GB2095561A - Disposable diaper with stressed crotch and waist seals - Google Patents

Abstract

A disposable diaper has elasticized crotch seals and an elasticized waist seal formed from elastic members 82, 84, 88, 90 secured to the backing sheet 22. The elastic members are under such tension as to provide an initial stretching of the elastic members extending substantially at right angles to each other thereby maximizing the comfort of an infant wearing the disposable diaper. The elastic members may be spaced from the edge of the pad or may overlie the front or back surface of the pad to minimize leakage. <IMAGE>

Description

SPECIFICATION Disposable diaper with stressed crotch and waist seals The present invention relates to disposable diapers and more particularly to a contoured diaper having crotch seals or waist seals or crotch seals and waist seals.

In the past, elasticized contoured diapers have been developed such as that disclosed in the U.S. Patent to Buell No. 3,860,003, issued January 14, 1 975, for "Contractable Side Portions for Disposable Diapers" wherein elastic strips are secured to the crotch portions of the diaper and spaced at least 3/4 inch (1 9 mms) from the absorbent pad to form elasticized crotch seals for securement over the legs of the infant to prevent loss of fluid from the interior of the diaper along the legs of the infant. The elasticized strips are placed more than 3/4 inch 619 mms) from the absorbent pad to provide a wide contractable side flap for improved containment.

In U.S. Patent to Woon and Encores, No.

4,050,462, elastic strips are provided in the crotch area of the diaper whereby a plurality of gross transverse rugosities across the width of the crotch section are formed to improve the absorbent capacity at the crotch area.

However, it has been found that these pleats may act as a channel resulting in excessive diaper leakage and the pleats in the crotch area make the infant's bottom uncomfortable when sitting especially while the diaper is not saturated.

Elasticized waist seals are old and well known for various garments including diapers.

These waist seals have been for the purpose of maintaining the garment in place and håve not been for the two additional purposes of the present invention so as to provide for a fluid barrier while also providing for a cooperative effect in conjunction with the crotch seals whereby the crotch seals provide an initial stress on the waist seals and the waist seals provide an initial stress for the crotch seals. Additionally, the elastic waist seals may be structured to serve as z means for securing the diaper as well.

The present invention overcomes the disadvantages of the prior art diapers by providing for elastic members along the opposite sides of the diaper and along the waist portion of the diaper whereby crotch seals and waist seals are formed which enact to provide initial stress on each other because of the tension they place on the material of the diaper itself.

in carrying out the invention, a substantially hour-glass shaped diaper is formed having a backing sheet, an absorbent pad on the backing sheet, and a top sheet overlying the absorbent pad. Opposed side elastic members are secured to the backing sheet as well as an opposed waist elastic member forming respec lively crotch seals an a waist seal which cooperate to place an initial stress and stretch on the waist seal and crotch seal respectively.

The elastic crotch and waist seals may serve as fluid barriers particularly when they overlie the absorbent pad. The waist seal or seals may also be extended beyond the side edges of the diaper to provide integral means in place of the conventional separate tape tab means, for securing the diaper around the infant.

The invention may be put into practice in various ways and a number of specific embodiments will be described by way of example to illustrate the invention with reference to the accompanying drawings in which: Figure 1 is a plan view of a disposable diaper constructed in accordance with a first embodiment of the present invention; Figure 2 is a partial plan view of a second embodiment of the invention, employing elasticized waist members; Figure 3 is a sectional detail view taken along the plane of line 3-3 in Fig. 2; Figure 4 is a sectional detail view taken along the plane of line 4-4 in Fig. 2; Figure 5 is a view similar to Fig. 4, but showing a third embodiment of the invention;; Figure 6 is a plan view of a fourth embodiment of the invention; Figure 7 is a plan view of a diaper according to Fig. 6 folded for shipment; and Figure 8 is a perspective view illustrating the manner in which the diaper is arranged for placement on an infant.

In the accompanying drawings, like reference numerals designate similar parts through-out the various views. The reference numeral 10 generally designates an elasticized and contoured diaper constructed in accordance with the present invention. The diaper 110 is of an hour-glass configuration having a crotch area 12 and four portions of greater width defining ears 14, 1 6, 18 and 20. The diaper includes a backing sheet 22 of an impervious material such as polyethylene.

A top sheet 24, preferably of non-woven fibres e.g. of non-woven polyethylene or polypropylene fibres is secured to the backing sheet 22 along the peripheral edges of the diaper 110 preferably with adhesive, for exam ple either hot melt or pressure-sensitive. An absorbent pad 26 is disposed between the top sheet 24 and the backing sheet 22 and may be of woodfluff or the like. Wadding sheets may be provided as desired, e.g. between the top sheet 24 and the pad 26 or between the backing sheet 22 and the pad or at both locations.

A A pair of elasticized strips 34 and 36 are provided. The backing sheet 22 is coated with adhesive lines or spots 25 on its top surface thereof and the strips 34 and 36, in stretched state, are thus bonded to the backing sheet 22 along the crotch portion 1 2 of the pad with a portion of each strip 34 and 36 thereof overlying the pad 26 and optionally entirely overlying the pad at the ears 14, 16, 18 and 20. The strips 34 and 36 are secured by the adhesive preferably in the crotch area with the ends which overlie the ears 14, 16, 18 and 20 being free of attachment.

In the arrangements shown in Fig. 2, elasticized members, in stretched state 38 and 40 are bonded to the backing sheet 22 spaced from the pad 26. An elasticized and water impervious barrier 42 (Fig. 4) is secured between the backing sheet 22 and the top sheet 24 either by adhesive or by heat sealing and serves to form a waist seal. Alternatively, as shown in Fig. 5, an elasticized and water impervious waist member 4 may be secured to the top sheet as by adhesive thereby providing a waterproof waist seal against the skin of the infant to prevent moisture from seeping above the waist, such as when the infant is lying down. As in Fig. 1, the ends of members 38 and 40 are preferably free of attachment, and may overlie the pad ears as well.

The elastic strips 38 and 40 extend at substantially right angles to the elasticated barrier 42 or the elasticized waist member 44 and are bonded to the backing sheet 22 with a slight initial tension thereon, i.e. with the strips 38 and 40 slightly stretched prior to bonding to the sheet 22. Thus, the strips 38 and 40 and the strips 42 or 44 cooperate to place initial stress and stretch'to the respective crotch seals and waist seal formed thereby and thus assure a more comfortable and better fit. The strips 38 and 40 and the strips 42 and 44 are preferably made of a waterproof material further assuring fluid seals.

In Fig. 6, there is shown a modified form of the invention generally indicated as reference numeral 70. Herein the diaper 70 is of generally hour-glass shape having a crotch portion 72 and ears 74, 76, 78 and 80. The diaper has the conventional backsheet, absorbent pad and top sheet arrangement of the diaper of Fig. 1. Elasticized side members 82 and 84 are secured as by adhesive lines 75 to the backing sheet at a location spaced from the pad 86 and likewise, an elasticized waist member 88 (and optionally 90) is secured under tension as by bonding or adhesive to the backing sheet spaced from the pad 86.

The side members 82 and 84 serve to form a waist seal, and both serve to provide for secure and close fit of the diaper about the infant. The side members and the waist member are preferably of a waterproof material. As in Fig. 1, it is preferred to have the ends of the members 82 and 84 unattached and free of adhesive securement.

The side members 82 and 84 are spaced from 5 to 18 millimeters from the absorbent pad 26. The backing sheet is generally provided with spaced longitudinally parallel lines of adhesive to stabilize the pad on the backing sheet. The side edges and top of the diaper assembly are secured as previously described.

As shown in Fig. 7, the diaper may be conveniently folded with the ears, side members, and the like folded inwardly to form a substantially rectangular shape 100 for convenience in packing and shipping.

In use, as shown in Fig. 8, any suitable tabs which may be provided with self-stick adhesive and which are indicated as 102 may be used to hold the diaper on the infant substantially in the position as shown in Fig.

8.

In lieu of the tabs 102, elastic waist member 88 (see Fig. 6) may be extended beyond the two side edges of the diaper 70 and the projecting portions provided with a suitable adhesive (e.g. pressure-sensitive) to provide means for securing the diaper about the infant. The projecting segments may be provided with suitable, removable release sheets to protect the adhesive before securement.

Further, in place of "throw-away release sheets the diaper may be provided with release sheets affixed to the diaper as described and shown in U.S. Patents 3,893,460 and 4,100,921. In this construction the projecting end of the adhesive-coated elastic waist member is folded over so that the adhesive layer is in contact with the release surface of the release sheet.

It will be noted that in the embodiments of Figs. 2 and 6, the elastic waist members lie between the top sheet and backsheet of the diaper but as shown in Fig. 5, the elastic waist member(s) 44 may be over the top sheet. So similarly, where the elastic waist member projects beyond the pad edges as described above, the said waist member may also lie over the top sheet; still further, it may also be positioned on the back-side of the diaper (i.e. on the outside or external surface of the backsheet). In those instances where a permanently fixed release sheet is used, the said release sheet would be on the front surface (i.e. the top sheet surface) of the diaper with the adhesive on the elastic waist member adapted to contact the release sheet when the elastic waist member is folded over in the "before use" condition.

A still further modification lies in utilizing the back (or exposed) surface of the elastic waist member as the release surface. This embodiment is particularly useful when the elastic waist member is secured to the front (top sheet) surface of the diaper, and in this construction the back surface of the elastic member (i.e. the surface opposite that which is secured to the front surface of the diaper) is zone coated or constructed to provide at the end thereof a pressure sensitive adhesive zone and adjacent the said adhesive zone, a release zone, at least contiguous with the said adhesive of a release nature.

Claims (9)

1. A disposable diaper comprising a backing sheet, an absorbent pad on said backing sheet, a top sheet overlying the said absorbent pad, the said top sheet being secured to the said backing sheet on at least two opposite peripheral edges thereof, opposed side elastic members secured to the said backing sheet along two opposite side edges thereof to define crotch seals, and an elastic member secured to the said backing sheet along an end edge, to define a waist seal, the said crotch seals an the said waist seal cooperating to place initial stress and stretch on the said waist seal and the crotch seals respectively to effect an improved fit and conformance on the body when used.

2. A disposable diaper as claimed in Claim 1, in which the said absorbent pad is of an hour-glass shape defining ears spaced from the said crotch area.

3. A disposable diaper as claimed in claim 1 or claim 2 in which the said side members and the said waist member are waterproof forming fluid barriers.

4. A disposable diaper as claimed in claim 2 or claim 3 in which the said side elastic members overlie the said ears of the pad.

5. A disposable diaper as claimed in claim 2 or claim 3 in which the said side elastic members terminate short of the said ears of the pad.

6. A disposable diaper as claimed in anyone of the preceding claims in which the said top sheet and the said backing sheet are bonded together along the peripheral edges thereof.

7. A disposable diaper as claimed in anyone of the preceding claims in which the said top sheet is heat sealed to the said backing sheet.

8. A disposable diaper comprising a backing sheet, an absorbent pad on the said backing sheet, a top sheet overlying the said absorbent pad, the said top sheet being secured to the said backing sheet on at least two opposite peripheral edges thereof, opposed side elastic members, adhesive means securing the said side elastic members to the said backing sheet along two opposite side edges thereof to define crotch seals, and a waist elastic member secured to the said backing sheet along an end edge to define a waist seal, the said crotch seals and the said waist seal cooperating to place initial stress and stretch on the said waist seal and crotch seals respectively, the said side members and the said waist member being waterproof forming fluid seals, the said absorbent pad being of an hour-glass shape defining ears spaced from the said crotch area, the said adhesive means extending substantially the full length of the said backing sheet for preventing pulling apart of the said diaper and shifting and balling of the said absorbent pad.

9. A disposable diaper as claimed in claim 1 substantially as specifically described herein with reference to Fig. 1 or Figs. 2, 3 and 4 or Fig. 5 and Fig. 6.