Plastic and nonmetallic article shaping or treating: processes – With measuring – testing – or inspecting
Reexamination Certificate
1999-10-29
2001-11-27
Tentoni, Leo B. (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
With measuring, testing, or inspecting
C100S038000, C100S043000, C100S334000, C162S206000, C264S288800, C264S289600
Reexamination Certificate
active
06322732
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to apparatus and methods for finishing paper (or other materials) from multiple webs and in particular to registering, or matching, paper which has been preprinted by heating and reforming one or more of the webs.
BACKGROUND OF THE INVENTION
Many characteristics of paper conventionally employed in printing processes are unstable. One set of such characteristics is the dimensions of the paper, and in particular the length and width. These dimensions change as functions of heat, moisture, and tension, for example, creating potential difficulties in registering repeated patterns appearing on two or more webs which, at some point, have been processed differently.
Historically, dimensional instability of paper has not caused any significant problem for the printing industry. This is because the problem largely can be avoided merely by simultaneously printing and finishing multiple webs, thereby subjecting the webs to essentially the same heat, moisture, tension, and other environmental and equipment-related factors. A recognized drawback, of course, is the limited number of colors available to printing on the webs, as use of the available print stations must be divided to service the two (or more) webs.
Prior attempts to resolve this issue have involved continual varying of the tension on the webs throughout the finishing line. In other words, variably-increased tension is applied throughout the process to cause the shorter or narrower patterns on the webs to match the longer or wider ones. While theoretically capable of matching certain characteristics of webs, these tension-oriented attempts typically have been disadvantageous, in that they disrupt aspects of the finishing process such as (but not necessarily limited to) folding, gluing, and die-cutting of the webs.
SUMMARY OF THE INVENTION
The present invention, by contrast, overcomes the limitations described above without resort to continual varying of the tension on one or more webs for purposes of matching the lengths and widths of aspects of multiple webs. Instead, the invention utilizes heat to reform smaller webs at desired dimensions. Although usually coupled with an initial increase in the tension of the smaller web, unlike prior efforts such increased tension is not required throughout the finishing process and, in some cases, is not required at all.
Once reformed, the paper or other webs usually retain their increased dimensions for a period sufficient to complete the printing and finishing processes. As a consequence of employing the present invention, therefore, papers of different types may be utilized as the multiple webs yet still have substantially-identical repeat lengths. Printing, furthermore, may occur at a time or location (or both) remote from the finishing line, thus avoiding any need to divide available print stations in order simultaneously to print multiple webs. Indeed, certain registration-related printing errors can be corrected through the present invention, thus relaxing the specifications of repeat lengths and other parameters which the printing must meet. Likewise advantageous is that any tension adjustments to the webs after reformation may be made simply to facilitate the finishing processes, rather than to maintain printed matter in registration.
In some embodiments of the invention, feedback loops also are used beneficially during the initial reformation. Such feedback typically results from monitoring the dimensions of the multiple webs and can be used to adjust the tension present on one or more of the webs. If registration of printed matter does not occur through mere initial tensioning of the webs, information from the feedback loop can be used to activate heaters to facilitate the paper-reformation process.
It thus is an object of the present invention to provide apparatus and methods of matching multiple webs.
It also is an object of the present invention to provide apparatus and methods of registering printed matter on multiple webs of paper through use of heat to reform dimensions of one or more of the webs.
It additionally is an object of the present invention to provide registration techniques not dependent on continual varying of tension on webs to change their lengths and widths.
It is another object of the present invention to permit pre-printing of webs, thereby avoiding any need to divide available print stations in order simultaneously to print multiple webs.
It is a further object of the present invention to provide apparatus and methods permitting employment of different types of paper yet maintaining ability to register their repeat lengths.
It is yet another object of the present invention to monitor characteristics of webs under tension and employ feedback loops to adjust that tension and, possibly, to activate heaters whose heat will be incident upon the webs.
Other objects, features, and advantages of the present invention will be apparent with reference to the remainder of the text and the drawing of this application.
REFERENCES:
patent: 4712686 (1987-12-01), Lancaster et al.
patent: 5483873 (1996-01-01), Koivukunnas et al.
patent: 6003440 (1999-12-01), Koskinen et al.
Bowen Reed
Leidig, Jr. Daniel Winfield
Dittler Brothers Incorporated
Kilpatrick & Stockton LLP
Russell Dean W.
Tentoni Leo B.
LandOfFree
Method for finishing pre-printed paper from multiple webs does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for finishing pre-printed paper from multiple webs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for finishing pre-printed paper from multiple webs will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2590288