US 3921639 A
A disposable diaper is provided with an adhesive tab having a relatively long free end which is removably tucked in a facing sheet of the diaper. The tab is attached to a diaper backing sheet on the outside surface of the diaper and at a marginal location thereof, and the free end, having a tacky surface covered with a release strip, is removably received in a slot provided for that purpose in the diaper facing sheet.
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United States Patent [191 Cepuritis 1 Nov. 25', 1975 1 1 DISPOSABLE DIAPER HAVING FASTENING TABS TUCKED IN FACING SHEET THEREOF  Inventor: Talivaldis Cepuritis, Kenilworth, Ill.
 Assignee: Johnson & Johnson, New
22 Filed: Nov. 4, 1974 21 AppL No; 520,754
 US. Cl 128/287; 128/284; 128/290 R  Int. Cl. A61F 13/16  Field of Search... 128/284, 287, 290 R, 290 H,
 References Cited UNITED STATES PATENTS Barlet .7 128/290 R l.283,632 11/1918 Beck 128/290 R 2,082,276 6/1937 De Ville... 128/290 H 3,626,945 12/1971 Mobley v 128/289 3,749,627 7/1973 Jones. Sr 128/290 R X 3,838,694 1 0/1974 Mesek 128/287 Primary Examiner-Aldrich F. Medbery  ABSTRACT A disposable diaper is provided with an adhesive tab having a relatively long free end which is removably tucked in 21 facing sheet of the diaper. The tab is attached to a diaper backing sheet on the outside surface of the diaper and at a marginal location thereof, and the free end, having a tacky surface covered with a release strip, is removably received in a slot provided for that purpose in the diaper facing sheet.
7 Claims, 4 Drawing Figures US. Patent Nov. 25, 1975 TUCKED IN FACING SHEET THEREOF BACKGROUND OF THE INVENTION This invention relates to disposable diapers. More particularly, this invention relates to disposable diapers adapted to be secured in place by adhesive tabs.
Disposable diapers provide substantial advantages in convenience over conventional diapers and commonly have a generally quadrilateral configuration with straight or curvilinear longitudinal edges. Disposable diapers comprise a moisture-impermeable backing sheet and a moisture-retaining layer anchored thereto, and are conveniently secured aboutan infant by means of adhesive tape tabs which are affixed to the diaper along a longitudinal edge thereof, thus eliminating the need for extraneous fasteners, such as pins. In order to protect the adhesive surfaces of the tape tabs, usually a release sheet is applied over these adhesive surfaces for subsequent removal when the diaper is about to be used. However, such tabs usually project beyond the confines of the diaper to a considerable extent and interfere with the efficient manufacture and packaging of the diaper.
In an attempt to solve the foregoing problems, US. Pat. No. 3,776,234 to Hoey proposes to fold the tab over on itself at the diapers edge and to adhesively attach a portion of the folded-over tab segment to the inside surface of the diaper in order to keep the tab from interfering with the manufacturing machinery and with the folding and packaging operations. This requires that the edge of the diaper backing sheet be folded over to present an attachment surface at the front or inside face of the diaper and a relatively involved tab design is necessary for this purpose. Also, undesirable tearing of the diaper facing fabric may result if such a tab is adhesively attached to the facing fabric of the diaper.
US. Pat. No. 3,646,937 to Gellert shows a fastening tab which is provided with a release surface which is permanently bonded to the inside surface of the diaper; however, such an arrangement is disadvantageous because the release surface may be placed in contact with the infants skin when the diaper is used.
Additionally, for ease of application of the diaper about an infant, a relatively long free end for the adhesive tab is desirable, yet the longer the free end the more severe are the manufacturing and packaging problems.
SUMMARY OF THE INVENTION The present invention contemplates a disposable diaper provided with an improved adhesive tab fastener having a relatively longer free end. The disposable diaper embodying the present invention comprises a thin, moisture-impervious backing sheet, a moistureretaining layer attached to the backing sheet and which includes a pad of absorbent material superposed on the backing sheet and a facing sheet overlying the pad and substantially coextensive with the backing sheet, and an adhesive tab having a fixed end secured to the backing sheet on the outside surface of the diaper and at a marginal location thereof. The free end of the tab, preferably longer than the fixed end, provided with a tacky surface which faces in the same direction as the inside surface of the diaper, is folded over the inside surface of the diaper and is removably received in a slot in the facing sheet. A cover strip provided with a release coating on one surface thereof is releasably attached to and covers the tacky surface of the free end. Preferably, the cover strip extends longitudinally beyond the tacky surface of the free end.
BRIEF DESCRIPTION OF THE DRAWING In the drawing,
FIG. 1 is a perspective view of a disposable diaper embodying the present invention, parts of the diaper being broken away to show interior construction;
FIG. 2 is a fragmentary elevational view, on an enlarged scale, taken along plane 2--2 in FIG. 1;
FIG. 3 is a fragmentary perspective view of a diaper illustrating another embodiment of the present invention; and
FIG. 4 is a perspective view showing the diaper of FIG. 1 in a configuration assumed when the diaper is applied about an infant.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, disposable diaper 10, having a substantially quadrilateral configuration, is provided with moisture-impermeable backing sheet 11 which forms an outside surface for direction away from an infant and with an absorbent pad means 12 situated on backing sheet 11 and attached thereto by means of an adhesive bead such as bead 13, or the like. Moisture-pervious facing sheet 14, forming an inside surface for direction toward the infant, overlies absorbent pad 12 and is substantially coextensive with backing sheet 11. Facing sheet 14 is similarly attached to backing sheet 11 by a plurality of adhesive beads, such as bead 15, for example. Adhesive tab fastener 16 comprises fixed end 17 attached to the outer surface of backing sheet 11 at a marginal location of diaper 10 by adhesive layer 19 and free end 18 which extends beyond the longitudinal margin of diaper 10. Free end 18 usually is longer than attached or fixed end 17 and is provided with a pressure-sensitive adhesive layer such as layer 21 which can be a continuation of adhesive layer 19.
Cover strip 20 covers pressure-sensitive adhesive layer 21 and extends longitudinally beyond the tacky surface of layer 21 to provide grippable end portion 22 which facilitates the removal of cover strip 20 so as to expose adhesive layer 21 when tab 16 is prepared for use. Grippable end portion 22 is folded back against the main portion of cover strip 20 as shown in FIG. 2.
For removable retention of tab fastener 16 against facing sheet 14 until such time when fastener 16 is about to be used, longitudinal slot 23 is provided in facing sheet 14 near a longitudinal margin of diaper 10 for receiving the terminal portion of tab fastener 16 therein. Preferably slot 23 is situated between consecutive adhesive beads on backing sheet 11, e.g., adhesive beads 13 and 15 so that facing sheet 14 will lie relatively flat against backing sheet 11 after insertion of free end 18 in slot 23. Longitudinal slot 23 can be substantially parallel to the longitudinal margin of diaper 10; however, to facilitate insertion of free end 18 into slot 23 during manufacture, preferably slot 23 forms an acute angle with the longitudinal margin of diaper 10, more preferably an acute angle of about 40 to about degrees. Additionally, in some instances, and depending on the length of free end 18, it may be desirable to select the size of absorbent pad 12 so that the terminal portion of free end 18 also underlies pad 12 as illustrated in FIG. 2.
Adhesive tab fastener 24 in FIG. 1 is shown after it has been pulled from longitudinal slot 27 which is situated in facing sheet 14 between adhesive beads 28 and 29. Grippable end portion 26 of cover strip 25 extends upwardly and can be readily grasped and pulled away from tab fastener 24 to expose the underlying tacky surface thereof.
FIG. 3 illustrates disposable diaper 28 provided in facing sheet 31 with longitudinally-disposed slots 29 and 30 which run substantially parallel to the longitudinal edges of diaper 28. Tab fastener 32 is shown lying flat against facing sheet 31 and tucked in slot 29 whereas tab fastener 33 is shown in a configuration assumed after being pulled out from slot 30.
When diaper is applied about an infant, it assumes the configuration shown in FIG. 4 with tab fasteners 16 and 24 being adhesively attached to diaper backing sheet 11 and holding diaper 10 in place.
The adhesive tab suitable for the purposes of the present invention can be made from a wide variety of materials. Particularly preferred materials for thispurpose are polyalkylene webs such as polyethylene sheet, polypropylene sheet, and the like.
The pressuresensitive adhesive layers such as layer 21 are provided by applying a coating of a pressuresensitive adhesive composition known in the art to the appropriate Surfaces of respective tab free ends such as free end 18. The applied adhesive shall have good tack, good cohesive strength, good resistance to moisture and good resistance to aging. Illustrative of such adhesive compositions are mixtures of natural or synthetic rubber, zinc oxide, and various resins, also latices of natural or synthetic rubber, or water dispersions of acrylic tacky polymers or copolymers, and the like.
Cover strips and can be made from smooth plastic film having a relatively non-adhering surface, from paper coated with a silicone release'compound, or similar materials.
Several different types of facing materials may be used for diaper facing sheet 14. For example, facing sheet 14 may be made up of a mixture of fibers consisting predominantly of inexpensive short cellulosic fibers such as wood pulp fibers or cotton linters, in amounts of about 75% to about 98%, the balance being textile length fibers such as rayon as described in U.S. Pat. No. 3,663,348 to Liloia et a1.
Facing sheet materials suitable for use in this invention can have fabric weights in the range of about 1 to 5 oz/yd and densities of less than 0.15 g/cc, generally in the range between 0.05 and 0.1 g/cc. The dry strength of the facing sheet for a fabric having a weight of about 1.5 oz/yd is at least 0.15 lbs/in of width in the machine direction and at least 0.1 lbs/in of width in the cross direction. Such fabrics have unusually good elongation, loft, softness, and drape characteristics in comparison to prior products incorporating any substantial amount of short fibers.
Facing sheet 14 may also be made of an apertured, nonwoven fabric which is formed, for example, in accordance with the teachings of commonly assigned US. Pat. Nos. 2,862,251; 3,081,514; and 3,081.515. Briefly. such fabrics are foraminous structures wherein groups or groupings of fibers have been rearranged from a fibrous nonwoven starting web into positions surrounding less dense fabric portions by passage of a fluid through the starting material. The fibers'within the groupings are mechanically interlocked, and may. be arranged into various patterns, as is well known by those skilled inthe art. A suitable binder may be utilized to help retain the fibers in their rearranged locations, as is also well known by those skilled in the art. The fabric can be made of naturally occurring fibers, synthetic fibers, or blends thereof. Typical facing sheets made of a polyester type material can have a weight of about 0.75 oz/yd In addition, facing sheet 14 can be formed of a non apertured material, such as a nonwoven isotropic web, or the like. In all of the aforementioned facing materials, the material should be relatively hydrophobic so as to retard wicking within the facing layer.
Highly moisture-absorbent fibrous pad or batt 12,
which usually is substantially rectangular in shape but smaller than the facing sheet and the backing sheet, is centrally disposed between facing sheet 14 and backing sheet 11. Pad 12 is usually anchored to backing sheet 11 by means of an adhesive bead, heat sealing, or similar expedients. Pad 12 can be formed in accordance,
with the teachings of US. Pat. No. 3,612,055 to Mesek et al. If desired, a highly moisture-absorbent layer can be provided substantially coextensive with backing sheet 11 and facing sheet 14.
A suitable backing sheet material for the diapers em-. bodying the present invention can bean opaque poly ethylene web about 0.001 inch thick. Another suitable material for this purpose is a polyethylene terephthalate web having a thickness of about 0.0005 inch. Typical disposable diapers which can be fitted with tab-type adhesive fasteners described hereinabove are shown in US. Pat. No. 3,612,055 to Mesek et al. and in US. Pat. No. 3,683,916 to Mesek et al. Other suitable disposable diaper structures which can be improved by the present tab-type fasteners are shown in US. Pat. Re. 26,151 to Duncan et al.
.In use, a diaper equipped with the adhesive fasteners of the present invention is applied to the infant by laying out the diaper on a suitable flat surface and placing the infant thereon so that the waist-underlying end of the diaper is that having the fastener means. The other end of the diaper then extends downwardly between the infants legs. Next, the downwardly-extending end of the diaper is brought up between the infants legs to a position contiguous with the front of the infants waist. The diaper is thereafter secured to the infant by placing the corners of the waist portion of the abdomen covering end as far around the infants waist as p 7 they will go and by bringing the corners of the underlying end of the diaper into an overlapping relationship with the aforementioned corners so that the diaper p snugly encircles the infants waist and provides a custorn fit.'The adhesive fasteners are then prepared for use by grasping cover strip terminal portions such as tion can be manufactured in any convenient manner. For example, a backing sheet web and a facing sheet web can be fed simultaneously fromappropriate web supply rolls and absorbent pads or panels positioned therebetween to form a laminar composite which is subsequently severed into a plurality of segments to form the disposable diapers. As the backing sheet web is fed from the appropriate supply roll the web is lined with a plurality of adhesive beads. As the facing sheet web is fed from the corresponding supply roll, the web is perforated at predetermined intervals to form slots, such as slot 23 and slot 27 therein. The perforating means. e.g.. a flat knife edge, can also serve as a guide for adhesive tape stock which can be fed into the formed slots at about the same time the perforations are made. The adhesive tape stock is, of course, covered with a suitable cover strip having a release-coated surface in contact with the tacky surface of the adhesive tape. Thereafter the adhesive tape stock is cut to provide individual segments which ultimately become the tab fasteners. The cover strips on the terminal portions of the cut segments which are not fed through the slots in the facing sheet web are then peeled off and folded back onto themselves while the underlying tape portion, presenting an exposed tacky surface is folded around the opposed marginal edges of the laminar composite and adhesively adhered to the backing sheet web to form the fixed ends of the tab fasteners. The foldedback portions of the cover strips form the aforementioned grippable end portions. Thereafter the produced laminar composite is cut into segments of predetermined size to form the disposable diapers.
The foregoing description and the drawing are illustrative but are not to be taken as limiting. Still other variations and modifications are possible without departing from the spirit and scope of the present invention.
1. A disposable diaper, having an inside surface for direction toward an infant when the diaper is worn by that infant and an outside surface for direction away from said infant, which comprises a moisture impervious backing sheet; a moisture-retaining layer attached to said backing sheet and including a pad of absorbent material superposed on said backing sheet and a facing sheet overlying said pad, substantially coextensive with the backing sheet, and having a slot provided in the facing sheet near a longitudinal margin of said diaper; and an adhesive tab fastener having a fixed end secured to said backing sheet on the outside surface of the diaper and at a marginal location thereof, and a free end provided with a tacky surface facing in the same direction as the inside surface of the diaper and releasably covered with a release-coated cover strip; said free end being removably received in said slot.
2. The disposable diaper in accordance with claim 1 wherein said free end is longer than said fixed end.
3. The disposable diaper in accordance with claim 1 wherein said moisture-retaining layer is attached to said backing sheet by a plurality of spaced adhesive beads, and wherein said slot is situated in said facing sheet between consecutive adhesive beads.
4. The disposable diaper in accordance with claim 1 wherein said slot forms an acute angle with a longitudinal margin of said diaper.
5. The disposable diaper in accordance with claim 4 wherein said acute angle is about 40 to about 50 degrees.
6. The disposable diaper in accordance with claim 1 wherein said slot is substantially parallel with a longitudinal margin of said diaper.
7. The disposable diaper in accordance with claim 1 wherein the terminal portion of said free end underlies said pad of absorbent material.
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