Prefolded Disposable Diaper

Abstract

A prefolded disposable diaper utilizing an inward longitudinal fold at each edge in combination with triangular shaped folds adjacent the leg area. An improved arrangement for pressure sensitive fastening tapes is also disclosed.

Description

BACKGROUND OF THE INVENTION

In the art of disposable diapers it is known that by prefolding rectangular diapers in a suitable manner it is possible to provide a somewhat better leg fit at the inner thigh when compared to diapers without a prefold. The better fit thus provided tends thereby to minimize leakage of both fluid and solid excrement. However, there is always a need for still further improvements in fold configurations which result in still better leakage control. This invention is directed to one such improvement.

An example of a commercial form a prefolded disposable diaper which is applied in part to the improved structure of this invention may be found in U.S. Pat. No. 3,196,874 to Hrubecky and assigned to the assignee of this invention. The diaper described in that patent, has inward and outward diagonal folds on each side of a central pocket at the medial transverse fold line which form leg receiving areas on each side of the diaper. The style of fold defined in the Hrubecky patent will for convenience, sometimes be referred to hereinafter as a triangular wing fold.

SUMMARY OF THE INVENTION

The invention is directed to an improvement in prefolded rectangular-shaped disposable diapers of the triangular wing fold type.

In the improved structure, a narrow panel section extending the full length of the rectangular diaper is folded inwardly along each edge. The inner contacting faces of the panels formed by these folds are then secured to the face of the diaper in areas adjacent to and spaced a short distance from the transverse mid-line of the diaper measured along its length. The width of these panel sections is preferably 1 inch, but may vary from 3/4 inch for small new-born size diapers to the 11/4 inches for larger size diapers. When the edge panel sections are folded over and secured as indicated, the diaper is then folded in the manner similar to that described in U.S. Pat. No. 3,196,874. That is, the diaper which has been narrowed down by the longitudinal edge folds forming the narrow panel sections at each edge is now further folded transversely in half into approximate half sections. Each half section including the narrow edge panel section is then folded inwardly on a first pair of diagonal lines starting from near the midpoint of the transverse fold and extending away from each other to the edge of the fold which defines the respective longitudinal edge panel sections and at a point short of the diaper ends. Each half section of the diaper again including the prefolded narrow edge panel sections, is then folded outwardly along a second pair of diagonal fold lines with each of said fold lines starting from a point on the transverse fold located midway between the center of the transverse fold and the edge of the fold which defines the narrow panel sections, and extending to the edge of the narrow panel section fold to terminate at approximately the same point on the edge fold as the first diagonal folds.

In this improved fold, the amount of absorbent material within the area defined by the narrow edge panel sections may also be reduced in thickness to make that area less bulky if desired.

The prefolded narrow panel sections at each edge of the diaper also make possible a simplified arrangement for the fastening tapes, which is another aspect of the invention. In such an arrangement, a strip of tape is affixed to each corner of the face of the diaper with the pressure sensitive side of the tape facing upward. Release strips are located on the diaper face at a position where when the edge panel sections are folded, the pressure sensitive areas of the tape will press against, and be releasably held by, the release strips. In applying the diaper to the child, the panel sections are unfolded at the ends and the pressure sensitive tape is thereby, pulled away from the release strip and is ready for use in attaching the diaper in place on the child.

The above folded structure and other features of the invention will be more clearly understood by reference to the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a plan view of the face of a rectangular diaper before folding.

FIG. 2 is a plan view of the diaper of FIG. 1 in which a narrow panel section has been folded inwardly along each edge.

FIG. 3 is a section taken through line 3--3 of FIG. 1.

FIG. 4 is a section taken through line 4--4 of FIG. 2.

FIG. 5 is a perspective view of the diaper of FIG. 2.

FIG. 6 is a perspective view of the diaper of FIG. 5 with the diagonal folds partially developed.

FIG. 7 is a perspective view of the diaper of FIGS. 5 and 6 with the diagonal folds more fully developed.

FIG. 8 is a perspective view of the final folded diaper configuration.

FIG. 9 is another plan view of the face of the diaper before folding illustrating an improved tape fastening arrangement.

FIG. 10 is a plan view of the FIG. 9 diaper with the narrow edge panel sections folded inwardly.

FIG. 11 is a section taken through line 11--11 of FIG. 10.

DETAILED DESCRIPTION OF THE DRAWINGS AND PREFERRED EMBODIMENTS OF THE INVENTION

In the plan view of FIG. 1, the facing surface of the diaper is a fluid-pervious liner 10 of any conventional structure. Many variations of such liners are well-known, and they may include non-woven sheets, woven gauze, scrimreinforced materials, perforated films, etc. The liner may be hydrophobic or hydrophilic, but must be fluid-pervious for efficient transfer of fluids to the inner absorbent pad. FIG. 1 also shows conventional arrangement for pressure sensitive fastening tapes at 12.

By referring to FIG. 3 it will be noted that the rest of the diaper is also of conventional construction. It has a central main absorbent pad 14 which may be multilayers of cellulose wadding or a mat of loosely associated wood pulp fibers, or other absorbent fibers such as cotton, rayon or modifications thereof. The absorbent pad 14 is bottomed by an impervious backing 16 which may comprise a thin plastic film or other flexible sheet treated for fluid repellancy. In this embodiment, the backing extends around the edges of pad 14 and under liner 10 and is secured to line 10 along its length. In other embodiments, the backing and liner may also be coterminous and secured to each other along the pad edges, or the backing may extend over the liner edges and be secured to the top of the liner. Many other variations are possible.

In any event, any of the known disposable diaper construction, of which there are many, may be adapted to the improved prefolded structure as disclosed herein.

Returning now to FIG. 1 it will be noted that along each edge there is marked off a narrow longitudinal panel section 18, demarcated by lines 19. It is preferred that these panel sections be from about 3/4 inch to 11/4 inches wide. On each of these panel sections 18 and spaced from transverse center line 20 are adhesive spots 21. These adhesive spots or similar attachment means are utilized to firmly attach the longitudinal edge panels 18 to the face of liner 10 after the panels are folded along line 19 as shown in FIG. 2. It is preferred that these spots be spaced a distance of about 1 inch from the transverse center line 20.

As further shown in FIG. 2, the backing side of longitudinal edge panels 18 now faces upward. At this stage of folding, the diaper with its longitudinal edges folded inward is now narrower than the unfolded form of the diaper by the sum of the width of these folded edge panel sections.

This narrowed down diaper, with the longitudinal edge panels 18 folded over and held in place by adhesive spots 21 is now folded into a triangular wing fold, with the folds 19 which define the narrow edge panel section now comprising the narrowed down diaper edges. Thus, the narrow panel sections in their prefolded condition are folded once again along the diagonal and transverse lines which define the triangular wing fold.

The triangular wing fold of the narrowed down diaper is achieved by first folding the diaper transversely in half along line 20, and then folding the diaper inwardly along diagonal lines 22 and outwardly on diagonal lines 22.

The diaper with its completed fold is shown in FIG. 8, and the various stages of the folding sequence as it develops are shown in the series of FIGS. 5 to 8.

The completed prefolded diaper is narrower and more compact than the prior art diaper in U.S. Pat. No. 3,196,874. When applied to the infant, the narrow edge panel sections are completely unfolded at the ends only, in order to permit fastening of the corners together at the waist. The central portion of each of the narrow edge panels remains folded because of the adhesive spot bonds previously mentioned. The backing sheet which covers the longitudinal edge panel at the transverse medial fold lines thus will contact the infant's thighs and provide a close fit in that area even though the ends of the diaper are spread open at the waist and attached with tapes 12 in the conventional manner.

When the performance of the prefolded diaper as described herein was compared with the performance of the prior art U.S. Pat. No. 3,196,874 diapers a significant improvement was noted in minimizing leakage incidents. This is attributed to the spring-like action which the longitudinal fold in combination with the triangular panels formed by the diagonal folds exert against the inner thigh when the diaper is worn. However, such attribution is only theoretical, as the exact reason for improved leakage performance is not known. In any event an improvement in leakage control did occur when this diaper structure was compared with a triangular wing fold diaper without the additional longitudinal edge folds.

When this improved fold is used, the amount of disposable material within the area defined by the narrow edge panel may also be reduced to make that area thinner and less bulky. Such modification permits easier folding and retention of the folds in the finished diaper and does not appear to materially affect the improved performance which the narrow edge folds provide.

The employment of the narrow edge panels in the improved construction defined herein also permits a simplified arrangement for the pressure sensitive fastening tapes used to attach the diaper to the child. This simplified arrangement is shown in detail in FIGS. 9 through 11.

In FIG. 9, which is a plan view similar to FIG. 1, each of the lower corners of the diaper has a strip of pressure sensitive tape 32 affixed to the surface of the diaper with the pressure sensitive surface of the tape facing upward. Adjacent to each of these strips and across fold line 19 from the tape itself are two matching strips of release paper 34. When narrow edge panel sections 18 are folded over onto the face of the diaper as shown in FIG. 10, pressure sensitive surface 33 of tape 32 is pressed into contact with release strip 34 as shown in FIG. 11, where it is releasably held in place. When the diaper is to be applied to the child, the corners of the narrow edge panels are pulled open exposing the pressure sensitive tape surface which then may be applied to the matching corner at the opposite end of the diaper in the customary way when attaching the diaper to the child. It should be noted that in this arrangement, no free ends of the fastening tapes extend beyond the edge of the diaper but the entire tape is within the diaper margins.

While the versions of the diaper depicted in the drawings are idealized for clarity, it will be understood that in a mass manufacturing process the folds will not necessarily be as precise as shown. However, the general configuration is intended to follow the drawings except that the triangular sections need not come to a point at the center of the diaper. For example, a central flat portion on the transverse fold line may separate points where the inner diagonal lines centrally intercept the transverse fold line without changing performance materially.

When the diaper is in its prefolded configuration, adhesive securement means may be used, if desired, in the triangular areas where like surfaces contact each other as is frequently done in prior art prefolded diapers. The function of adhesive securements, of course, is to maintain the diaper folds in better operational condition when the diaper is worn.

Claims

What is claimed is:

1. A prefolded disposable diaper of generally elongate rectangular shape having a central absorbent pad, a fluid permeable face, a fluid impermeable backing, two side edges and two ends; a narrow panel section at each of said edges being folded inwardly to thereby narrow the transverse dimension thereof; the internal face of each of said inwardly folded narrow panel sections being securely attached to the face of said diaper at areas adjacent to and spaced a short distance from the transverse mid-line of said diaper; said narrowed diaper and said folded narrow panel sections being folded in half transversely into diaper half sections with the fluid permeable face portions disposed on the interior of said transversely folded diaper; each of said half sections including said narrow panel sections being folded inwardly on a first pair of diagonal lines starting from near the midpoint of said transverse fold and extending away from each other to the edge of the fold defining said narrow panel section and at a point short of said diaper ends; each of said half sections including said narrow panel section also being folded outwardly along a second pair of diagonal fold lines with each of said fold lines starting at a point on said transverse fold located midway between the center thereof and the edge of the fold defining said narrow panel section and extending to the edge of said panel section fold at approximately the same point as each of said first pair of diagonal folds, the attachment of said narrow panel sections being such that the full width of the inward fold of the narrow panel sections adjacent the transverse mid-line of the diaper is maintained when worn.

2. The diaper of claim 1 wherein the width of said narrow panel section is from about 3/4 inch to 11/4 inches.

3. The diaper of claim 1 wherein the area at which the internal face of each of said inwardly folded narrow panel sections is attached to the face of the diaper is spaced about 1 inch from said transverse mid-line.

4. The diaper of claim 1 wherein contacting surfaces near the transverse fold area are also adhered to each other in selected areas to assist in maintaining the prefolded condition.

5. The diaper of claim 1 wherein a strip of pressure sensitive tape is affixed to the face of the unfolded diaper at each of the diaper corners at one end of the diaper, with the pressure sensitive surface of said tape facing upward, and matching strips of release material are affixed on the face of the diaper at the same end across from and adjacent to the fold line defining said narrow panel sections.