WO1995012370A1

WO1995012370A1 - Bandages

Info

Publication number: WO1995012370A1
Application number: PCT/GB1994/002433
Authority: WO
Inventors: Jane Edith Penrose
Original assignee: Smith & Nephew Plc
Priority date: 1993-11-04
Filing date: 1994-11-04
Publication date: 1995-05-11
Also published as: AU8110494A

Abstract

There are described non-slip bandages comprising a woven, non-woven or knitted fabric which is provided with a non-slip layer on at least one surface thereof, their uses and their methods of preparation.

Description

BANDAGES

This invention relates to a novel form of bandage in particular compression bandages and support bandages and methods for their manufacture.

Cohesive bandages are often manufactured by coating conventional bandages with a latex layer. However, bandages such as support bandages and especially compression bandages are reused and therefore washed several times. The latex coating on bandages may be degraded during washing and thus latex coated bandages for use in compression therapy tend not to be as reusable as would be liked.

We have now found that by coating conventional bandages with a non-slip coating these problems can be overcome or mitigated.

According to the invention we provide a non-slip bandage comprising a woven, non-woven or knitted fabric which is provided with a non-slip layer on at least one surface thereof.

The non-slip layer may be applied to any type of conventional bandage, but is particularly suited for compression or support bandages, and especially compression bandages. Thus the nature of the bandage may be any material used in conventional bandages known βer se.

The fabric material may comprise a sheet or strip of material of dimensions conventionally used in the art.

The non-slip layer preferably comprises a non-continuous layer. Thus the pattern may comprise any conventional coating pattern known in the art. The non-slip layer may comprise a plurality of filaments, which may be one or more layers of substantially parallel filaments or may be in the form of a net. Alternatively the non-slip layer may comprise a plurality of zones, eg. isolated spots of non-slip coating. The zones may include bands which run perpendicular to the longitudinal axis of the bandage or diagonally, ie. in the form of chevrons. When the non- slip layer comprises bands the size and shape of the bands may vary. The bands may run substantially the whole width of the fabric strip.

The most preferred embodiment of the invention provides the non-slip layer in discrete non-continuous zones or regions of coating. The discrete zones may comprise any conventional shape, eg. circular, oval, square, rectangular etc. When the bandage is in a stretched state the zones are generally from 0.5 to 3.0cm long, eg. from 1.0 to 2.0cm long (measured along the longitudinal axis of the bandage). The zones are spaced apart from 0.5 to 4.0cm, eg. from 1 to 2.5cm.

The non-slip layer may be on one surface of the fabric, preferably the non-slip layer is on both surfaces of the fabric. Generally the non-slip layer should cover from 1 to 50% of the area of the surface to which it is applied when in the stretched state, preferably from 10 to 20%, more preferably from 15 to 20%.

When the non-slip layer is on both sides of the fabric the discrete zones of the non-slip layer may be the same size, shape and spacing on both sides. However, it is preferable that the discrete zones differ on either side of the bandage fabric.

Generally, when compression or support bandages are wrapped around the limb of a patient they are wound with each layer overlapping the previous layer by about 50% of the width of the bandage. Thus the preferred pattern of the non-slip layer is one that allows sufficient cohesion between the overlapping layers to prevent the layers from slipping over one another. A particularly preferred pattern is one which comprises a pattern of three discrete zones covering substantially the whole width of a first surface of the bandage material and two discrete zones covering substantially the whole width of the second surface of the bandage. Thus, in use when the bandage is wrapped around the limb of a patient one of the two discrete zones should contact with at least two of the three discrete zones.

Generally, when the non-slip layer is applied in discrete zones, the amount of non-slip material applied to the zonal area may be from 1 to 20g nrr² in each zone, preferably from 1 to 10g rτr², more preferably from 1 to 5g rrr², eg. from 1 to 3g nrr² and especially 2g rrr² when in the stretched state.

The non-slip layer may be applied to the fabric using conventional methods known βer se. Such methods include methods for dispensing hot melt polymeric materials, eg. slot-die coating, gravure coating, roller coating, spraying, jetting and screen coating or printing.

According to the invention we therefore provide a method of manufacturing bandages as hereinbefore described which comprises coating a fabric with a non-continuous non-slip layer.

In the preferred method of the invention the non-slip layer may be applied to the fabric strip when it is in a stretched state. This method provides the particular advantage that the coating lies evenly on the surface of the fabric and in the interstices between the yarns of the fabric when the fabric is in the stretched state. When the fabric relaxes the non-slip coating is trapped in the intersteces between the yarns of the fabric and 'packers' on the surface of the yarns. The non-slip coating and particular that portion of it trapped in the intersteces is provided with additional protection from being removed during washing.

Thus according to a further feature of the invention we provide a non-slip bandage comprising a woven, non-woven or knitted fabric which after between 1 and 20 washes retains sufficient non-slip coating to retain it's non-slip properties.

The non-slip material layer may be made of pharmacologically acceptable non-slip material. The non-slip material, is a high friction material. It may preferably also be non- adherent (to a patient's skin) and may optionally be elastomeric. Preferred high friction materials provide a coefficient of friction from 2 to 3 times greater than that of an uncoated bandage. Thus, preferred coated bandages have a friction of from 200 to 600 gf, preferably from 300 to 500 gf and especially 400 to 450 gf.

When the non-slip material is elastomeric it is not essential that it's elastomeric properties are the same as those of the fabric material. It is preferred that an elastomeric non-slip layer should not inhibit the stretch or relaxation of the fabric material. It is however most preferred that the non-slip coating should possess the same coefficient of elasticity as the fabric material. Suitable elastomers include synthetic elastomers, such as polyurethanes, polybutadienes, silicones and the like, or non-synthetic elastomers such as natural rubber. A preferred material for the non-slip layer includes elastomers such as ethyl vinyl acetate (EVA) preferably in combination with a resin such as hydrogenated hydrocarbon resin. It is also preferable to include one or more antioxidants in the coating composition.

Examples of antioxidants include sterically hindered phenols. Thus an example of a preferred composition is,

EVA 70% w/w

hydrogenated hydrocarbon resin 30% w/w

antioxidant 0.1% w/w

A particularly preferred non-slip material is that known as BAM 679, sold by Beardow and Adams (Adhesives) Ltd in the UK. BAM 679 is made up of: a) Ethylene Vinyl Acetate Copolymer b) Hydrogenated polycyclopentadiene resin c) Sterically hindered phenol antioxidant The non-slip layer applied to the fabric material may contain an appropriate dye material to render the coating coloured. It is a further advantage of the present invention that if the bandage is cut along the width of the bandage where the non-slip coating is present, fraying of the ends of the fabric will be inhibited.

According to a further feature of the invention we provide a method of treatment of one or more of the following disorders; namely, venous disorders, lymphodoema, which comprises applying a bandage or article according to the invention to the affected site on a patient.

The invention will now be illustrated but in no way limited with reference to the accompanying drawings which are not drawn to scale, in which Figure 1 is a plan view of a first side of coated bandage according to the invention;

Figure 2 is a plan view of the reverse side of the bandage of Figure 1 ;

Figure 3 is a schematic representation of the non-slip coating applied to the fabric in a stretched state;

Figure 4 is a schematic representation of the non-slip coating when the fabric is in a relaxed state;

Figure 5 is a schematic representation of the bandage according to the invention wrapped around a patient's limb; and Figure 6 is a schematic representation of a method of manufacturing the bandage according to the invention.

With reference to Figures 1 and 2. A non-slip bandage (1 ) comprises a strip of fabric material (2) with a first surface (3) and a second surface (4).

The first surface (3) is provided with discrete zones (5) of non- slip material and the second surface (4) is provided with different discrete zones (6) of non-slip material.

Referring to Figures 3 and 4. A strip of fabric material (2) is stretched and non-continuous layers of non-slip material (5 and 6) are applied to the surfaces (3 and 4). In the relaxed state the fabric material (2) comprises peaks (7) and troughs (8) with the non-slip layers (5 and 6) lying randomly in both the peaks (7) and the troughs (8).

With reference to Figure 5, in use the bandage (1 ) is wrapped around a patient's limb (9) and non-slip layer (5) contacts with non- slip layer (6).

With reference to Figure 6, a method of manufacturing the bandage according to the invention comprises taking the uncoated fabric (9) from a "pay off unit" (10). The fabric passes around drive rollers (11 ) over chilled rollers (12 and 13) and under first and second coating heads (14 and 15). The coated fabric (16) is passed through nip rollers (17) and allowed to relax before being wound onto a rewind unit (18).

The invention will now be illustrated, but in no way limited by the following examples.

Example 1

Coating Method

A slot die head coater was used to coat an adhesive pattern onto one side of a bandage fabric, which was unwound from a roll. The fabric and adhesive were then passed over a chiller unit, which cooled the adhesive. A second slot die head coater was used to coat the reverse side of the bandage, which was cooled by a second chiller unit. The coated fabric was then spooled directly into bandage lengths. Alternatively it wound into a roll to be spooled via a separate piece of equipment.

Example 2 Friction Tests

Friction tests were carried out using conventional methods.

The results are illustrated in Table I. Table 1

Coating Weight Sides Coated Pattern Friction

/ gsm IM

Uncoated* N/A N/A 150

25 Both Continuous 425

17 Both Continuous 445

A 17 Both Blocks 400

B 17 Both Blocks 420

A = 2.5cm dry, 2.5cm coated B = 1.0cm dry, 0.5cm coated

Claims

1. A non-slip bandage comprising a woven, non-woven or knitted fabric which is provided with a non-slip layer on at least one surface thereof.

2. A non-slip bandage according to claim 1 wherein the non-slip layer is non-continuous.

3. A non-slip bandage according to claim 2 wherein the non-slip layer comprises a plurality of discrete zones.

4. A non-slip bandage according to claim 3 wherein the discrete zones are bands which cover substantially the whole width of the bandage.

5. A non-slip bandage according to claim 4 wherein the bands are from 0.5 to 3.0cm long when the bandage is in the stretched state.

6. A non-slip bandage according to claim 1 wherein the non-slip layer is on both surfaces of the bandage.

7. A non-slip bandage according to claim 6 wherein the pattern of zones of non-slip coating on a first surface of the bandage is different to the pattern of zones of non-slip coating on a second surface of the bandage.

8. A non-slip bandage according to claim 7 wherein, when the bandage is wrapped around a patient's limb so that each layer overlaps the previous layer by about 50% a non-slip zone on a first surface of the bandage will contact with a non-slip zone on a second surface of the bandage.

9. A non-slip bandage according to claim 1 wherein the non-slip coating covers from 1 to 50% of at least one surface of the bandage in the stretched state.

10. A non-slip bandage according to claim 3 wherein the amount of non-slip material in any zone is 1 to 20mg rrr² when the bandage is in the stretched state.

11. A non-slip bandage according to claim 1 wherein the non-slip coating is elastomeric.

12. A non-slip bandage according to claim 11 wherein the non-slip coating comprises a synthetic elastomer.

13. A non-slip bandage according to claim 12 wherein the non-slip coating comprises a synthetic elastomer and a resin.

14. A non-slip bandage according to claim 12 wherein the non-slip coating comprises a synthetic elastomer and an antioxidant.

15. A method of treatment of one or more of the following disorders; namely, venous disorders, lymphodoema, which comprises applying a bandage according to claim 1 to the affected site on a patient.

16. A method of manufacturing a bandage according to claim 1 which comprises coating a bandage with a non-continuous layer of a non-slip material.