Disposable adult diaper

A disposable adult diaper comprising a waterproof backing sheet, an absorbent pad assembly, and a non-woven hydrophobic top sheet. The top sheet overlies the absorbent pad assembly and is folded about the backing sheet with end margins overlapping. On the overlapped portion of the top sheet there is provided pressure-sensitive adhesive for removably attaching the diaper to an undergarment of the wearer. The diaper is folded into a box-pleated configuration for better fluid tightness and fluid capacity. The absorbent pad assembly may be made with or without top or bottom wadding sheets and the most preferable embodiment utilizes a bottom wadding sheet integrated to the wood fluff of the absorbent pad by a water spray.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to disposable absorbent articles and, more 
particularly, to a convenient disposable adult diaper. 
2. State of the Prior Art 
A great many disposable absorbent articles, especially disposable diapers 
have been previously devised. The disposable diaper now being marketed is 
characterized by havin a backing sheet, a top sheet and an absorbent pad 
assembly sandwiched therebetween. The backing sheet is made of a 
waterproof plastic film, the top sheet may be of tissue or other material 
but by far the most mass produced is non-woven hydrophobic material. The 
absorbent pas assembly is made from a variety of absorbent materials and 
the well-known "wood fluff" has proven highly marketable. 
In assembling the prior art diaper, the backing sheet is generally folded 
over and above the top sheet along two opposite peripheral edges thereof 
while the other two peripheral edges are bonded together by any suitable 
means, such as adhesives, or sonic or heat welding. The prior art diapers 
may be flat, box-pleated or contoured, with or without elasticized waist 
or crotch bands. 
In addition, various types of diapers have been used for adults, especially 
those persons who are incontinent due to mental or emotional problems, as 
well as physical illnesses including bladder or urinary disorders, postate 
involvement or senility. Persons having these problems can have useful 
lives if embarrassment is avoided by employing an adult diaper capable of 
being comfortably employed with conventional clothing. However, the 
backing sheet employed in prior art diapers when directly contacting the 
conventional undergarments of the wearer may pull away from 
pressure-sensitive adhesive applied thereon, and often makes a crinkling 
or like sound upon movement of the wearer, which is likely to cause 
discomfort or embarrassment. 
SUMMARY OF THE INVENTION 
The present invention overcomes the problems of prior art diapers by 
providing a convenient and safe disposable adult diaper which is capable 
of absorbing a substantial quantity of fluid, has box-pleated panels 
forming fluid traps to entrap sudden gushes of fluid, and has a top sheet 
folded beneath the backing sheet to provide means for applying 
pressure-sensitive adhesive which will not pull away from the diaper while 
preventing crinkling or other distrubing sounds from the diaper upon 
movement of the wearer. 
The disposable adult diaper according to the present invention includes a 
backing sheet of waterproof plastic film, an absorbent pad assembly, and a 
top sheet bonded to the backing sheet along two peripheral edges and which 
has two ends folded under and about the backing sheet to provide an 
overlap on which pressure-sensitive adhesive strips are coated and 
removably covered by strips of material having a low affinity for the 
adhesive strips. The adult diaper is box pleated forming security seals 
against fluid loss. Since the overlapping ends of the top sheet are bonded 
to the backing sheet and each other, they form a better base for 
attachment to the undergarment. Further, the adhesive utilized has greater 
affinity for the top sheet material than for undergarmet material 
preventing tacky residue remaining on the undergarment.

DETAILED DESCRIPTION OF THE INVENTION 
With continuing reference to the drawings and initial attention to FIGS. 1 
and 3, reference numeral 10 generally designates an adult diaper 
constructed in accordance with the concepts of the invention. The diaper 
10 is preferably of a generally rectangular shape and includes a top sheet 
12, a backing sheet 14, and an absorbent pad assembly which, in the 
embodiment shown, is a core 18 of wood fluff or similar mass produced 
absorbent material. 
The backing sheet 14 is a film of fluid impervious waterproof plastic 
material, such as polyethylene or polypropylene, and has side portions 20, 
22 folded over and overlying the pad assembly 16 since it is of greater 
outside dimensions. 
The top sheet is a tissue sheet of non-woven hydrophobic fibers of 
polyethylene or polypropylene or a combination thereof. The sheet 12 is 
much wider than the bottom sheet and is folded under to form end portions 
26, 28, which underlie the bottom sheet 14 and form an overlap 30. 
The backing sheet 14 is provided with glue lines of any suitable adhesive, 
such as hot melt or cold setting adhesives, on both sides of the backing 
sheet so as to bond the absorbent pad assembly thereto. The glue lines 
extend over the entire upper face 32 of the backing sheet 14 so that the 
end portions 20, 22 are also bonded to the absorbent pad assembly 16. 
The glue lines extend along the bottom surface of the underside 34 of the 
backing sheet 14 to bond the end portions 26 and 28 of the top sheet 
thereto. The end portions 26, 28 are bonded to each other at the overlap 
30. At the opposed edges at top and bottom of the diaper, the top sheet 12 
and the bottom sheet 14 are sealed together as by bonding using adhesives, 
using crossed glue lines, by heating sealing, sonic welding or other 
suitable bonding means. 
Applied on the undersurface of the overlap 30 are pressure-sensitive 
adhesive strips 40, which are covered by peelable strips 42. The strips 
are removed when the diaper is used to fix the diaper to an undergarment 
of the wearer. 
The diaper 10, as shown in FIGS. 2 and 4, is folded into a box-pleated 
configuration, including a base panel 50, inwardly extending panels 52 and 
outwardly bent wing panels 54. The edges 56 defined by the wind panels 54 
as they are bent away from the panels 52 are well spaced from each other. 
Glue spots 58 are used to hold the panels 52 to the base panel 50 so that 
the box-pleated configuration forms a suitable fluid seals. The glue spots 
58 are slightly offset from the center line of the daiper so that the 
diaper is equally useful for both male and female wearers. 
In the embodiment shown in FIG. 5, the absorbent pad assembly 16 includes a 
core 18 of wood fluff and an upper wadding sheet 70 and lower wadding 
sheet 72. The wadding sheets 70, 72 may be in the form of a single piece 
wrapped about the core 18. 
In the form of the invention shown in FIG. 6, only an upper wadding sheet 
70 is employed, the core 18 being bonded to the backing sheet 14. 
Referring now to the most preferred embodiment shown in FIG. 7, a bottom 
wadding sheet 72 has been integrated to the core 18 by a water spray so 
that the bottom wadding sheet 72 is integrally a part of the core 18. As 
shown, only a single peelable strip 80 may be employed in lieu of the 
separate peelable strips 42.