US3460536A - Sanitary napkin with conformable wrapper - Google Patents

Description

g- 1969 J; F. CHAMPAIGNE, JR 3,460,536

SANITARY NAPKIN WITH CONFORMABLE WRAPPER Filed on. 21, 1966 2 Sheets-Sheet 1 Aug. 12, 1969 J. F. CHAMPAKGNE, JR

SANITARY NAPKIN WITH CONFORMABLE WRAPPER Filed on. 21. 1966 2 Sheets-Sheet 2 United States Patent 3,460,536 SANITARY NAPKIN WITH CONFORMABLE WRAPPER John F. Champaigne, Jr., Neenah, Wis., assignor to Kimberly-Clark Corporation, Neenah, Wis., a corporation of Delaware Filed Oct. 21, 1966, Ser. No. 588,583 Int. Cl. A61f 13/16 US. Cl. 128-290 6 Claims ABSTRACT OF THE DISCLOSURE A sanitary napkin with a conformable wrapper which is retractable in its transverse dimension and substantially non-extensible in its longitudinal direction. The wrapper conforms readily to irregular shaped pads to provide a smooth outer surface While permitting the pad to be held in close association with the body when suspended by conventional suspension means.

This invention relates to an improvement in wrapper material for absorbent sanitary pads, and to absorbent pads wrapped therewith.

Absorbent pads, such as sanitary or catamenial napkins, are customarily enclosed in a pervious outer wrapper which functions to hold together the absorbent components of the pad, and in addition provides extensions beyond each end of the pad which serve as tabs for attachment of the pad to supporting devices, whereby the pad may be suitably positioned against the body of a wearer.

Various materials have been used for such wrappers including woven gauze, non-woven adhesively bonded thread webs, woven thread webs adhesively stabilized at the thread intersections, non-woven carded fiber webs, knit fabrics, and the like. This invention relates to an improvement in the construction of wrappers of the adhesively bonded non-woven and woven thread web types.

In recent years the shapes of the absorbent pads used in sanitary napkin construction have changed from a simple elongated rectangular shape with rounded ends to more intricate shapes. Included among the latter are pads with one end tapered; fully tapered pads; pads with thigh cut-outs to form a dumb-bell or hourglass shape; pads having built-up portions on the centers, ends, or sides; and the like. As a result, it has become more diflicult to apply the outer wrapper in a manner which gives a smooth, non-wrinkled surface, or a surface which is free of protrusions which might cause discomfort or undesirable abrasion.

It is an object of this invention to provide an improved wrapper for absorbent pads which automatically con; forms to the shape of the pads, even though such shape may be of irregular configuration.

It is another object to provide a wrapper which is retractable in its transverse dimension while being substantially non-extensible in its longitudinal direction whereby when such a wrapper is used to enclose an absorbent pad it will conform to the shape of the pad and provide a smooth, outer surface, while permitting the pad to be held in close association to the body when suspended by conventional suspension means.

It is a further object to provide an absorbent pad wrapped in a pervious material which conforms readily to the outer configuration of the pad.

Other objects and advantages of the invention will be understood by reference to the following specification and accompanying drawings which illustrates several preferred embodiments of the invention.

In the drawings:

FIGURE 1 is an enlarged plan view of a section of an embodiment of the wrapper material of this invention as it appears when the transverse threads are under tension.

FIGURE 2 is an enlarged plan view similar to FIG. 1 in which the transverse tension has been released.

FIGURE 3 is an enlarged plan view similar to FIG. 1 but where the threads are interwoven.

FIGURE 4 is a perspective view of a dumb-bell shaped sanitary napkin in which the outer wrapper is the improved wrapper material of this invention.

FIGURE 5 is a perspective view of a tapered sanitary napkin in which the outer wrapper is the improved wrapper material of this invention.

The wrapper material shown in FIG. 1 is formed of two sets of spaced threads. One set of threads 12 extend longitudinally and are identified hereinafter as the warp threads. The other set 14 extend crosswise, and are identified hereinafter as the fill threads. The two sets of threads are disposed in face-to-face relation to each other with the threads of one set extending transversely of those of the other set and wholly on one side thereof. The individual threads in sets 12 and 14 are also bonded to each other at substantially all of the intersections 16 by adhesive, or other suitable means, to stabilize the permeable mesh construction. While it is preferred that the two sets of threads be bonded to each other at substantially all of the intersections, it will be seen that satisfactory performance, as herein described, may be obtained even though all intersections are not bonded. However, there should be sufiicient number of bonds to provide a stable web.

In FIG. 1, warp threads 12 consist of conventional, substantially inextensible yarns, while fill threads 14 consist of stretch yarns, of which there are many known types. Also in FIG. 1, fill threads 14 are shown as being in their stretched or fully extended condition, and in such tensioned condition resemble the conventional yarns comprising warp threads 12.

When the tension is removed, and the stretch fill threads are allowed to relax, the wrapper material takes on the configuration shown in FIG. 2, wherein fill threads 14a are fully retracted and relaxed, and assume a sinuous, crimplike configuration of the type illustrated. Warp threads 120, being substantially unstretchable retain their relatively straightline condition, even when tension forces are removed.

FIG. 3 shows a material similar to FIG. 1 except that warp threads 22 and fill threads 24 are interwoven rather than having one set of threads wholly on one side of the other set of threads. However, as in FIG. 1, warp threads 22 are bonded to fill threads 24 at a substantial portion of the intersections 26 to stabilize the open mesh construction. Also, as in FIG. 1, warp threads 22 consist of conventional substantially inextensible yarns while fill threads 24 consist of stretch yarns. In FIG. 3, as in FIG. 1, the fill threads 24 are shown in the form they would appear when tensioned and stretched out in fully extended condition. When such tension is released, fill threads 24 retract and assume a sinuous, crimp-like configuration similar to the relaxed fill threads 14a shown in FIG. 2.

FIG. 4 shows a dumb-bell or hourglass shaped absorbent pad 31 as it appears when enclosed in a wrapper material of this invention, in which the warp threads 12 comprise conventional substantially inextensible yarns and fill threads 14 comprise stretch yarns.

The wrapper material is wrapped around absorbent pad 31 and sealed adjacent overlap 33 while fill threads 14 are fully extended in the condition more clearly shown in FIG. 1. When the fill threads are allowed to relax after the wrapper is wrapped around the pad and sealed,

the fill threads 14 located in the widest part of the pad 35 and 36 cannot retract and remain in their fully extended condition as shown. Those fill threads 14a located at the narrower portions of the pad 37 and in end tabs 38 and 39 retract in the absence of any restricting bodies or tension and take on the crimp-like configuration more clearly shown at 14a in FIG. 2. As a result of this transverse retraction of the fill threads, the wrapper material shrinks where the pad is narrow, and in the end tab portions, to conform closely to the shape of the pad and remain in tight intimate contact with the absorbent pad body providing a desirably smooth surface. Since the end tabs are also caused to shrink transversely as a result of the retraction of stretch yarns 14a, the tabs present a narrower width and are easier to thread through the attachment fixtures commonly used on suspension devices.

FIG. 5 shows a fully tapered absorbent pad 41 as it appears when enclosed in a wrapper material in which the warp threads 12 comprise conventional inextensible yarns and fill threads 14 comprise stretch yarns, with the warp threads and fill threads bonded to each other at their intersections.

As is true with the pad in FIG. 4, the wrapper material is applied to the pad and sealed adjacent overlap 43 while fill yarns 14 are held under tension. When the tension is released, the fill yarns 14a retract sufficient- 1y to pull the wrapper into intimate contact with the narrowing portions of the pad and at the end tab areas. The unrestrained fill yarns again assume the sinuous, crimplike configuration as more clearly shown at 14a in FIG. 2.

Thus it will be seen that the improved wrapper material of this invention provides a means whereby absorbent pads of irregular shape may be enclosed in a wrapper which automatically retracts transversely after application, to provide the pad with a smooth outer surface. In addition to providing a neat appearance the smoothly contoured wrapper also provides wearing comfort.

It should be pointed out here that knit wrapper materials, which have been used in the past, would appear to have a similar ability to conform around irregularly shaped pads. However, as is well known, knit fabrics stretch both transversely and longitudinally when tension forces are applied in those directions. As a result when an absorbent pad is wrapped in a knit fabric and subjected to longitudinal tension, as is the case when the pad is being worn, the fabric stretches in the direction of the applied tension and necks down in the transverse direction. Pads wrapped in a knit fabric thus are distorted and squeezed out of shape, so that they lose some of the special absorption characteristics the particular shape of the pad was meant to provide. The inherent stretchability of knit fabrics also causes the pad to sag away from the body after attachment; whereby the ability of the pad to absorb exudate without fluid loss or garment staining is impaired.

The wrapper of this invention overcomes these disadvantages. When tension is placed on the warp threads of the instant wrapper during use, these warp threads, being substantially inextensible, do not stretch and cause necking down of the cover. The fill threads are unaffected by longitudinal tension since the warp threads do not stretch. As a result, the fill threads remains in retracted condition, retaining their close contact with the absorbent pad, and avoiding the possibility of transverse pad distortion by wrapper pressure.

The threads employed in fabricating the improved wrapper material may be made up of natural or synthetic fiber, and should be of a weight consistent with the function described. For sanitary napkins a denier in the range of 30 to 150 has been found satisfactory. The warp threads should consist of conventional substantially nonextensible yarns for the reasons set forth above. The fill threads may consist of any of the known types of stretch yarns, natural or synthetic, and preferably should be in the same weight range as the warp threads.

It is not important whether the wrapper material is of non-woven construction as shown in FIG. 1 or of woven construction as shown in FIG. 3. It is important however for the sets of threads to be adhesively attached to each other at a sufiicient number of their intersections to provide a stable fabric wherein the threads do not slide with respect to one another. It is preferred that a majority of the intersections be attached. For attachment purposes, a soft thermoplastic adhesive is preferred although other suitable adhesives may be used. If thermoplastic materials are used in the thread construction, these may also be activated by heat to provide such attachment.

The absorbent pad element may be of any conventional type such as a pad of multilayered cellulose wadding, wood pulp fibers, cotton fibers, rayon fibers, other synthetic fibers, or mixtures thereof, and may include baffies, deodorants, sidestrips or the like in its construction.

It is apparent that numerous variations and changes may be made in the foregoing illustrative embodiments without departing from the spirit or scope of the invention as defined in the appended claims.

What is claimed is:

1. A sanitary napkin comprising an elongated absorbent pad and a pervious wrapper material enclosing said pad and extending beyond the ends of said pad, said wrapper material being comprised of two sets of spaced threads, one of said sets extending in the longitudinal direction of the pad, the second of said sets extending in the transverse direction of said pad and being in contact with said first set at their crossings, said threads being attached to each other at a majority of said crossings, said first set of threads consisting of conventional non-extensible yarns and said second set of threads consisting of stretch yarns, said stretch yarns being stretched in substantially fully extended condition where the wrapper is in contact with the full width of said pad and being contracted and unstretched in areas of the wrapper which extend beyond the ends of said pad.

2. The sanitary napkin set forth in claim 1 wherein said first set of threads in said wrapper are positioned wholly on one side of the threads in said second set.

3. The sanitary napkin set forth in claim 1 wherein the threads of said wrapping in said first set are interwoven with the threads in said second set.

4. The sanitary napkin set forth in claim 1 wherein said absorbent pad is of irregular width having Wide portions and narrow portions, and wherein the individual threads in said second set which are located contiguous to said narrow portions of the pad are contracted sufficiently to conform said wrapper closely to the configuration of said narrow portions.

5. The sanitary napkin set forth in claim 4 in which said pad is of dumb-bell configuration.

6. The sanitary napkin set forth in claim 4 in which said pad is of tapered configuration.

References Cited UNITED STATES PATENTS 2,404,837 7/1946 Goldthwait l28156 2,574,029 11/1951 Foster 139422 2,900,980 8/1959 Harwood 128-290 2,902,037 9/1959 Harwood et al. 128290 2,973,760 3/1961 Dudley 128290 3,169,558 2/1965 Aleixo et al 139-421 3,236,238 2/1966 Morse l28290 3,287,788 11/1966 Goodbar et al. 139-42l 3,371,668 3/1968 Johnson 12829O CHARLES F. ROSENBAUM, Primary Examiner US. Cl. X.R. 139-421

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