US 3356090 A
Description (OCR text may contain errors)
Dec. 5, 1967 O 5 PLANT|NGA ET AL 3,356,090
ABSORBENT BREAS T PAD Filed April 50, 1965 INVENTORS; Qua-7P LY zn/vn/vgm aa- 714 067(5 ATTORNEY.
United States Patent Filed Apr. 30, 1965, Ser. No. 452,111 Claims. (Cl. 128280) The present invention relates to breast pads and more particularly to breast pads to be worn by nursing mothers which, although designed to absorb milk or other body fluids, are comfortable and remain comfortable during use.
For breast pads for nursing mothers, it has been the practice to use absorbent pads which are cup shaped to fit the contour of the breast and which have in the inner convex surface an absorbent sheet backed by other absorbent material. These pads are worn by the mother during periods between the actual nursing of the infant. One of the difliculties with the breast pads heretofore used is that the inner surface of same became Wet and relatively uncomfortable. Also, as the fluids from the breast tend to dry on the wetted surface of the pad where it is next to the breast there is a tendency of the pad-t0 st'ck to the mother which is also uncomfortable.
It is an object of the present invention to prepare nursing pads which, although highly absorbent, will present a relatively dry face towards the patient even after they have absorbed substantial amounts of body fluid. It is a still further object of the present invention to prepare absorbent nursing pads which have a cushion layer of sponge material on the inner concave surface adapted to contact the breast of the patient which sponge-like material is not itself absorbent but provides a soft yielding surface. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example certain embodiments of this invention.
The nursing pads of the present invention have a layered construction, the pads being dish or cup shaped to better fit the contour of the breast. The inner or breast contacting layer of the nursing pads of the present invention is formed of a water-repellent synthetic cellular sponge-like material, such as polyurethane foam, that has been made pervious to milk and other body fluids, so that the same may pass thereth-rough. The synthetic cellular material itself, however, is hydrophobic in nature and will not absorb the body fluids so as to present a wet saturated layer next to the skin. This water-repellent sheet or layer is on the concave side of the breast pad which is adapted to be placed against the skin of the wearer. This water-repellent layer is followed by a fluid absorbing zone which is made up of several layers of fluid absorbent materials. This absorbent Zone is followed by a third zone which is adjacent to the convex side of the breast pad and may even be on the outer surface of the convex side of the breast pad, this third zone is waterrepellent so as to prevent absorbed fluids from striking through the breast pad to its outer surface. This flu'd repellent zone may be formed of a single layer of fluid impervious sheet material such, for example, as a sheet of plastic film or may be made up of several layers of cellulosic sheet material impregnated with a water-re- 3,356,@% Patented Dec. 5, 1967 same time not be as impervious as a plastic sheet, thus permitting air and moisture vapor to readily pass therethrough. As previously indicated, this water-repellent zone which is adjacent to the convex side of the breast pad may be on the outer surface of the pad, or it may in turn be covered by a further sheet of covering fabric or paper containing a decorative pattern or finish for the purpose of making the pads more attractive.
Referring to the drawings:
FIGURE 1 is a top plan view of a nursing pad of the present invention with portions of the upper layers of the pad broken away to show the internal structure;
FIGURE 2 is a side view of the pad of FIGURE 1;
FIGURE 3 is a side view of the pad of FIGURE 1 with a portion of the pad cut away to show its cross sectional structure;
FIGURE 4 is a top plan view of the composite fiber sponge sheet. lining the concave side of the breast pad with a portion of the fiber layer removed to show the underlying sponge; and
FIGURE 5 is a cross sectional view taken along line 5-5 of FIGURE 4.
The breast pad 10 is cup shaped to conform more readily to the breast of the wearer. This is best illustrated in FIGURE 3. The inner concave surface 11 is formed of a soft resilient cellular sponge-like material 12 which is hydrophobic and which provides a fluid, repellent, dry, soft, inner surface. Extending through this sponge layer 12 are fluid conducting channels 13 through which milk and similar fluids can pass to an absorbent fiber layer 14-, which is adjacent the inner surface of the sponge sheet 12. Adjacent the fiber layer 14, moving from the inner surface 11 of the breast pad 10 to the outer surface 15, is a second absorbent layer 16 formed of a plurality of absorbent sheets of cellulose wadding, the same being followed by a fluid impervious barrier 17 such as a sheet of film or paper treated so as to make the same water-repellent to provide a barrier through which absorbed fluids will not pass. The barrier 17 serves to maintain absorbed fluids within the breast pad. This fluid repellent layer 17 may form the outside convex surface 15 of the pad, as it does in the pad illustrated in FIGURES 1 through 3, or the same may be covered with a decorative material, as heretofore indicated, to add to the appearance of the present pad.
The composite is died into the cupped shape illustrated and compressed and sealed around the edge to provide a rim 18, best illustrated in FIGURE 3, which ma ntainS the various elements in their assembled position and provides a seal to prevent the escape of absorbed milk and other fluids emitted from the breast during periods between the feeding of the infant and absorbed by the breast pad.
The material forming the inner sponge surface 11 of the breast pad and the immediately adjacent absorbent fiber layer 4 is best illustrated in FIGURES 4 and 5. For the sponge layer 12, any cellular, hydrophobic sponge material may be used that is sufficiently flexible and resilient for the purpose intended.
The preferred materials for the sponge layer 12 are the soft, flexible polyurethane foams, such as the polyurethane polyester foams and the polyurethane polyether foams. These materials are thermoplastic. Other cellular synthetic foam resins may be used, as long as they are pellent agent so as to prevent strike-through but at the sufficiently soft and flexible for the purpose. Such other materials, for example, are those formed of nylon, polyethylene, rubber, polyvinyl chloride, and formularized polyvinyl alcohol. The material should be sufficiently flexible and conforming to fit over the natural contours of the breast and should be sufficiently soft and resilient to act as a protective cushion without irritation. Accordingly, it is generally desired that the sponge material have a flexibility of about 17 to 74% of original thickness and a resiliency of about '78 to 98% of original thickness. The flexibility and resiliency are measured in the following manner. The original thickness is measured with a micrometer having a dead weight of 56.7 grams per square inch of sample. A 500 gram weight is added, and the thickness is read after 60 seconds to find flexibility. The 500 gram weight is removed and after 60 seconds the thickness is read to find resiliency. Results are expressed in terms of percentage of original thickness. The inner sponge layer 12 is preferably quite thin, having a thickness in the order of about 0.03 to 0.05 inch. The sponge material may have either an open cellular structure or a closed cellular structure. However, it is generally preferred that the cellular sponge material used have suflicient open cells to permit the ready passage of air therethrough.
The sponge layer 12, although nonabsorbent itself, is provided with a plurality of fluid conducting channels 13 passing therethrough. These are formed of fiber bundles extending from the fiber layer 14 down through to the concave surface 11 of the sponge sheet 12. Such absorbent fiber cellular products are obtained by needling fibers from the fiber layer 14 down through the sponge sheet and are described, for example, in US. Patent No. 3,122,142 issued Feb. 25, 1964.
In the preferred construction of the breast pads of the present invention, the fiber layer 14, immediately adjacent the cellular foam sheet 12, contains a small amount of thermoplastic fibers and preferably is formed of a blend of polypropylene fibers as the thermoplastic fibers with rayon fibers. This fiber web or layer 14, from which fibers extend down through the cellular sheet 12 to form the fluid conducting channels 13, may be followed where desired by a second fiber layer 19 containing a somewhat higher concentration of thermoplastic fibers. This aids in forming the sealing rim 18 where the same is formed through heat and pressure. The two fiber webs 14 and 19 are followed by a further absorbent zone 20 comprising a plurality of sheets of cellulose wadding 21. Absorbent zone 20 is followed by a water impervious fluid barrier 22 preferably formed of a thermoplastic film material. Polyvinyl chloride films, for example, are well suited for this fluid barrier sheet 22. By using a thermoplastic barrier film and incorporating thermoplastic fibers, such for example as the polypropylene fibers in the fiber layers 14 and 19, a structure is provided that is readily sealed at the edge 18 by heat and pressure through conventional heat sealing methods.
The breast pads can be readily formed by first forming a composite laminate by superimposing, one on top of the other, the particular sheet materials and fiber webs in the order previously referred to, and then placing this laminate in a conventional heat and pressure die, which simultaneously molds the composite sheet into the cupped shape, and compresses the same around the edge to fuse the thermoplastic materials into the sealing rim 18.
The thermoplastic fibers in the fiber webs 14 and 19, not only help in providing the heat and pressure seal at the edges of the pressed pad but also serve to help maintain the pad in its molded cupped shape.
As milk and other fluids, which may exude from the breast between feedings, are not absorbed by the hydrophobic cellular foam sheet 12 which forms the inner concave surface 11 of the breast pad but are conducted through this cellular sheet 12 away from the breast by means of the fluid conducting channels 13 a relatively dry, nonsoggy surface is maintained in contact With the patient while fluids are removed and contained within the absorbent layers 14, 19, and 20. By placing the highly absorbent cellulose wadding sheets 21 near the outer convex surface of the pad 10 the fluids are drawn through the breast pad so as to prevent too great an accumulation of fluids in the initial fiber layers.
The fiber layers 14 and 19, which are formed of carded fibers, besides providing some absorbency help to distribute the absorbed fluids laterally through the breast pad, thus improving the over-all absorbent characteristics of the same.
The following specific example will help to further illustrate the practice of the present invention. The same is given for purposes of illustration only, however, and the invention is not limited thereto.
A circular cup shaped, absorbent nursing pad with a compressed rim extending around the edge of the pad is molded by a heated die using a composite of the following materials:
A soft, flexible, polyurethane foam sheet having a thickness of 0.039 inch and a carded fiber web comprising a blend of rayon and polypropylene fibers, the fibers having a denier of one and one-half and a length of one and a half inches, and the polypropylene fiber content comprising 9% of the fiber web, fibers of the web being needled into the polyurethane foam sheet so as to just extend through the opposite surface. This composite fiber foam sheet forms the bottom sheet of the composite structure fed into the die, with the foam surface opposite the web of needled fibers being on the outside. Superimposed on this on the needled fiber web side is a carded web consisting of a blend of rayon and polypropylene fibers. The polypropylene fibers comprise 12% of the web, and the rayon and polypropylene fibers have a denier of 1 /2 and a length of 1 /2 inches. Placed on top of this second fiber web is a sheet of polyvinyl chloride plastic film. This composite structure is placed in the die, the top plate of which has a temperature of 390 to 400 F., and the bottom plate of which has a temperature of 380 to 390 F. The composite is placed with the bottom curved plate of the die being in contact with the polyurethane foam sheet which forms the concave surface of the breast pad. The die is closed and the breast pad formed at a pressure of approximately 300 pounds ram pressure per square inch with a dwell time of six seconds. The die is so formed that this pressure is applied around the edge of the breast pad formed. The die is then opened, and the breast pad removed. A soft, cushion-like pad having good feel and good absorbent characteristics is obtained.
A particular embodiment of the invention has been used to illustrate the same. The invention, however, is not limited to the specific embodiment illustrated. 'In view of the foregoing disclosure, variations or modifications will be apparent and it is intended to include within the invention all such variations and modifications except as do not come within the scope of the appended claims.
Having thus described our invention, We claim:
1. An absorbent cupped breast pad having a concave inner surface and a convex outer surface said concave inner surface being formed of a resilient water-repellent cellular sheet, a first absorbent zone containing an absorbent fiber web formed of water wetable fibers adjacent said cellular sheet, fibers from said web extending through said cellular sheet as fiber bundles to form fluid conducting channels extending through said cellular sheet said fiber bundles acting to conduct fluids from the outer surface of said cellular sheet to said first absorbent zone, a second absorbent zone formed of a plurality of sheets of absorbent cellulose wadding, and a water impervious sheet adjacent said second absorbent zone on the convex side of said breast pad said second absorbent zone being between said first absorbent zone and said water impervious sheet, and a rim extending around said breast pad formed from the compression of said materials.
2. An absorbent breast pad of claim 1 in which said cellular sheet is formed of a thermoplastic material and in which said fiber web contains thermoplastic fibers therein.
3. An absorbent breast pad of claim 2 in which said cellular sheet is formed of polyurethane foam.
4. An absorbent breast pad of claim 3 in which the fibers in said first absorbent zone are a blend of rayon fibers and polypropylene fibers.
5. An absorbent breast pad of claim 4 in which the first absorbent zone contains two webs of carded fibers and in 6 which only the fibers from the carded web adjacent said cellular sheet extend down through said cellular sheet.
References Cited 5 UNITED STATES PATENTS 2,727,278 12/1955 Thompson 128463 2,891,544 6/1959 London 128--280 2,896,623 7/1959 Fitzgerald 128280 10 RICHARD A. GAUDET, Primary Examiner.
C. F. ROSENBAUM, Examiner.