Improved bandage

Abstract: A layer of plastic (12), either in film or coating form, is bonded to a sheet of non-woven material (10) to form a base. When film is used, it is preferably smaller in size than the non-woven material and affixed to the top surface thereof by an acrylic adhesive (11). The plastic film is coated, on its exposed surface, with a layer of acrylic adhesive (16). When the plastic is in the form of a coating, it is bonded to the bottom surface of the non-woven material. A superabsorbent pad (18), smaller in size than the base, is wrapped in non-woven material (20) and affixed to the base by the exposed adhesive layer. The remaining portion of the exposed adhesive layer forms a border around the superabsorbent pad for adhering the bandage to the skin.

Description: The present invention relates to bandages and more particularly provides an improved bandage structure which has superior absorbency and retention properties and demonstrates the ability to adhere tightly to the skin even as it is flexed. Post operative ileostomy and colostomy patients have a temporary or permanent opening or stoma in the abdominal wall through which waste from the intestine is secreted. The waste, which may be fluid or semi-fluid, is periodically collected in a receptacle. It is necessary that the stoma be covered when the secretions are not being collected. This requires a bandage which has a high degree of absorbency and substantial ability to retain fluids. High bulk is normally associated with bandages which have high absorbency and retention characteristics. However, in this case, bulk cannot be tolerated. Bandages used for this purpose must have minimum bulk so as not to be visible from outside of the patient's clothing. Further, since the skin surrounding the stoma is very sensitive, particularly immediately after the operation, the bandage must be able to be applied and removed in a way that does not produce or contribute to skin irritation. At the same time, the bandage must be relatively secure with respect to the skin. Many bandages employ materials which stretch in one direction so as to accommodate creasing of the skin so that no "channels" or spaces form between the bandage and the skin as the skin is flexed. However, materials which stretch in only one direction cannot prevent channeling when the skin is flexed in the other direction. It is therefore highly advantageous to have a bandage which is bidirectionally flexible so as to prevent channeling in both directions. US Patent US-A-4,564,010 describes a polyolefin/ethylene-vinyl ester copolymer laminate provided with a water-based acrylic resin for securing it to the skin. A matrix comprising a drug or a medicament in an inert vehicle can be bonded to a central part of a non-woven layer, and a backing layer which carries a circular scrim-reinforced tissue pad on its inner surface can be adhered to the outer surface of the non-woven layer. The use, in diapers, of a superabsorbent material beneath a non-woven facing layer has been proposed in GB Patent Application GB-A-2144995, and a bandage comprising a wrapped absorbent filler on an adhesive backing strip is disclosed in US Patent US-A-3,256,881. Advantageous features of the preferred embodiments of the present invention hereinafter described in detail include:- (a) bidirectional flexibility so as to prevent channeling in both directions. (b) increased absorbency characteristics. (c) increased fluid retention abilities. (d) prevention of superabsorbent material from contacting the stoma. (e) prevention of fluids from seeping out of the ends of the superabsorbent pad. (f) adherence to the skin during flexing regardless of the direction of flexing. (g) possibility of manufacture using simple relatively inexpensive processing techniques. In accordance with the present invention, there is provided a bandage comprising a bi-directionally stretchable base comprising a non-woven material and a water-impervious plastics layer bonded to said non-woven material, a layer of acrylic adhesive on one surface of said base and a pad of superabsorbent material, smaller in size than said base, said superabsorbent pad being wrapped in a sheet of non-woven material and affixed to said one surface of said base by said adhesive layer, a portion of said adhesive layer forming a border around said pad and being adapted to adhere the bandage to the skin of the wearer. The plastics layer may be a film bonded to the upper surface of the non-woven material. The film is preferably smaller in size than the non-woven material. A portion of the surface of the non-woven material is thus exposed. This exposed portion of the non-woven material is also coated with the adhesive. However, in its most preferred form, the plastics layer is in the form of a plastics coating bonded to the lower surface of the non-woven material. Preferably, the coating and the non-woven material are substantially coextensive. The non-woven material is preferably composed of polyester or polypropylene. The plastics layer is preferably composed of polyethylene. Preferred embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:- Figure 1 is an exploded isometric view of a preferred embodiment of the bandage of the present invention; Figure 2 is an isometric view of the bandage illustrated in Figure 1; Figure 3 is a cross-sectional view of the preferred embodiment of the present invention taken along line 3-3 of Figure 2; Figure 4 is an isometric view showing how the superabsorbent pad is wrapped; Figure 5 is an isometric view showing how the wrapped pad is sealed; Figure 6 and 7 are end views of the superabsorbent pad showing how the wrapping material is folded; Figure 8 is an exploded isometric view of the most preferred embodiment of the present invention; Figure 9 is an isometric view of the bandage shown in Figure 8; and Figure 10 is a cross-sectional view taken along the line 10-10 of Figure 9. As shown in Figures 1 and 2, the first preferred embodiment of the present invention comprises a substantially rectangular sheet of non-woven material 10 with rounded corners. Material 10 is preferably air-laid, wet-laid or spun-laid rayon, polyester or polypropylene having a basis weight of from 10 to 50 grams per square meter. Most preferably, polyester or polypropylene is used. This material is essentially non-absorbent and permits both air and liquid to pass therethrough. It also is extremely flexible. Material 10 is coated with a layer of acrylic dermal adhesive 11 on its top surface. Adhesive 11 bonds the top surface of non-woven material 10 to a sheet of thin plastics film 12. Plastics film 12 also has rounded corners and may be composed of any suitable plastics material, but is preferably, a polyethylene sheet between .3 to 3 mils (7.62 to 76.2 µm) thick. Non-woven material 10 and plastics film 12 form the base, generally designated B, of the bandage. The exposed surface of plastics film 12 is coated with an acrylic dermal adhesive 16 preferably of the same type as layer 11. This adhesive is gentle on the skin but will retain its adhesive properties even when wet. A pad of superabsorbent material 18 is affixed to the base by layer 16. The pad may be composed of multiple sheet layers, and consists of an air-laid composite of cellulose wood pulp fiber, polyethylene fibers and superabsorbent granules. One such material is commercially available from Dry Forming Processes of Orkelljunga, Sweden, under tradename CELL-O-SOFT. This material, as illustrated in Figure 4, is die cut into rectangular pads and then placed on a strip of non-woven material 20, similar to the material 10. Non-woven material 20 is then wrapped around the superabsorbent pad 18, as seen in Figures 5, 6 and 7, such that the flaps 20a and 20b align and overlap and may be folded over in face-to-face relation as shown in Figure 7. The ends of the unit are then crimped, cut and sealed along lines 22. As shown in Figure 1, the wrapped pad, with the flaps folded but not sealed, is placed in the center of the adhesive coated surface of the base B such that the wrapped pad adheres to the plastics film 12. The adhesive layer 16 maintains the unsealed flaps of the wrapping non-woven material 20 in the closed condition. The pad 18 is framed by a border of adhesive 11, 16 so as to adhere to the skin. The most preferred embodiment of the present invention is illustrated in Figures 8, 9 and 10. The most preferred embodiment of the present invention has corresponding elements to those described above with respect to the first preferred embodiment, shown in Figures 8, 9 and 10 with primes. The major difference between this embodiment and the embodiment shown in Figures 1 and 2 is the structure of base B. In this embodiment, base B is formed such that the plastics layer 12' is in the form of a plastics coating heat bonded to the bottom surface of material 10' and hence has the same length and width dimensions as the non-woven material 10' but is on the surface opposite to that to which pad 18' is affixed. Preferably, coating 12' is composed of a very thin layer of polyethylene. Base B, which is a combination of non-woven material 10' and plastics coating 12' bonded together, can be manufactured and provided in rolls with the acrylic adhesive layer 11' already in place and covered by release paper. During the manufacturing process, the base material is cut to size and the wrapped superabsorbent pad placed thereon. Release paper is then placed over the interior surface to protect same. Using a base layer consisting of a non-woven material with a plastics coating or film bonded thereto is advantageous because the non-woven material is bilaterally flexible and therefore will adhere to skin folds surrounding the stoma better than a plastic alone. However, the plastics layer 12' is required because it is water impervious and stretchable. The multilayer base material provides both properties. The border of adhesive 11' surrounding the superabsorbent pad creates a fluid tight seal between the skin and the base B'. The seal extends around the pad 18' and prevents fluid from escaping from the sides of the pad 18'. It should be noted that non-woven wrapping material is wrapped completely around superabsorbent pad so as to prevent any contact between the superabsorbent pad and the skin. Moreover, if any of the superabsorbent material crumbles, the wrapping will prevent same from spilling out of the bandage. Preferably, a relatively slow action superabsorbent material is employed. Such a material absorbs moisture slowly but is highly retentive. A sheet of silicon release paper (not shown) can be used to cover the bandage so as to maintain the sterility thereof. The release paper is simply peeled from the bandage prior to application thereof to the skin, as is customary. It should now be appreciated that there has been described an improved bandage with a unique structure which results in a highly absorbent and retentive article in which the superabsorbent pad is isolated from the skin. The base has a multilayer structure which provides bidirectional flexibility to reduce channeling. The bandage includes a base including a non-woven material to which a plastics layer is bonded. The exposed top surface of the base is coated with an acrylic adhesive. A pad of superabsorbent material is wrapped in a non-woven material and sealed at its ends. The superabsorbent pad is then placed on the base and affixed thereto by the adhesive. The remaining exposed surface of the base, which is coated with the adhesive, forms a frame around the pad so as to adhere the bandage to the skin.

Claims: A bandage comprising a bi-directionally stretchable base (B) comprising a non-woven material (10; 10') and a water-impervious plastics layer (12; 12') bonded to said non-woven material, a layer of acrylic adhesive (16; 11') on one surface of said base (B) and a pad of superabsorbent material (18; 18'), smaller in size than said base (B), said superabsorbent pad being wrapped in a sheet of non-woven material (20) and affixed to said one surface of said base (B) by said adhesive layer (16; 11'), a portion of said adhesive layer (16; 11') forming a border around said pad (18; 18') and being adapted to adhere the bandage to the skin of the wearer. The bandage of claim 1 wherein said plastics layer (12) is a film and further comprising a second acrylic adhesive layer (11) on said non-woven material (10) to bond said film (12) to said non-woven material (10). The bandage of claim 2 wherein said plastics film (12) is smaller in size than said non-woven material (10) so as to expose a portion of the surface of non-woven material (10) with said second adhesive layer (11) thereon. The bandage of claim 1 wherein said plastics layer comprises a plastics coating (12') bonded to the other surface of said non-woven material (10'). The bandage of claim 1 wherein said non-woven material (10; 10') is composed of polypropylene. The bandage of claim 1 wherein said plastics layer (12; 12') is composed of polyethylene.

Inventors: JENSEN OLE ROGER, JENSEN, OLE ROGER
Applicants: SQUIBB & SONS INC, E.R. SQUIBB & SONS, INC.
Application year: 1989
Main classification: A61F13
IPC codes: A61L15, A61F13