HEAD IN A WEB PRINTING PRESS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 62/025,809, filed July 17, 2014, which is herein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.

[0003] The present disclosure relates to web printing presses, and more specifically, to web printing presses that include, or are augmented to include, liquid jet printheads, such as inkjet printheads.

[0004] A rapid change is occurring in the commercial and industrial printing marketplace with an expanded use of digital printing presses to replace or augment their analog counterparts. Digital printing presses have an advantage of lower set-up costs, in that a change to a print pattern is accomplished with a file change. This improves the economics of short run printing and reducing a need to print large inventories of a given design.

[0005] One common form of digital printing press is a web press based upon inkjet printing of water-based or radiation curable inks. In this type of press, a roll of media is unwound and then passed through a paper path defined by a series of rollers along a media transport direction. A part of the paper path is a print zone within which inkjet printheads eject a dot matrix pattern of fluid drops on a surface of the media thereby forming images and/or text on the media surface. These inkjet printheads span at least a portion of the print media along a transverse or cross-web direction that is generally orthogonal to the media transport direction. Such presses may be used, for example, in the manufacture of flexible packaging, in laying down coatings such as an adhesives or varnishes, or in depositing conductive materials, microencapsulated mixture, or other materials in either a pattern or continuous film thickness. [0006] Such presses are particularly suited to laying down an opaque white background on a clear film over which other graphics are printed. In practice, the opaque white background pattern is typically printed utilizing a rotary screen process. However, technological advances have made it possible for inkjet printing systems to apply an equally opaque white background pattern. Being digital in nature, inkjet simplifies job makeready, reduces consumable costs, and increases speeds.

[0007] However, the spacing of the inkjet printhead from the web, which is critical for proper printing, can be difficult to control. The web must also be very stable (i.e., not fluttering), and must be directly under the inkjet printhead. The inkjet printhead must be at a precise distance from the web, and at a precise angle relative to the web. Additionally, the inkjet printhead must be movable into different locations within the print stations of the press. Typically, if the inkjet printhead is configured to its own backing roll, and that assembly is moved between two given printing stations, it is almost certain the web span will need to be broken and webbed through the repositioned inkjet printhead assembly. This is disruptive to production as web tension and web tracking are disturbed, causing a great deal of waste restarting.

[0008] For these reasons, the present inventors recognized a need for an improved system for mounting an inkjet head in a web printing press.

SUMMARY OF THE INVENTION

[0009] In one embodiment, a web printing press includes a liquid jet print station. The liquid jet print station includes a frame; a rotatable support roll configured to support a web to be printed; a first pair of support arms rotatably mounted to the frame, each support arm having a support surface, at least a portion of the support surface extending along a portion of an outer circumferential surface of the rotatable support roll; a pair of positioning elements supported at least in part by respective ones of the first pair of support arms; a liquid jet printhead supported by the positioning elements at a location between the positioning elements, the liquid jet printhead being locked or lockable in place with respect to the positioning elements; and at least one first adjustment mechanism configured to move the first pair of support arms and the positioning elements supported thereby, to adjust a distance between the liquid jet printhead and the rotatable support roll.

[0010] In one aspect, the liquid jet print station further includes a second pair of support arms rotatably mounted to the frame, wherein the positioning elements are further supported by the second pair of support arms; and a second adjustment mechanism configured to move the second pair of support arms and the positioning elements supported thereby, to move the liquid jet printhead in a circumferential direction around the rotatable support roll.

[0011] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet print station further includes a third adjustment mechanism configured to spread a lower portion of the first pair of support arms with respect to a lower portion of the second pair of support arms, such that the positioning elements supported by the first and second pairs of support arms are adjustable in a vertical direction.

[0012] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet printhead is rotationally adjustable with respect to the rotatable support roll.

[0013] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet print station further includes a pulling device that is attachable to the positioning elements and configured to pull the positioning elements towards the first pair of support arms.

[0014] In one aspect, which is combinable with any of the above embodiments and aspects, the pulling device includes a pair of latches, and each of the positioning elements includes a groove with which the latches are configured to engage to pull the positioning elements towards the first pair of support arms.

[0015] In one aspect, which is combinable with any of the above embodiments and aspects, the web printing press includes a plurality of print stations including the liquid jet print station recited in claim 1, and wherein the liquid jet printhead is movable from the liquid jet print station recited in claim 1 to another of the print stations.

[0016] In one aspect, which is combinable with any of the above embodiments and aspects, the plurality of print stations includes a flexographic print station that includes a frame; a rotatable impression roll configured to support a web to be printed; a first pair of support arms rotatably mounted to the frame, each support arm having a support surface, at least a portion of the support surface extending along a portion of an outer circumferential surface of the rotatable support roll; a pair of positioning elements supported at least in part by respective ones of the first pair of support arms; a flexographic printing plate roll supported by the positioning elements at a location between the positioning elements, the plate roll being rotatably supported with respect to the positioning elements; and a first adjustment mechanism configured to move the first pair of support arms and the positioning elements supported thereby, to adjust a distance and/or pressure between the plate roll and the rotatable impression roll.

[0017] In one aspect, which is combinable with any of the above embodiments and aspects, the pair of positioning elements and the liquid jet printhead of the liquid jet printing station are removable from the liquid jet printing station and placeable in the flexographic print station in place of the pair of positioning elements and the plate roll of the flexographic print station, and vice versa.

[0018] In one aspect, which is combinable with any of the above embodiments and aspects, the flexographic print station further includes a rotatable anilox roll configured to contact the flexographic plate roll to provide ink to the plate roll; a second pair of support arms, each of the support arms of the second pair of support arms having a support surface, at least a portion of the support surface extending along a portion of an outer circumferential surface of the rotatable anilox roll, wherein the positioning elements are further supported by the second pair of support arms; and a second adjustment mechanism configured to move the second pair of support arms and the positioning elements supported thereby, to adjust a distance and/or pressure between the flexographic plate roll and the anilox roll.

[0019] In one aspect, which is combinable with any of the above embodiments and aspects, the flexographic print station further includes a third adjustment mechanism configured to spread a lower portion of the first pair of support arms with respect to a lower portion of the second pair of support arms, such that the positioning elements supported by the first and second pairs of support arms are adjustable in a vertical direction.

[0020] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet printhead is rigidly attached to the positioning elements, and the liquid jet print station further includes at least one adjustable indexing block configured to engage with at least one of the positioning elements, such that the positioning elements and the liquid jet printhead supported thereby are rotationally adjustable with respect to the rotatable support roll by adjusting a position of the indexing block. [0021] In one aspect, which is combinable with any of the above embodiments and aspects, the rotatable support roll is configured such that a temperature controlled fluid is flowable therethrough, such that a temperature of the web supported by the rotatable support roll is controllable via the temperature controlled fluid and the rotatable support roll.

[0022] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet print station further includes a UV lamp configured to cure ink deposited by the liquid jet printhead on the web.

[0023] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet print station further includes a hot air tunnel through which the web is passable.

[0024] In one aspect, which is combinable with any of the above embodiments and aspects, respective portions of the positioning elements that contact the first pair of support arms are rounded.

[0025] In one aspect, which is combinable with any of the above embodiments and aspects, the at least one first adjustment mechanism includes a pair of adjustment mechanisms configured to independent move respective ones of the first pair of support arms and respective ones of the positioning elements supported thereby.

[0026] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet print station further includes a pair of fixed support arms, wherein the positioning elements are further supported by the pair of fixed support arms.

[0027] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet printhead is rotationally adjustable with respect to the pair of positioning elements.

[0028] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet printhead is an inkjet printhead configured to dispense ink.

[0029] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet printhead is configured to dispense a material selected from the group consisting of an adhesive, a varnish, a coating, a conductive material, a silicone release, and an olieophilic material.

[0030] In another embodiment, a method of using a liquid jet printhead in a web flexographic printing press includes providing a flexographic printing press that includes a flexographic print station that includes: a frame; a rotatable impression roll configured to support a web to be printed; a first pair of support arms rotatably mounted to the frame, each support arm having a support surface, at least a portion of the support surface extending along a portion of an outer circumferential surface of the rotatable support roll; a first pair of positioning elements supported at least in part by respective ones of the first pair of support arms; a flexographic printing plate roll supported by the first pair of positioning elements at a location between the first pair positioning elements, the plate roll being rotatably supported with respect to the positioning elements; and a first adjustment mechanism configured to move the first pair of support arms and the positioning elements supported thereby, to adjust a distance and/or pressure between the plate roll and the rotatable impression roll; providing a liquid jet printhead supported by a second pair of positioning elements at a location between the second pair of positioning elements, the liquid jet printhead being locked or lockable in place with respect to the second pair of positioning elements; and replacing the first pair of positioning elements and flexographic printing plate roll supported thereby with the second pair of positioning elements and liquid jet printhead supported thereby.

[0031] In one aspect, which is combinable with any of the above embodiments and aspects, the flexographic print station further includes a rotatable anilox roll configured to contact the plate roll to provide ink to the plate roll; a second pair of support arms rotatably mounted to the frame, each of the support arms of the second pair of support arms having a support surface, at least a portion of the support surface extending along a portion of an outer circumferential surface of the rotatable anilox roll, wherein the positioning elements are further supported by the second pair of support arms; and a second adjustment mechanism configured to move the second pair of support arms and the positioning elements supported thereby, to adjust a distance and/or pressure between the plate roll and the anilox roll.

[0032] In one aspect, which is combinable with any of the above embodiments and aspects, the flexographic print station further includes a third adjustment mechanism configured to spread a lower portion of the first pair of support arms with respect to a lower portion of the second pair of support arms, such that the positioning elements supported by the first and second pairs of support arms are adjustable in a vertical direction.

[0033] In one aspect, which is combinable with any of the above embodiments and aspects, the method further includes adjusting a rotation of the liquid jet printhead with respect to the rotational impression roll.

[0034] In one aspect, which is combinable with any of the above embodiments and aspects, the flexographic print station further includes a pulling device that is attachable to the first and second pairs of positioning elements and configured to pull the positioning elements towards the first pair of support arms.

[0035] In one aspect, which is combinable with any of the above embodiments and aspects, the pulling device includes a pair of latches, and each of the positioning elements includes a groove with which the latches are configured to engage to pull the positioning elements towards the first pair of support arms.

[0036] In one aspect, which is combinable with any of the above embodiments and aspects, the step of replacing the first pair of positioning elements and flexographic printing plate roll supported thereby with the second pair of positioning elements and liquid jet printhead supported thereby includes: unlatching the latches from the grooves of the first pair of positioning elements; removing the first pair of positioning elements and flexographic printing plate roll supported thereby; placing the second pair of positioning elements and liquid jet printhead supported thereby on the first pair of support arms; and latching the latches to the grooves of the second pair of positioning elements.

[0037] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet printhead is an inkjet printhead configured to dispense ink.

[0038] In one aspect, which is combinable with any of the above embodiments and aspects, the liquid jet printhead is configured to dispense a material selected from the group consisting of an adhesive, a varnish, a coating, a conductive material, a silicone release, and an olieophilic material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIGS. 1A-1C are side plan views of a web printing press according to a first embodiment of the invention, FIG. 1A showing the printing press with a web passing through the press in a first configuration, FIG. IB showing the printing press with a web passing through the press in a second configuration, and FIG. 1C showing the printing press with a web passing through the press in a third configuration.

[0040] FIG. 2 is a rear, side perspective view of a support and adjustment mechanism for a positioning element configured to hold a plate roll or a liquid jet printhead, according to one embodiment of the invention.

[0041] FIG. 3 is a side view of the support and adjustment mechanism shown in FIG. 2, showing a positioning element supported by the support and adjustment mechanism.

[0042] FIG. 4 is a rear, side perspective view of the support and adjustment mechanism shown in FIG. 2, showing a positioning element supported by the support and adjustment mechanism.

[0043] FIG. 5 is a side view of the support and adjustment mechanism shown in FIG. 2, showing a positioning element supported by the support and adjustment mechanism, and showing a schematic representation of a liquid jet printhead supported by the positioning element.

[0044] FIG. 6 is a side view of a support and adjustment mechanism according to another embodiment of the invention, in which one pair of support arms is rigidly attached to a frame, and in which an indexing block is included.

[0045] FIG. 7 is a front view of the support and adjustment mechanism shown in FIG. 6.

DETAILED DESCRIPTION

[0046] FIGS. 1A-1C are side plan views of a web printing press according to a first embodiment of the invention. The press 10 includes a first print station 10a and a second print station 10b, but may include any number of print stations, depending on the material to be printed. A web 20 is transported through the press 10 from left to right.

[0047] The press 10 shown in FIGS. 1A-1C is configured for use in both flexographic printing or liquid jet printing, such as inkjet printing. Therefore, the press 10 includes elements necessary for flexographic printing. However, in other embodiments a press is provided solely for liquid jet printing, in which case certain elements present in the press 10 of FIGS. 1A-1C may be omitted, as discussed in more detail below.

[0048] The press 10 of FIGS. 1A-1C includes a rotatable anilox roll 30 and a pan 40. The pan 40 holds the fluid (such as ink, adhesive, varnish, conductive material, or any other liquid suitable for flexographic printing) that is to be deposited on the web 20. When used for flexographic printing, the anilox roll 30 transfers the fluid from the pan 40 to a flexographic plate roll 160 (not shown in FIGS. 1A-1C, but shown in FIG. 4) supported by a pair of positioning elements 50. The flexographic plate roll 160 is supported between the positioning elements 50 and is rotatable relative to the positioning elements 50. A flexographic plate (not shown) is attached to the flexographic plate roll 160. The flexographic plate roll 160, with the flexographic plate mounted therearound, is contacted against the web 20 as the web 20 passes over a support roll 60, to transfer fluid to the web and thereby create an image on the web 20 as the web 20 passes over the support roll 60. In a flexographic press, the support roll 60 is typically referred to as an "impression roll." The support roll 60 may be configured such that a temperature controlled fluid is flowable therethrough, such that a temperature of the web 20 supported by the rotatable support roll 60 is controllable via the temperature controlled fluid and the rotatable support roll.

[0049] After passing over the support roll 60, the fluid deposited on the web 20 is cured using a radiation emitter 210. For example, wherein the fluid is photopolymerizable, the radiation emitter 210 may be a UV lamp. In the embodiment shown in FIG. 1A, the support roll 60 is cooled by a temperature controlled fluid flowing therethrough. Therefore, the radiation emitter 210 is configured to cure the fluid deposited on the web 20 while the web 20 is still on the support roll 60. In the embodiments shown in FIGS. IB and 1C, the support roll is not liquid cooled. Therefore the radiation emitter 210 is configured to cure the fluid deposited on the web 20 after the web 20 is no longer supported by the support roll 60.

[0050] The embodiment shown in FIG. 1C further includes a hot air tunnel 100 configured to provide hot air to the web 20 as the web 20 passes therethrough.

[0051] When it is desired to use one of the stations 10a, 10b as a liquid jet print station rather than a flexographic print station, the positioning elements 50 and the plate roll 160 supported thereby are removed from the station 10a, 10b, and replaced by positioning elements 50 supporting a liquid jet printhead 70. In some embodiments, the positioning elements 50 supporting the liquid jet printhead 70 may be configured the same or similar to the positioning elements 50 supporting the flexographic plate roll 160, so that the positioning elements 50 with the liquid jet printhead 70 supported thereon are interchangeable with the positioning elements 50 with the flexographic plate 160 supported thereon, in a single print station.

[0052] In one embodiment, the liquid jet printhead is an inkjet printhead configured to dispense ink on the web 20. In other embodiments, the liquid jet printhead is configured to dispense a material selected from the group consisting of an adhesive, a varnish, a coating, a conductive material, a silicone release, and an olieophilic material.

[0053] In another embodiment, one or more of the print stations 10a, 10b of the press 10 is configured solely for liquid jet printing. In such print stations, the anilox roll 30 and ink pan 40 may be omitted.

[0054] Embodiments of the mechanism for supporting and adjusting the positioning elements 50 will next be described, with reference to FIGS. 2-7.

[0055] In one embodiment, a print station 10a, 10b of a web printing press 10 includes a frame 170, a first pair of support arms 110 (left and right side support arms 110) rotatably attached to the frame 170, and a second pair of support arms 130 (left and right side support arms 130) attached to the frame 170. The first and second pairs of support arms 1 10, 130 support a pair of positioning elements 50 thereon, as shown in FIG. 3. The positioning elements support a liquid jet printhead 70 at a location between the positioning elements 50, the liquid jet printhead 70 being locked or lockable in place with respect to the positioning elements 50, as described in more detail below.

[0056] The first pair of support arms 110 are adjustable using one or more first adjustment mechanisms 90. In some embodiments, an adjustment mechanism 90 may be provided for each of the support arms 110, so that the support arms 110 are independently adjustable. In some embodiments, a single adjustment mechanism 90 may be provided to adjust one or both support arms 110. Each support arm 110 has a support surface, at least a portion of the support surface extending along a portion of an outer circumferential surface of the rotatable support roll 60, as shown in FIGS. 3, 5, and 6. The first pair of support arms 1 10 may be rotatable about pivots 120. The adjustment mechanisms 90 is configured to cause the upper part of the support arms 110 to move towards or away from the positioning element 50. For example, the adjustment mechanisms 90 can include a knob and screw to cause movement of the support arms 110. In other embodiments, the adjustment mechanism 90 may include an electronically controlled servo positioning motor and a screw to cause movement of the support arms 110. Due to the rotation of the support arms 110 around the pivots 120, this movement causes the positioning elements 50, and thus liquid jet printhead 70 (or plate roll 160), to move towards or away from the support roll 60, so that a distance between the plate roll 160 or liquid jet printhead 70 and the rotatable support roll 60 can be precisely adjusted. Where the press 10 includes an anilox roll 30, the pivots 120 are preferably located such that rotation of the support arms 110 about the pivots 120 causes the positioning elements 50 to move circumferentially around the anilox roll 30.

[0057] The second pair of support arms 130 may either be rotatably attached to the frame 170 (as shown in FIGS. 2-5), or rigidly attached to the frame 170 (as shown in FIGS. 6 and 7). Where the press 10 is configured for both flexographic and liquid jet printing, the second pair of support arms is preferably rotatably attached to the frame 170. In this embodiment, the second pair of support arms 130 are adjustable using one or more second adjustment mechanisms 80. In some embodiments, an adjustment mechanism 80 may be provided for each of the support arms 130, so that the support arms 130 are independently adjustable. In some embodiments, a single adjustment mechanism 80 may be provided to adjust one or both support arms 130. Each support arm 130 has a support surface at which the positioning elements 50 are supported. Where the press 10 includes an anilox roll 30, at least a portion of the support surfaces of the support arms 130 extends along a portion of an outer

circumferential surface of the anilox roll 30, as shown in FIG. 3. The second pair of support arms 130 are rotatable about pivots 140. The adjustment mechanisms 80 is configured to cause the upper part of the support arms 130 to move towards or away from the positioning element 50. For example, the adjustment mechanisms 80 can include a knob and screw to cause movement of the support arms 110. In other embodiments, the adjustment mechanism 80 may include an electronically controlled servo positioning motor and a screw to cause movement of the support arms 130. Due to the rotation of the support arms 130 around the pivots 140, this movement causes the positioning elements 50, and thus the liquid jet printhead 70 (or plate roll 160), to move towards or away from the anilox roll 30, so that a distance between the plate roll 160 or liquid jet printhead 70 and the anilox roll 30 can be precisely adjusted. The pivots 140 may be located such that rotation of the support arms 130 about the pivots 140 causes the positioning elements 50 to move circumferentially around support roll 60. [0058] In some embodiments, the print station 10a, 10b further includes a third adjustment mechanism 150. The third adjustment mechanism 150 is configured to spread a lower portion of the first pair of support arms 1 10 with respect to a lower portion of the second pair of support arms 130, such that the positioning elements 50 supported by the first and second pairs of support arms 1 10, 130 are adjustable in a vertical direction. In some embodiments, the third adjustment mechanism may include a knob attached to a cam. The cam may be located between the first and second pairs of support arms 110, 130, so that when the cam rotates such that a horizontal width of the portion of the cam between the first and second pairs of support arms 1 10, 130 is larger, the distance between the first pair of support arms 110 and the second pair of support arms 130 increases, thereby raising the positioning elements 50. Similarly when the cam rotates such that a horizontal width of the portion of the cam between the first and second pairs of support arms 1 10, 130 is smaller, the distance between the first pair of support arms 110 and the second pair of support arms 130 decreases, thereby lowering the positioning elements 50.

[0059] In another embodiment, the second pair of support arms 130 may be rigidly attached to the frame 170 (as shown in FIGS. 6 and 7). The shape of the support arms 130 in this embodiment is similar to that of the support arms 130 in the embodiment of FIGS. 2-5, except that the support arms 130 in the embodiment of FIGS. 6 and 7 are not rotatable relative to the frame 170.

[0060] While the positioning elements 50 are shown to be cylindrical in FIGS. 2-7, the shape of the positioning elements 50 is not so limited. The positioning elements 50 may be any shape, as long as they have a surface that can be supported by the first pair of support arms 110 and/or the second pair of support arms 130. However, it is preferable that the surfaces of the positioning elements 50 that contact the first pair of support arms 1 10 and/or the second pair of support arms 130 be rounded. For example, in some embodiments, the positioning elements may have a semicylindrical shape.

[0061] The print station 10a, 10b further includes at least one pulling device 180 that is attachable to at least one of the positioning elements 50 and configured to pull the positioning elements 50 towards the first pair of support arms 1 10 and/or the second pair of support arms 130. For example, the pulling element 150 may include a latch 180a configured to be engaged in a groove located in an end surface of a positioning element 50, as shown in FIG. 4. In some embodiments, the pulling element 150 may include two latches, one latch configured to be engaged in a groove of a first one of the positioning elements 50, and one latch configured to be engaged in a groove of a second one of the positioning elements 50.

[0062] In the embodiments of FIGS. 6 and 7, the liquid jet printhead 70 is rotationally adjustable with respect to the rotatable support roll 60. The liquid jet printhead 70 is rigidly attached to the positioning elements 50. In some embodiments, the print station 10a, 10b may further include at least one adjustable indexing block 190 configured to engage with at least one of the positioning elements 50, such that the positioning elements 50 and the liquid jet printhead 70 supported thereby are rotationally adjustable with respect to the rotatable support roll 60 by adjusting a position of the indexing block 190. The indexing block 190 may be, for example, attachable and detachable to the frame 170. In some embodiments, the indexing block 190 is mounted on a track on the frame 170. For example, at least one of the positioning elements 50 may have a groove or grooves in which the indexing block 190 engages. The print station 10a, 10b may include two of the positioning blocks, one for each of the positioning elements 50. In this case, each positioning element 50 may be provided with a groove in which a corresponding indexing block 190 engages.

[0063] The liquid jet printhead 70 may be rotationally adjustable with respect to the pair of positioning elements 50. For example, the liquid jet printhead 70 may be mounted on a shaft located between the two positioning elements 50, and may be rotatable about the shaft and selectively locked in place relative to the positioning elements 50 using a locking element, such as a clamp. This embodiment may be used, for example, when the liquid jet printhead 70 requires inspection, cleaning, repair, etc. First, the positioning elements 50 and liquid jet printhead 70 may be raised away from the support roll 60 using the first, second, and/or third adjustment mechanisms 80, 90, 150. Then, the liquid jet printhead 70 can be rotationally unlocked from the positioning elements 50, and rotated for inspection, cleaning, repair, etc. This way, the web 20 on the support roll 60 remains undisturbed when the liquid jet printhead 70 is rotated.

[0064] In some embodiments, the support roll 60 is cooled by a temperature controlled fluid flowing therethrough. This feature assists in maintaining a good flowout of the liquid dispensed by the liquid jet printhead. For example, an inkjet head jets droplets of ink in a matrix pattern. Even if every position of the matrix is jetted, the ink film is initially a matrix of droplets and the surface is not flat. If the surface of the ink film is not flat, the gloss of the surface is reduced. In other words, the specular reflection is reduced by having more diffuse reflection. To the degree the ink droplets flow together on the surface of the web to form a uniform ink film thickness before the ink is cured by, for example, UV photopolymerization, the specular reflection is increased and the gloss is increased. In some applications, gloss may be very important to the quality of an article of flexible packaging. The rate of flowout can be accelerated reducing the viscosity of the ink which, in turn, can be influenced by increasing the temperature of the ink which can be done by controlling the temperature of the web between receiving the inkjet droplet and the UV photopolymerization. This web temperature control can be done by flowing the temperature controlled fluid through the support roll over which the web is supported.

[0065] In some embodiments, a web printing press may include a plurality of print stations, including a liquid jet print station in which a liquid jet printhead is mounted, and other print stations in which another type of printing device is mounted. For example, one of the print stations may be a flexographic print station that includes a frame; a rotatable impression roll configured to support a web to be printed; a first pair of support arms rotatably mounted to the frame, each support arm having a support surface, at least a portion of the support surface extending along a portion of an outer circumferential surface of the rotatable support roll; a pair of positioning elements supported at least in part by respective ones of the first pair of support arms; a flexographic printing plate roll supported by the positioning elements at a location between the positioning elements, the plate roll being rotatably supported with respect to the positioning elements; and a first adjustment mechanism configured to move the first pair of support arms and the positioning elements supported thereby, to adjust a distance and/or pressure between the plate roll and the rotatable impression roll. The flexographic print station can further include a rotatable anilox roll configured to contact the flexographic plate roll to provide ink to the plate roll; a second pair of support arms, each of the support arms of the second pair of support arms having a support surface, at least a portion of the support surface extending along a portion of an outer circumferential surface of the rotatable anilox roll, wherein the positioning elements are further supported by the second pair of support arms; and a second adjustment mechanism configured to move the second pair of support arms and the positioning elements supported thereby, to adjust a distance and/or pressure between the flexographic plate roll and the anilox roll. The flexographic print station can further include a third adjustment mechanism configured to spread a lower portion of the first pair of support arms with respect to a lower portion of the second pair of support arms, such that the positioning elements supported by the first and second pairs of support arms are adjustable in a vertical direction. The pair of positioning elements and the liquid jet printhead of the liquid jet printing station may be removed from the liquid jet printing station and placed in the flexographic print station in place of the pair of positioning elements and the plate roll of the flexographic print station, and vice versa.

[0066] In another embodiment, a method of using a liquid jet printhead in a web flexographic printing press is provided. The method includes providing a flexographic printing press that includes a flexographic print station that includes a frame; a rotatable impression roll configured to support a web to be printed; a first pair of support arms rotatably mounted to the frame, each support arm having a support surface, at least a portion of the support surface extending along a portion of an outer circumferential surface of the rotatable support roll; a first pair of positioning elements supported at least in part by respective ones of the first pair of support arms; a flexographic printing plate roll supported by the first pair of positioning elements at a location between the first pair positioning elements, the plate roll being rotatably supported with respect to the positioning elements; and a first adjustment mechanism configured to move the first pair of support arms and the positioning elements supported thereby, to adjust a distance and/or pressure between the plate roll and the rotatable impression roll; providing a liquid jet printhead supported by a second pair of positioning elements at a location between the second pair of positioning elements, the liquid jet printhead being lockable in place with respect to the second pair of positioning elements; and replacing the first pair of positioning elements and flexographic printing plate roll supported thereby with the second pair of positioning elements and liquid jet printhead supported thereby.

[0067] The method may further include adjusting a rotation of the liquid jet printhead with respect to the rotational impression roll.

[0068] The step of replacing the first pair of positioning elements and flexographic printing plate roll supported thereby with the second pair of positioning elements and liquid jet printhead supported thereby may include unlatching the latches of a pulling device from the grooves of the first pair of positioning elements; removing the first pair of positioning elements and flexographic printing plate roll supported thereby; placing the second pair of positioning elements and liquid jet printhead supported thereby on the first pair of support arms; and latching the latches to the grooves of the second pair of positioning elements. [0069] The above-described embodiments offer several advantages over previous systems. For example, one problem that may manifest with a completely separate liquid jet head assembly, i.e., one having its own backing roll, has to do with pacing or displacing the web. If a web is wrapping a roll that is not driven, the web must turn the roll, which requires torque. This torque comes from web tension. The strain, or stretch, of the web will change when turning non-driven rolls. Thus, the length of any image on that span will change. If a digital inkjet image is "matrixed" down the length of a web and started from a single printed indicia (this is done to register the inkjet image to another image), then the fit of the inkjet image to the other image may be off if the strain changes the length of the other image. If the web displacement can be controlled under the inkjet as the image is printed, better image fit is acheivable. In embodiments of the present invention, the web is supported by a support roll naturally at every print station. Furthermore, in some embodiments, this roll can be temperature controlled with a fluid flow, as discussed above. Thus, in such embodiments, two problems may be solved: 1) there is no additional expense of an extra support roll and 2) temperature control of the web is available to better control flowout and gloss. Second, the liquid jet printhead can be connected and positions by the same precise mechanism that connects and positions a flexographic plate roll. Thus, in such embodiments, four additional problems may be solved: 3) the moveable liquid jet assembly does not need to carry a support roll, so it is easy to move, 4) because the parts for capture and parts for structural support may be already present, the expense of those parts, if otherwise dedicated to a liquid jet printhead, is avoided, 5) the support roll may be driven, providing control of the liquid jet image length and fit to other images, and 6) because the liquid jet printhead can connect over the web where the flexographic plate roll connects, the web does not need to be disturbed. In some applications, this latter point may be significant because disturbing the web when adding the liquid jet printing in sequence with flexographic printing stations takes time and causes waste.

[0070] The foregoing description of embodiments has been presented for purposes of illustration and description. The foregoing description is not intended to be exhaustive or to limit embodiments of the present invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments. The embodiments discussed herein were chosen and described in order to explain the principles and the nature of various embodiments and its practical application to enable one skilled in the art to utilize the present invention in various embodiments and with various modifications as are suited to the particular use contemplated. The features of the embodiments described herein may be combined in all possible combinations of methods, apparatus, modules, systems, and computer program products.