Abstract:
A modular decorator ink temperature control system for use with a blanket wheel, the blanket wheel having inker station configured with an inker station panel and at least one roller operatively mounted thereto. The modular decorator ink temperature control system includes a thermal transfer fluid conduit having an entry end distal to the blanket wheel and an exit end proximate to the blanket wheel with the thermal transfer fluid conduit in contact with the at least one roller and configured to convey at least one thermal transfer fluid therethrough. The modular decorator ink temperature control system also includes at least one control manifold device mounted on the inker station panel in operative communication with the thermal transfer fluid conduit.

Description:
CROSS-REFERENCE 
       [0001]    This application claims priority benefit to U.S. Provisional Patent Application Ser. No. 61,535,338 filed Sep. 15, 2011, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to decorators used to apply ink to containers including but not limited to cans, plastic containers and the like. More specifically, the present invention relates to a system and method for controlling the temperature of ink used in a decorator. 
         [0003]    Cylindrical containers such as cans are often decorated using ink applied by high speed machines called decorators. The decorators can operate at high speeds and can be configured to process over 2000 objects per minute. As such, they are configured to apply a multi-color ink pattern or print image having two or more colors by rotating the cylindrical container past a printing blanket loaded with ink. 
         [0004]    Typical decorators have a number of mandrels arrayed on the periphery of a mandrel wheel. The mandrels are each configured to support an individual object such as a can so that the objects can continually rotate around the axis of the mandrel wheel. The mandrel wheel turns in coordination with a blanket wheel that is configured with a number of printing blankets arranged around the periphery of the blanket wheel to engage the objects positioned on the mandrels located on the mandrel wheel. Each printing blanket rotates past one or more inker roll to pick up a volume of ink with each individual inker roll, applying a different color ink based upon the desired final print image. 
         [0005]    After the printing blanket has been inked, the printing blanket rotates past and contacts an object to transfer the ink image to the object&#39;s surface. The mandrel wheel can advance the object past additional printing blankets to impart the decorated surface as desired or required. Once the design has been printed on the object, the object can be advanced to suitable post-printing processing stations such as varnishing and curing operations. The printing blanket(s) continue to rotate with the associated blanket wheel and the process can be repeated on subsequent objects. 
         [0006]    The various printing blanket(s) are supplied with ink in a continuous repeatable manner. In certain devices, each inker device contains a number of rollers that transfer ink from an ink reservoir such as an ink tray or ink fountain to the printing blanket located on the blanket wheel. Eventually the ink is transferred to a suitable printing plate cylinder. 
         [0007]    One challenge associated with using decorators operating at high speeds is maintaining the ink at proper temperature. In order achieve successful high-speed ink application, each individual ink composition should be maintained within an optimum temperature range. Deviation outside this prescribed optimum temperature range can alter physical and/or chemical properties of the ink composition can result in improper image transfer. For example, elevated ink temperature can lead to volatilization of ink components of the ink that can alter the ink chemistry. Similarly application temperatures below optimum can alter the viscosity of the composition of one or more or the constituent parts of ink. Temperatures that are below optimal can result in phenomena such as misting or slinging. Temperature variations can lead to changes in color hue and intensity. Temperature changes can also lead to improper or irregular deposition of ink material including but not limited to runs bleeds and the like. 
         [0008]    Image transfer difficulties can occur at system startup or restart as the various inks are brought to temperature. Other difficulties are encountered during system operation. During prolonged high speed operation, temperatures of the various component parts of the applicator as well as the associated inks can exceed optimum recommended application temperatures. The application temperatures of the various inks can also be affected by fluctuations in surrounding ambient temperature in certain applications. 
         [0009]    Various temperature control systems have been proposed to minimize the amount of time that the temperature of the ink is outside the desired temperature range. These systems provide a central ink temperature conditioning system composed of a central recirculation loop that is configured to recirculate a temperature conditioning solution and a feeder line that controls the flow of the temperature conditioning solution and delivers it to a remote location located on at least one ink roller on a decorator. The system is configured to deliver temperature conditioning solution that includes a dedicated a heating solution or a dedicated cooling solution to the plurality of ink rollers based on the detected temperature of the ink to be applied. 
         [0010]    Such systems typically circulate water through the various rollers to control temperature and typically pass water through a rotary union into a bore prepared in a shaft that extends under the entire width of the associated roller. Holes bored through the shaft perpendicular to its axis near each end of the roller are intended to allow the water to flow through the hollow body of the roller to transfer heat away from the associated assembly. Water circulation is controlled via a pump located remote from both the circulation conduits and the printing blanket(s). 
         [0011]    Heretofore the various systems required large control loops and operated on a manually controlled duty-cycle model. It would be desirable to provide a system that provides an automated system that provides a closed loop system that is feedback controlled and is proximate to the inker. It would also be desirable to provide a modular decorator temperature control system that allows the temperature of the ink being applied to a container to be accurately controlled in a small, easy-to-install interface mounted directly to the inker station providing local control of temperature at the point of use. 
       SUMMARY 
       [0012]    A modular decorator ink temperature control system for use with a blanket wheel, the blanket wheel having inker station configured with an inker station panel and at least one roller operatively mounted thereto. The modular decorator ink temperature control system includes a thermal transfer fluid conduit having an entry end distal to the blanket wheel and an exit end proximate to the blanket wheel with the thermal transfer fluid conduit in contact with at least one roller and configured to convey at least one thermal transfer fluid therethrough. The modular decorator ink temperature control system also includes at least one control manifold device mounted on the inker station panel in operative communication with the thermal transfer fluid conduit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The various features, advantages and other uses of the present apparatus will become more apparent by referring to the following detailed description and drawing in which: 
           [0014]      FIG. 1  is an elevation view of a portion of a temperature control system attached to a decorator; 
           [0015]      FIG. 2  is a perspective view of a portion of a decorator with an embodiment of a decorator inker station temperature control system as disclosed herein; 
           [0016]      FIG. 3  is a plan view of an embodiment of a manifold and controller as depicted in  FIG. 1 ; 
           [0017]      FIG. 4  is a perspective view of the manifold and controller of  FIG. 4A ; 
           [0018]      FIG. 5  is a plan view of an embodiment of a hot/cold selection manifold that can be used with the device of  FIG. 1 ; 
           [0019]      FIG. 6  is a perspective view of the device of  FIG. 5 ; 
           [0020]      FIG. 7  is a plan view of an embodiment of a host controller module that can be used with the device disclosed herein; 
           [0021]      FIG. 8  is a graph depicting flow versus pressure for four rollers in an inker device; 
           [0022]      FIG. 9  is a graph depicting roller thermal gradient; 
           [0023]      FIG. 10  is a graph depicting a typical roller temperature profile; 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    Disclosed herein is a temperature control system for a decorator inker station associated with a suitable decorator system  10  for applying printed indicia to suitable objects such as cans and the like. The inker station is typically composed of a blanket wheel  12  that has multiple inking blankets  14  disposed in spaced relationship around the outer circumference of the blanket wheel  12 . Cans  16  to be imprinted are held in position on associated mandrels  18 . The mandrels  18  are positioned in spaced relationship about a mandrel wheel  20  located in spaced but operatively engaging position relative to the blanket wheel  12 . The blanket wheel  12  and mandrel wheel  20  rotate in opposed relation to one another and are oriented such that the cans  16  engage the printing blankets  14  on rotating blanket wheel  12  transferring ink the surface of the respective cans. 
         [0025]    The blanket wheel  12  is composed of one or more inker station(s)  22  located round the periphery of the blanket wheel  12  and generally projecting therefrom. The inker station(s)  22  supply a specific ink to the various printing blankets  14 . Each inker station  22  includes one or more inker rollers (not shown) that distribute and transfer ink from a suitable ink supply or tray (also not shown) to a printing blanket  14  or blanket wheel  12 . The rollers are mounted to a suitable support such as an inker station frame plate  24  and connected to suitable communication fittings. In the embodiment depicted in  FIG. 2 , the inker station  22  is configured with four inker rollers connected to four respective communication fittings  26 ,  28 ,  30 ,  32 . 
         [0026]    The communication fittings  26 ,  28  etc. each communicate with an associated thermal fluid conditioning supply conduit and a thermal conditioning fluid discharge conduit. In the embodiment depicted in  FIG. 2 , the various four communication fittings  26 ,  28 ,  30  and  32  each have a supply line  26   a,    28   a,    30   a,  and  32   a  associated with them as well as a suitable fluid discharge conduit  26   b,    28   b,    30   b  and  32   b.    
         [0027]    As disclosed herein, the decorator system  10  has at least one decorator inker station including a plurality of ink rollers that are configured to distribute ink in a defined ink temperature range. At least one inker station  24  can be configured to accomplish ink temperature control and regulation utilizing a suitable temperature conditioning fluid passage system. As disclosed herein one or more inker stations  22  can be configured with an ink temperature control system that is mounted on the associated panel  24  of the decorator inker station  22 . As such, where desired or required, one or more of rollers can be configured to permit the passage of thermal conditioning fluid through the interior region of the roller. The various communication fittings  26 ,  28 ,  30 ,  32  can be configured to communicate with through-passages defined in each respective roller to permit transit of thermal conditioning fluid into and out of the associated roller. In the embodiment depicted, the communication fittings are standard rotary union fittings configured such that the thermal conditioning fluid feeds into the roller through the center of the fitting and out through the peripheral region. 
         [0028]    Thermal conditioning fluid can be conveyed to each inker station  22  from a thermal conditioning fluid source via a suitable conduit such as conduit  28  and can be removed from each inker station  22  by means of a suitable conduit such as  30 . In the embodiment depicted, thermal conditioning fluid is delivered to each roller in parallel. Other configurations are also contemplated. Systems can be configured in series or in parallel. 
         [0029]    The decorator temperature control system as disclosed herein includes at least one temperature control module  34  located proximate with an individual inker station  22 . The temperature control module  34  configured to regulate the supply of thermal conditioning fluid and thereby regulate the temperature of ink being dispatched from the inker station  22  to the inking blankets  14  in response to certain command and control inputs. The temperature control module  34  can act on either the supply side or the exit side of the inker station thermal conditioning system as desired or required. 
         [0030]    In the embodiment depicted the ink temperature control module  34  is composed of a modulating balance supply manifold  50  that communicates with at least one of the individual ink rollers and to regulate flow of thermal conditioning fluid passing through the ink roller to a flow rate proportional to the temperature conditions of the specific ink roller or rollers associated with the specific inker station  22 . The inker temperature control module  34  is located proximate to the rollers and associated communication fittings  26 ,  28  etc. located on the inker station  22 . In the embodiment depicted in  FIG. 2 , the inker temperature control module  34  is mounted on one face  36  of the inker station frame plate  24  with the various ink rollers projecting from the opposed face. 
         [0031]    The modulating balance supply manifold  50  is configured to regulate flow of the thermal conditioning fluid though the various rollers in response to suitable command inputs. The modulating balance supply manifold  50  as disclosed herein can include an interface that can communicate with a suitable master control center module  100  that can be centrally located and configured with suitable operator communication and connection to the line PLC if desired or required. 
         [0032]    In the embodiment disclosed, the master control center module  100  is configured to receive various operational data from various locations on the decorator device  10  and to formulate operational commands that can be promulgated to modulating supply manifold(s) located on one or more of the inker stations  22 , either independently or in coordination with one another. The operational data can be derived from various sources including, but not limited to, temperature sensors associated with one or more rollers on a given inker station  22 . A non-limiting example of suitable temperature sensors include dedicated non-contact temperature sensors  52  such as IR sensor(s) mounted on the inker station panel  24  or other suitable location. In various embodiments, the IR sensor can be configured to monitor the temperature of any of the various rollers; one non-limiting example would be monitoring the temperature of the lower oscillating roller. It is contemplated that the data derived from the sensor(s) can be used to coordinate the operation of the modulating balance supply manifold  50  in one or more of the inker station  22  to perform the temperature control function in response to feedback. 
         [0033]    In the certain embodiments such as an embodiment disclosed herein, the master control center module  100  can have operating parameters suitable for use in the application specified. For example the modulating balance supply manifold  50  can operate on 90-240V 50/60 Hz 1 ØAC power with a control voltage of 24 VDC. The master control center module  100  can have suitable connection means to establish electronic connectivity with modulating balance supply manifold  50 . 
         [0034]    Where desired or required, the multiple inkers each can be equipped with the temperature control device  10  as disclosed herein. The configuration disclosed herein permits temperature control tailored to the desired parameters of each ink administered. 
         [0035]    An embodiment of the modulating balancing manifold  50  is illustrated in  FIG. 3 . A modulating balancing modulating manifold  50  is positioned at one or more inkers station  22  in the manner depicted in  FIG. 1 . The modulating balancing manifold  50  is configured with mounting centers (not shown) configured to mount on a suitable face of inker station  22 . Where desired or required, the modulating manifold  50  is configured to facilitate easy incorporation into the inker station  22 . 
         [0036]    The modulating balancing manifold  50  is configured with at least one modulating valve  56  providing and regulating fluid flow and access through at least one water port  36 . The manifold has at least one on-board controller  58 . Water conveyed through the elliptical modulating valve  56  passes through a plurality balancing valves  60 . 
         [0037]    In operation, the controller in the inker control module adjusts the modulating valve to regulate the volume of water supplied to the rollers. The balancing valves  60  set the ratio of the total volume that is sent to each roller so as to individually control the temperature of that roller relative to the others. This allows the thermal profile of the inker station  22  to be easily manipulated to produce optimum ink pull-down and distribution, then apply it to the can at the proper temperature to produce perfect color every time. The operating temperature, determined to be that of one of the various rollers, is set at the controller and can be adjusted to strike a balance between color, pull-down, misting and slinging, solvent evaporation, etc. In certain embodiments, the operating temperature is set at the first oscillating roller. 
         [0038]    The device  10  can be configured to convey and regulate the flow of either chilled or heated thermal conditioning fluid such as water. It is also within the purview of this disclosure that the device be configured to convey and circulate both heated and cold water. This can be accomplished by providing the modulating inlet port with multiple water inlet ports that can communicate with a cold water source and a heated water source respectively. 
         [0039]    In systems utilizing heated and cold water for temperature conditioning, the device  10  can also include heat/cool selection manifold. One embodiment of a heat/cool selection manifold is illustrated in  FIG. 5 . As depicted, the heat/cool selection manifold is used only with heat/cool systems and determines whether the water being circulated through the inker flows from the warm water supply to the warm water return or from the cold water supply to the cold water return. By separating these, mixing of the warm and cold water supplies is eliminated, assuring the most energy efficient operation possible. This also ties to the inker control module with a pre-assembled cable and is controlled automatically in conjunction with the modulating heat/cool balancing manifold. 
       Comparative Example I 
       [0040]    It has been found that color quality of the applied ink varies with temperature of application. For example, color shifts can occur as a function of temperature. In many situations cooler ink temperature is equated to darker coloring and warmer ink application temperatures equating to lighter color. Temperature variation alters viscosity of the ink applied. When ink is too cool, the ink can glob and get stringy due to increased viscosity. Additionally, if the ink at the fountain is too cold the ink may not “pull down” to the other rollers properly. If ink gets too warm, the elevated temperatures can drive off solvent that can alter ink performance. Variations in ink temperature at application can also result in slinging and misting of the ink. This can create clean up challenges and, if overly excessive, can also result in plant health and safety concerns. 
         [0041]    With a few qualifiers, the ability to cool is directly proportional to the volume of water that can be passed across the roller surface in a given period of time. In our examination of this system we found several issues each of which can result in a restriction of the flow through the roller and thus a limitation to the cooling capacity of the system. Flow versus pressure for four rollers in an inker is illustrated in the graph of  FIG. 8 . Maximum possible flow possible with traditional water supply systems determines the cooling capacity available in the fountain, first steel, upper oscillating roller and lower oscillating roller. 
         [0042]    Many of these systems are cooled with city water which is generally supplied at 30-80 PSI depending on usage, location with respect to the nearest pumping station, demand on the rest of the system supplied by that pumping station, etc. This can vary by season, time of day, pump condition, etc. Though many plants have a booster pump on their system, most will still be limited to a maximum pressure of 60-80 PSI. The actual pressure available to the decorator is determined by its distance from the source as well as the size of the pipe between the two and the flow being supplied. From this it is clear that for any given pressure, the flow through each roller will be different and therefore the cooling capacity for that roller will be different. This differential becomes more pronounced as the flow requirements (read: cooling) increase and therefore some kind of balancing system is required and has thus been incorporated into the temperature control system design. 
         [0043]    While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.