Process and apparatus for making individually packaged disposable absorbent articles

Abstract

The present invention relates to a process for manufacturing disposable absorbent articles, typically sanitary napkins or pantiliners, which are individually packaged in a bag or pouch. The articles are directly attached to the wrapper material forming the bag or pouch by means of their panty fastening adhesive. The articles are cut from a continuous layered structure, and the cut is made directly through the layer of panty fastening adhesive applied onto the outer surface of the continuous layered structure. The present invention also relates to an apparatus for performing the process.

Description

[0001] The prior art teaches numerous variations of and elements in addition to the basic absorbent core, topsheet and backsheet arrangement, with each variation or additional element being directed to improving a specific characteristic of the disposable absorbent article. [0002] While there are a great many variations in the specific structural features of disposable absorbent articles, they are frequently presented to the consumer in the same manner. Essentially, the disposable absorbent article, irrespective of what specific structural features are used, is packaged in a box or bag from which the consumer withdraws the article as needed. [0003] The problem of protecting the disposable absorbent article once it is removed from the package in which it is sold has been addressed in the prior art. Catamenial pads, for example, are commonly packaged individually and sold to the consumer in some sort of container, typically a bag or box, which holds a convenient number of the individu...

AI Technical Summary

Benefits of technology

[0004] U.S. Pat. No. 4,556,146 entitled Individually Packaged Disposable Absorbent Article discloses a disposable absorbent article, such as a catamenial pad, associated with a wrapper which overlays one major surface of the catamenial pad, and is releasably attached thereto, typically by means of the catamenial pad panty fastening adhesive. The wrapper is larger than the external perimeter of the disposable absorbent article, so that when the disposable absorbent article and the wrapper are folded as a unit, typically around two fold-axes, the respective longitudinal side flaps of the wrapper may be frangibly sealed together along common longitudinal edges, thereby providing the disposable absorbent article with an individual package. Preferably, the disposable absorbent article is releasably attached directly to the wrapper by means of its panty fastening adhesive element, thereby eliminating the need to provide a release paper.

[0006] From a process point of view, the adhesive coating can be actually applied to the release paper, and then transferred to the backsheet of the disposable absorbent article by joining the release paper in the desired position to the backsheet, before formation of the individual package, which can be performed either according to WO 94 / 14396, or according to U.S. Pat. No. 4,556,146, both documents as mentioned above. In the latter case, the release paper has to be permanently attached to the wrapper material before formation of the individual package. Alternatively, direct application of the adhesive coating onto the backsheet in the desired pattern can be provided, with subsequent joining of the absorbent article to the wrapper material, which eliminates the need of a separate release paper, simplifies the process and saves material. This method is particularly suitable for the individually packaged disposable absorbent article according to U.S. Pat. No. 4,556,146.

[0008] It has been discovered that in disposable absorbent articles, particularly of the thin type such as thin sanitary napkins and pantiliners, the coverage of the panty fastening adhesive onto the backsheet should be preferably extended substantially to the whole surface of the backsheet intended to get in contact with the undergarment in use, or at least to portions of the outer perimeter of the article, preferably those portions extending along the longitudinal edges of the disposable absorbent article. This is advantageous in terms of stability during use of the article, which in turn is capable of staying in place in the crotch area of the undergarment, where it has been applied by the user, more effectively withstanding the stresses and tensions induced by the user's movements.

[0010] It has been surprisingly discovered that the problem of providing in a reliable and simple way individually wrapped disposable absorbent articles where each article is releasably attached to the wrapper element without the need of a release paper, and moreover where the panty fastening adhesive extends along at least part of the outer perimeter of each individual disposable absorbent article, can be solved by combining in a process for providing release paper-free, individually wrapped disposable absorbent articles, the direct application of the adhesive for panty fastening onto the backsheet layer in a continuous web-like layered structure from which the individual disposable absorbent articles are to be formed, and the cutting of the individual disposable absorbent articles from the continuous web-like layered structure at least partially through the adhesive layer, at least along the portions of the outer perimeter where the adhesive must be present. Direct cut through the adhesive layer without adhesive sticking and build up on the cutting implement is done by applying the technique of cutting with a knife which is internally cooled.

Problems solved by technology

On the other hand, according to the known technique, a patterned coating of adhesive which is exactly registered with at least part of the outer perimeter of a disposable absorbent article is not practically feasible, either when the coating is applied before or when is applied after the single disposable absorbent article has been formed from a continuous web-like structure by cutting it along the desired outer perimeter.

As it is known in the art, this leads to adhesive sticking to the knife implement, with obvious problems of adhesive build up on the knife and unreliability of the process.

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