The present invention relates to a liner-free label printing apparatus (system and method), and particularly to a liner-free label printing apparatus using a common print head or array of print heads for both printing on front side or surface of a liner-free label and application of a fluid (e.g., solvent, liquid, or solution) for activating a layer of material on the back side or surface of the same label to become adhesive. The print head(s) may be inkjet print heads which are utilized at different times both for printing and then applying a fluid for label adhesive activation in the same apparatus housing. The advantage of dual function print head(s) for printing and adhesive application enables miniaturization of the label printer housing, and lower cost by having the same mechanism provide both functions one after the other but along different sides of the same label.
U.S. Pat. No. 5,768,991 describes a label printer for printing on liner-free labels having a single label path onto which a printhead prints indicia and the like on the front side of the label, and then downstream along the path a brush moistens an adhesive coating prior to exiting the printer. This requires two separate mechanisms, one for printing and another for adhesive activation. It would be desirable to provide a printer which unlike this patent does not require two separate mechanism, but the same mechanism which can provide both printing and then adhesive activation.
Accordingly, it is an object of the present invention to provide an apparatus, method, and system for printing having a common print head or print heads for both printing and applying a fluid for activating adhesive of activatable liner-free labels prior to exiting the apparatus.
Briefly described, the present invention embodies an apparatus having a print head, and a path along which a label travels to the print head for printing on a front surface of the label. The path after printing reverses the orientation of the label to present the back surface of the label to the print head for applying a fluid (e.g., liquid or solvent) for activating adhesive material on back surface of the label prior to the label exiting the apparatus.
Preferably, the print head is an inkjet print head having nozzles extending along at least the width of a label which operates as a typical inkjet print head for printing liquids on a label in the form of different color inks, but in which one of such liquids in its reservoir is a fluid for activating adhesive of a liner-free label. Optionally, the print head may have additional nozzle(s) to its nozzles commonly used for application of different color inks or a single color ink for applying a fluid for activating adhesive of a liner-free label. In either case, the print head is considered as having multiple nozzles, in which a first group of one or more such nozzles provides one or more inks for enabling printing by the print head, and a second group of one more such nozzles provides such fluid from the print head for activating the adhesive material of the label. The print head moves with respect to the label when printing or when applying label adhesive activating fluid. Preferably, a single print head is used having nozzles activatable for applying ink(s) for printing and label adhesive activating fluid, where the print head extends at least the width of the label. However, such print head may represent multiple different print heads disposed along a common side of the path of the label.
The print head may print a single or multiple color images or text, and label adhesive activating fluid when the front and back surface or sides of the label, respectively, are presented to the print head. Labels may be supplied in the apparatus from a stack of one or more individual labels, or each label may be cut from either a roll, or a fan-folded continuous stack of label stock or web.
The liner-free adhesive labels used in the apparatus each consist of a facesheet that is coated with a polymer type adhesive which possesses no tack in its dry or non-activated state, and a front printable surface.
In the apparatus, the liner-free label travels along the path by a first series of rollers to present its front printable surface to the print head for printing, and then the path reorients or inverts the label using a second series of rollers back to the first series of rollers back to the print head for application of the adhesive activating fluid along the label's back side to wet the back side's layer of such fluid activatable adhesive. The addition of the activation fluid to the adhesive layer creates a tacky adhesive label. The label is then expelled from the printer and can be applied to a variety of substrates. During the printing and activation process preferably no internal printer parts come into contact with the activated adhesive layer.
Optionally, the apparatus may operate in a first mode as described above for printing and activating adhesive on a liner-free label, and in a second mode where no printing is carried out upon the front surface of the label, but only for application of a fluid for activating the adhesive of the label prior to exiting the apparatus. Such second mode may be desirable when the labels are already pre-printed, or if blank labels are desired, or when utilizing the labels as adhesive strips or forms for sealing and/or adhering to containers in a manner which may be similar to that of typical adhesive tape.
A method is also provided for printing and activating an adhesive upon labels with fluid activatable adhesive having the steps of: guiding a label along a path to present a front side of the label to a print head; printing one or more inks through a first group of one or more nozzles of the print head when guided along the path to present a front side of the label to the print head; reversing orientation of the label to present the back surface of the label to the print head; and applying a fluid for activating an adhesive along the back side of the label through a second group of one or more nozzles of the print head when the back side of the label is presented to the print head.
A print head is further provided for use in the above apparatus having an inkjet print head having a plurality of nozzles, and a reservoir for supplying at least one fluid to one or more of the nozzles onto a label for activating adhesive material along a surface of the label.
The foregoing objects, features and advantages of the invention will become more apparent from a reading of the following description in connection with the accompanying drawings, in which:
Referring to
The adhesive agent layer along back surface 12 of label 8 mimics the adhesion properties of a pressure sensitive adhesive (PSA) and/or a contact adhesive, but only after the adhesive agent layer has been activated, thereby making tacky the liner-free adhesive label. Activation fluid is for activating the liner-free adhesive layer on back surface 12 of the label 8 provides optimal activation of the adhesive component(s) of the layer of adhesive composition of the liner-free label. The activating fluid composition penetrates into the adhesive layer along back surface 12 to moisten the adhesive components without over-wetting the adhesive surface of the label 8, which can compromise adhesive performance. In addition, the activating fluid is compatible with existing inkjet printer heads allowing its application in a desired amount and pattern. The activation fluid introduces moisture into the adhesive layer to allow for the conversion of the adhesive from its non-tacky to tacky state. Once the adhesive layer is remoistened with the activation fluid, it possesses visco-elastic flow and behaves in a manner very similar to a typical pressure sensitive adhesive. The chemical composition of the adhesive layer dictates the proper solvent selection for the activation fluid.
Suitable fluids for activating the adhesive layer may be as follows: water; acetone; acetonitrile; lower alcohols (i.e., having from 1-10 carbons) including, but not limited to, methanol, ethanol, isopropyl alcohol, n-propanol, n-butanol, 2-butanol, isobutanol, 2-methy-2-butanol, n-pentanol, n-hexanol, 2-hexanol, cyclohexanol, n-heptanol, n-octanol, n-nonanol, n-decanol; glycols including, but not limited to, propylene glycol, ethylene glycol, and butylene glycol; fatty alcohols (i.e., having more than 10 carbons) including, but not limited to, undecanol, dodecanol, 1-tetradecanol, arachidyl alcohol, docosanol, tetracosanol, hexacosanol, octanosol, triacontanol, cetyl alcohol, stearyl alcohol, and polycosinol; ketones, such as methyl ethyl ketone; esters, such as ethyl acetate, mineral spirits; oils, such as linseed oil and vegetable oil; citrus based solvents, such as limonene, other primary, secondary, and tertiary alcohols, and combinations thereof. Less volatile fluids for activating the adhesive layer may also be used, such as ethylene glycol, polyether polyols, phalates, plasticizers and propylene glycol are particularly effective in increasing wet out on hydrophobic surfaces and extending the tacky period after activation.
The polymer selection for the adhesive layer may be such that the activation fluid required to activate the label is water. However, selecting polymers that only require water to rapidly transition from non-tacky to active may not be desirable as the finished labels are highly vulnerable to blocking due to absorption of atmospheric moisture, causing a transition from the non-tacky state to the tacky state, at an undesired time.
To decrease surface tension, enhance fluid spreading on the adhesive film surface, and/or promote activating solvent penetration, surfactants may be added to the activation fluid. Surfactants may also help in the delivery of the activation fluid by allowing for the creation of finer mists with smaller particle sizes during atomization (when used to apply the activation fluid to the adhesive layer of a label) which can promote adhesive activation by increasing the surface area for the interaction between the activating solution and the adhesive layer. Classes of surfactants that can be used include anionic, cationic, non-ionic and amphoteric surfactants. Specific examples include lecithin, Span™-60, Span™-80, Span™-65, Tween™-20, Tween™-40, Tween™-60, Dynol™ 604 (Air Products), Surfynol™ (Air Products), Pluronics™ (BASF, Germany), Polysorbates™ (Tween™), Sodium dodecyl sulfate (sodium lauryl sulfate), Lauryl dimethyl amine oxide, Cetyltrimethylammonium bromide (CTAB), Polyethoxylated alcohols, Polyoxyethylene sorbitan, Octoxynol™ (Triton X100™), N,N-dimethyl-dodecylamine-N-oxide, Hexadecyltrimethylammonium bromide (HTAB), Polyoxyl 10 lauryl ether, Brij™ 721™, Bile salts (sodium deoxycholate, sodium cholate), Polyoxyl castor oil (Cremophor™), Nonylphenol ethoxylate (Tergitol™), Cyclodextrins, Lecithin, or Methylbenzethonium chloride (Hyamine™)
Additives may be incorporated into the activation fluid, such as acids, bases, buffers, antimicrobial agents, stabilizers, emulsifiers, and/or defoaming agents, as needed for the particular application.
Referring to
Printing is by a print head 25 having a housing 25a with an array of nozzles 25b as best shown in
After printing occurs, the reversible rollers 23 reverse the direction of the label 9 into a back feed paper path 29a so that the orientation is reverse by the time the label reaches point 28 along such path. Thus, front surface 10 and back surface 12 are now switched or inverted in orientation from when the label was original feed from tray 20, as shown in
The mechanism provided by roller 21 from supplying labels 8 from tray 20 may be typical of paper feed mechanisms of desk top or portable printers. Alternatively, such mechanism may supply labels 8 from a roll 30 of web or label stock, as shown for example in
Although pairs of rollers on opposite sides of path of label are shown in
As stated earlier, print head 35 has nozzles (or elements) 25b utilizing inkjet printing technology and inkjet print heads, which may be the may be the same as typically used in inkjet printers. In summary, an inkjet print head is an array of small nozzles containing either a piezo-electronic or thermal based driver used to force ink from a reservoir, through the nozzle, and onto a desired medium. Software drivers are used to control which nozzles are active at a specific time. In drop on demand inkjet printing small droplets of ink are selectively emitted through a nozzle and onto the desired medium. The amount of fluid propelled onto the label 8 is determined by the printer driver software that dictates which nozzles emit droplets and how frequently they do so. Either thermal or piezo-electric driven inkjet systems can be used.
Print head 25 may be a typical inkjet printing system containing four individual reservoirs, such as schematically illustrated as chambers 17a-d of
The activation fluid 19 provided by the inkjet print head 25 to label 8 may be applied in a uniform pattern with coverage of 9.8 milliliters per square meter (˜0.15 ml per 24 square inches). Alternatively, the fluid 19 is applied in a grid pattern with coverage of 5.0 milliliters per square meter. In yet another alternative, the fluid 19 is applied in a specific pattern as to only create adhesive areas corresponding to specific geographies of a substrate to which adhesion upon is desired. This is enabled by selection of nozzles used to apply fluid 19 with movement of label 8 and print head 25 with respect to each other.
Referring to
An alterative print head 25 is shown in
Optionally, print head 25 may have a first print head of
Although print head 25 is shown stationary or fixed with respect to horizontal movement of label 8, optionally print head 25 or heads described above may be movable with respect to label 8 as shown for example in
Preferably, the print head 25 is a wide fixed inkjet print head as shown for example in
Activation of the adhesive layer of the label 8 by fluid 19 is provided preferably by an inkjet print head as described above. The print head 25, reservoir 24, may be provided by a inkjet printing system having software and hardware as typically used in inkjet printers. As such the print engine (hardware and software) is provided in a controller 14 (or may be a separate controller in communication with controller 14) to control operation of the print head 25 for printing. The same or another engine may be used to control operation of the same head 25 for applying adhesive actuation fluid.
Controller 14 may be a programmed microprocessor, processor, or the like, which is in apparatus housing 16 (or connected to apparatus 25) to control its operation to enable printing and fluid 19 application. Controller 25 also is programmed to control all other operations of apparatus 10, and as such is connected to motorized reversable roller 23 to control their activation and direction to drive label along path 29 or path 29a as descibed above, and also actuation of motorized roller 21 for label feeding. Sensors (optical or mechanical) may provide signals to the controller as to location of a label along its path, and when motor(s) coupled to roller(s) should be actuated and in the direction needed to move the label forward or to reverse the orientation of the label as described earlier. Such sensors may be are present at points 26 and 28 to determine the presence or absence of a label along paths 29 and 29a. If supply mechanism of
Thus in print head 25 described above, there is programmed selection by controller 14 enabling operation of the first or second group of nozzles 25b when the front or back sides, respectively, of the label passes by along its path as described above. Preferably, the print engine may be such as typical used in a fixed inkjet head for controlling release of ink from nozzles. A preferred fixed print head and print engine for apparatus 10 is manufactured by MemJet (San Diego, Calif., USA), but other fixed print head and print engines may be used. Another example of a commercial inkjet printer utilizing fixed print head is the AstroJet M1 (Astro Machine Corporation, Ill., USA).
For example, print head(s) may be the disposable Hewlett-Packard P940 Magenta/Cyan OfficeJet print head, or the print head or print head array described in U.S. Pat. Nos. 0,147,056A1, 0,280,670 A1, and/or 6,543,887 B2. Commercial analogs of inkjet print heads capable of delivering said inks and/or fluids are commonly available from companies including Hewlett-Packard Company (Palo Alto, Calif., USA), Brother Industries, Ltd. (Nagoya, Japan), Canon, Inc. (Tokyo, Japan), and/or Seiko Epson Corporation (Tokyo, Japan). Less preferably, the inkjet print heads, controllers, and software accompanying the Hewlett-Packard OfficeJet 6500 E709n Series (Hewlett-Packard, Palo Alto, Calif.) may be operated to function to deliver ink and/or activation fluid to the liner-free solvent-sensitive label. This utilizes a traveling carriage inkjet type print head array.
In summary, the present invention utilizes automatic reversing the orientation of the liner-free label 8. Unlike the prior art automated duplex printing on media, such as paper, where two-sided printing is provided using only one set of print heads, the present invention does not print on the reverse side of the media printing, but using the same mechanism used for printing to apply a fluid for activation adhesive of the . The first pass of the media through the print area of the print head(s) 25 is used to print an image or text onto one side of the label. The second pass—the inverted pass—is used to apply activation fluid to the solvent-sensitive polymer adhesive layer of the label. Ink can also be applied during this pass to place an image on the backside of the label. This is particularly applicable to the labeling of clear substrates, such as plastic bottles. After the activation fluid is applied to the adhesive layer, the adhesive layer transitions from its dry and non-tacky state to its active and tacky state and can be applied to a desired substrate.
From the foregoing description, it will be apparent that there has been provided a label printing apparatus which both prints and applies fluid for activating adhesive of labels using the same print head(s). Variations and modifications in the herein described improvement, method, or system will undoubtedly suggest themselves to those skilled in the art. Accordingly, the foregoing description should be taken as illustrative and not in a limiting sense.
This application claims the benefit of priority to U.S. Provisional Patent Application No. 61/574,510, filed Aug. 4, 2011, which is herein incorporate by reference.
Number | Date | Country | |
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61574510 | Aug 2011 | US |