Abstract:
An edge cleaning device, a system for cleaning an outside edge of a movable, coated web, and a method of cleaning the outside edge of the movable, coated web include a unique combination of desirable features. An edge cleaner device is automatically positioned with respect to an outside edge of a movable, coated web, wherein the edge cleaner device is positioned upstream from a backing roller for operatively engaging an underside of the moving, coated web. A fluid jet from a nozzle assembly of the edge cleaner device is applied toward the underside and the outside edge of the moving, coated web. A scraper device can be operatively engaged with an upper surface of the moving web without contacting an upper surface of the backing roller and the collection device may be imparted with a vacuum to assist in the removal of excess coating collected by the edge cleaning device.

Description:
BACKGROUND ART 
     1. Field of the Invention 
     The present invention is generally directed toward an edge cleaning device for a coated web, and more particularly to a non-contact edge cleaning device for a moving web that has been coated and transported with the benefit of rollers. 
     2. Description of the Background Art 
     The following discussion of the background art is a result of the present inventors analysis of the systems and features of the related technology of the background art. The present inventors have determined that there are unique problems associated with coated webs and the available technology related to the cleaning of coated webs, particularly along the edges of coated webs moving through a coating or other similar process. 
     U.S. Pat. No. 3,351,039 to Heisterkamp, the entirety of which is hereby incorporated by reference, describes an exemplary roll cleaning device of the background art particularly designed to clean the edges of a sheet coating roll. Heisterkamp describes problems associated with the coating of certain sheet materials, such as sheets coated with latex materials. Often the coated sheet is applied with a coating in a quantity greater than the desired coating thickness to ensure full or adequate coverage over the sheet. The coated sheet is then carried over a backing roll where a proper coating weight is achieved by a knifing action of an air jet. The excess coating is subsequently sheared off to a collection pan below the air jet. The excess coating often carries over the edges of the sheet with the result that the backing roll is eventually coated with the excess coating material. 
     As seen in  FIG. 1  of the present application, a coating is applied between a coating roll  22  pressed against a rubberized backing roll  20  in an exemplary coating process. However, another problem encountered in coating the web  10  is that some of the excess coating will try to wrap around the moving web from a first coated side  12  (underside of the web  10 ) to an opposite, typically uncoated side  14  both upstream of and at the backing roller  20 . The present inventors have determined that there are variety of edge cleaning approaches that can be advantageously applied to overcome these problems associated with coated, moving webs moving through similar processes. 
     SUMMARY OF THE PRESENT INVENTION 
     The present invention overcomes the shortcomings associated with the background art and achieves other advantages not realized by the background art. 
     An aspect of the present invention, in part, is directed toward an edge cleaner device for a moving web that is capable of cleaning the edge of a moving web both at and before (upstream) of a backing or coating roller. 
     An aspect of the present invention, in part, is directed toward an edge cleaner device for a moving web that is capable of cleaning the edge of a moving web while minimizing undesirable carryover of excess coating to uncoated portions of the moving web. 
     An aspect of the present invention, in part, is directed toward an edge cleaner device for a moving web that is capable of cleaning the edge of a wide range of sizes of moving web(s) and automatically aligning and positioning the edge cleaner device with respect to the outside edge or width of the moving web. 
     One or more of the foregoing aspects of the present invention is accomplished, in part, by an edge cleaning device for an outside edge of a moving, coated web, the device comprising a nozzle assembly imparting a fluid jet toward the outside edge of the moving, coated web; and a scraper device operatively secured with the nozzle assembly to a common carriage, wherein the nozzle assembly and the scraper device are capable of being simultaneously positioned by the carriage along the outside edge of the moving, coated web. 
     One or more of the foregoing aspects of the present invention is also accomplished, in part, by an edge cleaning device for an outside edge of a moving, coated web, the device comprising a nozzle assembly imparting a fluid jet toward the outside edge of the moving, coated web; and a collection container operatively secured with the nozzle assembly to a common carriage, wherein the collection container and the nozzle assembly are capable of being simultaneously positioned by the carriage along the outside edge of the moving, coated web, and the fluid jet of the nozzle assembly is directed in a direction toward an opening of the collection container. 
     One or more of the foregoing aspects of the present invention is also accomplished, in part, by a system for cleaning an outside edge of a moving, coated web, the system comprising a moving, coated web; a roller for operatively engaging the moving, coated web; a movable carriage supporting an edge cleaning device; a nozzle assembly imparting a fluid jet toward the outside edge of the moving, coated web; and a scraper device operatively secured with the nozzle assembly to the movable carriage, wherein the nozzle assembly and the scraper device are capable of being simultaneously positioned by the carriage along the outside edge of the moving, coated web. 
     One or more of the foregoing aspects of the present invention is also accomplished, in part, by a system for cleaning an outside edge of a moving, coated web, the system comprising a moving, coated web; a roller for operatively engaging the moving, coated web; a movable carriage supporting an edge cleaning device; a nozzle assembly imparting a fluid jet toward an outside edge of the moving, coated web; and a collection container operatively secured with the nozzle assembly to the movable carriage, wherein the collection container and the nozzle assembly are capable of being simultaneously positioned by the carriage along the outside edge of the moving, coated web, and the fluid jet of the nozzle assembly is directed in a direction toward an opening of the collection container. 
     One or more of the foregoing aspects of the present invention is also accomplished, in part, by a method of cleaning an outside edge of a movable, coated web, the method comprising positioning an edge cleaner device with respect to an outside edge of a movable, coated web, wherein the edge cleaner device is positioned upstream from a roller for operatively engaging the moving, coated web; imparting a fluid jet from a nozzle assembly of the edge cleaner device toward an underside and an outside edge of the moving, coated web; and simultaneously positioning a scraper device along the outside edge of the moving, coated web, wherein the scraper device is operatively engaged with an upper surface of the moving web without contacting a surface of the roller. 
     One or more of the foregoing aspects of the present invention is also accomplished, in part, by a method of cleaning an outside edge of a movable, coated web, the method comprising positioning an edge cleaner device with respect to an outside edge of a movable, coated web, wherein the edge cleaner device is positioned upstream from a roller for operatively engaging the moving, coated web; imparting a fluid jet from a nozzle assembly of the edge cleaner device toward an underside and the outside edge of the moving, coated web; and simultaneously positioning a collection container operatively secured with the nozzle assembly, wherein the collection container and the nozzle assembly are simultaneously positioned along the outside edge of the moving, coated web, and the fluid jet of the nozzle assembly is directed in a direction toward an opening of the collection container. 
     Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings that are given by way of illustration only, and thus do not limit the present invention. 
         FIG. 1  is a side view of a coated web moving past a backing roller and an edge cleaner device of the present invention; 
         FIG. 2  is a perspective view of an edge cleaner device according to an embodiment of the present invention; 
         FIG. 3  is a schematic view of an edge cleaner device according to an embodiment of the present invention; 
         FIG. 4  is perspective view of an edge cleaner device according to an embodiment of the present invention; 
         FIG. 5  is a perspective view of a scraper blade device according to an embodiment of the present invention; 
         FIG. 6  is a schematic view of a scraper device being applied to an underside of a moving web; 
         FIG. 7  is a schematic view of a scraper device being applied to an underside of a moving web; and 
         FIG. 8  is a schematic view of a scraper device being applied to an underside of a moving web. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be described in detail with reference to the accompanying drawings. The present inventors have analyzed the needs of the background art and identified several shortcomings associated with the systems of the background art.  FIG. 1  is a side view of a coated web moving past a backing roller and an edge cleaner device of the present invention.  FIG. 2  is a perspective view of an edge cleaner device according to an embodiment of the present invention.  FIG. 3  is a schematic view of an edge cleaner device according to another embodiment of the present invention.  FIG. 4  is perspective view of an edge cleaner device according to another embodiment of the present invention. 
     As seen in  FIG. 1 , a coating is applied to a moving web  10  having a first coated side  12  and a second, uncoated side  14  moving through a process along a first process direction W. The web  10  is moved between a coating roll  22  (as seen in  FIG. 3  in a retracted position) pressed against a rubberized backing roll  20  in order to ensure an even distribution of the coating applied to the web  10 . However, the present inventors have determined that some of the coating will appear to wrap around the moving web  10  from a first coated side  12  to an opposite, typically uncoated side  14  both before (upstream with respect to direction W) and at the backing roller  20 . 
     A first edge cleaning device of the present invention can incorporate a thin scraper device  30 , e.g., a blade is shown in  FIG. 1 , constructed of foil or other thin metal, or thin non-metallic substances exhibiting non-stick properties such as Teflon (tetrafluoroethylene). The scraper device  30  is arranged to be positioned generally in parallel to the moving direction W of the web  10 . As seen in  FIG. 1 , a portion of the scraper device  30  is positioned in contact with the moving web  10  and with a portion of the rubberized backing roll  20 . Accordingly, the scraper device  30  is designed to scrape away any excess coating attempting to carryover from the coated side  12  of the web to the surfaces of the backing roll  20  and/or the underside of the web, e.g., the uncoated side  14  of the web. 
     However, the present inventors have determined that abrasion marks form over time in the surface of the rubberized backing roll. In order to compensate for the effects of the scraper device  30 , coating runs are often scheduled so that the widest webs are ran through the rollers  20 ,  22  first and the narrower webs are then gradually processed as the rubberized backing roll  20  is abraded or otherwise worn. After repeated coating runs, the rubberized backing  20  typically requires replacement resulting in costly machine down times and/or maintenance and repair. 
     Alternatively, the present inventors have determined that the scraper device  30  can be optimally positioned so that it only contacts the moving web, e.g., and does not significantly contact the surface of the backing roll  20 . The inventors have determined that this approach is successful in minimizing carryover of excess coating to the surfaces of the backing roller  20  and/or the underside  14  of the moving web  10 . The scraper device  30  rides only on the paper web  10  to the edge but does not overlap to touch the adjacent backing roller  20  surface (as shown in  FIG. 1 ). 
     Accordingly, by not touching the backing roller  20  surface, the problem of marring of the roll is effectively eliminated. However, the present inventors have determined that additional features in combination with the optimized scraper device  30  and/or standing alone, when incorporated into a non-contact edge cleaning device will further optimize and/or offer alternative approaches to minimizing carryover of excess coating along the edge of the moving web. For example, the scraper device  30  preferably rides only on the paper web, e.g., riding on the underside or uncoated side  14  of the paper web  10  to the edge of web but not overlapping to touch an adjacent roller, e.g., such as backing roller  20 . 
     Alternatively, the scraper device  30  is preferably applied to a slightly or moderately tensioned web without need for a backing roll, e.g., the use of a backing roller  20  may be optional. In a more preferred embodiment, the scraper blade is positioned at about a 90° angle θ to the underside or uncoated side  14  of the paper web as part of the moveable carriage  70  assembly, although a wide range of angles may be employed as discussed in greater detail hereinafter. The scraper blade or scraper device  30  can be integral to the carriage assembly or a separately supported and movable component. By riding on the uncoated underside of the web, any coating that wraps around the web is easily and conveniently removed by scraper device  30  and the water jet of nozzle assembly  50 . The scraper device  30  is positioned in proximity to collecting container  40  and nozzle assembly  50 . The fluid jet from nozzle assembly  50  is directed toward the underside edge of the moving web (and in the direction of container  40 ) so as to direct excess coating toward container  40 . Therefore, any remaining coating or water wrapping around to uncoated side  14  is conveniently removed by scraper device  30 . 
       FIG. 6  is a schematic view of a scraper blade device being applied to an underside of a moving web.  FIG. 7  is a schematic view of a scraper device (blunt object) being applied to an underside of a moving web.  FIG. 8  is a schematic view of a scraper device (roller) being applied to an underside of a moving web. The role of the scraper device  30  is to remove any excess fluid or coating remaining or wrapping around to the uncoated underside  14  of the web. It will be readily evident to the skilled artisan that scraper device  30  can take the form of a blade ( FIG. 6 ), blunt object ( FIG. 7 ) or even a similar width (to this blade) small roller ( FIG. 8 ), such as a small metal or nylon wheel or roller, to which drag is applied to hinder rolling such that a dragging or scraping effect is achieved, or even a stationary roller separate from the movable carriage  70 . Drag can also be effectively created by offsetting such a small roller at a slight angle θ to the direction of travel of the web creating a slight scraping effect. The scraper device  30  can also take the form of a forceful air jet or air knife, though a blade as shown in a preferred embodiment in the enclosed figures. Therefore, all such variations are viewed as a scraper device  30  for purposes of simplicity in description for the present invention. 
       FIG. 5  is a perspective view of a scraper blade device according to an embodiment of the present invention. As mentioned hereinabove, the term scraper device  30  and scraper device  30  have been used interchangeably. One of skill in the art will appreciate that in a preferred embodiment, the scraper device (blade)  30  may include a blade  32  having a working edge that is operatively secured into a clamping mechanism and holder  31 . The holder  31  and the blade  32  can be positioned at a variety of angles θ with respect to each other to optimize the desired angle of attack with respect to the underside  14  of the moving web  10 . Although a variety of acute and obtuse angles θ may be employed, a desired range of angle θ is between 75 and 95 degrees, and more particularly between 90 and 95 degrees. In addition, the blade  32  may be secured to the holder  31  via fasteners, e.g., such as the pair of thumb screws  33  shown in  FIG. 5 . 
     For example, as seen in  FIG. 2  and  FIG. 3 , the present inventors have determined that an edge cleaner device can incorporate a fluid jet from a nozzle assembly  50  that is directed at the underside  14  of the coated web  10  in a direction toward the outside edge of the moving web  10 . The fluid jet from the nozzle assembly  50  can be a jet of air, water or air/water mist that is directed in a position that will separate and/or carry away any excess coating migrating from the upper edge  12  of the coated web  10  toward the underside or uncoated side  14  of the coated web  10  away from the coated web  10 . As seen in  FIGS. 2 and 3 , an optional receiving drain or collection container  40  is positioned with respect to an edge of the moving web  10  in a position that permits the container  40  to collect any excess coating separated and/or carried away with the fluid jet of the nozzle assembly  50 . 
     The nozzle assembly  50  may incorporate a needle nose jet of water, air, or combination thereof directed toward the opening  42  of the container  40 . U.S. Pat. No. 2,653,566 to Worden; U.S. Pat. No. 3,351,039 to Heisterkamp; U.S. Pat. No. 4,359,964 to Johnson; and U.S. Pat. No. 6,176,939 to Oechsle et al. describe the construction, materials and operation of several nozzle assemblies of the background art employing water, air and/or water/air mist fluid flows that may be incorporated into the unique edge cleaning device of the present application. Accordingly, the entirety of each of the above-identified applications is hereby incorporated by reference. 
     The collection drain or container  40  can be formed in a variety of shapes and positions that allow the container  40  to collect and/or carry away excess coating. For example, the container  40  can be a conical or cylindrically shaped receiving cup  40  or cone that includes a vacuum supplied by a vacuum hose  62 , e.g., such as a reinforced, flexible hose. The receiving cone or container  40  can be supplied with vacuum, but this arrangement is optional depending upon the desired application. As seen in  FIGS. 2 and 3 , the container  40  is provided with an opening  42  at a front side of the container  40  for collecting excess coating and one or more optional guides  48  extending from the sides of the container  40  to engage the upper surface  12  of the moving web  10  and prevent the web from excessively deviating from the moving path W, e.g., curling in response to the fluid jet of the nozzle assembly  50  directed at the underside  14  of the web. 
     The nozzle assembly  50  is supplied via a supply hose  52 ,  60  or rigid tubing providing some structural support and positioning of the nozzle assembly  50  with respect to the web  10 . The fluid of the nozzle assembly  50  is preferably a water jet positioned to disperse the coating material without need of applying a vacuum. The fluid jet can be a stream of water, preferably a needle stream or sharp stream of water under pressure. However, one of skill in the art will appreciate that various pressures and/or combinations of water/air and spray patterns may be useful for some coatings, e.g., depending upon the characteristics of the coating such as viscosity or rheology. However, a needle stream of water directed at the edge of the web  10  in the direction of the container  40  is utilized in a preferred embodiment. 
     As aforementioned, the scraper device  30  may be used in combination with the nozzle assembly  50  and/or the vacuum container  40 . The scraper device  30  in combination with water jet  50  moves or disperses the bead of any excess coating into the receiving container  40 . In addition, the edge cleaner device is preferably provided with a moveable carriage  70  or support structure that permits movement of the edge cleaning device sideways, e.g., movable toward and away from the edge of the web, and even vertically if desired. In a preferred embodiment, the carriage  70  includes a position controller  84  and a motor  75  or other device permitting movement and positioning of the carriage  70  of the edge cleaner device. Since the edge cleaning device is sideways movable toward and away the edge of the web  10 , it can be quickly and accurately positioned relative to a wide range of sizes of coated webs  10 . In addition to the guides  48  for controlling the positioning of the moving web  10  with respect to the edge cleaner device, the present invention may incorporate other self-positioning or position control features. 
     For example, as seen in  FIGS. 3 and 4 , a positioning device  80  for detecting the position of the coated web  10  with respect to the edge cleaning device is provided in a position that allows the web  10  to pass through opposite sides  80  of the positioning device  80 . The positioning device  80  may include two or more electric eyes or sensors that are operatively coupled to the edge cleaning device. The sensors may be set so that a first beam is broken or interrupted by the web passing therebetween. A second set of sensors may be employed in an offset position that allows the beam passing therebetween to be uninterrupted when the edge cleaning device is engaged with the moving web  10 . 
     One of skill in the art will appreciate that the edge cleaning device is shown positioned in a retracted position, e.g., away from the moving edge of the coated web  10  in  FIG. 4 . A logic circuit within the controller  84  of the positioning device  80  will maintain a proper positioning of the edge cleaning device, e.g., by moving the edge cleaning device along rails of the carriage  70 , with respect to the web. The signals from the sensors of the positioning device  80  may be transferred via communication lines or cables  82  operatively connecting the controller  84  with the sensors of the positioning device  80 . In a preferred embodiment, the nozzle assembly  50 , receiving container  40 , scraper device  30  (not shown in  FIG. 4 ) and positioning device  80  are all mounted directly or indirectly to the movable carriage. Accordingly, the electronic eyes or sensors can be used to facilitate rapid and accurate positioning of the edge cleaning device and all its components with the outside edge of the moving web  14 . Since the resulting combination of components, e.g., scraper device  30 , nozzle assembly  50 , etc., is quickly and accurately positioned along the edge of the moving web  10 , the undesirable contact with the surfaces of the abradable, rubberized backing roll  20  of previous systems is effectively eliminated. Accordingly, coating processes of various webs may be scheduled in a variety of manners while effectively eliminating costly downtime to repair components, e.g., such as the replacement of the worn backing rollers  20 . 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.