The present invention is related to an improved method for forming a fan-folded web of labels, particularly pressure sensitive labels, with improved registration of the fold relative to the position of the labels. More particularly, the present invention is related to an improved method of forming a fan-folded web of labels wherein the formation of fan-fold creases can be correctly registered even with perturbations in the motion of the web.
There has been a long standing need for the formation of fan-folded arrangements of webs containing labels. Typically, the webs are formed with labels adhered thereto in a repeating pattern typically with a fixed frequency. The web is then passed through a creasing station wherein creases are formed in the web, between labels, and the web is folded in alternating fashion at the creases. Typically, perforations have assisted in forming a fold. Previously webs have been creased or perforated in line transversely across the web on alternating sides to form folds at the creases or perforations in alternating directions thereby allowing the fan-fold labels to be stored and boxed for transport and subsequent use. Such a web 10 is illustrated in FIG. 1 with labels 12 and folds 14 being placed in bin 16.
To ensure the creases, and therefore folds, are correctly registered between labels the mechanism for transporting the web through the crease station has been mechanically coupled with die rolls thereby insuring that any fluctuation in speed of the web, the length of the labels or the web tension will be in concert with the rotation of the die rolls. An exemplary teaching of such a machine is described in U.S. Pat. No. 7,762,939.
While the in-line machines currently available in the art have enjoyed much success in commerce they still have certain deficiencies in flexibility which have become accepted.
In spite of the relative success of web creasing machines for formation of fan-fold webs the art still has a strong desire for an improved design which will advance the art of fan-folding webs of material, particularly, webs comprising labels such as self-adhesive or pressure-adhesive labels.