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United States Patent m
Minetola et al.
[li] Patent Number:  Date of Patent:
 DIAPER WITH SOURCE REDUCTION
OVERLAY AND HAVING IMPROVED
 Inventors: James A. Minetola, Peachtree City;
L. Jane Weeks; M. Carletta
Shelhorse, both of Newnan, all of Ga.
 Assignee: Pope & Talbot Company,
 Appl. No.: 710,993
 Filed: Jun. 6,1991
Related U.S. Application Data
 Continuation-in-part of Ser. No. 472,052, Jan. 31, 1990, abandoned.
 Int. CI.' A61F 13/15; A61F 13/20
 U.S. CI 604/385.2; 604/385.1;
 Field of Search 604/385.2, 385.1, 398
 References Cited
U.S. PATENT DOCUMENTS
3,842,838 10/1974 Gellert 604/365
4,037,602 7/1977 Hawthorne 604/385.1 X
4,636,207 1/1987 Buell .
4,657,539 4/1987 Hasse .
4,695,278 9/1987 Lawson .
4,704,116 11/1987 Enloe .
4,738,677 4/1988 Foreman .
4,743,246 5/1988 Lawson .
4,795,452 1/1989 Blaney .
4,795,454 1/1989 Dragoo .
4.808.177 2/1989 DesMarais et al 604/385.2 X
4.808.178 2/1989 Aziz .
4,816,025 3/1989 Foreman 604/385.2
4,822,435 4/1989 Igaue et al 604/385.2 X
4,834,740 5/1989 Suzuki .
4,834,742 5/1989 Wilson .
4,842,596 6/1989 Kielpikowski .
4,846,823 7/1989 Enloe .
4,846,825 7/1989 Enloe .
4,892,528 1/1990 Suzuki et al 604/385.2
4,904,251 2/1990 Igaue et al 604/385.2
5,061,260 10/1991 Callahan et al 604/378
Primary Examiner—Randall L. Green
Assistant Examiner—Elizabeth M. Burke
Attorney, Agent, or Firm—Francis J. Bouda
An absorbent disposable sanitary product such as a disposable baby diaper has an absorbent core and a multi-ply body-contacting topsheet. The construction of the diaper reduces raw material consumption and also waste at the source of manufacture and, therefore, is environmentally attractive. One of the plys of the topsheet contacts the body but not the core, and another contacts the absorbent core, as well as the body, with a space between the plys. The body-contacting ply has a plurality of upstanding cuffs which improve fecal containment, and the space between the plys reduces wet-back. The thickness of the multi-ply body-contacting topsheet is less than the thickness of conventional, single ply, nonwoven topsheets.
15 Claims, 2 Drawing Sheets
DIAPER WITH SOURCE REDUCTION OVERLAY AND HAVING IMPROVED FECAL CONTAINMENT CHARACTERISTICS
This application is a continuation-in-part of U.S. application Ser. No. 07/472,052 filed Jan. 31, 1990, now abandoned.
BACKGROUND OF THE INVENTION
Disposable baby diapers have been on the market for 40 years, but for the first 15 of those, the most popular version was the European two-piece, or Swedish diaper, which had a plastic pant arrangement with a separate removable and disposable absorbent pad or core.
In the mid-1960's, Procter & Gamble Company developed and effectively commercialized the one-piece disposable diaper having a rectangular absorbent pad with an integral plastic backing sheet folded into a "wing"-shape and marketed under the trademark "PAMPERS". Such a product is illustrated by the Duncan U.S. Pat. No. 3,180,335.
Ten years later, in the mid-1970's, the shaped elastic leg diaper became popular and has dictated the baby diaper development for the last 15 years. This product is illustrated by the Buell U.S. Pat. No. 3.860,003.
During the last few years, at least nine specific significant changes have been made to the disposable baby diaper:
1) Dry-touch covers with transport sub-layers (Meyer U.S. Pat. No. 4,798,603).
2) Frontal tapes with fit guides (Hirotsu U.S. Pat. No. 4,662,875).
3) Elastic waist bands (Kievit U.S. Pat. No. 4,515,595).
4) Multistrand elastic legs (Suzuki U.S. Pat. No. 4,425,127).
5) Superabsorbent cores (Weisman U.S. Pat. No. 4,610,678)
6) Leakage control end dams (Woon U.S. Pat. No. 4,296,750).
7) Stretchable tapes (Jacobs U.S. Pat. No. 3,800,796).
8) Gender specific cores (Weisman U.S. Pat. No. 4,673,402).
9) Fecal control cuffs (Enloe U.S. Pat. No. 4,704,116).
Of these improvements, the most recent and technically intriguing are the dry-touch cover and the fecal control cuffs.
The dry-touch cover creates a body-contacting surface which is hydrophobic and, therefore, presents no moisture against the body of the infant wearing the diaper. To accomplish this end-result, the covers have been made of plastic film or of carded, melt-blown, spun bonded or hydroentangled hydrophobic fibers, to permit rapid pass-through of the fluid to the diaper cores which have been made particularly and effectively absorbent, so that the fluid can be entrapped in the core. The core is designed so that it reduces as much as possible the wet-back of the fluid, under pressure, toward the body of the infant.
This dry-touch cover can also be made more effective by increasing the thickness of the coverstock material as shown in the Brock U.S. Pat. No. 4,766,029, or by the utilization of the Procter & Gamble perforated plastic film illustrated by the Thompson U.S. Pat. No. 3,929,135.
The thickness of the coverstock material can also be increased by utilizing high-loft fibers as shown in the Muhlratzer U.S. Pat. No. 4,761,323 or, as in the Kimberly-Clark Meyer U.S. Pat. No. 4,798603, by introducing one or more sub-layers of material between the coverstock and the core to draw the fluid away from the coverstock by capillary action.
The thicker the caliper of the web of the coverstock, the more expensive it becomes (because of material 10 costs and production costs) and, quite frequently, it also becomes stiffer. All of this renders it less desirable than a lightweight, thin coverstock material.
As for the fecal control feature, changes to the early wing-fold "PAMPERS" included upstanding edges as 15 shown in Schroeder U.S. Pat. No. 4,246,900 and Buell U.S. Pat. No. 4,636,207. The barrier "cuffs" were first commercialized in Japan as illustrated by the Suzuki U.S. Pat. No. 4,834,704 and Igaue U.S. Pat. No. 4,822,435. More recent diapers have featured the barri20 ers shown in the Enloe U.S. Pat. No. 4,704,116 and the Lawson U.S. Pat. No. 4,695,278.
The effectiveness of such a construction is in its ability to contain feces (which generally do not penetrate into the absorbent core as does urine), by preventing the 25 feces from spilling over the edge of the diaper, soiling the infant's garments or the surrounding environment.
Each of the features referred to above, particularly the dry-touch cover and the fecal containment cuffs have been developed independently of each other, and 30 it is the object of the present invention to improve the performance by decreasing the wet-back of the diaper and, at the same time, by providing better fecal containment. This is done by providing a multi-ply coverstock of thin web material, one web of which also provides 35 the fecal containment cuffs. The end result is that the cost of the coverstock is significantly reduced, the passthrough of the fluid from the body-side into the core is enhanced, the wet-back of the fluid from the core back to the body is reduced, the feces are kept on the diaper, 40 and the overall performance of the diaper is enhanced. As significant as is the design with regard to performance, it also is important in that it is a major step in the source reduction of waste and in the consumption of less raw material, and thus it reduces the adverse envi45 ronmental impact of disposing of disposable diapers.
DESCRIPTION OF THE INVENTION
The disposable diaper of the present invention is generally similar to the shaped elastic leg products pres
50 ently on the market, in that it includes (1) a backsheet which may be pervious to moisture vapor, but is impervious to fluid, (2) a topsheet which is in contact with the body of the infant and permits rapid pass-through of the urine into the absorbent core, and (3) an absorbent core,
55 between the backsheet and the topsheet, which may be enhanced by the addition of superabsorbent materials or the like.
The diaper of the present invention, however, has a construction which provides better performance, be
60 cause it does not have a sub-layer under the topsheet but, in fact includes an overlayer which improves the re-wet characteristics of the diaper without increasing the caliper of the coverstock material of which current diapers are made. Furthermore, there is a cost-improve
65 ment characteristic, because each of the layers of the multi-ply coverstock is less than half as thick as the conventional coverstock, and, in a major portion of the diaper, only one of the layers of the topsheet extends the