Patent Application
20120297993
The present invention generally relates to a perforation process of IOD (inline offset die-cutting) and/or perf jackets, which are used in the offset printing industry. More particularly, but not exclusively, the present invention relates to an in-line perforating process and perforation material for same.
The background of the invention is discussed in the context of offset printing presses and more specifically IOD (inline offset die-cutting) utilized on offset printing presses. Offset printers are very often utilized to produce printed material requiring perforating, cutting or creasing. Printed material may include checks or advertising material such as coupons. A perf jacket or plate creates perforations, cuts or creases on paper as the paper passes over an impression cylinder so that the printed material may be easily separated. Presently, perf jackets and plates are chemically-etched, machined, flexible dies produced by third party manufacturers. The present invention is not to be limited to this specific context.
A large number of printing presses presently use perf jackets. A jacket is attached to an offset press by jacket bars. A specific design is configured and sent to a third party manufacturer, who chemically etches the design onto one or more jackets and who also attach the jacket bars to the jackets. One jacket is needed for smaller project, but two jackets are used together in larger-sized perforating projects, such as when the projects are plate-sized. However, the third-party perf jackets are expensive. The design must be sent to a third party, who then must perform the chemical etching before mailing or returning the finished product. In addition, the price charged for producing the perforated materials is usually less than the cost of producing the perf jacket. Therefore, the cost and amount of time it takes to produce the perf jackets results in lost money by a printing press business.
In newer printing presses using in-line coating units, plates are used instead of the jackets. The plates allow for easy access to the presses, which reduces the set-up time for a printing or perforation process. The plates are made into perf plates for creating perforations or creases in printed materials, similar to the perfjackets. The plates are produced by a third party, similar to perf jackets. The third party chemically etches the design on the plates in a foreign country, which adds to the amount of time it takes to receive a perf plate. However, the cost to produce perf plates is extremely high, and the process generally takes more than four days.
Prior to the plate-making process, digital files are arranged on a computer in such a way as to maximize the use of the sheet of paper being used. This process is called imposition. Digital files must be imaged onto printing plates. Information from digital files is transferred to printing plates in much the same way as digital photographs are imaged. When exposed to light, a chemical reaction occurs that activates an ink-receptive coating on the printing plate. This results in the transfer of the digital image onto the plate. This process is known as the computer-to-plate (CTP) process.
There are different materials for printing plates, including aluminum and polyester. The best plate material is aluminum, which is more costly, but provides the quality and durability necessary to produce high-quality offset printing. Each of the primary process colors: black, blue, red, and yellow have a separate printing plate. This is known as the four-color or CMYK printing process.
As a sheet of paper is fed into the printing press, it will move through a series of rollers and blankets where the ink is transferred onto the paper. A four-color press will have 4 or more printing units which have separate sets of rollers and blankets for each color. As the press sheet moves from one unit to the next, another color will be transferred to the sheet of paper. A perf plate may be used on any of the printing units as needed.
The press sheet is left slightly damp by all of the ink and water being applied to it. At this point in the process, there is a risk of the ink smudging. Smudging is minimized by applying a water-based coating to the press sheets. This coating is called an aqueous coating, and the coating may be either a glossy coating, or a dull coating. Once the coating is applied, the press sheets move through an infra-red dryer. Heat from infra-red radiation is used to quickly dry the ink and coating, so that smudging does not occur.
Each perf plate is made from a similar digital file as used to image each color plate, and indicates the perforation, cuts or crease locations. A few benefits of using each IOD (inline offset die-cutting) perf jacket or perf plate simultaneously on an offset printing press or coater is to print and cut in a single operation at normal press speeds which reduces delivery periods, allows reuse of the flexible dies, and accords optimum flat sheet alignment after finishing.
There are also disadvantages to using IOD (inline offset die-cutting) or perf jackets simultaneously on the sheet-fed printing press or coater. A few disadvantages are the time to manufacture each IOD (inline offset die-cutting), perf jacket or perf plate and the high cost when processing small printing jobs. Also, the IOD (inline offset die-cutting) or perf jacket requires manual alignment by a technician after installation.
What is needed is an apparatus and method for producing an in-line perforation, cutting or creasing device and perforating, cutting or creasing process for same having the advantage of being less expensive and having a shortened time to manufacture.
Therefore, it is a primary object, feature, and/or advantage of the present invention to improve over the state of the art.
It is another object, feature, and/or advantage of the present invention to provide an improved method for producing a perf jacket for use with offset printing presses.
It is yet another object, feature, and/or advantage of the present invention to provide an improved method of producing a perf jacket that is less expensive and time consuming.
It is a further object, feature, and/or advantage of the present invention to provide a perforation plate which utilizes a standard printing plate.
Another object, feature, and/or advantage of the present invention is to provide a perforation plate which utilizes standard printing plate and that is less expensive to create.
One or more of these and/or other objects, features, or advantages of the present invention will become clear from the specification and claims that follow. No single embodiment need exhibit each and every object, feature, or advantage.
According to one aspect of the present invention, a method of making a perf plate for producing perforations in a sheet of paper in an offset printing press is provided. The method includes creating an image. At least one perf rule guideline is printed on a printing plate according to said image. Finally, a perf rule is applied onto the at least one perf rule guideline.
According to another aspect of the present invention, a method of perforating a sheet of paper in an offset printing press is provided. The method includes producing a perf plate by creating an image in a desktop publishing application, printing the image onto a printing plate to create perf guidelines, and applying at least one perf rule to the perf guidelines. The perf plate is operably attached to a combination plate and blanket cylinder in line of an offset printing press. A sheet of paper is passed through the offset printing press such that the perf plate contacts the sheet of paper to produce perforations therein.
According to yet another aspect of the present invention, a method of making a perf jacket for producing perforations in a sheet of paper in an offset printing press is provided. The method includes creating an image. At least one perf rule guideline is printed on a printing plate according to said image. A perf rule is applied onto the at least one perf rule guideline. Finally, plate bars are attached to opposite ends of the printing plate, the plate bars configured to operatively attach to a blanket cylinder of a printing station of a printing press.
Presently, die-cutting, perforating, cutting or creasing directly on the offset printing press system 10 is facilitated using an IOD (inline offset die-cutting) perf plate 30 (refer to
Another method presently used for perforating, cutting or creasing in a single operation involves securing perf rule 44 to a carrier sheet 38 (refer to
The preferred embodiment utilizes a standard printing plate 46 to create a perf plate 48. As with the creation of a printing plate 46, the location for the perf rule 44 is imaged onto the printing plate 46 and visible guidelines 50, as shown in
An example of the process of preparing a perf plate for producing perforations in a sheet of paper in an offset printing press will now be described in more detail. While the specific steps and equipment are mentioned, it is contemplated that any such equipment for performing the steps is part of the present invention. Before any steps in the pressroom, the follow steps occur to create a printing plate having perf guidelines to attach the perf rules to:
After the perf guidelines are printed onto a standard printing plate, the perf rules can be applied to the plate to complete the perf plate. To aid in these steps, additional supplies may be useful. For instance, a rule cutter will aid in cutting many pieces of perf rule the same size quickly. An optivisor (5× or smaller) will give clear magnification for the perf rule that needs ground out and to cut miters for corners in the form. A high speed engraving tool such as a Presto turbo grinder available from NSK America, 700 B Cooper Court, Schaumburg, Ill. 60173, having 1/16 inch burrs may be used for precision work. Finally, it is beneficial to have a well-lighted area with a work bench and a light table or solid table. To attach the perf rules to the printing plate, the following steps may be completed:
Once all the steps of the example have been completed, the perf plate has been prepared and is ready to attach to an impression plate. However, it should be noted that the example given is merely an exemplary method to complete the process of making the perf plate, and that any number of variations or steps are included within the scope of the present invention. For example, different programs, machines, and tools may be used, and different methods may be used to attach the perf rules to the plates.
The plate 102 of the perf jacket 100 of the present invention generally comprises aluminum. A preferred size of the plate 102 is 35.5 inches in length by 40.5 inches in width. The wider plate is more desirable than the standard width of jackets because currently, two jackets must be used together to provide the same or approximately the same width as a plate. It can be extremely difficult to make sure that the two jackets are perfectly aligned to produce the desired perforation or crease in the printed material. Having only one plate also decreases the cost of the jacket. However, it should be appreciated that the plate 102 used in the perf jacket 100 may be the same plate as the standard printing plate 46 discussed above. The main difference will be that the plate 102 used with the perfjacket 100 will not have the notches or cutouts along the edges of the plate, and instead will be a generally straight-edged rectangular piece of material.
The first step of producing the perfjacket 100 is to print guidelines 106 on the plate 102. The guidelines 106 are printed on the plate 102 using the same method as described above. Namely, an image is created using a desktop publishing program or application. The image is a collection of guidelines to lay out exactly where the perf rules will be positioned on the plate 102. An output file of the image is then sent to a printer, which “prints” the image or guidelines 106 onto the plate 102. Once the guidelines 106 have been printed onto the plate 102, the desired perf rule 108 is added to the plate. The location of the perf rule 108 is designated by the guidelines 106. For instance, the perf rule 108 should preferably be affixed to the plate directly in the center of the guidelines 106. The perf rules 108 are attached to and affixed to the plate 102 in the same manner as was described above regarding
Finally, the plate bars 104 are attached and affixed to opposite ends of the plate 102. The plate bars 104 may be standard bars used with blanket cylinders that allow the bars to attach to the cylinders. In addition, while different brands of presses use different sizes and shapes of bars, it should be appreciated that the present invention is to be considered universal in that any particular bar used with any particular press may be added to the perf plate 102 to produce the perf jacket 100 of the present invention. While generally printing press bars are made of a metal, such as aluminum, it should be appreciated that any other rigid material may be used to make the bars. The bars need only be strong enough to be affixed to the plates and to not break when in use with the press. However, it is preferred that the bars have a width of ⅝ inches, and a length of 41 inches. Therefore, the bars will be approximately 0.5 inches longer than the width of the plate 102, which allows the bars to extend on each side by approximately 0.25 inches.
The bars 104 may be attached or affixed to the perf plate 102 in many different ways. For instance, as shown best in
The bars 104 may be attached to the plate 102 in any number of ways, however. For instance, the bars may be attached to the plate by high frequency welding, spot welding, strong adhesives such as a glue or epoxy, screws or bolts, rivet and rivet gun, friction fit, tape, staples, arc welding, solid-state welding, gas welding, resistance welding, or any other manner that will keep the bars 104 affixed to the plate 102. Once the bars 104 have been attached to the plate 102, the resulting perfjacket 100 may be attached to a blanket cylinder 24 of a printing press system to create the desired perforations or creases. By producing the perfjackets in the manner described and shown in
An example of the process of preparing a perfjacket for producing perforations in a sheet of paper in an offset printing press will now be described in more detail. While the specific steps and equipment are mentioned, it is contemplated that any such equipment for performing the steps is part of the present invention.
The invention has been shown and described above with the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. The present invention is not to be limited to any specific embodiment described herein.
