US2864362A - Mouldable absorbent material - Google Patents

Description

Dec. 16, 1958 w. A. HERMANSON ETAL 5 5 MOULDABLE ABSORBENT MATERIAL Filed Dec. 1, 1953 INVENTORS William Al /m BY Gerald I.//cm1arzsan {K /4M My 4; M

Unite States Patent 2,864,362 MOULDABLE ABSORBENT MATERIA William A. Hermanson, Brookline, and Gerald L Hermanson, Newton, Mass.

Application December 1, 1953, Serial No. 395,476

Claims. (Cl. 128-156) The present invention relates to. a multiple ply moulded web and more particularly to an absorbent moulded integrated web adapted for use as a bandage or dressing.

In many medical and surgical conditions, it is desirable to have an absorbent dressing shaped or moulded to a particular part of the body, designed to absorb secretions from the body over a period of time. The ordinary bandages or dressings are flat or are not particularly designed for application to concave or convex portions of the body, such as the heel, nose, elbow or shoulders. Further those dressings which are ordinarily used and which do have a degree of absorbency as for example, cotton wadding or batting very often are undesirable because their fibers are often absorbed by the wound which causes infection or discomfort.

It is an object of the present invention to provide a dressing particularly shaped for use on concave or convex portions of the body which is both highly absorbent and which will not lose its shape over a period of time.

lt is further an object of this invention to provide a dressing in which the portion of the dressing in contact with the body has a relatively smooth finished surface with little tendency for its fibers to be absorbed into the wounds.

It is further an object of this invention to provide a dressing which has a high degree of fluid capacity and latent water absorbency for absorption.

In this invention, three plies are secured together forming the dressing. An inner web or web normally close to the body is a permeable porous absorbent wet strength sheet. Although the inner web described herein is preferably a paper web, other thin non Woven webs may also be utilized. The center or middle web, which is secured to the inner web by thermo-pla'stic means, comprises multiple plies of absorbent creped fibers having no wet strength and which are held together preferably by embossing.

The outer sheet of material is a latex impregnated paper formation with sufficient latex impregnation to render this sheet latently water absorbent, and which when moulded by die means, will retain the shape in which is has been formed under normal conditions. This outer layer of material is held to the center layers by cementitious means. 1

The particular construction of this invention as well as other objects and advantages will be more clearly understood when considered in connection with the accompanying drawings in which:

Figure 1 is an enlarged cross sectional view of. a portion of the dressing.

Figure 2 is an elevational view of one form of the invention.

Figure 3 is an elevational view of a modification of the invention.

Referring particularly to the drawing of Figure 1, it will be noted that there is provided three types of webbing material; an inner web 1 of cellulosic fibers or synthetic fibers such as wood pulp, vegetable or rayon, normally adapted to contact the surface of the body, a center web 2 comprising multiple plies of sulphite or sulphate paper formation and an outer heavier covering web 3 of an elastomeric latex impregnated paper formation of cellulosic fibers. The inner web 1 may be made of any cellulosic or synthetic fiber, provided it is formed with a relatively smooth finished outer surface and has a substantial degree of softness. This inner cellulosic web should also have wet strength and a high rate of permeability, but at the same time to maintain the wet strength of this web, it is preferable to provide a web of long fibers in which relatively little wet strength resin need be added. The use of a chemical material in a cellulosic web of long fibers, particularly rayon cellulose, imparts a relatively smooth texture to the surface of the web, while at the same time maintaining a substantial softness of the material. In such a construction, the inner layer of web material is relatively smooth and, therefore, unlikely to permit fibers from the web to be absorbed into the wound and is also quite permeable to liquids or dispersions emitted from the wound. Because of its long fiber structure and wet strength, it will maintain its body and not disintegrate.

The web 2 is secured to the lower side of the web 1 by suitable means such as pressure sealing and heat sealing with a thermoplastic resin or fibers 4 which may be deposited on the lower side of the web 1. The web 2 comprises multiple plies of absorbent creped sulphite or sulphate paper formations which are designed to absorb relatively large amounts of liquid material, but which are somewhat less permeable than the web 1. This web 2, however, has no wet strength at all and is, therefore, a great deal softer and more absorbent than the web 1. The amount of absorbency as well as the amount of resiliency of this web may be varied by the amount of creping provided in this web. The combination of multiple plies and their ereping makes this center web a great deal thicker than the web 1. This factor substantially increases the absorbency of the web, but somewhat reduces the rate of permeability of this web as compared with web 1. Thus when organic particles pass quickly through the web 1 into the web 2, they are subjected to more mechanical action upon them. Each of these organic particles if they are in a dispersion will coagulate as they pass through these multiple layers. This reduces the amount of liquid reaching the outer web 3. The amount of liquid, therefore,

absorbed by the web 2 may be varied substantially by changing the number of plies and the degree of creping of these plies.

It is preferable to have three or more of these plies in the web 2. These multiple plies are held together by suitable means preferably embossing. The third web 3 constituting the layer furthest away from the part of the body which the dressing is designed to cover, is secured to the web 2 by cementitious or other suitable means. This third web is an elastomeric latex impregnated formation of cellulosic fibers having a suflicient percentage of latex retained after impregnation and coagulation to render the web latently water absorbent.

It has been found that a web impregnated with approximately 40 to 60 percent of its weight with latex is suitable. This web has a substantially more compact formation than either the multiple plies of web 2 attached to its face or the inner web attached to the multiple plies of web 2. The latex contained in this web permits ab sorption very slowly through its strata of fibers. This third web may if desired, be coated with a moisture repellent coating or moisture proof plastic film in order to prevent any body secretions from passing through it. Those body secretions which do pass through the web 2 to the web 3 are partially coagulated as described above and, therefore, do not flow through this outer web very readily.

The heavy density of this web together with the latex impregnation provides a substantial latent water absorbency to this web 3 without any additional means. This latent water absorbency substantially increases the amount of liquid which may be held in the web 3. The latex contained Within this Web 3 acts to permit the web to be formed in concave (see Figure 3) or convex (see Figure 2) shapes which will not be distorted under ordinary conditions. By subjecting the three webs to the action of a male and female die of a desired concave or convex shape, a substantially permanent moulded dressing will be formed. The concave or convex curvature which may be formed in this manner may be as deep as 1 /1 inches on a radius from the plane of the opening to the center of the depression. In forming these concave or convex shapes, if desired, the three webs may be subjected to the action of the forming die before they are joined one to the other. In this manner, there will be less distortion between the three webs because of the difference in area of each of the webs formed in the depressed section. In the event that the pad is moulded before the three webs are secured together, they may if desired, be secured one to the other by crimping the side edges, by embossing or by other suitable means.

Having now described our invention, we claim:

1. A medical dressing of material comprising a porous inner paper web having \vet strength. permeability and absorptivity, and adapted to lie over a wound, a center web of multiple plies of absorbent, permeable creped paper material, and a covering web of elastomeric latex impregnated paper material lateutly water absorbent in nature, and means securing said webs together.

2. A medical dressing of paper material comprising a porous inner cellulosic Web having wet strength, permeability. absorptivity and a smooth finished surface adapted to lie over a wound, a center web of multiple plies of absorbent, permeable, creped paper material, and a covering web of elastomeric latex impregnated paper 4, material latently water absorbent in nature and means securing said webs together.

3. A medical dressing comprising a combination of paper webs having a surfacing cellulosic web of porous, permeable, absorbent, wet strength properties, a center Web of absorbent creped paper sheets heat sealed to said cellulosic web, a mouldable elastomeric latex impregnated Web, and means securing said impregnated web to said center web.

4. A medical dressing comprising a porous inner cellulosic web having porous, permeable wet strength properties, a center web of multiple plies of creped material slightly less permeable but having more absorptivity than said cellulosic web, a covering web of elastomeric latex 15 impregnated material less permeable than said center web,

and means securing said webs together.

5. A contoured paper medical dressing comprising an outer mouldable elastomeric latex impregnated web adapted to assume a contour to which the entire dressing conforms, a center web fitting into the elastomeric web of absorbent creped paper sheets bonded to said clastomeric web and a surfacing cellulosic web of porous, permeable, absorbent, wet strength properties and means securing said surfacing web to said center web.

References Cited in the file of this patent UNITED STATES PATENTS 1,930,114 Straus Oct. 10, 1933 no 1,979,899 OBrien Nov. 6, 1934 2,019,842 Bussing Nov. 5, 1935 2,190,378 Hinkamp Feb. 13, 1940 2,344,021 Bouziane Mar. 14, 1944 2,682,873 Evans et al. July 6, 1954 35 FOREIGN PATENTS 101,404 Australia June 21, 1937 OTHER REFERENCES Johnson 8: Johnson Catalog and Service Book, Eighth 40 Edition, copyright 1951, page 32.

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