US 3626944 A
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Description (OCR text may contain errors)
United States Patent lnventor Charles H. Schaar Lake Zurich, 111.
App]. No. 38,324
Filed May 18, 1970 Patented Dec. 14, 1971 Assignee The Kendall Company Boston, Mass.
DISPOSABLE ABSORBENT ARTICLE 6 Clalms, 4 Drawing Flgs.
U.S. CI 128/287 lnt. Cl A611 13/16. Field 01 Search 128/284,
 References Cited UNITED STATES PATENTS 3,043,307 7/1962 Weston 128/288 X 3,081,772 3/1963 Brooks et al 128/287 3,225,764 12/1965 Magid 1281288 3,417,751 12/1968 Murdoch 1281287 3,426,756 2/1969 Romanek 128/287 3,568,676 3/1971 Del Guercio 128/287 Primary ExaminerCharles F. Rosenbau AuorneyRoland V. Patrick ABSTRACT: A disposable absorbent article having a backing comprising a sheet of liquid and air impervious material with one or more sealed pockets, having a volume of air trapped therein, being formed on the periphery of the sheet.
PATENTEU [[814 B71 3525; 944
SHEET 1 UF 3 DISPOSABLE ABSGRBENT ARTICLE This invention relates to disposable absorbent articles for the collection of body excretions and exudates, such as diapers, sanitary pads, wound dressings and the like.
A recurrent problem with such articles is leadage around the periphery of the article when either the rate of absorbency or the total absorbent capacity is inadequate to accommodate the material to be absorbed. It is an object of the invention to provide an improved absorbent article of the type described which eliminates the foregoing problem.
The invention features a disposable absorbent article comprising an absorbent body having a fluid pervious surface on its front side and a fluid impervious surface on its back side, and at least one air-containing pocket formed of a supple, liquid and air impervious material disposed along at least a portion of the periphery of the article.
In preferred embodiments there is provided a sheet of liquid and air impervious material covering at least a portion of the back side of the absorbent body and extending beyond the absorbent body over at least a portion of its periphery. In this form the air-containing pocket may conveniently comprise a folded-back, sealed portion of the sheet.
Other objects, features, and advantages will appear from the following description of a preferred embodiment of the invention, taken together with the attached drawings thereof, in which;
FIG. I is a perspective view of a portion of a disposable diaper incorporating the invention showing an early stage in the construction of the diaper;
FIG. 2 is a perspective view of a complete disposable diaper incorporating the invention;
FIG. 3 is a plan view of the diaper of FIG. 2 showing preferred fold lines; and
FIG. 4 illustrates the diaper of FIG. 2 as folded in the preferred fashion.
The preferred embodiment of the invention will be described as incorporated in a disposable diaper. It will be apparent, however, that the invention is not limited thereto but may be incorporated in any disposable absorbent article of the type mentioned above.
FIG. 1 illustrates the customary plastic back sheet 12 of a disposable diaper prior to being affixed to an absorbent body to form the completed diaper. As shown in FIG. 1, the sides of the plastic sheet 12 are folded over and heat sealed to the main body of the sheet for the full length of the sheet as indicated by broken lines 14 and 16.
After the step shown in FIG. 1 the absorbent body and the sheet 12 (with its folded over and sealed portions) are assembled into the final disposable diaper as shown in FIG. 2. The absorbent body preferably comprises any customary absorbent material 18 (e.g., comminuted wood pulp or fluff," cellulose wedding, or any other absorbent tissue sheet material) and an overlying top sheet 20, which is preferably a nonwoven fabric. The plastic sheet 12 is folded over to overlap the sides of the absorbent body, with the folds occurring substantially along the heat-sealed lines 14 and 16.
With the diaper in this configuration further heat sealing takes place. In the preferred embodiment illustrated in FIG. 2, heat and pressure are applied over the entire extent of the areas C. This application of heat and pressure laminates the two layers of the folded over portions of the plastic sheet 12 and the upper layer of the absorbent body. The upper layer of the absorbent body to which the plastic is thus laminated in the areas C comprises the upper layer of the absorbent material 18 throughout most of the areas C; but comprises the top sheet 20 along the inner edges of the areas C where the narrower top sheet 20 underlies the folded over portions of the plastic sheet 12. With this structure, the areas C may be used as pinning areas with the dual purpose of providing increased pinning strength and providing a pinning location which is segregated from the air pockets, A and B, so as to insure against the puncture of the air pockets.
It should be noted that, unlike areas C, the pockets A and B are free of attachment to the underlying absorbent body throughout substantially their entire length and width. The advantage of this structure is that it permits movement of the body portion of the diaper in the crotch region relative to the pockets A and B. Thus, the body portion of the diaper will have some degree of freedom of movement while the baby moves while the air pockets A and B will continue to be relatively immobile in place against the body of the baby.
In an alternative embodiment of the disposable diaper shown in FIG. 2, the areas C may be constructed so that the layers of the plastic sheet 12 are fused together but that they are either not fused or laminated to the underlying absorbent body at all or are fused to the absorbent body, for only a portion of each area C (for example, a single line of attachment for each area C running across the entire width of each area C at the end of the area away from the air pocket A or B).
If for some applications the increased pinning strength ob tained by the lamination of the entire area C were not required, the fusion of the two layers of plastic 12 could be limited to a narrow peripheral strip around each area C (with or without lamination to the underlying absorbent body as desired). This structure would permit pinning in the areas C without puncturing the air-filled pockets A and B and thereby losing the gasketing efr'ect desired.
In the preferred embodiment care is taken that pockets A and B are neither totally deflated nor inflated to a balloonlike appearance, since it has been determined that a semiinflated condition of pockets A and B gives a conformability desirable to attain as much gasketing effect as possible against the irregular surfaces of the legs, groin and buttocks without attendant discomfort for the infant.
To overcome difficulties attendant the packaging of the diaper just described a preferred medially folded form of the diaper has been developed. FIG. 3 is a plan view of the diaper of FIG. 2 illustrating the necessary fold lines required to obtain the preferred folded diaper. The fold lines are the broken lines I, u, v, w, .x, y, and z. Of these fold lines 1 and u represent folds wherein the crease is on the back side of the diaper. The remaining lines all represent folds wherein the crease is on the front side of the diaper. With folds in these directions along the lines indicated the folded diaper appears as shown in FIG. 4.
The reason for folding the diaper as shown in FIGS. 3 and 4 is that upon such folding the great bulk of air trapped in pockets A and B is forced into the regions indicated by dotted lines in FIG. 3 and labeled with the letter D. The thickness of these regions D, however, is approximately matched by the thickness of the remainder of the folded diaper, since, as seen in FIG. 4, the remainder in this folded condition is predominately multiple thicknesses of the diaper. Thus the resultant is a folded diaper of approximately uniform thickness and approximately rectangular shape. Both of these factors are important for ease of packaging.
Other embodiments of the invention will occur to those skilled in the art and are within the following claims.
What is claimed is:
l. A disposable absorbent article comprising an absorbent body having a fluid pervious surface on its front side and a fluid impervious surface on its back side, and at least one completely sealed pocket of supple, liquid and air impervious material disposed along at least a portion of the periphery of said article and a volume of air trapped within and inflating said pocket to provide surfaces which will readily conform to irregular surfaces over which said article is applied.
2. A disposable absorbent article as claimed in claim 1 wherein there is provided a sheet of supple liquid and air impervious material covering at least a portion of the back side of said absorbent body, and extending beyond said absorbent body over at least a portion of the periphery thereof, portions of said impervious material forming said completely sealed pocket.
3. The article of claim 2 wherein a portion of said sheet overlaps said absorbent body and a folded back portion of said overlapping portion of said sheet forms one side of said pocket.
4. The invention as claimed in claim 3 wherein said article is a diaper having back and front waistline portions joined by an intermediate crotch portion and having two of said pockets disposed along opposite edges of said crotch portion and extending from said back waistline portion to said front waistline portion. I
5. The diaper of claim 4 having pinning areas adjacent said front and back waistline portions of said absorbent body, beyond the ends of said pockets, whereby puncture of said pinning areas by a securing pin will not result in a loss of trapped air from said pockets.
6. The diaper of claim 4 further folded into an end-to-end packaging configuration with one folded over end having longitudinal side folds reducing the width of said one folded over end to less than the side of the other end and less than the distance between the inner sides of said pockets in said other end, the areas of said pockets remote from the crease lines lying in side-by-side nonoverlapping relation, wherein the pockets are only partially inflated and the trapped air therein is largely in the nonoverlapping portions of said pockets in said folded packaging configuration to render the thickness of each diaper in a stack thereof more uniform throughout its overall extentv l i i i P0-1050 UNITED STATES PATENT OFFICE 9 CERTIFICATE OF CORRECTION Patent No. 3, ,9 Dated December 1 4, 1971 Inventor) Charles H. Schaar It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 1, line 6, change "leadage" to --leakage;
Column 4, line 5, after the, change "side" to --width--.
Signed and sealed this 27th day of June 1972.
BEWARE MELETGHERNR. ROBERT GQTTSGHALK Attesting Officer Commissioner of Patents