US 3143113 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
g- 4, 1954 v. MILLS 3,143,113
ABSORBENT BANDAGE Filed Aug. 15, 1962 INVENTOR ATTORNEY United States Patent 3,143,113 ABSORBENT BANDAGE Victor Mills, Wyoming, ()hio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio Filed Aug. 15, 1962, Ser. No. 217,217 Claims. (Cl. 12829tl) This invention relates to an absorbent bandage and more particularly to a sanitary napkin comprising a multiplicity of plies of absorbent materiaL.
The common shortcoming found in presently used catamenial pads is that such devices fail in use prior to the time that the absorptive capacity thereof is utilized to its fullest extent. The underlying reason for such failure is that the menses, upon entering the napkin, tend to seep toward the sides and ends of the device at substantially the same rate of flow and since the napkin is considerably longer than it is wide, the menses will fiow to the side margins of the napkin prior to reaching the ends of the napkin. In order to avoid soiling of undergarments and to promote comfort, it is the usual practice for the napkin to be replaced prior to the time that the side margins of the device become wetted. At the time of changing, therefore, substantial areas of the napkin at each end thereof are still unwetted by the fiuid and consequently a substantial portion of the absorptive capacity of the napkin is not utilized.
Many arrangements designed to eliminate the undesirable consequences of side failure of catamenial pads have been proposed in the past. Examples of such proposed solutions would be the use of moisture impermeable side, bottom and edge enclosures or pouches to support a sanitary napkin in use. Another approach to the solution of the problem (and the one toward which the present invention is directed) has been an effort to cause the flow of menses to be distributed over a greater area of the napkin. To date it appears that none of the prior art solutions have attained the practical or commercial success intended. In some cases, the devices were too expensive, others were uncomfortable and in some cases the solutions were unworkable.
It is an object of the present invention to obviate the above diificulty.
Another object of the present invention is to provide a sanitary napkin with means to direct the flow of menses toward the ends of the napkin at a faster rate than toward the sides.
Briefly stated, in accordance with one aspect of this invention there is provided a sanitary napkin having an uppermost absorptive layer which is adapted to promote lengthwise flow of fluid to be absorbed and which comprises a multiplicity of plies of cellulosic webs in face-toface contact and oriented perpendicularly with respect to the plane of the face of the napkin. The layer has substantially all of its plies extending substantially lengthwise of the napkin in at least the central transverse region thereof, the outermost edges of the plies of the layer being contiguous to the face of the napkin to be placed next to the body of the user.
While the specification concludes With claims particularly pointing out and distinctly claiming the subject matter which is regarded as the present invention, it is believed that the invention will be better understood from the following description taken in connection with the accompanying drawing, in which:
FIGURE 1 is a perspective view, partly broken away, of a folded sanitary napkin utilizing the present invention;
FIGURE 2 is an enlarged section of the sanitary napkin illustrated in FIGURE 1 taken along the line 22;
FIGURE 3 is a perspective view of an alternative emice bodiment of the flow directing layer of FIGURES 1 and 2; and
FIGURE 4 is a section of the alternative embodiment of FIGURE 3 taken along line 44.
Referring to FIGURE 1, there is shown a sanitary napkin having an absorbent pad indicated generally at 11 and comprising a multiplicity of plies, the pad 11 being partly cut away to clarify its construction. As with other sanitary napkins, an outer wrap 12 of gauze or similar textile material of greater length than the pad 11 and ex tending beyond each end of the latter is utilized to enclose the absorbent pad 11 and to provide means by which the catamenial device can be supported in use. The gauze wrap 12 is depicted with the lengthwise edges 12a and 12b in position and overlapped on thelower face of the pad 11. The point of overlap on the pad is not critical insofar as this invention is concerned and may be placed where thought most practical in view of other considerations. A moisture impermeable membrane 13 is provided under the superposed absorbent layers of the pad 11. The membrane 13 is adapted to serve as a shield which prevents liquid strike-through or spotting at the bottom of the napkin, and may be constructed from any flexible impermeable material such as polyethylene having a thickness of approximately /2 to 1 /2 mils.
Directly over the membrane 13 is a lower layer or course of the absorbent pad 11. This layer may comprise lamina 14 of a suitable absorbent product such as a multiplicity of plies of crepee paper or, preferably, a thickness of airfelt. This absorbent lamina extends to the full planar dimensions of the pad and is sized to have sufficient absorptive capacity to make it well adapted for use in the catamenial field. It has been found that airfelt which is approximately 4" thick is suitable material for the absorbent lamina. In a pad having face dimensions of approximately 2.5" x 7.0", airfelt weighing 3.4 grams has an absorptive capacity of approximately 50 grams of water under no mechanical pressure.
The uppermost course of the absorbent pad 11 is a flow direction control element or layer 15. The layer 15 as shown in FIGURE 1 also is coextensive with the length and width of the pad, and comprises a multiplicity of plies of cellulose webs in face-to-face contact, with the plane of each ply being perpendicular to the planes of the upper and lower faces of the napkin and extending substantially longitudinally of the pad. While it is possible to derive some of the benefits of this invention when the layer 15 is smaller than (not coextensive with) the balance of the pad 11, maximum benefits are attained by making the face dimensions of the layer correspond to. those of the pad.
Preferably the material constituting the layer 15 should be a light basis weight (air dry, in the range of 5 to 15 pounds per ream of 3000 square feet before creping) embossed crepe paper with the machine direction thereof parallel to its depth. It has been found that the layer 15 should preferably contain 50 to 60 plies per inch of width and should be about 4- /2" in depth. The layer 15, for example, has been made from a stack of a sub: stantial number of superimposed plies of embossed creped paper having a basis weight (as stated above) of 10 pounds per ream. The plies had a length of about 6" and the stack was approximately 2" high. Slices of about thickness were cut lengthwise from the stack so as to form a plurality of layers 2" wide, 6" long and /8" deep.
Prior to use, the napkin illustrated in FIGURE 1 is enclosed completely in the gauze Wrapping. Then the device is applied with the layer 15 in a position whereby the liquid to be absorbed by the device first enters that layer, i.e., with the face 11a of the pad next to the body of the user. Because of the orientation of the plies constituting the layer 15, the portion of the menses which is not absorbed by the plies themselves is directed substantially in the longitudinal direction of the device, the spread of flow being in the planes between theindividual plies of paper, so that such flow is primarily toward the ends and into the napkin. Due to the influence of such orientation, therefore, flow toward the side of the napkin is curtailed and consequently a greater percentage of the absorptive capacity of the pad will be utilized prior to the time that in-use failure thereof occurs.
FIGURE 2 shows an enlarged lateral cross-sectional view of the assembled napkin illustrated in FIGURE 1. Here the orientation of the plies of the layer is clearly shown to be vertical or normal to the plane of the face of the napkin. The impervious membrane 13 is coextensive with the length and width of the lamina 14- and layer 15, but it should be understood that these dimensions are not critical. The membrane 13 could be extended in length and in width in order to cause it to cover the side and/or end edges of the absorbent material in the pad so as to give the wearer additional protection against failure of the device. Alternatively, the impermeable membrane may be made smaller than the largest planar dimensions of the pad, in which case it would preferably be centered so as to provide the maximum protection against liquid strike-through.
In FIGURE 3 there is shown an alternative construction for the flow direction control layer 15, utilizing a spirally wound slice 15a made from an annular roll of the absorbent tissue desired. Preferably for use with a pad 11 of 2" x 6" face dimension the initial roll should have an outer diameter of about 4%" and an inner diameter of approximately 2%". The slice or layer 15a is desirably in the range of 1" to /2" in depth, has to convolutions of the tissue per inch of diameter in excess of its inner diameter and can be severed from a flattened roll of material by utilizing cutting means which are well known to those skilled in the art. After the slice has been obtained, it is retained in the elongated or flattened shape illustrated in which sides 16 and 17, which are ultimately intended to be placed contiguous to the side edges of the pad 11, are pressed inwardly. It will be observed that when the spiral layer 15a is thus formed, the plies of the web comprising the layer are oriented as shown in FIGURE 4, in a direction normal to the plane of its face. Moreover, the direction in which the plies extend is substantially parallel to the flattened side edges 16 and 17, at least over a substantial portion of the central transverse region of the layer.
In use, the layer illustrated in FIGURES 3 and 4 may be placed atop the absorbent layer 14 of the pad 11, centered thereon and oriented so as to place the flattened sides 16 and 17 of the slice in parallelism wtih the side edges of the balance of the pad 11. It will be understood from the foregoing that in the sanitary napkin formed with the spiral layer 15a illustrated in FIGURE 3, small portions of the absorbent material 14 will not be covered by the spiral layer, but this does not significantly affect the performance of the napkin.
The statements made previously with respect to the performance of the layer 15 of the embodiment of FIG URES l and 2 are equally applicable to layer 15a, since the modified construction of FIGURE 3 also promotes the spread of flow in the longitudinal direction of the napkin and thereby limits flow in the lateral direction thereof. Consequently, the alternative embodiment flow directional device is also useful in increasing the effective absorptive capacity of a sanitary napkin.
Many modifications of the above invention may be used and it is not intended to hereby limit it to the particular embodiments shown or described. The terms used in describing the invention are used in their descriptive sense and not as terms of limitation, it being intended that all equivalents thereof be included within the scope of the appended claims.
What is claimed is:
1. A sanitary napkin for placement next to the body of the user, said napkin having a plurality of courses of absorptive material, at least one of said courses comprising an absorptive layer adapted to promote lengthwise flow of fluid to be absorbed by the napkin, said layer comprising a multiplicity of plies of cellulosic webs in face-to-face contact and normal to the plane of the face of said napkin, substantially all of said plies extending substantially lengthwise of said napkin in at least the central transverse region thereof, the outermost edges of said plies of said layer being contiguous to the portion of said napkin to which the fluid to be absorbed is first supplied.
2. In a sanitary napkin having a plurality of layers of absorptive material, an absorptive layer adapted to promote lengthwise flow of fluid to be absorbed by the napkin, said layer comprising a multiplicity of plies of cellulosic webs containing about to about 60 plies per inch of width, said plies being in face-to-face contact and normal to the plane of the face of said napkin, substantially all of said plies extending substantially lengthwise of said napkin in at least the central transverse region thereof, the outermost edges of said plies of said layer being contiguous to the portion of said napkin to which the fluid to be absorbed is first supplied.
3. The sanitary napkin of claim 2 in which said layer has a depth of about /4" to about /2".
4. The sanitary napkin of claim 1 in which said plies comprise convolutions of creped paper.
5. In an absorbent bandage, a pad having a multiplicity of layers of materials of which the bottom layer is a thin flexible waterproof film, at least one intermediate layer is a thickness of airfelt, and the uppermost layer is l a flow spreading element comprising a multiplicity of References Cited in the file of this patent UNITED STATES PATENTS 2,917,049 Delaney Dec. 15, 1959 2,952,259 Burgeni Sept. 13, 1960 FOREIGN PATENTS 883,695 Great Britain Dec. 6, 1961