US 3587579 A
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O United States Patent Reinhardt N. Sabee 728 8. Summit St., Appleton, Wis. 54911 [2 1] Appl, No. 768,091  Filed Oct. 16, 1968  Patented June 28, I971  inventor 541 REINFORCEDDIAPER 9 Claims, 14 Drawing Figs.
Primary ExaminerCharles F. Rosenbaum. Attorney-Wheeler, House & Wheeler ABSTRACT: The fluff-type pad portion of a diaper is so reinforced as to increase pin strength and to preclude tearing even if extremely lightweight paper or films of synthetic resin are used to enclose the fluff. The reinforcement preferably comprises a scrim made either of woven or nonwoven fabric and incorporated in the pad either at the top or bottom or at an intermediate level and extending close enough to the side or end margins of the diaper to connect with and strengthen the portions which receive a diaper pin. The preferred scrim comprises monofilaments which are flexible and yield under tension and are attached to each other at junction points.
sum 2 OF 2 i7. w ll! REINFORCED DIAPER BACKGROUND OF THE INVENTION A paper web such as frequently provides the cover sheet for a diaper has considerable strength lengthwise of the diaper but very little lateral strength or pin strength. It is easy to break such a web and to tear the contained fluff pad either in applying the diaper or during use thereof. Consequently, it has been the practice to use cover webs of much greater thickness than would otherwise by required.
Reinforcement with scrim of the pulp pad or filler takes lateral as well as longitudinal stress and the upper and lower facings of the diaper may consequently be made of such lightweight material that the overall cost of the diaper is reduced by an amount in excess of the cost of the reinforcing scrim. The resulting diaper is not only less expensive but much lighter in weight, and more flexible and therefore more comfortable to the wearer. The scrim prevents the fluff from separating under tension. Yet liquids pass freely without such retardation as is caused by multiple or heavy plies of creped tissue.
SUMMARY OF THE INVENTION The invention consists in the provision of high tensile strength reinforcing fabric at some level in the interior of the fluff pad of a disposable diaper to resist stresses, and particularly lateral stresses, and thereby to enable the use of a very thin film of waterproof bottom ply material and a very thin and low tensile strength cover ply material. The reinforcing fabric is lighter in weight than the paper webs which it displaces and the net effect is to produce a diaper which has greatly reduced overall weight and cost as compared with conventional practice, at the same time being a very substantially more desirable product for reasons above-stated.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in perspective of a completed diaper embodying the invention.
FIG. 2 is a fragmentary detail view in perspective showing a pad for such a diaper with portions broken away above the intervening reinforcement.
FIG. 3 is a fragmentary detail view in perspective showing the leading end of a composite web of pulp and reinforcing scrim, portions being broken away and an appropriate length of such a web being cut offto provide to diaper pad.
FIG. 4 is an enlarged fragmentary detail view in cross section on the line 4-4 of FIG. 1.
FIG. 5 is a view similar to FIG. 4 showing a modified embodiment of the invention using scrim of less width.
FIG. 6 is a view similar to FIG. 4 showing a further modified embodiment of the invention in which the scrim is superimposed on the fluff pad instead of being incorporated within it.
FIG. 7 is a view similar to FIG. 4 showing a further modified embodiment of the invention in which the scrim is beneath the ad. p FIG. 8 is a view similar to FIG. 4 showing a further modified embodiment in which the facing ply is carried about the margins of the pad and cemented to the bottom ply beneath the ad. p FIG. 9 is a view similar to FIG. 8 showing a further modified embodiment in which a waterproofing strip extends about the side margin of the pad and is held in place by the facing ply when the facing ply is attached.
FIG. 10 is a detail view on an enlarged scale taken in cross section on the line 10-10 of FIG. I.
Flg. 11 is a fragmentary detail view similar to FIG. 4 showing a further modified embodiment of the invention in which a separate side sealing strip is bonded both to the facing and the backing.
FIG. 12 is a fragmentary view similar to FIG. 4 showing a further modified embodiment in which the side sealing strip is extrusion-coated to the side margin of the facing strip and is folded about the filler and adhesively bonded to the backing.
FIG. 13 is a view like FIG. 6 in which there are upper and lower plies of scrim.
FIG. 14 is a view like FIG. 13 in which the upper and lower plies of scrim are connected as an envelope about the pad.
DETAILED DESCRIPTION closures of the manner in which the pad itself may be rein-.
forced to permit the use of very lightweight facing and bottom plies.
By way of exemplification, and not by way of limitation, I have shown in FIGS. 4, 8 and 9 a fluff pad 12 having upper and lower components 14 and 16 with an intervening web 18 of scrim, scrim being an extremely lightweight fabric which may either be woven or nonwoven and may, for example, have openings, of perhaps one-eighth to one-fourth inch across. This fabric is made from intersecting natural or' synthetic threads or strands 20 preferably bonded together where they cross and which have very substantial tensile strength as compared with batts of fluff such as constitute the upper and lower layers 14 and 16 of the fluff filler 12. Preferably the scrim comprises extruded monofilaments of polyethylene or the like which are not merely flexible but are resiliently stretchable.
The scrim 18 preferably is substantially coextensive with the pad as shown in FIGS. 3, 8 and 9 but for some purposes, it may be less wide than the pad as indicated at 19 in FIG. 5. In the preferred construction, any pin or other fastening device used to apply the diaper will engage the scrim reinforcement and thereby make use of the very substantial tensile strength of the scrim to hold the diaper securely to the child and to resist tearing and subsequent leakage.
The reinforcing fabric or scrim 18 need not necessarily be at an intermediate level in the pad 12. FIG. 6 shows the scrim l8 superimposed on the top of pad 12 while FIGS. 7 and 10 show it underlying the bottom of pad 12. FIGS. 13 and 14 show plies of scrim above and below the pad. In FIG. 14, the plies are connected at their sides, thereby making an envelope in which the pad is enclosed.
In stating that the reinforcing scrim is, or may be, coextensive with the pad, it isnot intended to preclude the possibility of having it extend beyond the pad as at 22 in FIG. 10. The section in which FIG. 10 is taken may be either a longitudinal or a lateral section. Thus it would look the same in a different diaper design if the scrim extended laterally beyond the pad and provided an anchoring flange such as that provided at 24.
The present invention is more concerned with the reinforcement of the pad than with the manner in which the pad is enclosed to constitute the diaper. In the construction shown in FIGS. 4 and 5, a film 26 of synthetic resin constitutes the bottom ply of the diaper and it has its side margin 28 enclosing the sides of pad 12 and secured at 30 to the facing ply 32 where the margin 34 of the bottom ply laps the top surface of the facing ply.
FIGS. 5, 6 and 7 are similar in this regard. FIG. 8 shows how the facing ply 32 may have a flange 36 extending downwardly beside the pad and folded inwardly at 38 beneath the pad and connected at 40 with the bottom ply 26. In FIG. 9, the connection between the facing ply 32 and the bottom ply 26 is made by a line of adhesive at 40 substantially as shown in FIG. 8 but, to further waterproof the pad 12, I have incorporated a strip 44 of impervious synthetic film to extend about the side margins of' the pad and to be held against the pad by the side flange 36 of the top ply 32 in themanner clearly illustrated.
FIG. 10 shows how the top ply 32, with or without a waterproofing film 44, such as is shown in FIG. 9, may be extended out beyond the pad 12 to rest flat'on the upper surface of the reinforcing scrim 18, the heat seal 46 readily penetrating the scrim to secure both the scrim and the facing ply 32 to the bottom ply 26.
As already indicated, it is contemplated that in any of these various diapers in which l do not already have a flange 28'of the impervious bottom ply 26 folded up beside the pad 12 for retention of moisture, l may incorporate a moistureproof strip such as that shown at 44.
FIG. 11 shows a separately fabricated side sealing strip 50 which is adhesively bonded at 52 to the facing 32 and adhesively bonded at 54 to the backing 26. The filler q2 may be of fluff separately reinforced with scrim 18 at any level, as herein disclosed. It will, of course, be understood that the side strip 50 will be waterproof, usually being made of a strip of synthetic resin film.
In the construction shown in FIG. 12, the waterproof strip 60 is an extrusion having its margin 62 extrusion-coated directly upon the facing strip 32 so that it constitutes, in effect, a lateral extension of the facing sheet. While the strip is waterproof, the facing sheet is readily pervious to water. The strip 60 then has its margin 65 folded about the filler 12 and connected by adhesive 66 to the backing sheet 26.
In the construction shown in FIGS. 11 and 12, the filler may be either fluff or layers of tissue. It is preferably fluff and provided with scrim reinforcement in accordance with the showing made in FIGS. 2 and 4 to 9.
The constructions shown in FIGS. 11 and 12 are particularly desirable in that they contemplate the possibility of using separately fabricated side sealing strips made of materials having properties and qualities differing from the bottom ply materials in particulars such as softness, pliability, and cost. The arrangement also permits of the use of side sealing strips of more than one ply, or of selected thickness either for control of softness, or to increase pin strength, or for other objectives.
1. A diaper or the like having a pervious facing and an impervious backing and an intervening filler having scrim reinforcement, said scrim reinforcement being comprised of monofilaments attached to each other at junction points, said monofilaments being flexible and stretchable.
2. A diaper or the like according to claim 1 in which the reinforcement is disposed at an intermediate level in thefiller 3. A diaper or the like according to claim 1 in which the reinforcement is a pouch enveloping said tiller.
4. A diaper or the like according to claim-l in which the reinforcement is proximate the backing.
5. A diaper or the like according to claim 1 in which the impervious backing has integral portions which extend about a side of the filler, such portions extending upwardly beside the filler and being marginally connected with the facing.
6. A diaper or the like according to claim 1 in which the pervious facing and the backing are connected by an impervious means extending about the sides of the tiller 7. A diaper or the like according to claim 6 in which the impervious means extending about the sides of the filler comprises prefabricated strips of impervious material connected with the backing and extending at least partially onto the to surface ofthe filler.
8. A diaper or the like according to claim 7 in which said last-mentioned means has adhesive connection with the facing.
9. A diaper or the like according to claim 7 in which said last-mentioned means comprises a strip of film extrusioncoated upon a margin of the facing.