive, sometimes referred to as patterned coating.

[0463] Traditionally, the direct thermal printing coating on the label substrate has prevented the use of water-based adhesives for liner-less labels. After the adhesive is applied to the label's surface 110, such adhesives are typically dried to allow water to evaporate. The use of water-based adhesives requires drying, and any thermal layer or portion of the label may preclude drying or heating at or above the activation temperature of the thermal layer. Drying at lower temperatures and with a lower coating weight (i.e., less mass to dry) is feasible, but without very careful selection of drying process parameters, this will at least result in ineffective and longer drying times and / or changes in the size (length) of the drying chamber or oven.

[0464] Low coating weight can negatively impact PSA adhesion on the labeling surface. In particular, a higher PSA coating weight is required if good adhesion, removability, and / or repositionability are needed, especially in the case of water-based adhesives. Furthermore, if the adhesive needs to be dried at lower temperatures due to the sensitive heat-sensitive coating, extra care must be taken to ensure complete drying and achieve optimal pressure-sensitive adhesion.

[0465] The apparatus may include at least one drying unit 560 for drying the adhesive coating 121. The drying unit may include at least one drying device 561.

[0466] The adhesive coating 121 can be dried on the surface 110 or the carrier 611. The result of drying is a pressure-sensitive adhesive 120.

[0467] Adhesive 121 is dried to evaporate moisture from the water-based adhesive. Drying includes heating. Heating can be achieved by at least one of the following: infrared heating, microwave heating, or air blowing. Preferably, adhesive 121 is dried by air blowing or by air blowing in conjunction with another type of drying. The other type of drying may include infrared energy and / or microwave energy. This ensures an appropriate level of preheating of the adhesive to begin evaporating moisture from it, but prevents skin formation on the top surface of the adhesive, which would prevent moisture from escaping from deeper layers of the adhesive.

[0468] The drying stage of a machine, including the drying unit, can have a total length of 20 to 30 meters.

[0469] If the adhesive coating 121 dries on the surface 110, the temperature of the drying unit 560 can be between 60°C and 90°C, or in some cases even higher than 100°C. Preferably, the drying temperature is at least 75°C to ensure that the water-based adhesive is completely dry and provides maximum adhesive properties, such as adhesive strength. The surface 110 on which the adhesive coating 121 is attached can be configured to travel through the drying unit 560. Thus, a linerless label web 100 is formed.

[0470] When exiting heat drying, the temperature of the liner label web 100 can be set 5 to 15°C lower than the activation temperature of the coating that can be directly thermally printed. From an economic point of view, it may be preferable to set the temperature of the liner label web 100 when exiting heat drying as close as possible to the activation temperature of the coating that can be directly thermally printed.

[0471] After the adhesive dries, the face 110 with pressure-sensitive adhesive, i.e., the linerless label web 100, can be wound onto the roll 570 of the linerless label web 100.

[0472] According to one embodiment, the adhesive for the linerless label web is dried separately on the carrier material 611 before the adhesive is adhered to the label surface. This avoids problems caused by heat sensitivity and allows the use of environmentally friendly water-based adhesives in such linerless labels. This approach allows for a wider selection of substrate materials for the labels, including substrate or coating materials, even if their physical or chemical properties are lower, yet still perfectly suitable for on-demand linerless printing and short-term label applications. It should be understood that such label products do not need to be designed for normal conversion steps (printing, die-cutting, perforation, potential waste matrix removal, etc.) but can be simply printed and manually assigned to their end use after manufacturing and slitting into customer rolls. For such applications, even lower-grade and more economical materials can be used because the adhesive is dried separately using a separate carrier material 611 (e.g., metal strip or mesh).

[0473] A water-based adhesive is used in the following embodiments. When the adhesive is first applied to the carrier for drying / curing, solvent-based adhesives or hot-melt adhesives will require some changes in the details of the adhesive coating technique. Furthermore, using other types of adhesives to achieve the PSA may result in some variations in the drying and / or curing of the adhesive on the carrier material. However, for the reasons discussed herein, the PSA in this specification is a water-based adhesive.

[0474] In this embodiment, the adhesive coating 121 is applied to the carrier material 611 in the first step 402. Then, in the second step 405, the adhesive coating 121 is dried / cured into PSA 120 on the carrier material 611 by conveying the carrier through a dryer. In the third step 406, the dried water-based adhesive 120 is transferred to the surface 110 of the label web 100. Finally, in the fourth step 407, the surface with the pressure-sensitive adhesive is wound into a roll of the linerless label web 100. In this embodiment, the drying / curing of the adhesive coating 121 occurs on the individual carrier material 611, so the heat-sensitive coating on that surface is not exposed to temperatures exceeding the activation temperature of the heat-sensitive coating.

[0475] Two example methods of manufacturing using carrier materials are presented in Figure 8 and 9 As shown in the diagram. The main difference between the two methods lies in how the carrier material 611 used for drying the adhesive coating is set. Figure 8 In the illustrative embodiment described herein, the carrier material is configured as an annular strip. According to... Figure 9 In another embodiment illustrated in the diagram, the carrier material is configured as a batch of web material that can be reused.

[0476] Drying may be carried out by one or more drying devices 560, 561. The adhesive coating 121 may be dried on one or both sides of the carrier, i.e., above and / or below the carrier. The adhesive coating 121 may be dried directly and / or indirectly. The drying temperature of the water-based adhesive on the tape may be at least 75°C, preferably at least 80-85°C, to ensure that the water-based adhesive is fully dried and provides maximum adhesive properties, such as adhesion strength. It should be understood that all heating / drying / curing methods explained above, if applicable to the selected carrier, also apply herein.

[0477] If carrier material 611 is used, a dried adhesive coating 120 is applied to the face 110. The label web, including the face 110 and the adhesive, can be wound onto roll 570 using a winder 770.

[0478] The apparatus may include an uncoiler 612 for face 110. Face 110 may be in the form of a web wound into a roll. Face 110 can be unwound from the roll. After drying, adhesive 120 can be adhered to face 110. The unwound face 110 on the tape 611 and the dried water-based adhesive can be attached in the roll gap 660 to form a linerless label web 100. The formed linerless label web 100 can be wound into a roll 570.

[0479] The device may also include a cooling cylinder 650. The cooling cylinder may be located before the dry water-based adhesive layer is adhered to the surface 110. The rollers in the device of Figure 10 can operate at substantially the same speed to avoid damaging the surface 110, such as tearing the paper surface 110. The speed difference between the rollers in the device is preferably less than 0.5%.

[0480] If used, the carrier material 611 can be a tape, such as a silicone tape, a plastic tape, such as a nylon tape, or a metal tape, such as a steel tape. Alternatively, the carrier material 611 can be a batch web material. The carrier material 611 can be a film web material, preferably polyethylene terephthalate (PET) web material or other film materials resistant to drying temperatures. For the purposes of this specification, the terms "carrier" and "carrier material" can refer to an annular tape or a batch web material.

[0481] Reusable web material batches allow for production in batches of predetermined lengths and reuse of the carrier material multiple times. The advantages of this method include, but are not limited to, the use of existing lining materials, such as silicone-treated PET lining, as carriers. The carrier 611 can be unwound at the carrier uncoiler 710 and guided to the adhesive coating station 580. The carrier is preferably a pre-silicified carrier. Used carrier material 611, from which PSA 120 has been removed, is guided to the carrier rewinder 780. The carrier material is reusable and can be conveyed back to the uncoiler 710 for reuse. Because the typical length of linerless label webs in customer rolls can be 20-100 meters, such as 40 meters, this makes adhesive preparation using reusable carrier 611 feasible.

[0482] The formed liner label web 100 is configured to be wound onto the liner label web roll 570.

[0483] Subsequently, the wider web width of the machine rolls produced in this manufacturing process will be cut to the appropriate customer roll width, for example, with a width of 20-100mm.

[0484] Label web roll 570 can be stored and / or transported for later processing. Label web roll 570 can be further processed at other locations.

[0485] Many advantages can be obtained from this invention. For example, at least the following advantages can be obtained:

[0486] 1) Water-based acrylic PSA, together with the intermediate layer, can reduce dust generation issues in on-demand printers.

[0487] 2) Water-based acrylic PSAs, when combined with silicone additives, can offer additional benefits such as better sustainability, involving fewer fossil-based raw materials and less volatiles in the manufacturing and end-use processes.

[0488] 3) Reliable adhesion / stickiness of the adhesive can be obtained for all those different types of surfaces on which labels will be manually applied or applied, for example, during order preparation (e.g. in the kitchen) or when labeling various items (e.g., cups, boxes, parcels, bags or other packaging) for an order.

[0489] 4) Easy repositioning is possible, allowing the label to be applied to one surface first and then repositioned to another. For example, the label might first be used as a note in the kitchen and then affixed to a cooked dish.

[0490] 5) It allows for easy removability, such as allowing customers to remove labels used as packaging seals or closures.

[0491] 6) Permanent final tack of the label can be achieved in applications where lower initial tack is beneficial for reducing adhesive buildup in the printer, but a permanent type of tack is preferred once the label is applied to the item to be labeled.

[0492] 7) It can obtain chemical properties suitable for direct or indirect contact with food.

[0493] 8) Sustainability can be achieved to support the shorter lifespan of such labels, meaning that their chemicality does not impose an excessive burden on the environment or require any special waste management procedures compared to other waste generated during the processes and activities of using such labels.

[0494] This invention specifically relates to a liner label to be cut by the blade of a liner label printer. With conventional liner labels, dust and adhesive quickly begin to accumulate on the blade of the liner label printer, thus shortening the printer's service life. Sometimes, it may be impossible to use liner labels with adhesives that are otherwise perfect, given the aforementioned drawbacks, because the printer service life becomes too short. Thanks to this novel invention, dust and adhesive accumulation on the blade, pressure roller, and other components of the liner label printer can be significantly reduced. The effectiveness of this novel solution can be enhanced by using silicone additives in the adhesive. This novel solution significantly reduces dust generation from direct thermal liner labels.

[0495] Experimental testing

[0496] Example 1

[0497] An adhesive coating containing silicone additives is formed by mixing a silicone emulsion with a water-based acrylic adhesive. This adhesive coating comprises emulsified silicone additives and a water-based acrylic adhesive. The total amount of silicone additives in the adhesive coating varies between 0% and 6%, calculated based on the total dry weight of the adhesive coating.

[0498] According to test results, 1% by weight of emulsified silicone additive in the adhesive improved adhesive performance. The best results were observed when the amount of emulsified silicone additive exceeded 2% by weight. For cost reasons, the silicone content was kept between 1% and 6% by weight, meaning the maximum amount of silicone was 6% by weight.

[0499] According to test results, liner labels containing emulsified silicone additives significantly outperform similar products without emulsified silicone additives. Without emulsified silicone additives, liner label printers can cut liner labels approximately 100,000 times (i.e., 100,000 cuts) before requiring printer maintenance. Using an adhesive coating containing an acrylic water-based adhesive and emulsified silicone additives, liner label printers can cut liner labels 300,000 to 500,000 times before requiring printer maintenance.

[0500] The amount of cutting depends on the amount of silicone additive, with optimal results obtained when the amount of silicone additive is between 2% and 6% by weight, calculated based on the total dry weight of the adhesive coating. Furthermore, labels containing an adhesive coating with silicone additives adhere firmly to the surface of the labeled product each time.

[0501] Example 2

[0502] A novel linerless label web was prepared and compared with standard linerless label webs on the market.

[0503] During experimental testing, the general functionality of the direct thermal liner label web on the printer was tested, including direct thermal printability, cutter slitting, and label dispensing of direct thermal liner labels on printers such as the Bizerba SC II 100.

[0504] Test results confirm that the new linerless label web has at least the same general functionality as standard linerless label web on the market. Furthermore, a significant difference in dust generation tendency was found between standard market materials and the new product.

[0505] The difference in dust generation tendency is clearly visible after a short printing cycle that includes printing and cutting 600 labels. This can be seen in... Figure 11aThe -b option shows the dust buildup on the direct thermal printer. Figure 11a The image shows a photograph after a standard market material printing test. Figure 11b The image shows photos after printing tests of the new product. It can be seen that the use of the new product has prevented, or at least significantly reduced, dust buildup on the direct thermal printer.

[0506] The present invention is not limited to the examples presented in the accompanying drawings and the above description, but can be modified within the scope of the appended claims.

Claims

1. A method for manufacturing a direct thermal linerless label web (100) comprising a face (110) having a multilayer structure comprising at least three layers, the face comprising: - a base layer (113), - a direct thermal printable coating (115), and - an intermediate layer (114) disposed between the base layer and the direct thermal printable coating, wherein, - the intermediate layer has a grammage in the range of 0.9 g / m 2 to 7 g / m 2 . - the intermediate layer comprises: ■ a binder, and ■ at least one mineral pigment, and optionally non-mineral pigments, - the total amount of mineral pigments in the intermediate layer is equal to or less than 4 g / m 2 and - the mineral pigment content of the intermediate layer is less than 85 wt.%, calculated on the total dry weight of the intermediate layer, - the total mineral content of the direct thermal linerless label web is equal to or less than 20 wt.%, calculated on the total dry weight of the direct thermal linerless label web, and wherein, the method comprises: - providing a face (110), - applying a water-based acrylic adhesive coating (121), and - thermally drying the adhesive coating (121) into a pressure sensitive adhesive coating (120), wherein, - the water-based acrylic adhesive coating (121) is applied on the face, or - the water-based acrylic adhesive coating (121) is applied onto a carrier material, and the method further comprises: - transferring the pressure sensitive adhesive coating from the carrier material onto the face.

2. The method of claim 1, wherein, The base layer is an uncoated base paper (113) having the following characteristics: - having a grammage in the range of 38 g / m 2 to 82 g / m 2 and - a mineral pigment content equal to or less than 18 wt.%.

3. The method of claim 1 or 2, wherein, The adhesive coating (120, 121) comprises: - an emulsified silicone additive in an amount ranging from 1 wt.% to 6 wt.%, calculated on the total dry weight of the adhesive coating (120, 121).

4. The method of claim 1 or 2, wherein, The intermediate layer has a grammage in the range of 1 g / m 2 to 5 g / m 2 2.

5. The method of claim 1 or 2, wherein, The total amount of mineral pigments in the intermediate layer is equal to or less than 2 g / m 2 .

6. The method of claim 1 or 2, wherein, The mineral pigment content of the intermediate layer is equal to or less than 60 wt.%, calculated on the total dry weight of the intermediate layer.

7. The method of claim 1 or 2, wherein, The binder content of the intermediate layer is equal to or greater than 20 wt.%, calculated on the total dry weight of the intermediate layer.

8. The method of claim 1 or 2, wherein, The coating weight of the adhesive coating is in the range of 10 g / m 2 to 25 g / m 2 , calculated on the total dry weight of the adhesive coating.

9. The method of claim 1 or 2, wherein, The pressure sensitive adhesive coating is on the second side of the face, and the total coverage of the adhesive coating ranges from 10% to 90%, calculated on the total area of the second side (112).

10. The method of claim 1 or 2, wherein, The coating directly thermally printable has a grammage in the range of 1 g / m 2 to 5 g / m 2 .

11. The method of claim 1 or 2, wherein, The face further comprises a top coating on the direct thermal printable coating, wherein the top coating has a grammage in the range of 0.5 g / m 2 to 3 g / m 2 .

12. A direct thermal linerless label web (100) obtainable by the method of any one of the preceding claims.

13. A direct thermal linerless label web (100) comprising: - a face (110), and - a water-based acrylic pressure sensitive adhesive coating on the face, wherein, the face comprises: - a base layer, - a direct thermal printable coating (115), and - an intermediate layer (114) disposed between the base layer and the direct thermal printable coating, wherein, - the intermediate layer has a grammage in the range of 0.9 g / m 2 to 7 g / m 2 . - the intermediate layer comprises: ■ a binder, and ■ at least one mineral pigment, and optionally non-mineral pigments, - the total amount of mineral pigments in the intermediate layer is equal to or less than 4 g / m 2 and - the mineral pigment content of the intermediate layer is less than 85 wt.%, calculated on the total dry weight of the intermediate layer, and - the total mineral content of the direct thermal linerless label web is equal to or less than 20 wt.%, calculated on the total dry weight of the direct thermal linerless label web.

14. The direct thermal, linerless label web of claim 13 wherein, The base layer is an uncoated base paper (113) having the following characteristics: - having a grammage in the range of 38 g / m 2 to 82 g / m 2 and - a mineral pigment content equal to or less than 18 wt.%.

15. The direct thermal linerless label web of claim 13 or 14, wherein, The pressure sensitive adhesive coating comprises: - an emulsified silicone additive in an amount ranging from 1 to 6% by weight, calculated on the total dry weight of the adhesive coating (121).

16. The direct thermal linerless label web of claim 13 or 14, wherein, The intermediate layer has a grammage in the range of 1 g / m 2 to 5 g / m 2 .

17. The direct thermal linerless label web of claim 13 or 14, wherein, The total amount of mineral pigments in the intermediate layer is equal to or less than 2 g / m 2 .

18. The direct thermal, linerless label web of claim 13 or 14, wherein, The mineral pigment content of the intermediate layer is equal to or less than 60% by weight, calculated on the total dry weight of the intermediate layer.

19. The direct thermal linerless label web of claim 13 or 14, wherein, The binder content of the intermediate layer is equal to or greater than 20% by weight, calculated on the total dry weight of the intermediate layer.

20. The direct thermal linerless label web of claim 13 or 14, wherein, The coat weight of the adhesive coating is in the range of 10 g / m 2 to 25 g / m 2 , calculated on the total dry weight of the adhesive coating.

21. The direct thermal, linerless label web of claim 13 or 14, wherein, The pressure sensitive adhesive coating is on the second side of the face and the total coverage of the adhesive coating ranges from 10 to 90%, calculated on the total area of the second side (112).

22. The direct thermal, linerless label web of claim 13 or 14, wherein, The coating directly thermally printable has a grammage in the range of 1 g / m 2 to 5 g / m 2 .

23. The direct thermal, linerless label web of claim 13 or 14, wherein, The face further comprises a top coating on the direct thermal printable coating, wherein the top coating has a grammage in the range of 0.5 g / m 2 to 3 g / m 2 2.

24. Use of the direct thermal sensitive linerless label web according to any one of the preceding claims 12 to 23 in on-demand printing.

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