GB1595393A

GB1595393A - Sanitary pad

Info

Publication number: GB1595393A
Application number: GB5447/78A
Authority: GB
Original assignee: Johnson and Johnson
Current assignee: Johnson and Johnson
Priority date: 1978-05-22
Filing date: 1978-05-22
Publication date: 1981-08-12

Description

(54) SANITARY PAD (71) We, JOHNSON & JOHNSON, a Corporation organised under the laws of the State of New Jersey, United States of America, of 501 George Street, New Brunswick, New Jersey, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to absorbent sanitary pads, and particularly to pads for placement against the body to receive and absorb liquid which may issue from the body, in such a manner as to minimise subsequent contact between body and liquid. Such pads may be required to absorb fluids exuded from the body such as blood, menstrual fluids, urine and the fluid content of faeces. Sanitary pads are preferably disposable and should not be expensive to provide.

Absorbent sanitary pads take a variety of forms, including sanitary napkins, diapers, wound dressings and incontinence pads and the invention applies generally to such forms.

The invention is described for convenience with reference to incontinence pads but it will be readily appreciated how and wherein the principle applies to other forms of sanitary pad.

An incontinence pad for a patient in bed should be capable of absorbing a considerable quantity of liquid without leaking, and should not create discomfort to the patient by virtue of thickness, shape or texture. It should be readily put into position, withdrawn or replaced even when the patient must remain in bed.

An incontinence pad or other sanitary pad should prevent as far as possible discomfort to the patient due to contact with a quantity of liquid, for instance by sitting or lying in a pool or even merely on a surface that feels damp. It is an object of the invention to provide means in a pad for alleviating such discomfort and moreover the undesirable results such as skin irritation which tend to accompany such discomfort. It is a further object of the invention to provide a pad which promotes increasing cleanliness in a convenient manner.

If an absorbent sanitary pad is placed against a wet body, under appreciable pressure as when the weight of an incontinent patient is placed on an incontinence pad, even a small amount of liquid will exhibit a tendency to concentrate at the region of pressure and form or feel like a puddle. This problem is not overcome even by the combined use of highly absorbent material and a hydrophobic facing which will pass liquid and yet continue to feel dry. It is a particular object of the invention to overcome this problem by seeking to put a barrier between the patient and the urine, or other body exudate.

A type of pad is described in U.K. patent Specification No. 1,425,179 by F.L. Willington, which is directed to fulfilling the abovementioned objects, and which comprises a permeable layer or memebrance, normally uppermost, an upper absorbent layer, an upper impervious layer, but with an aperture or window formed therein, the upper absorbent layer not extending over this aperture or window, a lower absorbent layer extending over substantially the full area of the pad, including the aperture or window through which fluid has access to said lower absorbent layer, and normally lowermost, a bottom impervious layer, the edges of the pad being sealed. When a patient resting on such a pad is incontinent the liquid passes directly to the lower absorbent layer and gradually spreads over the area of the pad. The pad is to be arranged in relation to the patient so that there will be no pressure over the window area and hence no puddle formation there.

The liquid within the lower layer cannot escape in any quantity, and any spillage or seepage through the window is absorbed by the upper absorbent layer and there will not be enough spillage or seepage to cause a puddle.

The sanitary pad of the present invention embodies a similar principle to that disclosed in Specification No. 1,425,179 and takes advantage of the availability of a liquid im pervious sheet material having a layer of fluid-absorbent fabric adhering to it.

According to the present invention we provide a sanitary pad which comprises: a first liquid-impervious sheet having upper and lower faces; a first layer of fluid-absorbent material, comprising a fluid-absorbent fabric adhering to the upper face of the first sheet; an aperture forming a window through both the first sheet and the absorbent fabric layer; a second liquid-impervious sheet underlying a portion of the first sheet and the whole of the window and peripherally sealed to the first sheet; and a second layer of fluid-absorbent material, this being sandwiched between the first and second sheets to underlie said portion and whole window. The pad preferably also comprises a fluid pervious cover constituting a facing layer over that part of the second absorbent layer exposed by the window, peripherally secured between that layer and the first sheet.

It will be observed that in comparison with the Willington pad, that of the invention requires no permeable uppermost facing layer over the whole pad although the absorbent exposed by the window preferably has such a cover, nor does the lower sandwiched absorbent layer extend over the whole pad but only over a portion underlying the window and an area around the window.

Preferably the liquid-impervious sheets, which may be of the same or different materials, include or consist of a plastics film, e.g.

a polypropylene, polyethylene or polyvinyl chloride film, which may advantageously have an embossed surface and be coloured for ready identification in a hospital context.

Polypropylene film may be preferred if it is desired to steam-sterilise the pad ; polyethylene is generally preferred. Other materials may be used for the sheets, e.g. regenerated cellulose film, impregnated fluid repellent paper, Kraft paper coated with polyethylene or other suitable polymer, water impervious fabrics such as the material sold by us under the Trade Mark "Barrier", or polymer-coated crepe tissue.

The layers of fluid-absorbent fabric may be the same or different and can be made from woven fabrics, paper, inherently hydrophilic foam, e.g. viscose rayon foam, natural or synthetic foamed polymeric material, e.g.

polyurethane, polyether, or styrene/butadiene rubber foams which have been rendered hydrophilic or readily wettable, comminuted wood pulp, cotton linters, and cotton wool of any grade, rayon fibres, cotton staple and bleached or unbleached crepe tissue. The absorbent material is preferably cellulosic or of hydrophilic foamed synthetic resin. The fluid-absorbent fabric adhering to the upper face of the first sheet is normally substantially coestensive with the firt sheet, and relatively thin compared with the other sanwiched layer of absorbent material. The adhering absorbent layer is preferably fully laminated by adhesive bonding to the first sheet and it may consist of a non-woven fibre web formed by such bonding.

The laminate of absorbent fabric and the first sheet may be produced by extrusion coating a layer of polyethylene, as the first sheet, onto one surface of an absorbent fabric web, the resulting laminate being cut transversely, to desired lengths, by guillotine.

The first absorbent layer, i.e. that adhering to the upper face of the first sheet, may constitute the facing layer of the pad, apart from the window, or it may have a fluidpervious and preferably non-wettable cover, for example a knitted, woven or non-woven fabric which may have perforations, such as wax-impregnated "Keybak" non-woven rayon fabric bonded and treated with a waterrepellent agent. (The word "Keybak" is a registered Trade Mark). Alternatively the cover may be of perforated paper or a polymer net. The cover, when present, preferably extends over the window and may extend slightly beyond the absorbent fabric and be secured by an adhesive to the first sheet. The first sheet may be folded over the absorbent fabric at the edges and secured to prevent liquid penetrating out of the pad sideways although the presence of the other absorbent material makes such leakage unlikely and thus permits simple cut edges on the first sheet.

The pad may be of any desired shape, a rectangular or square first sheet being convenient. The second liquid-impervious sheet suitably underlies a portion, representing about half the total area and towards one end, of the first sheet, with the window being approximately central to that portion. The second sheet is secured in sealed fashion along its edges to the first sheet, for instance by adhesive bonding.

The second layer of absorbent material sandwiched between the sheets preferably fills the available space between these sheets and is relatively thick, possibly of a multiply material. Normally in the absence of a cover fabric over the whole pad a fluid-pervious facing fabric will cover that part of the second absorbent layer exposed by the window, secured between that layer and the first sheet for instance by adhesive bonding at edge portions of the facing fabric which is made a little larger than the window.

The lowermost surface of the pad is constituted by the second sheet over a portion of the first sheet, and by the first sheet for the rest; these sheets thus serve the purpose of preventing strike-through of absorbed body exudates under the pad while the said portion of the first sheet alsp serves to prevent strikethrough of absorbed liquid from the lower absorbent to the upper in the event that body weight is applied over that portion elsewhere than on the window.

The resulting pad provides improved, convenient, comfortable and effective means of dealing favourably with incontinence in bed or in other situations, the principle being adaptable to nappies, diapers, and so forth, to be worn on the person.

Areas of pressure-sensitive adhesive may be provided on the lower, exposed faces of the impervious sheets, with pull-off release strips over them, to assist in placing and retaining the pad in position for use. The absorbent materials may be impregnated with substances to render innocuous the absorbed liquid.

The invention is illustrated by the accompanying drawings, in which Figure 1 represents a plan view of a pad according to the invention and Figure 2 represents an enlarged cross-section on the line II--II of Figure 1.

In the Figures there are shown a first sheet 1 of blue embossed polyethylene approximately 50 cm x 50 cm x 25 zm covered by a co-extensive non-woven web 2 of rayon fibres integrally bonded to the sheet 1, both the sheet 1 and web 2 having a circular aperture of 16 cm diameter providing a window 3. Strips of adhesive applied to the sheet 1 along the edges 4 of a piece of perforated non-woven facing fabric 5 of approximately 70 g/m2 secure the latter across the window.

A second plastics film 6 approximately 50 cm x 25 cm in area is secured by adhesive strips at the edges 7 to the underside of sheet 1 in sealing fashion, and a layer of 5-ply unbleached crepe tissue 8, weighing about 25 film2 per ply, and folded to produce 20 plies, substantially fills the space between the sheets 1 and 6 and has an effective thickness of about 5 mm.

The assembled pad is an effective incontinence pad which serves to conduct liquid away from an incontinent patient resting on the pad, but not pressing on the window area, into the lower absorbent layer where it no longer comes into contact with the patient.

Although the pad of the invention has been exemplified above by reference to particular materials and dimensions and othe features it will be appreciated that variations may be made, especially as to size, without departing from the scope of the invention. Fastening devices such as tabs, strings or press-fasteners may be provided on the pad when intended for wearing.

WHAT WE CLAIM IS 1. A sanitary pad which comprises: a first liquid-impervious sheet having upper and lower faces; a first layer of fluid-absorbent material, comprising a fluid-absorbent fabric adhering to the upper face of the first sheet; an aperture forming a window through both the first sheet and the absorbent fabric layer; a second liquid-impervious sheet underlying a portion of the first sheet and the whole of the window and peripherally sealed to the first sheet; and a second of fluid-absorbent material, this being sandwiched between the first and second sheets to underlie said portion and whole window.

2. A pad according to Claim 1, wherein the liquid-impervious sheets include or consist of a plastics film.

3. A pad according to Claim 1 or 2, wherein the fluid-absorbent fabric is cellulosic or of hydrophilic foamed synthetic resin.

4. A pad according to any preceding Claim wherein the fluid-absorbent fabric adhering to the upper face of the first sheet is laminated to the first sheet by adhesive bonding and consists of a nonwoven fibre web formed by such bonding.

5. A pad according to any preceding Claim further having a fluid-pervious cover constituting a facing layer over the window and the first absorbent layer, i.e. that adhering to the upper face of the first sheet.

6. A pad according to any of Claims 1 to 4, further having a fluid-pervious cover constituting a facing layer over that part of the second absorbent layer exposed by the window, peripherally secured between that layer and the first sheet.

7. A pad according to any preceding Claim wherein the second liquid-impervious sheet underlies a portion, representing about half the total area and towards one end, of the first sheet,with the window being approximately central to that portion.

8. A pad according to any preceding Claim with areas of pressure-sensitive adhesive on the lower, exposed faces of the impervious sheets.

9. A sanitary pad substantially as described and shown in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. weight is applied over that portion elsewhere than on the window. The resulting pad provides improved, convenient, comfortable and effective means of dealing favourably with incontinence in bed or in other situations, the principle being adaptable to nappies, diapers, and so forth, to be worn on the person. Areas of pressure-sensitive adhesive may be provided on the lower, exposed faces of the impervious sheets, with pull-off release strips over them, to assist in placing and retaining the pad in position for use. The absorbent materials may be impregnated with substances to render innocuous the absorbed liquid. The invention is illustrated by the accompanying drawings, in which Figure 1 represents a plan view of a pad according to the invention and Figure 2 represents an enlarged cross-section on the line II--II of Figure 1. In the Figures there are shown a first sheet 1 of blue embossed polyethylene approximately 50 cm x 50 cm x 25 zm covered by a co-extensive non-woven web 2 of rayon fibres integrally bonded to the sheet 1, both the sheet 1 and web 2 having a circular aperture of 16 cm diameter providing a window 3. Strips of adhesive applied to the sheet 1 along the edges 4 of a piece of perforated non-woven facing fabric 5 of approximately 70 g/m2 secure the latter across the window. A second plastics film 6 approximately 50 cm x 25 cm in area is secured by adhesive strips at the edges 7 to the underside of sheet 1 in sealing fashion, and a layer of 5-ply unbleached crepe tissue 8, weighing about 25 film2 per ply, and folded to produce 20 plies, substantially fills the space between the sheets 1 and 6 and has an effective thickness of about 5 mm. The assembled pad is an effective incontinence pad which serves to conduct liquid away from an incontinent patient resting on the pad, but not pressing on the window area, into the lower absorbent layer where it no longer comes into contact with the patient. Although the pad of the invention has been exemplified above by reference to particular materials and dimensions and othe features it will be appreciated that variations may be made, especially as to size, without departing from the scope of the invention. Fastening devices such as tabs, strings or press-fasteners may be provided on the pad when intended for wearing. WHAT WE CLAIM IS

1. A sanitary pad which comprises: a first liquid-impervious sheet having upper and lower faces; a first layer of fluid-absorbent material, comprising a fluid-absorbent fabric adhering to the upper face of the first sheet; an aperture forming a window through both the first sheet and the absorbent fabric layer; a second liquid-impervious sheet underlying a portion of the first sheet and the whole of the window and peripherally sealed to the first sheet; and a second of fluid-absorbent material, this being sandwiched between the first and second sheets to underlie said portion and whole window.