US 1910872 A
Description (OCR text may contain errors)
H. R. WILLIAMS CATAMENIAL NAPKIN Filed Feb. 6, 1929 W M M Patented May 23, 1933 PATENT OFFICE HARRISON R. WILLIAMS, OF NEW YORK, N. Y.
CLTAMENIAL NAIPKIN Application filed February 6, 1929. Serial No. 337,796.
The present invention relates to an improved catamenial napkin of the type which comprises a gauze wrapper and an absorbent pad within the wrapper, the pad con- 5 sisting of a material which is readily disintegrable in water and may therefore be readily disposed of through the household plumbing system.
It is the object of the present invention to provide an absorbent pad which is so constructed that it will circumfuse theffluid in-,
teriorly of the pad and thus tend to prevent any of the fluid from passing to the under face of the pad or napkin.
Another object of the present invention is to provide a pad having the above properties but which also consists wholly of the absorbent and readily disintegrable material without the use or addition of any materials or other addition agents which may interfere with the disintegration of the absorbent material in water.
' In order to accomplish the above purposes I provide the absorbent pad with an intermediate laterally disposed layer or stratum which has the pro erty' of rapidly spreading laterally the uid that enters the pad and holding the fluid absorbed within the pad, thereby making the absorptive capacity of the pad throughout its lateral dimensions available for holding and retaining substantially all the fluid that enters the pad.
This layer or stratum is, in accordance with the present invention, composed entirely of absorbent readily disintegrable material which has been subjected to such treatment as to give the material the quality of rapidly spreading laterally any fluid that reaches it.
The present invention may be applied to catamenial napkins whose absorbent pads may be made of any of a large variety of suitable materials. The materials most commonly employed are of a fibrous cellulosic nature and the present invention is prefkin in which the absorbent pad is made of fibrated wood pulp, the term fibrated being used herein to express briefly, that by carding or other suitable treatment, the wood pulp has been disintegrated in a manner such that erably applied to the type of catamenial napits fibers have been liberated so as to produce a highly absorbent material which is readily disintegrable in water. One process by. which such fibrated wood pulp may be prepared and the product obtained by such process are disclosed in my copending application, Serial No. 111,389 filed on May 24:, 1926. The fibrated wood pulp disclosed in the above application is a soft flufl'y shortfibered material which has high absorptive qualities and is highly desirable for the manufacture of the absorbent pads in catamenial napkins. While this material is highly absorptive, any fluid that enters a pad made of this material spreads laterally only within a. very limited distance from the point of applicationof the fluid. This is probably due to the fact that the material is short-fibered and that the interlocking between the fibers is comparatively loose.
' I have found that when a thin loosely felt ed layer of this material is passed between a pair of pressure rolls so that the material becomes compressed and the fibers become more intimately and more firmly associated and interlocked with each other, the absorptive qualities of the material are so altered that fluid entering or reaching the surface of such a compressed layer of fibrated wood pulp spreads laterally very rapidly within this layer .or stratum. I therefore utilize this new property of this or similar materials by interposing a thin compressed or matted layer or stratum of such material between two superimposed layers of similar or other absorbent readily disintegrable material.
A preferred embodiment of the invention is illustrated in the accompanying drawing which constitutes a part of the present application, the drawing serving only to illustrate one embodiment of the invention and not serving to limit the invention to the specific embodiment shown therein.
In the drawing:
Fig. 1 shows a perspective view of a sanitary napkin embodying my invention.
Fig. 2 is a sectional view taken on line 22 of Fig. 1.
Referring to the drawing, reference numeral 3 indicates the gauze wrapper for the grable in water.
napkin. The absorbent pad 4 consists of three layers of absorbent readily disinte rable material, the layers being designate by the reference numerals 5, 6 and 7 The upper and lower layers 5 and 7, respectively, may be made of anydesired absorbent and readily disintegrable material. It is preferred, however, that these layers be made of fibrated wood pulp which is manufactured in accordance with the process described in the copending application referred to hereinabove. This material is made of wood pulp, the fibers of which have been liberated in any manner desired and converted into loose felted sheets which are cut to the desired shape suitable for catamenial napkins. This material is soft and flufl'y, is highly absorbent and readily disintegrable in water.
The intermediate layer or stratum 6 is preferably made of the same fibrated wood pulp, and is therefore also readily disinte- This layer, however, instead of being loosely felted like the layers 5 and 7 has been previously subjected to pressure between the pressure rolls so that it is compressed and the fibers are firmly interlocked with each other.
This intermediate layer or stratum 6 which is very thin as compared with the thickness of the layers 5 and 7 and may be as thin as one-sixteenth or one-eighth of an inch and not substantially thicker than one-fourth of an inch, has the property of rapidly spreading laterally any fluid that enters the pad. As a consequence of the presence of the intermediate layer 6 in the pad 4 any fluid that enters the pad passes through the layer 5 until it reaches the layer 6. During the passage of the fluid through the layer 5 it spreads laterally only to a comparatively limited extent. When this fluid reaches the layer 6 it spreads laterally within the layer 6 and therefore the entire lateral area of the layer 6 is available for absorbing and holding any fluid that enters the pad, and for conveying the fluid into contact with the more remote portions of layers 5 and 7 for absorption thereby. The lower surface of layer 7 therefore tends to remain substantially dry throughout the use of the pad so that the clothes of the wearer are protected from contact with the fluid in the pad.
t will be seen, therefore, that the intermediate stratum is more compact than the remaining absorbent material of the pad, and that the stratum has a high-er rate of capillary flow than the adjacent layers of absorbent material. v
' The applicants copending Patent No. 1,702,530, shows a pad having an intermediate stratum having the property of rapidly laterally spreading the fluid absorbed thereby. In the said patent this property is imparted to the intermediate stratum by virtue of the employment of foreign spreading agents. In the pad embodying the present invention the intermediate stratum consists of any suitable absorbing and readily disintegrable material commonly employed in catamenial napkins, the same as the material of the adj acent layers or not, as desired, and which itself has the property of rapidly lat erally spreading the fluid.
While the present invention has been found to be of great eflicacy when applied to pads made of fibrated wood pulp, it may also be applied to other absorbentand readily disintegrable materials which are commonly used in catamenial napkins.
It will be seen from the above that the present invention provides an absorbent pad which is composed wholly and uniformly of absorbent readily disintegrable material and which has the property of retaining all the fluid entering the pad interiorly of the pad and which utilizes all of the lateral area of the pad for absorbing and holding the fluid interiorly of the pad.
Having thus described my invention I do not wish to be limited to the specific embodiment thereof, many modifications of my invention becoming apparent to those skilled in the art and which will fall Within the scope of the following claims.
1. A catamenial napkin, comprising a wrapper and an absorptive pad, said pad having a stratum intermediate the thickness of the pad, which stratum while substantially of the same material as the rest of the pad is of greater density than the rest of the pad, whereby it has the property of rapidly spreading the fluid entering the pad.
2. An absorbent elongated body of the class described, formed of a plurality of superposed layers of fibrous cellulosic material and having an intermediate layer of substantially the same material and which is more compact than the balance of the body, whereby said intermediate layer has a higher rate of capillary flow than the balance of the body, said intermediate layer extending longitudinally of the body. I
3. A catamenial napkin comprising a gauze wrapper and an absorbent pad, said pad being composed of readily disintegrable, absorptive material and having a stratum composed solely of substantially the same readily disintegrable absorptive material disposed intermediate the thickness of the pad, and of greater absorptiveness than the rest of the pad, said stratum also having a density sufficient to impart thereto the property of rapidly laterally spreading the fluid entering the pad. 4. A catamenial napkin, comprising a wrapper and a pad, said pad being composed of fibrous cellulosic material, and a stratum of greater absorptiveness than the rest of the pad intermediate the thickness of the pad and extending longitudinally thereof, said stratum consisting of fibrous cellulosic material and being compacted to a density suflici'ent to impart thereto the pmgwerty of rapidly laterally spreading the uid entering the pad and reaching said stratum.
In testimony whereof I have aflixed my signature to this specification.
HARRISON R. WILLIAMS.