Quilted diaper

Abstract

Improved absorbent article for diapers and the like comprising an outer backing sheet of a water impervious or repellant material, an optional inner top sheet having fluid passing properties, an absorbent pad therebetween, and a second water impervious or repellant interlayer sheet disposed between the top sheet and the absorbent pad. The interlayer has a plurality of spaced small holes therethrough. The interlayer and/or inner sheet are bonded directly to the outer sheet through the large holes in the absorbent pad. The outer margins of the layers may be sealed together. The construction shows improved penetration of fluid, substantially one-way transmission through the interlayer, and permits excellent spreading by the backing sheet. The bonding through the pad holes prevents pad shifting and balling in use without requiring a wadding sheet, and the edge margins around the holes provide added wicking surface for improved rate of absorption and retention. The inner sheet is preferably a non-woven material that minimizes skin contact with the plastic interlayer, providing a smooth hand surface.

Description

FIELD

This application relates to improvements in fluid absorbent and retentive articles, including diapers, catamenial pads, fluid absorbent bed sheets, surgical or medicinal absorbent pads or drapes, surgical or medicinal dressing pads or bandages, and the like. More particularly the inventions herein relate to improved diapers having apertured absorbent pads retained in combination with a plurality of sheets in a manner that provides improved performance.

BACKGROUND

Currently available absorbent pad systems have numerous disadvantages, particularly complexity of manufacture and use effectiveness. For example, pulverized wood pulp pads tend to have low wet strength integrity resulting in pulling apart and balling when contacted by fluid. Unless they have a special sheet, called a wadding sheet, they also disintegrate and shift in position when disposed between plastic sheets. Typically, they must be glued across one entire surface to retain them in position, with consequent loss of absorbency, use of large quantities of adhesive, and extra layers of material. The wicking action of the pad is reduced and the spreading action of backing sheets are also hindered. The requirement of additional layers makes for a bulky product, uncomfortable and ill fitting in use, and the rate of liquid penetration is reduced with each additional layer required, and particularly by the wadding sheet. Not only does the wadding sheet reduce the rate of fluid penetration, it also significantly adds to the cost of the diaper. Likewise, there is no way to prevent or reduce reverse fluid flow and excessive urine contact on the skin.

There is thus a substantial need for absorbent articles that have improved use properties, are simple to construct, and overcome such disadvantages of currently available articles.

OBJECTS

It is an object of this invention to provide an improved absorbent article having utility for diapers, bandages, sheets, drapes, catamenial pads and the like.

It is another object to provide an improved absorbent article having an absorbent pad retained between a plurality of sheets.

It is another object to provide an improved absorbent aritcle, such as a diaper, having an apertured absorbent pad disposed between differently functioning inner and outer sheets, which sheets are secured to each other through the apertures in the pad.

It is another object of this invention to provide an absorbent article which has improved use characteristics including positive location and retention of an absorbent pad without use of a special retention-type wadding sheet.

It is another object to provide improved absorbent articles which are simpler and cheaper to make than prior types of absorbent systems.

It is another object to provide an improved absorbent article having an apertured pad, which pad is retained between the interlayer and an outer sheet in a manner to provide for improved fluid transmission, one-way penetration, excellent fluid spreading, added wicking edges, and improved absorbency rates and retention.

It is a further object to provide a discontinuous front surface for contacting an infant's skin.

Still other objects will be evident from the description which follows. By way of example and not by way of limitation, specific reference will be had to diaper system, but the principles disclosed herein are equally applicable to the other aforementioned types and uses of articles.

FIGURES

The description refers to the drawing in which:

FIG. 1 shows in plan view a diaper system illustrating one embodiment of the instant invention, parts of which are broken away to show the several layers of the system;

FIG. 2 is a section view along line 2-2 of FIG. 1;

FIG. 3 shows in perspective the embodiment of FIG. 1 folded in a box pleat form ready for use; and

FIG. 4 is a fragmentary sectional view of another embodiment of the diaper of the present invention.

SUMMARY

By way of example, an absorbent article useful as a diaper in accord with the inventions comprises an outer or backing sheet and an apertured interlayer sheet having disposed therebetween an apertured absorbent pad, and, optionally, an inner or top sheet overlying the interlayer. The top and/or interlayer sheets serve as one or more cover sheets for the absorbent pad. The apertures of the pad are relatively large and permit direct bonding of the interlayer and/or inner sheet to the outerlayer therethrough without bonding to the pad. This retains the pad in the use position without need for a special wadding type retainer sheet, which would normally define the front surface of the pad, and without glue to position and retain the pad in place. The apertures also provide additional wicking surface for rapid absorption of fluid passing through the interlayer and/or inner sheets.

The interlayer has a plurality of smaller apertures which function to pass fluid one way from the inner sheet to the pad. The holes are preferably restricted in area to less than the areal extent of the pad to reduce the tendency for back-wicking from the pad through the inner sheet. The outer sheet and interlayer are preferably of a thermoplastic material to keep the outer surface of the diaper dry, to promote fluid spreading, and permit bonding without need for adhesives. The marginal edges of the sheets are preferably bonded to prevent fluid escape. The inner sheet is preferably a non-woven fibrous material that minimizes direct skin contact with plastic and has a suitable feel or "hand."

A portion of the pad may be removed in generally arcuate areas disposed along the mid-points of two opposed sides or in the diaper crotch region to provide for a better leg fit. The diaper conveniently is folded in a box pleat with one or more adherent tabs provided for removably retaining the diaper in a use position on the child. A diaper of this invention shows improved rate of fluid absorbency, improved penetration, excellent one-way fluid transmission through the interlayer, excellent spreading by the backing sheet and improved wicking into the pad and fluid retention. The diaper is simple to construct, permitting omission of a wadding sheet, yet having improved pad location and retention without balling in use.

DETAILED DESCRIPTION

Referring to FIG. 1, absorbent article 1, such as a disposable diaper, comprises an outer backing sheet 2 and an optional inner sheet 3 having disposed therebetween an absorbent pad 4, and an interlayer sheet 5. These sheets are shown for purposes of illustration as generally rectangular, each having a pair of lateral side edges 6, 7 and a pair of end edges 8, 9 connecting the side edges 6, 7, the edges being substantially in registry. However, other shapes, depending on use and preference, such as square, triangular, polygonal, arcuate or combinations thereof may be employed for the sheets.

The outer backing sheet is of a fluid impervious (preferred) or resistant material, typically thermoplastic or thermosetting plastic, such as a polyolefin (polyethylene, polypropylene), a polystyrene, a polyvinyl plastic, such as polyvinylchloride, and the like. Mixed polymers, laminates, co- and ter-polymers may also be used. This sheet may be made by a continuous extrusion, casting, or other operation, and is preferably a homogenous web. Where the desired fluid imperviousness is achievable, the sheet may be woven, non-woven, or felted. Sheet thickness may vary and typically is in the range of from about 0.1 to 3.0 mils, with lighter thickness on the order of 1.0 mils being used for diapering, with heavier sheets being used for heavy duty applications such as surgical pads or draping. The interlayer is preferably of the same material, impervious properties and gauge. The sheets, particularly the outer backing sheet and interlayer sheet, may be differently colored, for coding purposes in manufacture, to insure proper orientation in use, for sales appeal, and aesthetic reasons. For example, the outer backing sheet may be white while the interlayer is blue; the semi-translucent inner sheet takes on the blue color of the interlayer and the absorbent article thus has differently color-coded sides that can be referred to in manufacturing and use instructions. Other colors, patterns and designs may be used.

The absorbent pad may be any suitable absorbent material, such as pulverized wood pulp, cellulose wadding, or any woven, non-woven or felted, natural or synthetic, fibrous or non-fibrous (such as open or closed cell-sponge of foam-type) material. The pad, as best shown in FIGS. 1 and 2, has end margins 10, 11, and side margins 12, 13 when it is generally rectangular. These margins are generally spaced inwardly of margins 6, 7, 8 and 9, as shown. As noted above, the pad may have a variety of shapes and sizes. One diaper configuration is shown in FIGS. 1 and 3, wherein arcuate portions 14, 15 are removed from side margins 12, 13 in registry with the leg positions. As best shown in FIG. 3, this prevents excess bulk in the baby's crotch area, provides a better fit, and permits collection and spreading of fluid without loss to the exterior by means of the outer backing sheet, interlayer, and optional inner layer, which are not removed at that area.

Pad 4 also has a plurality of relatively large apertures 16 spaced inwardly from the outer margins 10, 11, 12, 13 of the pad. These apertures permit direct bonding of the interlayer 5 (and optionally inner sheet 3) to the outer backing sheet 2 in zones 17, in the manner shown best in the upper half of FIG. 2. The bonding may be by any suitable means, heat sealing (preferred), solvent sealing, adhesive and the like. The bonding zones occupy only a portion of the entire area defined by the aperture size 16. The bonds effectively retain the pad between the outer backing sheet 2 and interlayer 5 in proper use position, without adhesive being applied to the pad and present a generally quilted effect. The pad does not shift in position during transport or use, and does not pill, wad or ball upon contact with fluid. The lower portion of FIG. 2 shows an alternative embodiment wherein the inner sheet is not bonded to the interlayer and/or backing sheet in zone 17.

Further, this construction permits omitting the typical single or multi-layer wadding sheet, pad wrapper or pouch, with consequent improved rate of liquid permeability and reduced cost of the diaper to the consumer. The pad apertures have edges 18 which provide additional wicking surfaces for rapid absorption of fluid by the pad. Absorption by exposed fibrous ends, such as presented by edges 18, is generally faster than through the inner surface 19 or the pad.

The inner surface 20 of the outer backing sheet 2 serves to spread fluid passing through the optional inner sheet 3, and the interlayer 5 into contact with wicking edges 10, 11, 12, 13 and 18 facilitating absorption and into contact with the back surface of the pad 4 intermediate the pad apertures 16. Since no glue is requred to retain the pad in place, better fluid spreading is obtained. Between interlayer 5 and outer backing sheet 2 in the region of the apertures 16 are defined generally annular spaces 21, seen best in FIG. 2. These spaces serve as reserviors for fluid passing rapidly through apertures 22 in the interlayer 5. Thus, the penetration rate limiting factor is the speed of transfer through the interlayer apertures 22, rather than the absolute rate of absorption through the pad surface 19. Fluid does not tend to puddle on the inner surface 23 of the interlayer 5 while awaiting the relatively slow sorption through the surface of the pad. Rather, the fluid can run quickly through apertures 22 into reservoirs 21 and then wick through edges 18. Urine contact on skin is minimized.

The interlayer apertures 22 are generally smaller and more numerous than the pad apertures 16. As an example, apertures 16 in the pad may be 3/4 (1.9 cm) in diameter, while apertures 22 may be 1/8 (0.3 cm) in diameter. This provides a flow gradient effect permitting a large number of access ports for fluid to pad 4 or reservoirs 21, and minimizing back flow to the surface 23 and contact with skin. Further, the larger number of apertures 22 statistically insures registry with the apertures 16 and annular spaces 21. The small apertures 22 are limited in lateral extent (both horizontally and vertically as shown in FIG. 1) to an area generally smaller than the area of the underlying pad 4 (except as may optionally occur in the relieved areas 14 and 15) to eliminate leakage or backwicking from edges 10, 11, 12 and 13. Thus, the fluid impervious interlayer and backing sheets 5 and 2 provide a seal to prevent leakage at the side and end edges of the diaper.

The inner sheet 3 is optional but preferred to minimize skin contact with the plastic of the interlayer 5, and provide a smooth feel or hand. The inner sheet is preferably of a woven or non-woven, fibrous, natural (e.g., cellulosic) or synthetic material. It may be a paper-process type of non-woven material, felted, or randomly intertangled to form a self-supporting sheet. The sheet also helps provide fluid transfer to the interlayer and skin protection. As with pad 4, the inner sheet may be treated with medicaments, chemical agents, deodorants, emollients, powders (e.g., baby powder), surfactants, wetting agents, salves, perfumes, bactericides, germicides, and the like, as desired.

FIG. 3 shows the pad of FIG. 1 folded into a conventional box pleat configuration, having adhesive faced securing tabs 24, 24' with release sheets 25, 25' thereover. In use the baby is laid on the diaper, front end A brought up, the release sheets 25, 25' are removed, and the tabs 24, 24' are secured to the outer surface 26 of backing sheet 2. To form the box pleat, adhesive 27, 27' may be applied to spots C and D of the inner sheet (see FIG. 1) and the pleats 28, 29 formed and retained in place by the folds and adhesive. For packaging and shipping, the diaper may be folded along fold line F-F'. The relieved areas 14, 15 prevent bulking along the fold line, and permit better diaper fit.

Another embodiment of the present invention is illustrated in FIG. 4. In this embodiment, the interlayer is omitted and the inner top sheet 3 is secured directly to the backing sheet 2 through the pad apertures 16. The bonded top and backing sheets prevent shifting of the absorbent pad, as previously described in connection with the diaper of FIGS. 1-3.

As apparent from the drawings, the quilted diaper of the present invention has a plurality of raised and recessed surface portions 32 and 34, respectively, defining an undulating front and rear surface of the diaper which is aesthetically pleasing to the eye. When the diaper is placed on an infant, the tape strips are secured in place, the backing sheet is pulled somewhat taut, tending to accenturate the depressed front surface portions and the undulating front surface of the diaper. Accordingly, the diaper presents a discontinuous front surface with the raised portions contacting the infant's skin, and the depressed portions providing air pockets promoting the circulation of air within the placed diaper. To the extent that the inner top sheet becomes moist, the discontinuous front surface minimizes the wet front surface area which contact the infant. The discontinuous front surface also minimizes clinging of the top sheet against the infant's skin, which otherwise might be present in a continuous front surface.

It should be understood that various modifications within the scope of this invention can be made by one of ordinary skill in the art without departing from the spirit thereof. I therefore wish my invention to be defined by the scope of the appended claims as broadly as the prior art will permit, and in view of the specification if need be.

Claims

I claim:

1. An absorbent article for use as a diaper or the like comprising in operative combination:

a. a first backing sheet of generally fluid resistant material, having marginal edges,

b. a second sheet of generally fluid resistant material,

c. said second sheet having a plurality of apertures therein,

d. an absorbent pad structure disposed between said first and said second sheets,

e. said absorbent pad having a plurality of apertures therein, said apertures being larger than the apertures in said second sheet,

f. said first and said second sheets being secured to each other in registry with said pad apertures in at least a part of the area defined by said pad apertures, and

g. the marginal edges of said first and second sheets being secured to each other to make a unitary absorbent article.

2. An absorbent article as in claim 1 wherein said first and second sheets are generally water impervious, and said aperttures in said second sheet are disposed in a lateral area smaller than the area of said pad.

3. An absorbent article as in claim 2 wherein said pad is smaller in size than said first sheet.

4. An absorbent article as in claim 3 wherein said pad is adapted for use as a diaper.

5. An absorbent article as in claim 4 wherein said diaper adaptation includes relieved portions of said pad along at least two opposed margins defining leg-fitting portions.

6. An absorbent article as in claim 5 which includes a third sheet of fibrous material disposed adjacent to and outwardly from said second sheet, said third sheet being secured to at least one of said first and said second sheets.

7. An absorbent article as in claim 6 wherein said first and second sheets are of plastic material and said secured area is selected from heat bonding, solvent bonding and adhesive bonding.

8. An absorbent article as in claim 6 wherein two opposed pad margins have relieved portions defining leg-fitting areas.

9. An absorbent article as in claim 8 wherein said margins having relieved portions are pleated, and said pleats are secured by adhesive.

10. An absorbent article as in claim 1 which includes a third sheet of fibrous material disposed adjacent to and outwardly from said second sheet, said third sheet being secured to at least one of said first and said second sheets.

11. An absorbent article as in claim 1 including a plurality of longitudinal folds defining a box-pleat configuration of the article adapted for use as a diaper.

12. A disposable diaper, comprising: a fluid impervious backing sheet, a fluid transmitting cover sheet, and an absorbent pad intermediate said cover and backing sheets, said pad having a plurality of apertures extending therethrough, and said cover sheet being secured to said backing sheet through a plurality of said pad apertures the area of securing being less than the area of the apertures in said pad.

13. The diaper as in claim 12 wherein the apertures in said pad are spaced inwardly from marginal edges of the pad.

14. The diaper as in claim 12 wherein said pad includes a pair of side edges, and a pair of cut-out portions along said side edges in the crotch region of the diaper.

15. The diaper as in claim 12 wherein said cover sheet comproses a fluid pervious top sheet.

16. The diaper an in claim 12 wherein said cover sheet comprises a fluid impervious sheet having a plurality of apertures extending through said sheet and overlying said pad.

17. The diaper as in claim 16 including a fluid pervious top sheet overlying said fluid impervious cover sheet.

18. The diaper as in claim 17 wherein said fluid impervious cover sheet and fluid pervious top sheet are secured through said apertures to said backing sheet.

19. The diaper as in claim 16 wherein the apertures of the fluid impervious cover sheet are smaller in size than the apertures in said pad.

20. The diaper as in claim 16 wherein said pad has marginal side and end edges, and the apertures in said fluid impervious cover sheet are spaced from said marginal edges throughout a substantial areal extent of said pad.

21. The diaper as in claim 16 wherein said fluid impervious cover sheet and backing sheet are secured together defining marginal side and end edges of the diaper, and said apertures in the fluid impervious cover sheet are spaced from said marginal edges of the diaper to provide a fluid barrier adjacent the marginal edges of the diaper.

22. The diaper as in claim 12 including a plurality of longitudinally extending folds defining a box-pleat configuration of the diaper.

23. A disposable diaper, comprising:

a. a pair of side edges;

b. a pair of end edges connecting said side edges;

c. a fluid impervious backing sheet;

d. a fluid pervious top sheet;

e. an absorbent pad intermediate said top and backing sheets;

f. said pad having marginal edges and a plurality of apertures extending through the pad generally in a first (the crotch) region of the diaper, said first region being adapted for placement adjacent the crotch area of an infant;

g. a fluid impervious interlayer intermediate said top sheet and pad and secured to said backing sheet through a plurality of said pad apertures;

h. said interlayer having a plurality of apertures of smaller size than the apertures in said pad;

i. said interlayer apertures being spaced from the diaper side and end edges and the marginal edges of the pad throughout a substantial areal extent of the pad;

j. said top and backing sheets and said interlayer being secured together along the side and end edges of the diaper; and

k. a plurality of longitudinally extending folds defining a box-pleat configuration of the diaper.