A liquid dispensing device for activating an adhesive layer of a sheet and a method for using the liquid dispensing device

Abstract

A liquid dispensing device (1) for activating an adhesive layer (4) of a sheet (2) comprises an inlet (3) configured to provide the sheet (2) having the adhesive layer (4). A liquid supply (5) for an activating liquid (6) is configured to be dispensed to a surface of the roller (7). The roller (7) for the activating liquid (6) is configured to dispense the liquid and activate the adhesive layer (4). The roller (7) comprises a perforated roller surface (71). Openings (72) of the perforated roller surface (71) are configured to define inactive areas (41) on the adhesive layer (4), causing the activated adhesive layer to be interspersed with inactive areas (41).

Description

[0001] A LIQUID DISPENSING DEVICE FOR ACTIVATING AN ADHESIVE LAYER OF A SHEET AND A METHOD FOR USING THE LIQUID DISPENSING DEVICE

[0002] BACKGROUND

[0003] This disclosure is related to liquid dispensing devices specifically designed for the activation of adhesives on sheets, such as labels. More particularly, it concerns a device capable of dispensing an activating liquid to activate the adhesive that is applied to the sheet such as thermal papers, linerless papers, or stickers, facilitating its use in various applications, such as in packaging, labeling, arts and crafts.

[0004] Adhesive activation is a step to ensure the adhesive layer achieves its intended bonding strength and durability. There are many different types of adhesives that may be used. For solvent-based adhesives, a specific activating liquid must be applied to activate the adhesive layer. This process ensures that the adhesive could provide enough adhesion to bond effectively. A common example involves using water as the activating liquid, wherein the sheet is moistened with water.

[0005] The sheet may be a paper. One example of the sheet is a thermal paper used on the courier packages. The package delivery information is printed on the thermal paper by a thermal printer. Applying water on to the adhesive layer activates the adhesive layer to provide adhesion. This process ensures that the adhesive on the thermal paper bonds effectively with the substrate, for example cardboard. Other examples of sheets are paperboard, gum tape, wallpaper, natural fiber fabrics and plastics such as nylon.

[0006] Existing liquid dispensing devices for activating adhesive on the sheet include simple brushes, sponges, and spray bottles. A known problem with many prior art examples is that the activating liquid or adhesive accumulated from the adhesive layer may dry and harden on the liquid dispensing device. If not properly cleaned and stored, brushes and sponges can dry out, causing the adhesive to harden on the applicator. This hardening can render the brushes and sponges unusable, necessitating frequent replacement.

[0007] Repeated use of brushes and sponges that have not been cleaned can lead to the accumulation of contaminants, such as dust, dirt, and residual adhesive, which can degrade the adhesive quality and introduce impurities to the surfaces being adhered.

[0008] The dried residue may be difficult to remove from soft brushes or sponges. If not removed, the residue may result in inconsistent adhesive application. Dirty brushes and sponges may cause uneven activation of the adhesive, leading to inadequate or excessive wetting. This inconsistency can cause parts of the sheet to not adhere properly or to wrinkle due to over-wetting.

[0009] The materials of brushes and sponges are prone to wear and tear over time. Brushes may lose bristles, and sponges can disintegrate or become too hard, reducing their effectiveness in applying the adhesive uniformly. In addition, it may be difficult to control the amount of adhesive picked up by brushes or sponges, leading to wastage or insufficient adhesive application, which can affect the quality of the adhesion.

[0010] The bulk of the sheet is formed by fibers that provide its physical structure. In one example, recycled thermal paper has shorter fibers compared to standard paper. Shorter fibers may provide a smoother surface, which assists the thermal coating to work effectively. However, short fibers may be easily damaged by the activating liquid. Alternatively, the fiber structure of thermal paper may be damaged by brushes or sponges sliding on its surface during the application of the activating liquid. Some activating liquids may cause hydrolysis, breaking down the cellulose chains in the fibers. This process weakens the molecular structure, leading to a loss of strength and flexibility.

[0011] When the activating liquid is applied to the sheet, such as thermal paper, several unexpected situations may arise. One problem is curling of the wet thermal paper. The curling is primarily due to two factors: the short fiber structure of the thermal paper and its hydrophilic nature.

[0012] The adhesives and the thermal paper absorb moisture to different extents. When the activating liquid contacts the adhesive first, and then penetrates the thermal paper, the surface of the sheet in contact with the activating liquid absorbs more moisture and expands more than the other surface. The hydrophilic nature of both the adhesive and the sheet contributes to curling. The adhesives and the sheets absorb moisture to varying degrees. When the activating liquid contacts the adhesive first and then penetrates the sheet, the side in contact with the liquid may absorb more moisture and expand more than the opposite side, causing the sheet to curl. The adhesive may tend to absorb the activating liquid at a faster pace and to a greater extent than the sheet itself. These different expansion rates create internal stresses, with the adhesive swelling more than the sheet, resulting in curling. This phenomenon makes the moistened paper sheet difficult to handle, wherein the curled sheet may be difficult to apply onto a surface.

[0013] In one example, sheets having short fibers are more prone to curling when moistened. The curling can be attributed, as one example, to the short fiber structure of the thermal paper. Compared to long fibers of other papers, the short fibers of the thermal paper may be damaged easily by liquid. When thermal paper absorbs liquid, the fibers swell as the hydrogen bonds between the fibers and within the fibers themselves are disrupted, leading to an expansion of the thermal paper structure. This swelling may cause the thermal paper to expand, losing its mechanical strength and integrity. The swollen short fibers become more flexible and lose their rigidity, making the thermal paper more prone to tearing and mechanical damage. Short fibers are common with recycled paper materials. Therefore, recycled materials would be used less with liquid-activated sheets due to all induced problems in its handling.

[0014] The imaging principle of the information on the thermal paper relies on a thermochromic coating applied to the surface. Another undesired situation may occur when the activating liquid is applied to the sheet, such as thermal paper, where the printed information formed by a thermochromic coating may be damaged by the activating liquid.

[0015] During printing, the thermal paper is positioned between a thermal printer head and a platen roller. Heating elements of the thermal head generate localized heat. This heat activates the thermochromic coating of the thermal paper, triggering a chemical reaction that causes the affected areas to change color, typically black, thereby forming the desired image or text. To ensure that the thermochromic coating responds sensitively, it is typically applied as a thin layer with high porosity, making it susceptible to moisture penetration.

[0016] Activation of the adhesive layer on thermal paper may cause the sheet to curl, potentially affecting the quality of the printed information on it. To prevent this, the adhesive layer is preferably activated after the information has been printed. In one example, activating liquid may penetrate the thermal paper and interact with the thermochromic coating. The image formed by thermochromic coating may become smeared, causing it to appear distorted, discolored, or partially erased, thereby damaging the readability or durability of the printed information.

[0017] SUMMARY

[0018] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.

[0019] A liquid dispensing device for activating an adhesive layer of a sheet and a method for using the liquid dispensing device are disclosed hereinafter. The liquid dispensing device for activating an adhesive layer of a sheet is configured to dispense the activating liquid on the adhesive layer by a roller, ensuring that the adhesive layer may provide enough adhesion to bond effectively. The liquid dispensing device comprises a liquid supply for an activating liquid, such as water, configured to be dispensed to a surface of the roller. As the surface of the roller rotates, the activating liquid on the surface of the roller is configured to be dispensed on the adhesive layer and to activate the adhesive layer.

[0020] The sheet with the adhesive layer may be printed by a thermal printer to be adhered to a specific surface. Examples of specific surfaces include the surface of a cardboard box or a transport package, wherein the sheet is a water- activated delivery information label. The liquid dispensing device comprises an inlet configurated to receive the sheet from the printer or any other sheet providing device and pass the sheet to the liquid supply.

[0021] In one embodiment, the sheet is a linerless recycled paper that does not have a backing or a liner. The linerless recycled paper has short fibers. In one embodiment, the linerless paper has a first surface configured to be in contact with the roller. On an opposite side of the first surface, a second surface of the linerless paper is configured to receive printed content. In one embodiment, the first surface of the linerless paper is provided with an adhesive layer, and the second surface of the linerless paper is free of a silicone coating. In one embodiment, the adhesive layer is a water-based adhesive layer.

[0022] The presence of a silicone coating affects the adhesion performance of adhesives. Since silicone materials have hydrophobicity, the adhesive may be unable to establish full contact with the silicon surface, which prevents adhesives from properly bonding to the silicone surface.

[0023] In one exemplary embodiment, the linerless paper is a label used on the package. Since the label may be free of the silicone coating, it allows the use of such a label which, once text or images are printed and the adhesive layer is activated, can be easily adhered to another label also free of the silicone coating. By adhering a new label onto the previous label, the text or image on the new label is applied, thereby updating the previously printed contents. Examples of the contents on the label may be shipping addresses, names, images, or other suitable information.

[0024] The label with the adhesive layer may have content printed by a printer. In one embodiment, the printer is an inkjet printer, and the ink is a water-resistant ink. Since the content on the label is printed with the water-resistant ink, the display quality of the content remains unaffected by the activating liquid during the activation of the adhesive layer when the activating liquid is water.

[0025] When the content on the previous label is no longer needed, the new label can be applied over the previous label to display only the updated content. This approach ensures that the number of shipping labels affixed to a delivery package always appears as one, thereby minimizing confusion due to label accumulation. In cases where the packaging is reused, users may directly apply a new label without the silicone coating to cover the previous label, also without the silicone coating, eliminating the need to tear off the existing label and thus preserving the integrity of the packaging. Meanwhile, environmental sustainability is improved through the reduced use of silicone materials and paper liners.

[0026] In another exemplary embodiment, the linerless paper is stored by being wrapped around the spool so that its first surface of the linerless paper contacts and overlaps the second surface of the linerless paper of a previously wound portion, thereby forming an overlapping region. Since the adhesive layer on the first surface of the linerless paper remains non-tacky before activation, the overlapping region between the said first surface and the said second surface may not bond with each other. The linerless paper with the adhesive layer can be stored by wrapping it around the spool, and the silicone coating may be unnecessary.

[0027] The use of the activating liquid allows precise control over when and where the adhesive becomes tacky. This makes the sheet with the adhesive layer easier to handle, store, and transport without the risk of sheets unintentionally sticking to surfaces or to each other. Some of the adhesive layers such as water-based adhesive layers allow the adhesive to remain inactive until it is dispensed with water. This prevents premature bonding and ensures the adhesive only becomes tacky at the desired time and location.

[0028] In the arrangement disclosed herein, the roller of the liquid dispensing device comprises a perforated roller surface and / or indented roller surface. When the liquid supply dispenses the activating liquid to the surface of the roller, the activating liquid will not be lifted by the openings of the perforated roller surface and only be adhered to partial areas of the surface of the roller. Partial areas of the perforated roller surface dispense the activating liquid on the adhesive layer and activate the adhesion of the adhesive layer. Similarly, the areas having indents do not carry the activating liquid to the adhesive layer, leaving only partial areas of the roller contacting the adhesive layer. Partial areas of the perforated roller surface are configured to define activating areas on the adhesive layer. Openings of the perforated roller surface and / or the indents are configured to define inactive areas on the adhesive layer. The openings and / or the indents and the partial areas of the perforated roller surface cause the activated adhesive layer to be interspersed with inactive areas.

[0029] Since activating liquid is applied only to a part of the adhesive layer, hydrogen bonds between and within the fibers in these areas are broken. However, the fibers on the inactive areas still intertwine and cross each other. This interwoven structure provides additional support and stability to prevent sheets from curling or deforming. Therefore, the fibers of the inactive areas of the adhesive layer are more rigid than the fibers in activated areas of the adhesive layer. When uncurling or undeforming areas of the inactive areas are interspersed with the curled or swollen areas of small size, the uncurling or undeforming areas will provide support to prevent whole adhesive layer from curling.

[0030] The liquid dispensing device comprises at least one speed regulator, configured to adjust the rotational speed of the roller so as to adjust the amount of the activating liquid dispensed to the adhesive layer of the sheet. In one embodiment, the activating liquid is water. In one embodiment, the roller surface is a hard surface with sufficient hydrophilic properties to lift the water onto the sheet and the adhesive layer. By changing the roller’s rotational speed, a volume of water may be adjusted to lift and transfer onto the adhesive layer of the sheet.

[0031] The cohesion among water molecules, facilitated by hydrogen bonds, helps form a continuous water film, while the roller’s hydrophilic surface creates adhesion by attracting water molecules, enabling a stable attachment of the water film to the surface of the roller. At low rotational speeds, fewer water molecules remain attached, as gravity of the water molecules and insufficient inertial forces cause the thin water film to drip back from the roller’s surface. Less water may be lifted upwards to the adhesive layer and the sheet. At higher speeds, the water film carried by the roller surface experiences greater inertial forces, and increased inertial forces help overcome gravity. Increased inertial forces combine effectively with cohesion and hydrophilic surface of the roller, enabling a thicker and more stable water film to be lifted upwards, resulting in greater water delivery to the sheet.

[0032] The rotational speed of the roller may be selected according to the environment factors, material properties, thickness or length of the sheet, so as to appropriately activate the adhesive layer of the sheet.

[0033] In one embodiment of the dispensing device, the roller has a hard, solid surface. This solves many problems found in brushes, sponges or any other dispensing devices that apply soft materials to transfer activating liquid to the sheet. The hard roller is easy to maintain as there is no significant change in its operating characteristics. The device can be stopped for extended periods and can resume operation without requiring cleaning for activating liquid or adhesive buildup. The roller may be quickly wiped clean, or alternatively, the device may be equipped with a simple cleaning system configured to remove any buildup from the roller. The roller-based device is relatively maintenance-free and suitable for high-capacity applications or automated systems.

[0034] In one embodiment, the hard surface of the roller is configured to dry quickly. For example, the hard surface dries quickly, which enables the roller functions to switch rapidly. The dispensing device may be used for different types of sheets.

[0035] In one exemplary embodiment, the dispensing device may also be used for the sheet having an adhesive layer that does not need activation, by controlling the rotation of the roller. One example of such sheet is a roll of labels with gaps between subsequent labels, having continuous and repeated pre-printed content. A cutting mark may be arranged between the labels.

[0036] When the adhesive layer needs to be activated, the rotation of the roller may be turned on to dispense activating liquid to the adhesive layer. When the adhesive layer does not need activation, the rotation of the roller may be turned off or the activating liquid may be drained from a liquid supply. The roller of the dispensing device may then function as an outfeed roller to discharge the label from the label roll. In one embodiment, a tape feeder coupled to the dispensing device is configured to separate each label from the label roll at the cutting mark.

[0037] The device may be controllable to match any ambient condition, such as temperature or humidity. The device parameters are in some embodiments controllable, and per the requirement of the application for the sheet, the device may allow longer or faster drying times for the sheet, such as thermal paper. This allows more aggressive adhesives to be used, that adhere reliably to various surfaces, such as paper board, cardboard or glass bottles.

[0038] Another benefit of reducing the amount of water applied to the sheet is that it minimizes smearing for personnel handling the activated sheets. In traditional solutions, where the entire sheet is activated, the user's fingers frequently come into contact with the sticky adhesive, which can lead to uncomfortable residue buildup and an increased need for frequent handwashing.

[0039] Many of the attendant features will be more readily appreciated as they become better understood by reference to the following detailed description considered in connection with the accompanying drawings. The embodiments described below are not limited to implementations which solve any or all the disadvantages of liquid dispensing device for activating an adhesive layer of a sheet or methods for using the liquid dispensing device.

[0040] BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present description will be better understood from the following detailed description read in light of the accompanying drawings, wherein

[0042] FIG. 1 illustrates schematically one exemplary embodiment of a liquid dispensing device; FIG. 2 illustrates schematically one exemplary embodiment of a liquid supply;

[0043] FIG. 3 illustrates schematically a side view of the embodiment of FIG. 2;

[0044] FIG. 4a illustrates schematically a side view of one example of a liquid supply;

[0045] FIG. 4b illustrates schematically a side view of one example of a liquid supply;

[0046] FIG. 4c illustrates schematically a side view of one example of a liquid supply;

[0047] FIG. 4d illustrates schematically a side view of one example of a liquid supply;

[0048] FIG. 5 illustrates schematically one exemplary view of a roller;

[0049] FIG. 6 illustrates schematically one exemplary view of a sheet with an activated adhesive layer;

[0050] FIG. 7 illustrates schematically one exemplary embodiment of a sheet conveyor arrangement;

[0051] FIG. 8a illustrates schematically one exemplary embodiment of a roller;

[0052] FIG. 8b illustrates schematically one exemplary view of the sheet with the activated adhesive layer;

[0053] FIG. 9 illustrates schematically one exemplary embodiment of the roller; and

[0054] FIG. 10 illustrates a flowchart of a method of using the liquid dispensing device for activating adhesive layer of a sheet.

[0055] Like reference numerals are used to designate like parts in the accompanying drawings.

[0056] DETAILED DESCRIPTION

[0057] The detailed description provided below in connection with the accompanying drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present example may be constructed or utilized. However, the same or equivalent functions and sequences may be accomplished by different examples. Although the present examples are described and illustrated herein as being implemented in a liquid dispensing device for activating an adhesive layer of a sheet, the device or the method described is provided as an example and not a limitation. As those skilled in the art will appreciate, the present examples are suitable for application in diverse types of sheets, such as paper sheets, thermal paper sheets or linerless paper sheets that are free of the silicone coating. Thermal paper with short fibers is one example of many sheet types that may utilize the liquid dispensing device, other non-limiting examples are gum tapes, cardboard, and plastic materials.

[0058] Aspects of this disclosure are related to a liquid dispensing device that can be used to activate an adhesive layer of the sheet. One exemplary embodiment relates to the thermal paper. Another exemplary embodiment is related to the recycled linerless paper. In one embodiment, a liquid dispensing device comprises a roller with a perforated roller surface defining inactive areas on the adhesive layer of the sheet. The fibers of inactive areas may provide support to the sheet and prevent the sheet from curling.

[0059] FIG. 1 illustrates schematically one exemplary embodiment of the liquid dispensing device. In one embodiment, the liquid dispensing device 1 comprises an inlet 3 configured to receive the sheet 2 having the adhesive layer 4 and pass the sheet 2 forward. One example of the sheet 2 is the thermal paper. Other examples of the sheet 2 are the linerless paper, a gum tape, a paperboard, a plastic, or a natural fiber fabric.

[0060] The sheet 2 with the adhesive layer 4 may have information printed by a printer as a preliminary step. In one embodiment, the printer is an inkjet printer. The inkjet printer may provide inks of various colors, thereby enabling the printing of diverse textual information and graphical images onto the sheet. Examples of inks are dye ink, pigment ink or any other suitable inks. In one embodiment, the ink is a water-resistant ink.

[0061] Alternatively, or in addition, the sheet 2 may be premanufactured, stored and provided to the inlet 3 solely for liquid dispensing purposes. The adhesive layer 4 may then wait to be activated and adhered to a specific surface. Examples of the specific surface are a box’s surface or a package’s surface wherein the sheet 2 is an address label, a delivery information label or graphical images. The inlet 3 is configured to receive the sheet 2 having the adhesive layer 4 and deliver the sheet 2 to a liquid supply 5. As an example, the inlet 3 is configured to receive the sheet 2 from an inkjet printer, laser printer or thermal printer.

[0062] In one embodiment, the sheet 2 with the adhesive layer 4 is a roll of labels with gaps between subsequent labels, having continuous and repeated pre-printed contents on a second surface of the sheet. A cutting mark is arranged between the labels. One example of the cutting mark is a black mark. In one embodiment, the adhesive layer 4 of the sheet 2 does not need activation.

[0063] In one embodiment, the inlet 3 comprises a holding member configured to receive the sheet 2 from the preliminary step. In one embodiment, the inlet 3 comprises a passing member configured to pass the sheet 2 to a liquid supply 5. In one embodiment, the holding member is a storage configured to store one or more sheets 2 until the sheets 2 are passed to the liquid supply 5.

[0064] In one embodiment, the inlet 3 comprises a reel configured to hold the sheet 2. In one embodiment, the sheet 2 is wrapped around a spool of the reel. As the spool rotates in the reverse direction, the sheet 2 wrapped around the spool begins to unwind. The direction of the spool's rotation is such that the spool pulls the sheet 2 off the spool and into the sheet 2 path of a roller 7. An example of this configuration is a roll of pre-manufactured labels.

[0065] In one embodiment, the liquid dispensing device 1 comprises roll members 31 positioned after the inlet 3, configured to feed the sheet 2 straight to a liquid supply 5. One application where the roll members 31 improves the sheet 2 conveyor process is with an automated processing system, or systems aiming for faster output.

[0066] FIG. 2 and FIG. 3 illustrate schematically one exemplary embodiment of a liquid supply from different sides. The liquid dispensing device 1 comprises the liquid supply 5 for an activating liquid 6 configured to be dispensed to a surface of the roller 7. In one embodiment, the liquid supply 5 comprises a liquid storage 51 , where the activating liquid 6 is stored in. Examples of the liquid storage 51 are a tank, a bottle, a jug, or a bucket. In one embodiment, the sheet 2 has a first surface configured to be in contact with roller 7. The second surface of the sheet 2 is configured to be on an opposite side of the first surface.

[0067] In one embodiment, the second surface of the sheet 2 is free of the silicone coating. In one embodiment, the sheet 2 is the linerless paper. In one embodiment, the sheet 2 is the thermal paper.

[0068] In one embodiment, a cutter 32 is positioned at a distance from the inlet 3. The cutter 32 is configured to cut the sheet 2 to a predefined length and / or shape. In one embodiment, the cutter 32 is configured to automatically cut the sheet 2 into a suitable length. The cutter 32 may cut the label into the correct size. As the sheet 2 may be very fragile after getting wet from the activating liquid 6, it may be easier to achieve a sharp cut to the sheet 2 before getting in contact with the activating liquid. Examples of fragile sheets 2 are recycled papers having short fibers. The sheet 2 may be received from a roll and the length of the final sheet 2 may vary, so the cutting may be made in many stages or steps in the process. The leading edge of the sheet 2 may be already having the activating liquid 6 dispensed on, when the trailing edge is being cut by the cutter 32, before getting into contact with the activating liquid 6.

[0069] A tape feeder 9 is configured to separate the sheet 2 from the roller 7. The tape feeder 9 comprises at least one extrusion, an edge or a finger that goes under the sheet 2 when the roller 7 pulls the sheet 2 over the tape feeder 9.

[0070] In one embodiment, a sensor coupled to the tape feeder 9 is configured to detect cutting marks. In one embodiment, the tape feeder 9 comprises a cutter blade for separating the sheet 2 at the cutting mark. The sensor may be configured to detect the cutting mark to trigger the separation.

[0071] Figures 4a to 4d illustrate schematically a side view of examples of the liquid supply 5. In one embodiment, the liquid dispensing device 1 comprises the roller 7 for the activating liquid 6 configured to be dispensed on and to activate the adhesive layer 4.

[0072] In one embodiment, the roller 7 is configured to be partially immersed in the activating liquid 6. When the surface of the roller 7 passes through the activating liquid 6 in the liquid storage 51 , due to an adhesion and a friction between the liquid molecules and the surface of the roller 7, and a cohesion between liquid molecules, the activating liquid 6 is adhered to the surface of the roller 7.

[0073] In one embodiment, the liquid supply 5 comprises a liquid outlet 52, for example a tap or a nozzle, positioned near the roller 7. The liquid outlet 52 is configured to provide activating liquid 6 to the surface of the roller 7. The activating liquid 6 is configured to be dispensed to the surface of the roller 7 by the liquid outlet 52. One example of the position of the liquid outlet 52 is on one side of the roller 7, allowing the activating liquid 6 from the liquid outlet 52 to be dispensed on the surface of the roller 7.

[0074] In one embodiment, the liquid supply 5 comprises a sponge coupled to the liquid storage 51 configured to provide activating liquid 6 to the surface of the roller 7. In one embodiment, the liquid supply 5 comprises a spray 53 coupled to the liquid storage 51 configured to provide activating liquid 6 to the surface of the roller 7.

[0075] In one embodiment, the liquid supply 5 comprises a pipe configured to provide activating liquid 6 to the surface of the roller 7 from the liquid supply 5. The activating liquid 6 is configured to be dispensed to the surface of the roller 7 by the pipe. One example of the position of the pipe is on one side of the roller 7, allowing the activating liquid 6 from the pipe to be dispensed on the surface of the roller 7. In one embodiment, a liquid pump is configured to pump the activating liquid 6 into the pipe.

[0076] In one embodiment, the liquid supply 5 comprises a second roller 70. The second roller 70 is configured to be partially immersed in the activating liquid 6. The second roller 70 is configured to contact the roller 7 and dispense the activating liquid 6 from a surface of the second roller 70 to the surface of the roller 7. The second roller 70 transfers the activating liquid 6 from the liquid supply 5 to the roller 7. In one embodiment, the surface of the second roller is a sponge.

[0077] In one embodiment, the activating liquid 6 is configured to be dispensed on the surface of the second roller 70 by the liquid outlet 52 or by the pipe. When the surface of the second roller 70 meets the surface of the roller 7, the activating liquid 6 can be transferred and adhered to the surface of the roller 7. The cohesive forces within the activating liquid 6 help the activating liquid 6 form a continuous film or droplets that can stretch and transfer from the second roller 70 to the roller 7 without breaking apart easily.

[0078] At the same time, as the roller 7 presses against the second roller 70, the pressure helps to transfer the activating liquid 6 from the surface of the second roller 70 to the surface of the roller 7. Surface tension, pressure and friction enable the activating liquid 6 to move from the surface of the second roller 70 to the surface of the roller 7.

[0079] In one embodiment, the portion of the roller 7 contacts the adhesive layer 4 of the sheet 2 when the roller 7 rotates. In one embodiment, the activating liquid 6 adhered to the surface of the roller 7 from the liquid supply 5 is configured to be transferred to the adhesive layer 4 of the sheet 2 through the rotation of the roller 7 to certain angles.

[0080] FIG. 5 illustrates schematically one exemplary view of the roller. In one embodiment, the roller 7 comprises a perforated roller surface 71 . Openings 72 are positioned on the surface of the roller 7. In one embodiment, the distance between each opening 72 is same, the openings 72 are distributed evenly on the surface of the adhesive layer 4. In one embodiment, the openings 72 are distributed randomly on the surface of the adhesive layer 4. Any two openings 72 are isolated from each other.

[0081] In one embodiment, the perforated roller surface 71 comprises the openings 72 and solid areas 73. In one embodiment, solid areas 73 of the perforated roller surface 71 are configured to define activating areas on the adhesive layer 4. In one embodiment, openings 72 of the perforated roller surface 71 are configured to define inactive areas 41 on the adhesive layer 4.

[0082] When the liquid supply 5 dispenses the activating liquid 6 to the surface of the roller 7, the activating liquid 6 will bypass the openings 72 of the perforated roller surface 71 , and only be adhered to solid areas 73 of the surfaces of the roller 7. The activating liquid 6 adhered to solid areas 73 can be dispensed to the adhesive layer 4 of the sheet 2 when the roller 7 rotates and contacts the adhesive layer 4.

[0083] In one embodiment, the roller surface 71 is a hard surface. The roller surface 71 can be made of plastic, composite plastic, wood, metal, or any other material with sufficient hydrophilic properties to lift the activating liquid onto the sheet 2 and the adhesive layer 4. In one embodiment, the roller surface 71 is made of the same material as the roller 7. In one embodiment, the roller surface 71 is a coating over the roller 7. The hard roller surface 71 is easy to maintain, as it does not collect as much dirt, dried residue or buildup as any soft surface or brush might do. In one embodiment, the hard surface of the roller is configured to dry quickly after dispensing the activating liquid.

[0084] FIG. 6 illustrates schematically one exemplary view of a sheet 2 with an activated adhesive layer 4. In one embodiment, the activating liquid 6 adhered to solid areas 73 of the perforated roller surface 71 is configured to be dispensed to the adhesive layer 4 and to activate the adhesion of the adhesive layer 4. Meanwhile, since the activating liquid 6 bypasses the openings 72 of the perforated roller surface 71 , openings 72 remain free of activating liquid 6. In one embodiment, openings 72 of the perforated roller surface 71 define inactive areas 41 on the adhesive layer 4, causing the activated adhesive layer 4 to be interspersed with inactive areas 41 .

[0085] Similar effect is achieved with a series of indents 72 on the surface of the roller 7. The indents 72 will not touch the sheet 2 surface when the surface of the roller meets the sheet 2, causing the spot on the place of the indent 72 to remain dry. The activating liquid 6 is not spread to the indents 72 defined positions, keeping those areas inactive 41 . FIG. 2 illustrates schematically on example of the indent 72, in the form of a groove. Grooves are elongated channels that run along the roller surface 71 .

[0086] Examples of surface features on the roller 7 are the series of indents, which may encompass grooves, notches, perforations, or other similar shapes, placed along its cylindrical surface. The series of indents 72, which may include grooves and perforations, controls the inactive areas 41 on the sheet 2. The indents 72, which can take the form of grooves, perforations, notches, or other similar shapes, may be formed into the roller 7 using precision machining techniques. Each indent 72 may vary in depth, width, and pattern, depending on the specific requirements of the activating liquid 6 dispersion. The dimensions and spacing of these indents 72 can be customized to achieve the desired performance characteristics.

[0087] In one embodiment, the liquid dispensing device 1 comprises at least one groove 12 positioned on the roller surface 71 . In one embodiment, the groove 12 is configured to provide a larger inactive area to the activated adhesive layer. In one embodiment, the groove 12 is positioned away from openings 72.

[0088] In one embodiment, the groove 12 is arranged along the axial direction of the roller 7. In one embodiment, the groove 12 is perpendicular to the axial direction of the roller 7, positioned away from both sides 711 , 712.

[0089] In one embodiment, edges of the groove 12 are configured to provide friction when the sheet 2 goes through the roller 7.

[0090] In one embodiment, inactive areas 41 are evenly distributed throughout the adhesive layer 4, with all other areas being active. In one embodiment, inactive areas 41 are distributed randomly throughout the adhesive layer 4. Each inactive area 41 is isolated from the others.

[0091] Since inactive areas 41 are free of activating liquid 6, structure of short fibers in the inactive areas 41 remains unaffected. Structure of short fibers in activated areas 42 may be partially damaged by the activating liquid 6. Fibers in the inactive areas 41 of the adhesive layer 4 are more rigid and intact than the fibers in the activated areas 42 of the adhesive layer 4. Short fibers in the activated areas 42 absorb the activating liquid 6, causing the sheet 2 to curl. When unaffected areas in the inactive areas 41 are interspersed with the curled or swollen areas of small size, the unaffected areas will provide support to prevent the whole adhesive layer 4 from curling. The sheet 2 may experience small ripples, but any excessive curling is controlled by the inactive areas 41 .

[0092] The roller 7 is in one embodiment configured to place large droplets of activating liquid 6 to the activating areas. The definition of large in droplet size is such that it contains enough of the activating liquid 6 to fill in the previously unaffected areas when the sheet 2 is placed on its final contact, for example the delivery information label on a cardboard box. The droplet size may be controlled by the surface structure of the roller 7 and / or the method of dispensing the activating liquid 6 onto the roller 7. For example, submerging the roller 7 partially into the activating liquid 6 may produce larger droplets than transferring the activating liquid 6 onto the roller 7 from a sponge. The activating liquid’s 6 surface tension maintains the droplets. The surface tension may be controlled by adding a suitable substance in the activating liquid 6.

[0093] In one embodiment, the sheet 2 is configured to be positioned between a pressure member 8 and the roll 7. The pressure member 8 is configured to assist the roller 7 to grip the leading edge of the sheet 2 at the start of the activation process. At the same time, the pressure member 8 is configured to not accidentally activate a pressure sensitive sheet 2 such as the thermal paper.

[0094] Figures 4a to 4d illustrate schematically a side view of examples of the pressure member 8. In one embodiment, the pressure member 8 is a guiding plate. In one embodiment, the pressure member 8 is a pressure roller.

[0095] In one embodiment, the pressure member 8 is configured to contact the opposite side of the sheet 2 from the adhesive layer 4 and apply pressure to the sheet 2, ensuring that the adhesive layer 4 of the sheet 2 is in full contact with activating liquid 6 on the surface of the roller 7. In one embodiment, the adhesive layer 4 of the sheet 2 is configured to contact the above of the surface of the roller 7. The pressure roller 8 is positioned above the sheet 2.

[0096] In one embodiment, the adhesive comprises at least one from the group of: a water-based adhesive, a solvent-based adhesive, an epoxy adhesive, a polyurethane adhesive, and an acrylic adhesive.

[0097] In one embodiment, examples of the activating liquid 6 are corresponding solvent. In one embodiment, examples of the activating liquid 6 are hardener, catalyst and curing agent.

[0098] In one embodiment, the liquid dispensing device 1 comprises an opening adjuster coupled to the roller 7, configured to adjust the number of the openings 72 on the perforated roller surface 71 . In one embodiment, the opening adjuster comprises a door coupled to the openings 72. When the door is raised or rotated, the door blocks the opening, turning the location of the opening into a new land area, the number of the openings 72 decreases. The new land area is on the same plane as the previous land area of the roller 7. In one embodiment, the opening adjuster comprises a door coupled to the openings 72. When the door is lowered or rotated, the door releases the opening, the number of the openings 72 increases.

[0099] In one embodiment, the opening adjuster comprises an adjuster configured to adjust the door rotating or lifting. In one embodiment, the adjuster comprises a spring configured to adjust the door lowering or raising. In one embodiment, the adjuster comprises gears to adjust the door rotating. Other examples of the adjuster include a slider and a guide rail, a lead screw and a nut, a pulley, a turntable, a universal joint, a knob, or a motor. In one exemplary embodiment, the adjuster is a thin, second nested roller inside the outer roller 7. The second nested inner has similar openings as the outer roller 7. It rotates inside the outer roller 7. The openings are fully open when the outer roller 7 and the second nested roller are aligned. The openings are reduced when the second nested roller is in any other position.

[0100] In one embodiment, the liquid dispensing device 1 comprises an actuator coupled to the roller 7, configured to rotate the roller 7. In one embodiment, a second actuator is configured to provide power to inlet 3. In one embodiment, a third actuator is configured to provide power to the second roller 70. In one embodiment, the roller 7, and the second roller 70 are rotated manually. Examples of the actuator suitable to be used herein are small electric motors, stepper motors or servo motors.

[0101] In some situations, the liquid dispensing device 1 may not have been used for a while, causing the upper portion of the roller 7 to dry. That, in turn, could cause the leading edge of the sheet 2 to touch the dry portion of the roller 7, and only the trailing portion of the sheet 2 could have the adhesive correctly activated. Therefore, ensuring that the whole sheet 2 will be properly activated, one embodiment of the liquid dispensing device 1 comprises means for rotating the roller 7, before the sheet 2 is in contact with the roller 7. The roller surface 71 will therefore be in contact with the activating liquid 6 just before the leading edge of the sheet 2 meets the same spot of the roller surface 71 .

[0102] FIG. 7 illustrates schematically one exemplary embodiment of an arrangement to convey the sheet 2 from the inlet 3 to the roller 7. The inlet 3 comprises a detector configured to start the operation of the liquid dispensing device 1 . The roll member 31 and the roller 7 start rotating as a response to detecting reception of the sheet 2. In the schematic illustration, the roll member 31 and the roller 7 are interconnected by power transfer means 74. Examples of the power transfer means 74 are a belt, a chain, a gear wheel, pinion-and-gear, or any other means configured to transfer mechanical energy between two rotating objects. The liquid dispensing device 1 may comprise only one actuator, wherein the mechanical movement is transferred to other components. In the example of FIG. 7, the actuator is directly connected to the roller 7, and the roll member follows the rotation by the power transfer means 74. When the inlet 3 detects the incoming sheet 2, the actuator starts rotating the roller 7 and the roll member 31 to convey the sheet 2 further. The roller 7 rotates before the sheet 2 is in contact with the roller 7, ensuring that the roller 7 is sufficiently carrying the activating liquid 6 to the sheet 2 from the first contact.

[0103] In one embodiment, the liquid dispensing device comprises a speed regulator coupled to the actuator, configured to adjust the rotational speed of the roller 7, so as to adjust the volume of the activating liquid to be lifted to the surface of the roller 7. In one embodiment, a second speed regulator is configured to adjust the rotational speed of the second roller 70. In one embodiment, the rotational speed of the roller 7, and the second roller 70 are adjusted manually. Examples of the speed regulator are a slider, a knob, a push button or other suitable mechanical or electronic components.

[0104] In one embodiment, the activating liquid 6 is water. When the roller 7 rotates, the water is lifted to the sheet 2 by the hydrophilic properties of the roller’s surface 71 . At high speeds, the inertial force acting on the water film also increases. Increased inertia combines with cohesion among water molecules and the roller’s hydrophilic surface, resulting in more water being lifted onto the sheet and the adhesive layer. At low rotational speed, gravity dominates, causing activating liquid 6 to drip back from the surface of the roller 7, and reducing the amount of water transferred to the sheet 2 and the adhesive layer 4.

[0105] The rotational speed of the roller may be adjusted based on parameters such as the sheet materials, thickness, length of the sheet, or environmental factors, to ensure that the adhesive layer is properly activated under varying conditions. Examples of the environmental factors are temperature, humidity, PH, or other related factors. In one exemplary embodiment, when activating the adhesive layer 4 of the thermal paper, a lower rotational speed of the roller 7 may be required to lift a smaller amount of the activating liquid 6, ensuring the quality of the printed information.

[0106] In one embodiment, the liquid dispensing device comprises a switch coupled to the actuator, configured to enable rotation of the roller.

[0107] In one embodiment, the liquid dispensing device 1 comprises at least one processor and a memory for storing instructions. The instructions, when executed by the processor, control at least one function of the liquid dispensing device 1 . Alternatively, or in addition, the device comprises a user interface to control or adjust at least one function of the device. In one embodiment, the user interface data is received from another device connected to the liquid dispensing device 1 . Some functions may be executed by analog electronics or mechanical adjustments. Examples of functions that may be set or adjusted are rotating the roller 7 before the sheet 2 enters its surface, setting the sensitivity to detect the sheet 2, setting the speed of the rollers 31 and / or 7, providing sheet 2 cutting information or detecting that the user removes the sheet 2 from the liquid dispensing device 1 . In one embodiment, the speed regulator is electrically connected to the processor. In one embodiment, the switch is electrically connected to the processor. In one embodiment, the sensor is electrically connected to the processor.

[0108] Many parameters that relate to activating liquid may be adjustable. The droplet size of the activating liquid relates to drying time. In one embodiment, the droplet size is adjustable to get a sufficient working time to attach the sheet 2. In one embodiment, the liquid dispensing device 1 comprises sensors that, together with the processor, control the device parameters. For example, humidity influences the drying time - a humidity sensor is in one embodiment configured to provide control information for the processor that enables the processor to set up correct parameters for the liquid dispensing device 1 . The parameters may be preset in the memory, for example having correspondence to various parameters. In one embodiment, ambient information such as air temperature or humidity are provided by an external system to the processor.

[0109] FIG. 8a Illustrates schematically one exemplary embodiment of the roller 7. In this example, the roller 7 has an exaggerated inactive surface area 721 in the middle of the roller 7. The inactive surface area 721 is one example of the series of indents 72, as it may be produced by having a series of consecutive indents. The inactive surface area 721 is configured to leave a larger area of the sheet 2 dry. In some embodiments, the sheet has partial adhesive layer 4. The present example is configured to activate adhesives on the end portions of the sheet 2. The inactive surface area 721 may still be submerged in the activating liquid 6, but the shape of the roller 7 and / or the surface characteristics in the inactive surface area 721 prevent the activating liquid 6 to travel from the liquid supply 5 to the sheet 2. In one embodiment, the inactive surface area 721 comprises a hydrophobic coating. In one embodiment, the indents 72 comprise a hydrophobic coating.

[0110] FIG. 8b illustrates schematically one exemplary embodiment of the sheet 2, after being in contact with the roller 7 of FIG. 8a. The inactive areas 41 caused by the openings 72 are at distal ends of the sheet 2, causing the ends of the sheet 2 curling less than fully activated sheet 2 would. The middle portion comprises an exaggerated inactive area 411 , caused by the inactive surface area 721 . The middle portion may comprise adhesive, but as it is not activated, it does not adhere to any surface. The middle portion is separated by sheet perforations 43, that allow the sheet 2 to be torn. One application for the arrangement is a label with a removable receipt, wherein the middle portion may be torn away from the attached label. Such labels may be used for various purposes, such as warehouse management or marking a completion of a task, wherein the torn middle portion may be taken away from the target. In these examples the inactive surface area 721 and the corresponding inactive area

[0111] 411 may be designed to meet the shape and size most appropriate for the use.

[0112] In one exemplary embodiment, the sheet 2 shown in FIG. 8b is a gum tape used for sealing the cardboard box. After activation by the dispensing device, the middle portion of the gum tape comprises the inactive area 411 . The inactive area 411 is positioned at the closure gap between the flaps of the cardboard box, while the active area 42 covers the flaps away from the closure gap, thereby forming a secure closure. When the two flaps are closed, the closure gap remains between them. During sealing or transport, the flaps may receive external force, which may cause damage to the cardboard box, such as deformation or tearing near the closure gap. The inactive area 411 allows the closure gap to flex, forming a buffer. The buffer may absorb the external force, helping to prevent damage to the cardboard box. The buffer may also prevent the gum tape from wrinkling due to external force and ensure reliable sealing.

[0113] FIG. 9 illustrates schematically one exemplary embodiment of the roller 7. In this example, the roller 7 has a small inactive surface area 721 in the middle of the roller 7. The inactive surface area 721 of this example is another example of the series of indents 72, as it may be produced by having a series of consecutive indents. The small inactive surface area 721 will cause a narrow inactive area 41 , in the form of a strip to the middle portion of the sheet 2, not illustrated here. The tape feeder 9 interacts with the narrow strip 41 and pulls the sheet 2 off the roller 7 when the roller 7 rotates and moves the sheet 2 forward. For example, sheets 2 made of short fibers can be fragile when wet, risking unexpected tears. The narrow strip 41 mitigates the risk of tearing and allows more recycled material to be used with printers and the liquid dispending device 1 . The exemplary roller 7 of FIG. 9 may provide larger activated areas 42 than previous examples. Alternatively, or in addition, the roller 7 may comprise any feature disclosed herein. The effect of the perforations of series of indents 72 is that at least one area 41 of the sheet 2 is left inactive after passing through the dispensing device 1 . In one embodiment, the final step of the liquid dispensing device 1 comprises a cutter 32 configured to cut the sheet 2, utilizing the narrow strip 41 . The narrow strip 41 is inactive area within the sheet 2 and may be cut cleanly even after the rest of the sheet 2 is wet. In one embodiment, the liquid dispensing device 1 has two cutters 32, one before contacting the sheet 2 with the roller 7 and another after the roller 7, when the sheet 2 has distinct inactive areas 41 and activated areas 42.

[0114] FIG. 10 illustrates a flowchart of a method of using the liquid dispensing device 1 for activating adhesive layer of the sheet 2. Step 91 comprises getting the sheet 2 with the adhesive layer 4 from preliminary step and transmitting the sheet 2 to the liquid supply 5 by the inlet 3. Step 92 comprises dispensing activating liquid 6 to the surface of the roller 7 by the liquid supply 5. Step 93 comprises dispensing activating liquid 6 on and to activate the adhesive layer 4 by the roller 7 having the perforated roller surface 71 . Openings 72 are positioned on the surface of the roller 7, which defines inactive areas 41 on the adhesive layer 4. The short fibers in inactive areas can maintain their original structure and help to support the sheet 2 and prevent the sheet 2 from curling. In step 94, use the sheet 2 with the activated adhesive layer.

[0115] A liquid dispensing device for activating an adhesive layer of a sheet is disclosed herein. The device comprises an inlet configured to receive the sheet; a liquid supply for an activating liquid configured to be dispensed to a surface of a roller; and the roller for the activating liquid configured to be dispensed on and to activate the adhesive layer. The roller has a roller surface comprising perforations and / or a series of indents. The perforations and / or the series of indents of the roller surface are configured to define inactive areas on the adhesive layer; causing the activated adhesive layer to be interspersed with inactive areas. In one embodiment, the sheet is configured to be positioned between a pressure member and the roller. In one embodiment, the pressure member is a guiding plate. In one embodiment, the pressure member is a pressure roller. In one embodiment, the perforations and / or the series of indents comprise at least one groove. In one embodiment, the adhesive layer is a water-based adhesive layer. In one embodiment, the activating liquid is water. In one embodiment, the device comprises an opening adjuster coupled to the roller, configured to adjust the number or size of the openings on the perforated roller surface. In one embodiment, the device comprises an actuator coupled to the roller, configured to rotate the roller, before the sheet is in contact with the roller. In one embodiment, the device comprises a speed regulator coupled to the actuator, configured to adjust the rotational speed of the roller. In one embodiment, the sheet is a sheet of thermal paper or a sheet of linerless paper.

[0116] Alternatively, or in addition a method for using a liquid dispensing device for activating adhesive layer of a sheet is disclosed herein. The method comprises receiving the sheet via an inlet; dispensing to a surface of a roller by a liquid supply for an activating liquid; and dispensing on and activating the adhesive layer by the roller for the activating liquid. The roller has a roller surface comprising perforations and / or a series of indents; wherein the method further comprises defining inactive areas to the adhesive layer by the perforations and / or the series of indents of the roller surface; and causing the activated adhesive layer to be interspersed with inactive areas. In one embodiment, the method comprises positioning the sheet between a pressure member and the roll. In one embodiment, the method comprises adjusting the number or size of the openings on the perforated roller surface by an opening adjuster coupled to the roller. In one embodiment, the method comprises rotating the roller by an actuator coupled to the roller. In one embodiment, the method comprises adjusting the rotational speed of the roller by a speed regulator coupled to the actuator. In one embodiment, the sheet is a sheet of thermal paper or a sheet of linerless paper.

[0117] Any range or device value given herein may be extended or altered without losing the effect sought.

[0118] Although at least portion of the subject matter has been described in language specific to structural features and / or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts are intended to be within the scope of the claims.

[0119] It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will further be understood that reference to ‘an’ item refers to one or more of those items.

[0120] The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. Additionally, individual blocks may be deleted from any of the methods without departing from the spirit and scope of the subject matter described herein. Aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples without losing the effect sought.

[0121] The term ‘comprising’ is used herein to mean including the method blocks or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements.

[0122] It will be understood that the above description is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this specification.

Claims

CLAIMS1. A liquid dispensing device (1 ) for activating an adhesive layer (4) of a sheet (2), comprising: an inlet (3) configured to receive the sheet (2); a liquid supply (5) for an activating liquid (6) configured to be dispensed to a surface of a roller (7); and the roller (7) for the activating liquid (6) configured to be dispensed on and to activate the adhesive layer (4); characterized in that: the roller (7) has a roller surface (71) comprising perforations and / or a series of indents; the perforations and / or the series of indents (72) of the roller surface (71) are configured to define inactive areas (41) on the adhesive layer (4); causing the activated adhesive layer to be interspersed with inactive areas (41).

2. A liquid dispensing device (1 ) according to claim ^characterized in that the sheet (2) is configured to be positioned between a pressure member (8) and the roller (7).

3. A liquid dispensing device (1 ) according to claim 2, characterized in that the pressure member (8) is a guiding plate or a pressure roller.

4. A liquid dispensing device (1 ) according to any of the claims 1 to 3, characterized in that the roller surface (71 ) is a hard surface.

5. A liquid dispensing device (1 ) according to any of the claims 1 to 4, characterized in that the perforations and / or the series of indents comprise at least one groove (12).

6. A liquid dispensing device (1) according to any of the claims 1 to 5, characterized in that the adhesive layer (4) is a water-based adhesive layer.

7. A liquid dispensing device (1 ) according to claim 6, characterized in that the activating liquid (6) is water.

8. A liquid dispensing device (1) according to any of the claims 1 to 7, characterized by comprising an opening adjuster (12) coupled to the roller (7), configured to adjust the number or size of the openings (72) on the perforated roller surface (71).

9. A liquid dispensing device (1) according to any of the claims 1 to 8, characterized by comprising an actuator coupled to the roller (7), configured to rotate the roller (7), before the sheet (2) is in contact with the roller (7).

10. A liquid dispensing device (1 ) according to any of the claims 1 to 9, characterized by comprising a speed regulator coupled to the actuator, configured to adjust the rotational speed of the roller (7).

11. A liquid dispensing device (1 ) according to any of the claims 1 to 10, characterized in that the sheet (2) is a sheet of thermal paper or a sheet of linerless paper.

12. A method for using a liquid dispensing device (1) for activating adhesive layer of a sheet (2), comprising: receiving the sheet (2) via an inlet (3); dispensing to a surface of a roller (7) by a liquid supply (5) for an activating liquid (6); and dispensing on and activating the adhesive layer (4) by the roller (7) for the activating liquid (6); characterized in that:the roller (7) has a roller surface (71) comprising perforations and / or a series of indents; wherein the method further comprises defining inactive areas (41) to the adhesive layer (4) by the perforations and / or the series of indents (72) of the roller surface (71 ); and causing the activated adhesive layer to be interspersed with inactive areas (41).

13. A method according to claim 12, characterized by positioning the sheet (2) between a pressure member (8) and the roller (7).

14. A method according to claim 12 or 13, characterized by adjusting the number or size of the openings (72) on the perforated roller surface (71) by an opening adjuster (12) coupled to the roller (7).

15. A method according to any of the claims 12 to 14, characterized by rotating the roller (7) by an actuator coupled to the roller (7).

16. A method according to any of the claims 12 to 15, characterized by adjusting the rotational speed of the roller by a speed regulator coupled to the actuator.

17. A method according to any of the claims 12 to 16, characterized in that the sheet is a sheet of thermal paper or a sheet of linerless paper.

Images