US-12623249-B1 - Coating and curing a protective layer on large format printed graphics

US12623249B1US 12623249 B1US12623249 B1US 12623249B1US-12623249-B1

Abstract

A device and method for coating and curing a protective layer on large format graphics comprises a roll-to-roll machine having a coat stage and a cure stage. A roll of printed web material turns about a load reel, passing through the coat stage and cure stage, and is wound around a finish reel. The load and finish reels may be driven by servo-motors. The coat stage comprises a coat pan which is partially filled with coating liquid and a Mayer bar for removing excess coating liquid. The cure stage comprises a light source and a plate. One or more devices, such as idler rollers, dancer rollers, stationary rollers, or load cells, are placed between the load and finish reels to control the path, tension, and speed of the web material.

Inventors

Glenn Tomkins
Hayes Holzhauer
Brian Buisker

Assignees

Glenn Tomkins
Hayes Holzhauer
Brian Buisker

Dates

Publication Date: 20260512
Application Date: 20231018

Claims (15)

1 . A liquid film coating machine comprising: a load reel set upon a core housing a webbing material, feeding the webbing material downwards towards and below a containment roller, said webbing material fed upwards into a coating station and over a coated roller; said coating station comprising a sprayer set between said containment roller and said coated roller said sprayer set above said webbing said sprayer adapted to spray downwards; and further comprising a metering bar set between said sprayer and said coated roller, whereby said metering bar presses downwards and forwards on the webbing within the coating station; a curing station receiving the webbing past the coating station, said curing station comprising a source of light and a plate, wherein a top of the coated roller is aligned with the plate such that the webbing may be fed horizontally from the top of the coated roller to the plate; and a finishing roller receiving webbing past the curing station into a finish reel, said finishing roller having a top aligned with the plate to receive the webbing horizontally thereover.
2 . The liquid film coating machine of claim 1 further comprising a servo-motor unrolling the load reel.
3 . The liquid film coating machine of claim 2 further comprising a second servo-motor pulling taught the finish reel.
4 . The liquid film coating machine of claim 2 further comprising a dancer set between the curing station and the finish reel.
5 . The liquid film coating machine of claim 1 further comprising an idler bar set between the coating station and cure curing station.
6 . The liquid film coating machine of claim 1 further comprising a brake coupled to the load reel.
7 . The liquid film coating machine of claim 1 wherein said sprayer comprises an array of sprayers set in a line transverse a direction set between the load reel and the finish reel.
8 . The liquid film coating machine of claim 7 wherein said array of sprayer is offset from perpendicular from the webbing.
9 . The liquid film coating machine of claim 1 wherein twenty to thirty degrees of a circumference of the metering bar is exposed to the webbing.
10 . The liquid film coating machine of claim 9 wherein twenty-five degrees of a circumference of the metering bar is exposed to the webbing.
11 . The liquid film coating machine of claim 1 wherein a distance between a center of the containment roller and a center of the metering bar is one-and-a-half inches to five-point-nine inches.
12 . The liquid film coating machine of claim 11 wherein a distance between a center of the containment roller and a center of the metering bar is 2.97 inches.
13 . The liquid film coating machine of claim 1 wherein the metering bar has a diameter within 50% to 200% of one-and-a-half inches.
14 . The liquid film coating machine of claim 13 wherein the metering bar diameter is one-and-a-half inches.
15 . The liquid film coating machine of claim 1 wherein a center of the metering bar is positioned below a center of the coated roller and a top of the metering bar is set below the center of the coated roller.

Description

CLAIM OF PRIORITY The present continuation-in-part application includes subject matter disclosed in and claims priority to patent application Ser. No. 18/216,472 filed Jun. 29, 2023, and entitled “Coating and Curing a Protective Layer on Large Format Printed Graphics”, and provisional application Ser. No. 63/336,628 entitled “Coating and Curing a Protective Layer on Large Format Printed Graphics” filed Apr. 29, 2022, both describing inventions made by the present inventor, and herein incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to web printing, and more particularly to a method and apparatus for coating printed rolls of large format images with a protective coating and curing. 2. Description of Related Prior Art Large format graphics include signage placed on trailers of semi-trucks, vehicle wraps, wall murals, wallpaper, posters, and event banners. The graphics are printed using inks or dyes on large rolls of web material, such as paper, fabric, or vinyl. Large format graphics processes are also used to simultaneously make many smaller impressions, such as food container labels. After the labels are printed, they are cut out of the web to the desired smaller size. Often the graphics are used outdoors and exposed to the sun's ultraviolet rays, frigid and boiling temperatures, precipitation, and a wide range of humidity. To protect the graphics from fading and degrading, a protective layer is often applied on top of the printed web. Similarly, food labels are exposed to harsh environments and a protective layer is applied. In addition to protection from environmental damage, food labels have to be coated to protect the food and food handler in case of accidental contact with the food. Wallpaper used for commercial interiors such as hallways and common areas are often coated with a protective layer, too. Typically, large format graphics are printed using a web or roll-to-roll process, the benefits of which includes high output rates and long rolls of product enabling larger signs. The leading edge of a large roll of web material is fed into a roll-to-roll machine, which unrolls the web material from a first reel as it is continuously printed by digital, screen printing, or flexographic methods. The printed web material is continuously re-rolled onto a second reel. The printed web material is then ready for a protective layer. To apply the protective layer, the leading edge of the second reel is fed into a separate roll-to-roll machine. The protective layer is applied by one of several methods, including laminating a coating to the printed web material by heat, pressure or adhesive; screen printing a protective layer; or roll-coating the protective layer. These processes, however, are relatively slow due to the cure or dry time of the protective material. In addition, while a laminating process creates a smooth surface, the screen printing and roll-coating methods leave a tell-tale surface pattern, which can detract from the underlying image. It would be desirable to apply a smooth protective coating to a large format printed web material quickly, which increases the volume of production possible in a given amount of time and lowers the cost. Large format graphics are often installed by applying the printed image to a desired object by adhering the back of the graphic to the surface of the object. Adhered graphics can be removed, leaving the original surface in good condition for applying another graphic. The case of application and removal is dictated by several factors, including the type and thickness of the web material. Graphics made from a thin web material tends to fold upon itself, making installation tricky. Thin graphics tend to peel off in tiny pieces, making removal tedious. Graphics with thicker web material are easier to install and remove but are more difficult to process. It would be desirable to manufacture graphics using thicker web material yet maintain higher production speed and quality. It is therefore a primary object of the present invention to provide a coating system and method. These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds. SUMMARY OF THE INVENTION The present invention is directed to a device for coating and curing a protective layer on large format graphics comprises a roll-to-roll machine having a coat stage and a cure stage. A roll of printed web material turns about a load reel, passing through the coat stage and cure stage, and is wound around a finish reel. The load and finish reels may be driven by servo motors. The coat stage comprises a coat pan which is partially filled with coating liquid and a Mayer bar for removing excess coating liquid. The cure stage comprises ultraviolet LEDs and a cover to limit the escape of the UV rays. One or more devices, such as idler rollers, dancer rollers, stationary rollers, or load cells,