Patent Application
20070004575
The present invention relates to fan-folded webs of label products such as those typically produced on high-speed narrow web presses. More particularly, it relates to a fan-folded web label product having alternately reversely indented creases defining its fold lines that are substantially, if not entirely, devoid of perforations.
Pressure-sensitive labels are typically produced in web form on high-speed narrow web presses wherein the web width typically does not exceed 18 inches. Such machines may be of the offset, rotary letter press, flexographic, or gravure type. Typically, a pressure-sensitive label product is made from a carrier or liner that comprises a continuous web of paper coated with a release agent on the top side and a face paper stock that is coated on its underside with a pressure-sensitive adhesive. These two continuous webs are laminated together with the face stock situated above the liner. The adhesive on the underside of the face paper stock contacts the release coating on the top side of the liner so as to permit the face stock to eventually be separated in the form of labels from the liner without tearing. Prior to separation, the face stock is cut into shapes by rotary dies that do not penetrate through the liner, and the waste face paper stock around the die cut is lifted from the liner to leave a series of successive labels on the liner for further disposition. The labels adhere just enough to the liner to remain attached until being intentionally and automatically separated from the liner.
Rough handling may cause the fragile labels to accidently separate and fall from the liner. This is particularly true when repositionable adhesives are used as the pressure-sensitive adhesive, allowing the labels to be attached, removed and reattached numerous times to a selected surface.
In many instances, newspaper companies are now applying labels to the front page of a newspaper edition for advertising purposes. Such labels are removable from the newspaper by the reader without damaging the newspaper. Typically, the labels are printed on a narrow web press as a web label product, fan-folded into a stack as they issue from the end of the press, and packed into a box that is in turn provided to the newspaper printing establishment. At the newspaper company, the labels are dispensed and applied automatically to the newspapers at speeds sometimes exceeding 1,000 labels per minute.
Fan-folding of webs of pressure sensitive labels is currently accomplished by cross-perforating the web to produce a line of weakness at which the fold can be made. The perforations weaken the liner sufficiently that the web will bend easily at the perforation line and permit fan-folding into the shipping container. However, that same weakened condition creates problems when the labels are to be dispensed at high speeds and applied to the moving newspapers because the perforated liner has a tendency to break at the perforations as a result of the tension and rough handling to which the web is subjected. When a break of the liner occurs as the labels are being applied to newspapers, several thousand newspapers can pass without receiving a label by the time the labeling machine is rethreaded and back in operation. Advertisers have paid for the label to be on the newspapers, but there may be many delivered to customers without the advertisements adhered to the front pages.
Labels are typically supplied to newspaper companies in fan-folded stacks rather than rolls because several fan-folded stacks can be spliced together to provide a continuous supply of labels, whereas if the labels are supplied in roll form, the machine must be stopped when it is time to replace a depleted roll with a new full roll of labels. However, modem fan-folders that produce such stacks typically operate in line with the web presses at speeds approaching 500-1000 feet per minute, and tension must be kept on the web as it leaves the press and enters the fan-folding machine. Such tension and high speed can combine to cause the cross-perforated webs to break on occasion, and it is always important that the labels be handled as gently as possible to avoid accidentally knocking them loose from the liner.
Typically, adjacent labels on the liner are separated by very narrow gaps or spaces which are many times smaller than the length of the labels themselves. Such gaps are typically no larger than 0.125 inches wide. The cross perforation and subsequent fold line must occur precisely within such spaces without damaging the labels themselves.
The present invention provides a fan-folded web of pressure-sensitive labels wherein the successive fold lines of the product are presented by alternating, oppositely indented creases in the web that are substantially, if not entirely, free of perforations. Such a product substantially eliminates the handling and breakage problems associated with conventional cross-perforated webs of labels both at the production and application ends of the process. In a preferred method and apparatus for making the product, a single rotary die station of a narrow web label press is converted into a creasing station. At such creasing station, the web that carries the pressure-sensitive labels is trained around a stack of die and base rolls in such a manner that alternating, oppositely indented creases or pre-folds are produced in the liner web at predetermined intervals along its length at the gaps between the labels without damaging or loosening the pressure-sensitive labels. Immediately following the crease-forming operations, the web can be introduced into a fan-folding machine which prepares a stack of fan-folded web product for subsequent packaging, the web being slit if necessary longitudinally as it leaves the creasing station and before it enters the fan-folding machine. In a most preferred form of the invention, no perforations at all are present in the pre-fold creases so as to provide maximum strength. However, in some instances a small number of perforations may be acceptable.
The present invention is susceptible of embodiment in many different forms. While the drawings illustrate and the specification describes certain preferred embodiments of the invention, it is to be understood that such disclosure is by way of example only. There is no intent to limit the principles of the present invention to the particular disclosed embodiments.
The web label product 11 is provided with a series of transversely extending, alternately oppositely indented creases 18 that present the fold lines at opposite ends of each ply. Creases formed by indenting the non-label side of web 11 may, for convenience, be referred to as “outside creases” while those formed by indenting the label side of web 11 may be referred to as “inside creases.” Each crease 18 is located totally within a gap or space 16 between successive labels 14 and does not encroach upon adjacent portions of labels 14. The oppositely indented nature of successive creases 18 creates in the web 11 a predisposition to fold in a zig-zag or fan-folded manner as illustrated. In a most preferred embodiment of the invention, each crease 18 is devoid of perforations, although it is possible that a small number of perforation cuts could be included within a crease or at its opposite ends without departing from the principles of the present invention, i.e. without unduly weakening the web. In such instance the crease 18 would be substantially, but not totally, devoid of perforations. For example, depending upon the tear strength of the liner 12 as influenced by its width, the size of the perforations, and the nature of the paper stock from which liner 12 is made, having from one to ten perforations that resulted in no more than about 25% of the length of the crease being devoted to perforation cuts could probably provide satisfactory results.
As illustrated in
Among other things, creasing station 34 includes a stack of four rolls comprising a lowermost die roll 36, a base roll 38 immediately above and cooperating with die roll 36, a second base roll 40 immediately above base roll 38, and an uppermost die roll 42 that cooperates with base roll 40. The entire stack is maintained in position by schematically illustrated hold down mechanism 44, as well understood by those skilled in the art. Shafts of the rolls 36-42 project through vertical slots 46 (only one being shown) in opposed sidewalls 48 (only one being shown) of the press 30. Circumferentially extending gear teeth 50, 52, 54 and 56 associated with the rolls 36-42 respectively maintain such rolls in positive synchronous relationship when driving power is supplied to one of the rolls.
In addition to rolls 36-42, creasing station 34 also includes four guide rolls 58, 60, 62 and 64. Guide roll 58 is a lead-in guide roll positioned to help guide the liner with attached labels into position between die roll 36 and base roll 38. From there the liner with its labels is looped around guide roll 60 and returned to the stack to pass between base rolls 38 and 40. Upon leaving base rolls 38 and 40, the liner with attached labels loops around guide roll 62 and returns toward the stack to pass between base roll 40 and die roll 42, whereupon it exits the stack as alternately reversely creased web label product 11 under the guiding influence of the exit guide roll 64. From guide roll 64, web product 11 passes between a pair of downstream rolls 66 and 68, at which location it may be slit longitudinally to produce two or more side-by-side, narrower web products depending upon the nature of the product being produced and the downstream fan-folding mechanism. Preferably, at least guide roll 62, and preferably both guide rolls 60 and 62, are individually adjustable toward and away from the stack using conventional adjustment means represented in part by the horizontally disposed slots 70 as illustrated in
As illustrated best in
Base rolls 38 and 40 are identical to one another but are 90° out of phase with each other as best shown in
Each of the base rolls 38, 40 is specially configured so as to have alternating regions of working surfaces and voids. In the particular embodiment disclosed herein, each base roll 38, 40 has a pair of diametrically opposed work surfaces 82 (see
The two base rolls 38 and 40 are 90° out of phase with one another so that the cushions 92 of one base roll never come into contacting engagement with those of the other base roll. It will also be noted that the lower die roll 36 and the top die roll 42 have their blades 72 disposed for contacting engagement with a cushion 92 of their cooperating base roll on every other rotation of the die roll. Thus, taking lower die roll 36 as an example, after one 360° rotation of die roll 36 from the position illustrated in
The length of the liner 12 between bottom die roll 36 and top die roll 42 is exactly twice the circumference of the die rolls 36, 42. Thus, in one exemplary embodiment, die rolls 36 and 42 each have a circumference of 12.50 inches. Accordingly, the serpentine length of the liner from lower die roll 36 around guide rolls 60, 62 and to the top die roll 42 is exactly 25.0 inches. This accommodates labels that are 3.0 inches in length and are separated by a gap or space of 0.125 inches.
As illustrated in
By using a creasing station 34 in accordance with the present invention, the label length and ply length or distance between creases 18 can be easily varied. Appropriately sized rolls 36-42 can be readily utilized and replaced at station 34, along with the necessary adjustment of guide roll 62 and also guide roll 60 if available, to provide the desired “repeat” for the creases within the web. By utilizing a stack of multiple rolls, the individual roll diameters can be kept relatively small and manageable.
After leaving the press 30, the web product 11 passes between a pair of nip rolls 96 and 98 that continue to apply tension to web product 11 before it enters fan-folding machine 32. Upon entering machine 32, the web passes through an oscillating paddle 100 that, in cooperation with a pair of oppositely disposed compression wheels 102 and 104, causes web product 11 to become fan-folded in the manner illustrated in
On the front side or upper side of peel plate 108, the web product 11 passes under an idler roll or bar 114 before moving to the peel plate edge 108a. As illustrated best in
It should be apparent from the foregoing that in one aspect the present invention provides a delicate, fan-folded, at least virtually perforation-free, pressure-sensitive label product that will withstand the rough handling commonly experienced by such products both during their production and subsequent commercial applications. Among other things, it permits the application of pressure-sensitive, repositionable labels to high-speed articles such as newspapers and the like with substantially increased reliability. In another aspect of the invention, the web creasing station that enables production of such a product requires no off-press driving mechanism since it is powered by the press itself and it has no adverse effect on the normal operation of the press. It can operate at high speeds, will not damage the labels, fits within a narrow web press rotary die station, and can be easily removed or replaced when other fan-fold lengths are desired.
The inventor(s) hereby state(s) his/their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of his/their invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set out in the following claims.
