Paper making and fiber liberation – Processes and products – With cutting and/or slitting
Reexamination Certificate
1999-11-23
2002-05-21
Chin, Peter (Department: 1731)
Paper making and fiber liberation
Processes and products
With cutting and/or slitting
C162S286000, C162S193000, C226S109000
Reexamination Certificate
active
06391157
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119 of German Patent Application No. 198 56 277.2, filed on Dec. 7, 1998, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a device for producing a paper web which incorporates a paper machine and at least one refining device. The invention also concerns a process for producing a paper web in which the paper web is formed in a paper machine and is cut into longitudinal strips, and refined.
2. Discussion of Background Information
Paper webs are being produced in ever increasing widths. In fact, the use of paper machines with working widths of less than 6 meters are becoming very rare. At the same time, paper webs are also being produced at increasingly higher speeds. For example, modern paper machines typically run at speeds greater than 1000 m/min. Even speeds of 2000 m/min. are being attempted. These ever increasing speeds can cause significant problems in the further refining of the paper web. At this point it should be noted that the term “refining” is intended to signify processing steps which change the quality or the properties of the web. Refining is typically performed by devices such as calenders, glazers, coaters, wetting machines, dryers, and the like. This is to be contrasted with simply winding the paper web, for example, which does not have a refining effect.
Current processes for guiding such wide and fast-moving paper webs through calenders, coaters, or other processing or refining machines require a considerable expenditure of equipment and time as well as sophisticated control technology. Moreover, it has been found that the more complex the control, the more difficult it becomes to make changes in the path of the web.
SUMMARY OF THE INVENTION
The invention therefore provides for increased flexibility in the production of paper.
This is accomplished with a device similar in general to the type mentioned in the introduction which also utilizes a web cutting device located at the outlet of the paper dispenser.
A raw paper web is initially cut into several strips that have smaller widths than the raw web. These strips may have any desired width. It has been discovered that these narrower strips are easier to handle when being processed or refined, especially when they are handled at the typical running speeds disclosed above. Accordingly, because of this ease of handling, these narrower strips can be guided more effectively, which allows for flexibility in designating different web paths. Moreover, providing different paths for processing the strips means that it is no longer a requirement that all the strips be further processed or refined in the same manner. Consequently, even when using the more efficient wide paper machines, it becomes possible to manufacture paper in smaller lot sizes, with the desired quality characteristics.
Another advantage to processing these narrower strips is that it is possible to keep the properties of a narrower paper web more constant across their widths. Accordingly, the quality of the paper webs produced in this way can be improved. Although the longitudinal cutting of paper webs is already known per se, this cutting has conventionally only occurred as the last step in the production process, i.e., typically just before the winding of the paper webs into marketable reels. Thus, the conventional paper web underwent all refining and processing across its entire width prior to it being cut into strips. Processing paper in the way requires sophisticated and expensive handling, which can be avoided by simply placing the cutting before the beginning of the “refining” as per the instant invention.
Of course, the invention contemplates the use of, many identical processing machines, such as calenders or the like for the actual refining. The use of standard machines with standard processing widths is also contemplated. One advantage of the smaller standard machines is that they are delivered fully assembled. Another advantage is that they consume less energy. In certain circumstances, it may even be possible to guide several paper web strips next to each other through a common refining machine.
The present invention can also provide a turning arrangement which essentially causes a directional change in the plane of the paper web. This turning arrangement is located downstream from the longitudinal cutting device. With such a turning arrangement, it is possible to direct the paper web strips for further processing by machines which need not necessarily be located in a straight line with respect to the paper machine or raw paper dispenser. Such an arrangement allows for greater flexibility in the use of production facilities and equipment layout. It may also be desirable to deviate from the typical path of web travel, i.e., horizontal, so that the strips may be turned, e.g., upward or downward. However, such web paths may require a relatively tall structural height of the manufacturing building or deep basements if a plurality of processing machines are to be arranged, for example, one above another. However, when an essentially horizontal path is utilized, i.e., the typical plane of the paper web, the downstream machines can then be arranged on the same “level.”
Ideally, the output direction of the turning arrangement should be variable, i.e., the angle of the turning is adjustable. The turning arrangement can function as a sort of “switch”, which can turn the paper web selectively in one of a plurality of output directions. Accordingly, the paper web would then be allowed to pass through one of a plurality of processing devices or machines.
In a particular embodiment, processing devices of at least two different types are utilized and located downstream from the turning arrangement, in the desired direction of travel of the narrower strips. This would allow each of the longitudinal strips to be processed in at least two different ways, for example. One could control the type of processing the strip will experience by the selected output direction of the turning arrangement. Such a design would permit very flexible adaptation of paper web strip processing.
In the exemplary embodiment, a first group of processing devices is arranged in a first direction downstream from the turning arrangement and a second group of processing devices, also arranged downstream from the turning arrangement, in a second direction. This design would permit, for example, the processing of all strips in the same type of processing devices, if so desired. Additionally, this design allows for the guiding of individual paper web strips in other directions, upon leaving the turning arrangement, and accordingly, allows for processing the strips differently by simply turning them in the direction of the processing type.
Moreover, a third group of processing devices can also be arranged in a third direction downstream from the turning arrangement.
For the sake of simplicity, the term “turn” should be broadly construed to mean that the paper web strips can also run in a straight line through the turning arrangement, i.e., the turning arrangement can be set to allow for straight through processing. It is possible to arrange a plurality of different groups of processing devices, for example, calenders, coaters, or winders, downstream from the turning arrangement. The invention contemplates a relatively large matrix of potential applications and downstream equipment layouts.
As explained above in connection with the device, the process provides for further processing the relatively narrow paper web strips efficiently. This is because the handling of narrower strips makes for a simpler process.
The invention provides for the paper web to be cut into longitudinal strips at the output of the paper machine. After they are cut, the strips are available for turning and further processing.
The “outlet” of the paper machine, as this term is used here, is intended to mean
Chin Peter
Greenblum & Bernstein P.L.C.
Hug Eric
Stora Publication Paper AG
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