Prefolded Disposable Diaper

Abstract

A disposable diaper of substantially rectangular configuration folded in half transversely across its major length dimension, and having selected portions of the diaper which would ordinarily fall along the transverse mid-line on either side of a longitudinal centerline tucked into the interior of the diaper to form a centrally disposed substantially triangular pocket. The pocket is maintained by adhesively attaching together interior surface areas which are in face-to-face contact in the tucked-in portions.

Description

BACKGROUND OF THE INVENTION

Disposable diapers being sold to the consumer are prefolded in a number of ways in an attempt to provide the user with a style which readily fits around the child, especially in the interior leg area, to ward off leakage while maintaining a centrally depending pocket to entrap excrement. The most sophisticated of these folded styles enable the mother to obtain a neat close fit merely by positioning the diaper in place on the child. However, because the prior art folds are not all directly parallel to, or perpendicular to, the length of the diaper, complex mechanical motions are required to obtain the folds and it is therefore necessary to design elaborate and costly machinery to mass produce such diapers. Exemplary of one such style, is the diaper shown in Hrubecky U.S. Pat. No. 3,196,874 in which a set of complicated infolds and outfolds provide a substantially triangular-shaped contoured diaper with a centrally disposed pocket and leg-hugging side portions. It would be desirable to be able to make a somewhat similarly contoured diaper with less complicated folds, and yet provide many of the advantages obtained by the more sophisticated style of the prior art diapers mentioned.

The present invention is directed toward such a diaper, having a very simple fold construction which automatically provides a centrally disposed pocket, and which requires only a minor rearrangement of the side edges by the user to provide a good leg-hugging contour when applied to the child.

BRIEF DESCRIPTION OF THE INVENTION

According to the invention there is provided a disposable diaper of substantially rectangular configuration in its flat form with a major and a minor length dimension and being comprised of the usual multilayered structure, i.e., a main pad of absorbent material, a fluid pervious facing sheet, and a fluid impervious backing sheet. The rectangular diaper is folded in half transversely across its major length dimension with the pervious facing sheet on the inside. Portions of the diaper located on each side of the mid-point of the transverse fold line are tucked into the interior of the diaper by means of inward folds away from the transverse fold line to form a substantially triangular pocket centrally disposed within the folded diaper. This provides a pair of adjacent interior folds and four diagonal exterior folds. The adjacent internal edges of the interior folds formed by the tucked in portions are vertically inclined from the pocket base and may be substantially parallel to each other in the interior of the diaper in the longitudinal direction but may also diverge outwardly from the longitudinal center line, if desired. In the folded diaper, these internal edges may end up in contact with, or slightly spaced from each other, and may define either a narrow or wide pocket base at the transverse fold line, depending upon where the starting points for the inward fold lines are located with respect to the mid-point of the transverse fold line. The external edges of the exterior folds formed by the tucks extend diagonally from their starting points on the transverse fold line to the sides of the diaper short of the ends. The external edges of the exterior fold, the internal edges of the interior folds and the side edges of the diaper which are tucked in thus form the sides of four matched triangular panels having their surfaces in face-to-face association. Interior surface areas of the triangular panels defined by the edges of these interior and exterior folds of the infolded portions are fastened to surface areas of adjacent panels and serve to maintain the prefolded contour of the triangular shaped central pocket after the diaper is partially unfolded for use. When the partially unfolded diaper is applied to a child the outer sides of the diaper terminating at the top of the pocket are preferably first folded downward by the user in order to provide a better leg fit at the diaper sides.

The above features and other advantages of the invention will become apparent by reference to the following specification and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a plan view of a flat rectangular diaper suitable for folding in accordance with this invention, with a corner portion cut away.

FIG. 2 is a partial section taken along line 2--2 of FIG. 1.

FIG. 3 is a perspective view of the diaper of FIG. 1 showing the diaper partially folded along the dotted lines shown in FIG. 1.

FIG. 4 is a plan view of the completely folded diaper of FIG. 3.

FIG. 4a is a stylized section taken along line 4a--4a of FIG. 4.

FIG. 5 is a plan view of a modified diversion of a completely folded diaper.

FIG. 6 is a transverse section of a flat diaper showing a modified version of the internal structure of the absorptive pad before folding.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 there is shown a plan view of a disposable diaper 20 of conventional rectangular construction in its flat form before folding and with portions cut away to show structural elements. The elements of the diaper comprise an absorbent pad 21, a fluid pervious cover sheet 22, and a fluid impervious backing sheet 23, the latter usually being a thin flexible film such as polyethylene. FIG. 2 illustrates in partial section a conventional internal construction with impervious film 23 wrapped around the edge of pad 21 and sealed to the bottom edge of fluid-permeable cover sheet 22.

The elements shown are all the conventional ones commonly used in disposable diaper construction and the present invention does not reside in this generally old structure. The novel concept in this invention is the provision of a special fold arrangement in conjunction with suitable attachment means which join contacting faces of folded portions of the diaper to maintain a partially folded configuration during use.

In the plan view of diaper 20 in FIG. 1, broken lines 10a, 10b, 14a, 14b; and 15a, 15b represent lines along which the diaper is folded and which divide the diaper into substantially triangular segments designated as panels A through F.

In FIG. 3 the inward and outward fold direction along these lines is demonstrated. The folds defined by the transverse middle line are comprised of segments 10a and 10b. It will be seen that the diaper is tucked directly inwardly along these segments from each side of mid-point 18. As shown in this partially folded view, the fold along line segment 10a by the inward tuck on the right side extends from central point 18 to point 16. The fold along line segment 10b by the inward tuck on the left side extends from central point 18 to point 17. At the same time, the inward tuck provides outwardly disposed folds along diagonal line segments 14a and 15a on the right side, and diagonal line segments 14b and 15b on the left side. When viewed from above as in FIG. 3 it will be seen that when the diaper is eventually folded all the way to its prefolded form as in FIG. 4, point 18 will be disposed at the bottom of a pocket at the approximate geometric mid-point of the diaper and points 16 and 17 at the ends of line segments 10a and 10b respectively will be disposed at the top of the pocket inside the folded diaper.

In FIG. 4 a plan view of the completely folded diaper of FIGS. 1-3 is shown. Prior to, during, or after folding of the diaper, as shown here, a plurality of glue spots 30, or other joining means, are interposed between facing surfaces of the impervious backing sheet portion of triangular panels C & E, and D & F, as more clearly shown in the stylized sectional view of FIG. 4a. Joining portions of the contacting panel surfaces together stabilizes the pocket 18 formed by the folds, and maintains joined areas of the folds in positive association so that when the diaper is partially unfolded or opened for application to the child, the pocket configuration is held intact. As indicated in the drawings it is preferred that the joined areas be disposed approximately halfway between the diaper ends and the transverse fold line. When the diaper is applied to the child, the sides of the diaper radiating out from points 16 and 17 should preferably be folded down by the user to provide a better fit around the legs.

It will be seen that the use of the indicating joining means between adjacent faces of the panels which form the pocket in the folded diaper is essential to good performance. Without such positive attachment, the diaper would tend to unfold completely prior to, or during, application to the child, and the desired pocket configuration would thus be destroyed.

In FIG. 5 there is shown a modification of the invention. In this embodiment the bottom of the pocket extends for a short distance along the transverse fold line to provide a somewhat elongate folded segment 32 at the middle of the transverse line rather than deep, pointed pocket 18 as in FIG. 4. In this configuration, the matching triangular panels 33 also comprise less of the total planar area of the diaper and a shallower pocket results. Again, suitable attachment means between adjoining panel surfaces, such as adhesive spots 35, are required to assure stabilization and retention of the pocket when the diaper is unfolded. The manner of applying this style diaper to the child is the same as for the previously discussed embodiment.

In FIG. 6 a transverse section of a modified form of the absorbent pad structure in flat, unfolded form is shown. In this construction, absorbent pad 21a, disposed between cover 22a and backing sheet 23a, is thin at the longitudinal side areas 40 and 42 and thick at the longitudinal center area 43. This structure of the absorbent pads avoids excessive bulkiness along areas adjacent the sides and permits the sides to be turned down more easily when the diaper is applied to the child by the user. This sectional profile of the absorbent pad is readily adaptable to each of the fold modifications described.

While the attachment means 30 and 35 are shown as round spots of adhesive or the like, it will be seen that the form of attachment can be in the shape of squares, diamonds, lines, or the like as long as they are appropriately placed where indicated.

As shown in FIG. 4a the attachment means is disposed between contacting faces of the film backing sheet and this is the preferred embodiment. However, attachment may alternatively be made between contacting faces of the fluid pervious facing sheet and, in addition, such attachment means may be designed to penetrate therethrough, whereby the internal absorbent pad will become an integral part of the joint.

When the facing panels are thermoplastic such as polyethylene film or the like the fastening may be obtained by heat sealing the film surfaces together.

Claims

What is claimed is:

1. In a prefolded construction for a substantially rectangular disposable diaper with the major dimension defining the diaper sides and the minor dimension defining the diaper ends and in which said diaper comprises an absorbent pad, a fluid permeable facing sheet, and a fluid impervious backing sheet, the construction wherein the diaper is folded in half with said facing sheet inside on a line transverse to its major dimension and has selected portions of the diaper which would normally fall on each side of the mid-point of said transverse line tucked inwardly into the interior of the folded diaper a substantial distance to form a pocket, the base of said pocket being substantially centrally disposed on said transverse line, said pocket being defined by a single pair of inwardly disposed vertically inclined straight folds formed by said inward tucks on said transverse line and extending away from the base of said pocket to said midpoint of the respective diaper sides, and only four outwardly disposed folds extending diagonally from the base of said pocket to terminal points on the respective diaper sides spaced from said diaper ends, said pair of inward folds and said four outward folds forming only four internally disposed triangular panel sections along said transverse line, and fastening means securing surface portions of said triangular panel sections to contacting surface portions of said diaper.

2. The diaper of claim 1 wherein said inwardly disposed folds and said outwardly disposed folds radiate from the approximate geometric center of said diaper.

3. The diaper of claim 1 wherein said inwardly disposed folds are each less than half the length of said transverse line.

4. The diaper of claim 1 wherein said fastening means is disposed approximately halfway between the diaper ends and the transverse line.

5. The diaper of claim 1 wherein said absorbent pad is less thick in cross section along the longitudinal side portions of its major length dimension than along the longitudinal center portion of its major length dimension.

6. The diaper of claim 1 wherein said contacting surface portions are fastened together by means of adhesive spots.

7. The diaper of claim 1 wherein said contacting surface portions are thermoplastic film and said fastening means is a heat sealed joint.

8. The diaper of claim 1 wherein said contacting surface portions are comprised of the fluid pervious facing sheet.

9. The diaper of claim 8 wherein said contacting surface portions are fastened together by adhesive and said adhesive penetrates said facing sheet and into said absorbent pad adjacent said face portions.