AU657740B2 - Process for producing a cohesive, self-adhesive, rigid or elastic bandage for fixing, compression and support dressings for medical purposes and bandage produced by this process - Google Patents

Description

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657740

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPEC I F I CATION FOR A STANDARD PATENT

ORIGINAL

t t5 f t Name of Applicant: 0t KARL OTTO BRAUN KG Harald Jung, Gunter Langen and Ewald Schafer Actual Inventors: o oo 0 0 0 A o Address for Service: SHELSTON WATERS Clarence Street SYDNEY NSW 2000 11 5 t 11 I I Invention Title: "PROCESS FOR PRODUCING A COHESIVE, SELF-ADHESIVE, RGIb OR ELASTIC BANDAGE FOR FIXING, COMPRESSION AND SUPPORT DRESSINGS FOR MEDICAL PURPOSES AND BANDAGE PRODUCED BY THIS

PROCESS"

Details of Original Application No. 35293/89 The following statement is a full description of this invention, including the best method of performing it known to us:la Process for Producing a Cohesive, Self-Adhesive, Rigid or Elastic Bandage for Fixing, Compression and Support Dressings for Medical Purposes and Bandage Produced by this Process BACKGROUND OF THE INVENTION o ro onoL 1. Field of the Invention o o The invention relates to a process for producing a cohesive, oo |self-adhesive bandage, which does not adhere to the skin, hair Band articles of clothing and which is rigid or elastic for fi- 0 5 xing, compression and support dressings and permanent elastic j oo0 compression and support dressings for medical purposes and a bandage produced by this process.

2. Description of the Prior Art Dressing materials are known as compression and support dressings 0 10 which, in order to obtain a self-adhering action, are coated o on both sides with a contact adhesive in such a way that the adhesive, which is mainly formed from rubber, not only adheres to the outside of the warp and weft threads of the web, but 00ft also penetrates deeply into the porous fabric and fiber groups.

Even the spaces or pores between the individual warp and weft So. threads are filled, so that it is no longer really a dressing material, but a rubber strip or band which contains an elastic reinforcing fabric to increase its tearing resistance in the warp and weft. In the case of such dressing materials, it is not possible to refer to individual adhesives particles because y the rubber fills the entire volume of the pores, reducing or eliminating the porosity of the fabric, sealing the surface on either side like a film.

Due to the pronounced adhered state of the elastic warp threads in such bandages, the extensibility is greatly reduced, so that it is no longer possible to speak of a plastic behavior of such p. P_

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2 a bandage when appLied to parts of the body with a very small radius. Furthermore, such bandages can only be stretched by about 30 to 40%. As a result of this construction, there is no breathing activity of the fibers, i.e. the bridge formation SP4 5 between skin and external air is lost. In addition, such an impregnation by an adhesive greatly influences the air permea- 0 bility, and secretion absorptivity/water holding capacity, so oo that undesired heat and moisture chambers are formed which constitute an ideal medium for bacterial and fungal attacks to v 10 the skin. Furthermore, the extensibility is greatly reduced o by the pronounced adhesion of the elastic elements, because the latter are very seriously negati.vely influenced in their elastic bahavior due to the penetration of the adhesive into the fiber groups and through the covering or casing.

o s 15 A reusable, elastic compression bandage for medical purposes o is known and described in DE-AS No. 1,491,205. This banda-e 00 0 is in the form of an elangated support band from an at least rS longitudinally extensible elastic material, the support band being partially coated on either side with a cohesive substance which adheres to itself but not to the skin or articles of o cloth'ing. The cohesive substance is applied over the entire o o length of the support band onto those parts of the threads contained therewith which project from the fabric surface, while leaving substantially free the fabric gaps, so that the permeability for air and moisture is ensured. An elastic compression bandage constructed in this way is reusable and rests with a constant pressure on all sides on the body surface.

Despite the elastic stress, there is no reduction in the pressure due to sliding of the individual turns of the bandage, particularly in the transverse direction, even when the part of the body carrying the bandage moves. This bandage is also

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r I .i P Y- 3 intended to permit prolonged uninterrupted wear, i.e. it has good permeability for air and water vapor and, in particular, it does not adhere to the skin, hair or articles of clothing.

Whereas the adhesive coating can be applied to bandages by the dipping process, in the case of the bandage according to the o DE-AS No. 1,491,205, the adhesive coating is applied by rollers.

o000 In this process, rubber is removed from two spaced parallel o tanks and transferred to two fLrther rollers through which the on :c bandage is then guided tangentialLy upwards. Following a fine 000 10 adjustment, the two upper rollers uniformly apply the rubber 0000 a to the bandage moved past. However, it is not possible to achi- OO0oo o eve such a fine adjustment which permits the coating in a uniform manner of both sides of the bandage. Depending on the density of the fabric, as a function of more or Less stretched 0 15 state on being fed in, many portions of the bandage are not o *o coated by the two rollers or are only coated on one side, so P 'o that portions, or even a complete side of the bandage remains without adhesive, whereas in certain areas of the bandage imao pregnation has taken place deep down into the said bandage.

Therefore, the roller application process does not give a bandage having a uniform distribution of the rubber on both sides.

S U.S. Patent No. 3,364,063 to Satas describes a pressure-sensitive adhesive tape wherein the carrier material is a non-woven fabric and the adhesive substance is an adhesive polymer. The adhesive polymer is applied as a coating on the fibers of the non-woven fabric. Accordingly, the adhesive substance is an adhesive which adheres to skin and hair. Figure 3 of this patent shows an almost completely closed adhesive, nonporous layer This means that a self-adhesive tape has been provided, wherein the adhesive is applied, for example, by a spraying method. In order to obtain sufficient adhesiveness,

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4 0 00 0J 0 00 0000 c9 J 0.) 0o0Q 0 0000 0000 0 O 0 00 0 0 0 0 0 00 0000 0 a og0 0bQO0 it is necessary to place adhesive particles very densely on the surface, which has the result that the permeability to air and water is substantially reduced, i.e. the porosity of the fabric is reduced. IN U.S. Patent No. 3,364,063, a selfadhesive tape is produced which does not have any breathing activity of the fibers because the adhesive layer which is applied over the surface of the bandage material extends over the entire surface of the bandage material so that all threads of the fabric i.e. the warp threads as well as the weft 10 threads, firmly adhere to one another. The adhesive film closes the surface of the bandage fabric. In addition, the adhesive is applied under pressure to the surface of the bandage fabric so that there no longer is any air permeability of the bandage material. By supplying the adhesive under pressure, the adhesive penetrates into the interior of the fiber groups and encloses the threads in such a way that the bandages produced are very negatively influenced in their elastic behavior.

U.S. Patent No. 3,523,528 to Patience discloses spray-deposited discrete spots of e.g. tacky rubbery material, latex, or resin on fabric substrates. The fabric is a woven, ribbon-like bandage having a low weight per surface area with ravel-resistant side edges, containing elastomeric warp yarns synthetic crimp stretch warp yarns and spun warp yarns (inelastic), wherein spun threads are wound or spun around, for example, the elastomeric warp yarns, so that a differentiated stretchability of the elastomeric warp yarns is achieved. In principle, these are bandages which for three decades have been used as compression bandages in different sequences between rigid and elastic warp threads. In order to obtain a differentiated stretchability of the entire bandage, it is necessary that the threads always have material spun or wound around them, so that the elastomeric threads are limited in their elastic behavior.

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00 0 O000 5 When a bandage of this type is used, it Loses its compressive power during the wearing due to slackening. However, this is true in any elastic bandage because internal friction causes fatigue during wearing and the compression is thereby reduced.

In other words, the energy, once expended, is not recovered in S the form of compression, i.e. the efficiency must be lower than QC4 a 100%. This fact is true in all bandage materials known to the ou experts and represents a "basic axiom of physics" because o o o i oo every material, even if it is razor blade steel, is subjected 10 to fatigue when it is moved because of internal friction and 000 plastic changes. The claims are also exclusively directed to S the reduction of the compressive force during wearing of said bandages. This patent merely creates an elastic fabric which is provided with an adhesive layer, wherein this adhesive layer is applied on one side to the surface of the bandage material.

0 o It does not describe how the individual adhesive particles are o°°0 applied to the surface of the bandage fabric or !hat type of 0 00 elastic bandage is to be produced.

Sn4. U.S. Patent No. 3,577,516 to Gould, et al describes a "wound dressing" which is formed by spraying a hydrophilic, water-insoluble polymer. This reference does not describe a porous tex- S0 tile fabric structure having a cohesive design, such as a self- A t, a adhesive bandage, but rather, a bandage which is prepared from a spray can. After being sprayed onto the surface of the skin, the polymer which is not water-soluble forms a film. This film is only permeable to air. The spray-on bandage is supposed to protect the wound from bacteria and from contamination from the air.

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4 0 However, in the case of rigid or elastic bandages adhering only to themselves and not to the skin, hair and articles of clothing, it has proved itself to be disadvantageous that the inner layers of such cohesive bandages, during prolonged storage periods, are more firmly stuck to one another due to the compressive pressure of the outer bandage layers since the particles have a more intimate contact and a higher agglomeration thus results.

On account of this circumstance, it becomes increasingly difficult to unroll the bandage when applied from the outside to the inside, that is to say that in an appropriate application it will be necessary for the doctor, in order to eliminate the disadvantages arising due to the different adhesive forces, to unroll in each case a spe.cific length from the bandage body in order to then be able to apply this unwound section or por- 15 tion in a dosed manner always under the tension required for the therapy (DE-OS 29 12 129).

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4 44 Moreover, there is added the circumstance that when applying in several layers, the adhesiveness of the adhesive declines since, due to the agglomeration of the particles, a reduction 20 in the particle density takes place, i.e. on account of the agglomeration of the individual particles, the number of the Sindividual particles per surface unit is reduced.

SUMMARY OF THE INVENTION It is the object of the invention to provide a method for the production of a self-adhesive elastic bandage wherein the adhesive is applied in a uniform distribution on the surface of the bandage without causing the fiber packs to adhere to one another. It is a further object of this invention to provide a process of applying an adhesive to both sides of an elastic bandage in such a way that fiber groups cannot adhere in

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7 themselves or to one another. It is still a further object of this invention to provide a cohesive, self-adhesive bandage which does not stick to the skin, hair and articles of clothing, which is either rigid or elastic and in which the adhesive, i.e. the rubber, is uniformly applied to both surfaces without the groups of fibers adhering to one another or to the projec- 0o0 0 ting fiber ends of the two surfaces.

"oo o The foregoing objects as well as others are achieved by a cohe- 0 sive, self-adhesive, rigid or elastic bandage for fixing, como0" 10 pression and support dressings and oermanent elastic compression a" D and support dressings for medical purposes and a process for 0 o the manufacture thereof.

The bandage comprises a web of warp and weft threads or warp threads in the form of a woven fabric having a porous structure and an amount of ultrafine particles of an adhesive, such as S"a rubber adhesive, distributed over and bonded to both the expo- .oa sed surfaces of the warp and weft threads to provide adhesive particles bonded to the threads, on both sides of the fabric.

eo The adhesive particles are uniforly distributed over both S 20 bandage surfaces without the fiber groups adhering to one another or to the projecting fiber ends of the two surfaces, the particles being of a size distribution and amount sufficient 'to provide adhesion between overlying bandage surfaces without substantially reducing the porosity and elasticity of the fabric.

It is a further object of the invention to provide a method for producing a cohesive, elastic bandage which adheres only to itself and not to the skin, hair and articles of clothing according to the type described in the 'beginning, according to which the adhesive is applied in uniform application to the two surfaces of the bandage material or knitted bandage fabric and with the aid of which a bandage is obtained in which the 8 disadvantages increased sticking together of the inner layers and weakening of the adhesiveness of the individual layers when applied repeatedly are avoided.

This technical problem is solved with a method, in conformity with which and according'to the invention, in that to the adhesive, there is admixed, in an order of magnitude of 3% per weight to 15% per weight relative to the solid phase, acrylic acid or butadienestyrene derivates in the form of their esters, amides or nitriles, or acrylic acid or butadienestyrene polymers or rubber-like polymerisates which possess the same properties, the individual components preferably being added in the form of aqueous dispersions, in which the thusly obtained mixture is applied to the bandage surface by atomization in an eddy current field b oo preferably with a residence time of approximately 1 o* minute at R0°C.

"According to a broad aspect, the present invention consists in a method for the manufacture of a cohesive, elastic bandage for medical purposes, which o bandage adheres solely to itself but does not adhere to Sskin, hair or items of clothing and comprises a fabric in the form of a coarse or fine knit, the fabric having o- projecting fibre ends, said method being characterized °i 25 in that an adhesive in the form of superfine particles is admixed with from 3% to 15%, by weight of adhesive solids, of acrylic acid or butadiene styrene derivatives or rubber-like polymerisates which possess the same 8a properties and the admixture is uniformally applied to both surfaces of the fabric in a quantity of 1000 to 5000 particles of adhesive on approximately 500 mm 2 of fabric, the application being by atomization in an eddy current field whereby the adhesive is only applied to the projecting fiber ends in an application quantity of 10 to 40g/m 2 whilst preventing a group of fibers from adhering to one another.

In accordance with such a method, an elastic bandage is obtained, in which both sides are covered so finely and uniformly with adhesive particles that a strong cohesive force holds the individual turns together so that a slipping is prevented without the macrophysical behaviour and, consequently, the field of indication vis-a-vis the non-cohesively constructed bandage suffering a restriction, i.e. with excellent adhesion properties the bandage turns only adhere to one another, but not to the skin, hair and articles of j clothing water vapor permeability, the secretion absorptivity, the elastic behaviour with respect to the non-cohesively constructed bandages is not reduced in any way, so that heat and moisture chambers, so greatly 2 feared by doctors since they provide the prerequisite for foci of inflammation between skin and bandage, cannot be formed. In a bandage manufactured according to the method, subsequent to the application of the bandage, the individual bandage turns are held in a slip-proof manner until the bandage is removed.

.*g 9 The employment of such a small adhesive layer quantity in particular results in a strong cohesiveness. The small particles, in their exceedingly uniform distribution, provide a genuine interlinking without the breathing activity being significantly reduced in the process.

Especially by the addition of acrylic acid or butadienestyrene derivatives, it has surprisingly' been shown that the parti,:le distribution or the number of particles per surface unit and thus the cohesiveness of the individual bandage layers is subjected to a uniformization and that the disadvantages mentioned in the beginning are avoided. By the incorporation cf the aforesaid derivatives in the molecular state in the adhesive, the agglonieration of the rubber particles is controlled in such a way that the number of the adhesive particles per surface unit is very largely preserved and, consequently, also the agglomeration from bandage layer to bandage layer and do not, as in the known bandages, conglomerate and thus, when the bandage is applied repeatedly, a reduction in the number of particles per surface unit takes place.

By virtue of this method, the doctor is provided with a bandage which, it is true, no longer has such a high agglomeration, thus in the adhesion from bandage layer to bandage layer, but which enables the doctor to apply it in a more differentiated manner, and this without having to have misgivings that undesi- 25 red and dangerous constrictions will occur. This is a significant advantage when the bandage is to be applied by the patient himself or by a layman.

According to this method, cohesive, elastic bandages with an improved unrolling force are obtained, in which the adhesiveness is already predetermined and not obtained by the admixed additives. To this is added the circumstance that the storage o0 @0 0 O 0 o 9009 #099 00" 00 #0 C 0 p00~09 0 9 9 00O 0 0 0 i p.- 10 stability of such bandages is increased. The agglomeration of the particles of the adhesive which occurs due to pressure on the bandage layers during prolonged periods of storage is prevented. The admixed additives do in no way affect the adhesiveness, but see to it that the bonding and adhesive force predetermined beforehand are maintained so as to be invariable, even if the bandage is stored over a long period of time. A bandage is thus provided which possesses an unchanging unrolling force. In this connection it is essential and this is a prerequisite, that the adhesive be applied to the fiber ends of the bandage.

Furthermore, the invention comprises a cohesive, elastic bandage which fdheres only to itself and not to the skin, hair and articles of clothing for producing fixing, compression and support dressings and permanently elastic compression and support b 9 dressings, in which the bandage consists of a fabric of warp B: a and weft threads or of weft only as a coarsely or finely knito ted fabric with ultrafine particles disposed on both sides of 00o the exposed surface sections of the warp and weft threads of 20 an adhesive, such as an aqueous latex dispersion, in a distribution of 1000 to 5000 particles on approximately 500 mm at 2 a layer volume of an order of magnitude of 10 to 40 g/m more particularly of 15 to 20 g/m ,.characterized in that acrylic o6 *acid or styrenebutadiene derivatives on a scale of 3% by weight o 25 to 15% by weight relative to the solid phase in the form of o their esters, amides or nitriles, or acrylic acid or butadiene- 1 d o styrene polymers, or rubber-like polymerisates possessing the o 0**0 same properties are admixed to the adhesive, the individual 00 components preferably being added in the form of aqueous dispersions 0 or in the form of solids. Most preferably in the form of aqueous dispersions.

v 1 11 BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an enlarged perspective view of a portion of the fabric of the bandage of this invention covered by adhesive particles; Figure 2 is a perspective view of the bandage of this inven- 5 tion partly rolled up, the adhesive particles visible on the surface; Figure 3 is a perspective view of two fabric Layers applied to one another, held together by the adhesive par- 009900 S tic Les; Figure 4 is a perspective view of the bandage of this invention applied as a dressing; *o S Figures 5 and 6 show the size and percentage distribution of 6 OS the adhesive particles applied to a type 103 bandage by the process of this invention (see examples); jr 15 Figures 7 and 8 show the size and percentage distribution of the adhesive particles applied to a type 181 bandage by the process of this invention (see examples); o, 0 Figures 9 and 10 show the size and percentage distribution of the adhesive particles applied by the process of the invention (see examples); Figures 11,12 and 13 show the size and percentage distribution of the particles applied to a type 181 bandage produced in accordance wit.h prior art DE-AS No.1,491,205 (see examples); Figures 14, 15, 16 and 17 show the size and percentage distribution of the adhesive particles applied to a type 181 bandage produced in accordance with DE.-AS No.1.491,205 (see examples).

12 DESCRIPTION OF THE PREFERRED EMBODIMENT According to the present invention, an adhesive, such as rubber or the Like, is uniformly applied in the form of very fine particles and in a quantity of 1,000 to 5,000 particles per approximately 500 mm 2 to the two surfaces of a flat bano e dage, which is in the form of a knitted fabric constituted by oeaw a warp and a weft, or warp only, while preventing the group of fibers from adhering to one another, whereby an adhesive is 0 00 0 oo y only applied to the projecting fiber ends in an application o'oo 10 quantity of approximately 10 to 40 g/m by the aerosol method.

0000 o preferably by nozzle spraying in an eddy current. The invention u is als'o directed to a cohesive, self-adhesive rigid or elastic bandage which does not adhere to the skin, hair and articles of clothing in that the bandage comprises a web of warp and S 15 weft threads or warp threads only as a knitted or woven fab- S o ric with ultrafine particles of an adhesive such as rubber or "o the like, on either side of the exposed surface portions of the exposed surface portions of the warp and weft threads in oooo a distribution of 1,000 to 5,000 particles to approximately 2 500 mm in an application quantity of approximately 10 to g/m 2 whereby for most bandages a quantity of 15 to S. g/m is adequate.

0000 The invention is also directed to an arrangement of 1,000 to 5,000 ultrafine particles of an adhesive, such as rubber or the Like, applied by an aerosol method preferably under an 2 eddy current, to approximately 500 mm in the case of an 2 application quantity of approximately 10 to 40 g/m to either side of the surface of a web of warp and threads or warp threads as a knitted fabric for the purpose of forming a cohesive, self-adhesive, rigid or elastic bandage which does not adhere to the skin, hair and articles of clothing for use for fixing 1 13 compression and support dressings and permanent elastic compression and support dressings for medical purposes.

With the process of the present invention, a rigid or elastic bandage is obtained in which the two sides are so finely and uniformly covered with rubber particles that a high cohesive- S ness holds together the individual turns and prevents sliding 9 0 °OV9 without there being any limitation to the macrophysical behao 0 0 vior, and consequently, the indication range, as compared with the non-cohesive bandage, i.e. despite the excellent adhesive ere 10 characteristics, the different turns on the bandage only adc9s9 here to themselves and not to the skin, hair and articles of o clothing. Additionally, the water vapor permeability, air permeability, secretion absorptivity and elastic behavior are in no way reduced in comparison with the non-cohesive bandage, so 15 that heat localization and moisture chambers which are feared *9 9 by doctors as the prerequisite for inflammation foci between o the skin and bandage, cannot be formed. As a result of this cohesive construction of a bandage according to the process of the invention, the individual turns of the bandage are held in a slip-proof manner until the bandage is removed. Adhesiveness between the groups of fibers is prevented, particui ut Larly when using a minimum rubber application quantity and on 2 specifically approximately 10 to 40 g/m based on the solid substance being adequate for most bandages, and as a result of the fact that the ir;dividual particles are very fine and are uniformly distributed on both sides of the bandage surface, so that maximum cohesiveness is obtained between the individual bandage turns, no matter how they are arranged.

With the extremely uniform distribution of the small particles, a genuine interlinking is ensured in all cases without there being any significant deterioration in the breathing activity. The smaLL rubber particles applied to the bandage surfaces do not form a cohesive smeary or greasy application extending deeply into the bandage, so that the individual particles cannot influence the physical behavior of the bandage, such as, for example, the extensibility, the reversible energy of deformation or the breathing activity. Furthermore, a 0 the elastic behavior of the bandage is in no way impaired.

o 2" The bandage produced according to the process of the invention 0g is shown in the drawings, wherein FIG. 1 shows a fabric portion 10 of the bandage in a larger scale plane view, the fabric surface O" being covered by rubber particles; FIG. 2 shows a bandage in a partly rolled up state, the rubber particles being clearly visible on the surface; FIG. 3 shows two fabric layers applied to one another held together at the separating line by rubber particles; FIG. 4 shows a dressing applied with a bandage ac cording to the invention.

The bandage which is in the form of a web 10 has weft threads and warp threads 30 (FIGS. 1 to Very fine rubber par- 01t ticles 50 are applied by means of a known aerosol process to either side of the exposed surface portions of the warp and the weft threads 20,30. At 51 in FIGS. 2 and 3, it is possible to see pulled-apart rubber particles between rolled up and already unrolled fabric portions. These ultrafine particles are applied in a distribution of 1,000to 5,000 particles to approximately 500 mm 2 the applied quantity being in a magnitude of 10 to 40 g/m 2 FIGS. 2 and 3 in particular show the Shigh adhesiveness of two bandage layers. Fig. 3 shows two fabric layers applied to one another and' which are held together at separating Lines 60 by rubber particles 51.

1 lr i -Y I 14-Ill;i~ 15 As to the term "woven fabric", it is clear by virtue of the fact that throughout the specification and claims, reference is made to a warp and a weft, that it is a woven fabric which is being referred to. It is well known in the textile art that these two terms apply solely to a woven fabric.

The preferred value ranges of 15 to 20 g/m 2 1,000 to 5,000 particles per 500 mm 2 and 10 tO 40 g/m 2 are well understood by one skilled in the art. In the first instance, the amount 2 of 1,000 to 5,000 particles per 500 mm clearly relates to the distribution of the particles in terms of number of particles per area of the bandage. The weight relationship further defines the total amount of adhesive applied. The weight of the adhesive applied is influenced by the size of the particles which inherently could change the distribution. It is important that the size of the particles be such that an application of 2 1,000 to 5,000 particles per 500 mm would produce an approp- 2 riate weight range of 10 to 40 g/m These numerical values and parameters are clearly understandable by one skilled in Sthe art.

20 The type of adhesive particle used may be determined by one a skilled in the art of self-adhesive bandages and dressing materials. Such adhesives are based either on mixtures of rubber, resins (which make the material sticky), and softeners, or on special polymers without other additions. The development of the adhesive bandage began with the American "rubber bandage" S° which uses a pressure-sensitive, self-adhesive substance. The Sot! disadvantages of such a bandage are the lack of adhesive power on the skin and the limited resistance to aging. Such limitations were corrected by adding zinc oxide. Such bandages were known as "LEUKOPLAST" bandages. The adhesive bandages currently used c,'n be divided into two groups which differ in the type 16 of self-adhesive substance used. This categorization also applies to self-adhesive dressing materials. One group is based on conventional self-adhesive rubber substances and the other on synthetic polymer compounds and polyaddition compounds. The conventional substances are developments which are based on the old zinc oxide rubber formulae. It was believed that the S Qa V self-adhesive characteristics of a substance could be traced S,0 back to the presence of two disperse phases. It has been determined in more recent studies that this is not accurate, 10 but that the viscosity of the adhesive is the most important 0t t o factor. The prerequisite for self-adhesive characteristics is b o o a viscosity which is sufficient to moisten the surface. For practical usefulness, however, a sufficient cohesiveness is also required. In the conventional self-adhesive substances, 15 the correct viscosity obtained by adding auxiliary products a a a to the cohesive rubber, and in the synthetic self-adhesive substances which are based on hom-polymers or copolymers, the o 4 4 correct combination of viscosity and cohesiveness is obtained by adjusting the average molar substance and the distribution of the molar substance in the total polymer. In rubber selfadhesive substances, resins, softeners and fillers are used St as the required auxiliary products. The most important rubbers are the natural rubbers, cis-1.4-polyisoprene, styrenebutadiene polymer, polyisobutylene and butyl rubber.

Colophonium and its derivatives, in addition to the polyterpene resins of ,-pinene, the hydrocarbon resins which are produced from olefins of oil cracking are also used as resins.

EXAMPLES

By means of the following examples, the superiority of a bandage produced according to the process of this invention is demonstrated as compared with an elastic compression 17 bandage (type 103), an elastic fixing bandage (type 181), and a permanent elastic compression bandage (type 600), specifically when treated according to the known dipping process and production process of DE-AS No. 1,491,205.

It has surprisingly been found that the particle size, uniform ao o distribution, percentages of different sizes, state of the contact adhesive applied, the microphysical behavior, are S not without macrophysical consequences. These properties greatly influence the overall physical behavior, such as adhesive- 10 ness, energy of adhesion, aging, secretion absorptivity, air oo0 impermeability, water vapor permeability, water holding capav o city, extensibility behavior, etc. More detailed reference will be made hereinafter to the macrophysical behavior and consequently to the indication value of bandages 103,181 and 600 finished by the dipping process, the roller application process, and.the process of the present invention.

SA dressing material such as riqid or elastic lint fixing bandage like type 181, a compression anr support bandage like l type 103, whose elasticity can be attributed to the twisted crepe threads with different twisting characteristics, or a permanent elastic compre.ssion and support bandage of type 600, Swhose permanent elasticity is essentially due to the covered polyurethane or rubber fibers and/or textured, polyfilic, synthetic yarn, following such a cohesive construction there must be no significant differences compared with the values of an untreated bandage, i.e. the values which are very important for the treatment or healing of a wound. Good aging resistance of the adhesive, very good secretion absorptivity, good water holding capacity and air permeability, i.e. there must be a good bridge between the skin and the external air, are necessary to prevent the formation of heat and moisture i _~CC~ 18 chambers between skin and bandage which are feared because they form the prerequisite for bacterial attacks and inflammation. The Listed indication values are given numerically for bandages of types 103, 181 and 600. Account is taken of the macrophysical values, such as extensibility, Latex pera centage, water holding capacity, air permeability, adhesiveas ness without added aging, adhesiveness after one year, two o years, three years, etc., up to seven years are taken into account.

10 As can be gathered from Table 1, bandage 103 has an extensio a. bility of 95% in the raw state. As there is a zero latex percentage, the water holding capacity according to Bundesmann is relatively high and specifically 70%. The air permeability according to Frank is 7 seconds. This figure gives the time nR 15 in seconds for forcing 10 liters of air through the fabric uno o der identical physical conditions. As the latex percentage of s bandage 103 is zero, the adhesiveness is also zero. The ad- 4ttr hesiveness is calculated as follows: A cohesive bandage is folded to a length of 10 cm and is then rolled together at a temperature of 370C with a roller weighing 5kp, 45 rolling movements being performed in a minute. The two ends are then secured in a stress-strain machine and the rolled-together cm are pulled apart and the energy of adhesion is determined from the stress-strain diagram. The average adhesiveness can be determined from the path and the energy.

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co I a 0 OI~ 04 .4 a TABLE 1 Technical-Physical data Adhesiveness in cN Extensibility Latex Water Air per- Without after after after after after after after holding meability ageing 1 2 3 4 5 6 7 capacity 10 1 [sec -year years years years years years years Bandage 103 basic product 95 0 70 7.0 Bandage 103 application process 85 15 56 8.6 471 519 471 477 397 296 31-4 287 Bandage 103 according to DAS1,491,205 70 16 J63 12.8 337 202 176 147 293 222 251 261 Bandage 103 Dippiing process 50 79 28 14.3 182 226 295 155 61 69 71 47 Ohl A cohesive bandage is aged at 700 C over one or more days according to the formula a -1 2 in which a is the number of aging days and x is the aging years. Thus, if a bandage is stored for five 24-hour days in a dryer at 70° C, the formula gives 5-1=4:2=2, the normal storage tiAe of the bandage is two years. A seven year aging takes place according to formula 15-1=1A:2=7, the bandage must be stored for 15 days at a temperature of 70 C.

ooo O10 Following this storage period, the individual samples are fold ed up to 10 cm and rolled together 45 times for one minute a 4o with a 5kp roller at a temperature of 370C. As described here- Sinbefore, the two ends are then secured in the stress-strain 0 machine and pulled apart. The energy of adhesion is determined 15 from the stress-strain diagram and the average adhesiveness is determined from the course.

In accordance with the cohesive construction of a type 103 bandage by the process of the invention, the technological perfort mance leads to the extensibility being reduced from 95 to 0404 20 This extensibility is Large enough in order to be able to apply plastic dressings even to parts of the body with a relatively small radius.

With a latex proportion of 15%, based on the finished article, the water holding capacity drops from 70 to 66%, while the air permeability, i.e. for forcing 10 liters of air through the fabric, rises from 7.0 to 8.6 seconds. The adhesiveness is S471 cN with aging, and after aging for 1 year is 519 cN, after 2 years 471 cN, after 3 years 477 cN, after 4 years 397 cN, after 5 years 296 cN, after 6 years 314 cN and after 7 years 287 cN.

p.

I

21 I. 0 C 00 0000 00a o 0 t 00 0 4004) 0 0000i Thus the contact adhesive does not become greasy and therefore does not adhere to the skin, hair or items of clothing. A type 103 bandage was used for checking the individual values for its cohesive construction according to the dipping process.

Due to the technological performance of the dipping process, the extensibility is reduced to almost 50%, i.e. the bandage loses 45 percentage points. The Latex proportion was calculated as which explains the Limited water holding capacity of only 28% and the high resistance to air permeability. Thus, 10 the water holding capacity is only 28% compared with 70% in the untreated article. Under identical physical conditions, 14.4 seconds are required for forcing 10 liters of air through the bandage. Although the latex proportion is 79%, the adhesiveness without aging is only 182 cN. After aging for 1 year, ,15 it is 226 cN, after 2 years 295 cN, after 3 years 155 cN, after 4 years 61 cN, after 5 years 69 cN, after 6 years 71 cN and after 7 years 4? cN, there is a pronounced reduction in the adhesiveness due to aging. Furthermore, after only 1 year the bandage which no longer just adheres to itself, in- '20 stead adheres easily to hair, skin and clothing.

With a cohesive construction of a type 103 bandage according Sto DE-AS No. 1,491,205, the extensibility drops from 95 to According to this process, an extensibility range is obtained which is just sufficient to be able to apply plastic dressings, but with such extensibility values it is critical if the parts 0 of the body have only a relativly small radius. The latex proportion is 16%. The water holding capacity has dropped from to 63%, while the air permeability' has risen to 12.8 seconds, under identical physical conditions 12.8 seconds are required in order to force 10 liters of air through the fabric. The adhesiveness without aging was 337,'after aging for 1 year 2-2 cN, after 2 years 176 cN, after 3 years 147 cN, 0 0 1 0 0 o a a ft 22after 4 years 293 cN, after 5 years 222 cN, after 6 years 251 cN, and after 7 years 261 cN.

Thus, the type 103 bandage cohesively finished according to the process of the invention only had a 10% extensibility Loss, although the latex proportion was only 15%. The water holding capacity differed only insignificantly from the basic article.

There was an insignificant reduction in the air permeability from 8.6 seconds to 7.0 seconds compared with the basic article. The type 103 bandage with 79% rubber cohesively finished 0 60 °oo ,10 by the dipping process has relatively low advesiveness, des- 0on pite the high rubber percentage and after 2 years this has ind O 0 <e creased to an extraordinary level. The water holding capacity of 28% drops to a very low Level and the air permeability rises to 14.3 seconds, which is twice as high as in the basic o oi 15 article, with such a bandage it is to be expected that the bridge formation between s in and external air is disturbed so that moisture and heat chambers can form. The same bandage cohesively finished according to DE-AS No. 1,491,205 had an extensibility Loss of 25%, the extensibility dropped from 95 to 70%. Thus, the extensibility is at the lower limit for permitting the application of plastic dressings, particularly to parts of the body with a small radius. The latex proportion was 16%. The water holding capacity decreased only insignificantly from 70 to 63% compared with the basic article.

However, the air permeability dropped from 7.0 to 12.8 econds and is therefore much less advantageous than with a bandage finished according to the invention. The adhesiveness without aging was 337 cN, after 1 year 202 cN, after 2 years 176 cN, after 3 years 147 cN, after 4 years 293 cN, after 5 years 222 cN, after 6 years 251 cN, and after 7 years 261 cN. Since the adhesiveness Levels were low'er than with a bandage /!1 I I

I

-23cohesively finished according to the present invention, despite identical Latex percentages, it can be assumed that the individual adhesive strips did not engage directly on one another or that the sides were cohesively impregnated to a differing degree.

The conditions are similar in the case of type 181 bandages according to Table 2.

9 0

D

1 000 9 9 1 0 j o A, Jl -1- V j WM 9XIINO Ii .b 0 04 0 4 CCC U C 040 3 0 0 a TABLE 2 Technical-Physical Data Adhesiveness in cN Extensibility Latex Water. Air-per Without after after after after after after after holding meahility ageing 1 2 3 4 5 6 7 capacity 101 /sec year yOears years years years years years Bandage 181 basic product 235 0 152 3.3 Bandage 181 application process 120 19 140 3.4 419 462 390 356 413 279 283 371 Bandage 181 accolding to DAS 1.491.205 90 21 118 3.9 277 431 411 235 159 262 214 139 Bandage 181 dipping process 40 79 67 4.2 289 176 145 222 159 140 76 13 25 The extensibility of the type 181 bandage which was not cohesively finished is 235%, the water holding capacity 152% and the air permeability 3.3 seconds. The bandage produced according to the process of the invention contains 19% Latex and has an extensibility Loss of 115%, decreasing from 235 to 120%. The water holding capacity of the bandage decreased from 152 to 140%, while the air permeability dropped only insignificantly from 3.3 to 3.4 seconds. The adhesiveness without aging was 419 cN. After aging for 1 year the adhesiveness was 462 cN, after 2 years 390 cN, after 3 years 356 cN, after 4 o o0 years 413 cN, after 5 years 2(7 cN, after 6 years 283 cN, and after 7 years 371 cN. When the same bandage was finished accoroo 0 ding to DE-AS No. 1,491,205 and with a 21% latex content, the 00o o 0 extensibility loss was 145%, the extensibility dropped o! 15 from 235% in the basic product to 90%. The water holding ca- 0000 a pacity dropped from 128%, by 34% and this value is well 0 below that of the basic product. The air permeability dropped from 3.3 seconds from the basic article to 3.9 seconds. The adhesiveness without aging was 277 cN, after 1 year 431 cN, after 2 years 411 cN, after 3 years 235 cN, aft.r 4 years 235 cN, after 5 years 262 cN, after 6 years 214 cN and after 7 years 139 cN. In order to arrive at comparative values, bano 9 dage type 181 was cohesively finished by the dipping process, o Q "but the extensibility dropped from 235 to 40%. This value is so Low that such a bandage could not be used for a plastic dressing. The Latex proportion was 79%.

A oo This Led to the low water holding capacity of only 67%, which is well below half that of the basic 'article. The air permeability dropped from 3.3 seconds in the case of the non-cohesive bandage to 4.2 seconds. The adhesiveness without aging was, despite the high Latex percentage of 79%, only 289 cN, after

K

-:i 26 1 year 176 cN, after 1 years 145 cN, after 3 years 222 cN, after 4 years 159 cN, after 5 years 140 cN, after 6 years 76 cN, and after 7 years 13 cN. It can be concluded from this that, although the Latex percentage was extremely high, the adhesiveness had dropped to an extraordinary extent after 2 years, the cohesive adhesive Loses its characteristics and becomes greasy, sticking to skin, hair and articles of clothing.

Thus, an elastic fixing bandage of type 181 made cohesive by 10 the process of the invention has very advantageous values for oo ooo0 the water holding capacity, the air permeability, the adhesive- 0000oo o g ness and the elastic behavior.

*000 0000 As can be gathered from Table 3, the conditions are much the °oU same with type 600 bandages having a basic extensibility of 00 20 S 15 200%.

*I 00 0000 00 0 0000) 00 Do00

V

r 0° a ft a o S0 0 o a o 0 0 o C 0 0 00 o o o c S o 0 0 oa 0 000 0 0 60 0 TABLE 3 Technical-Physical data Adhesiveness in cN Extensibility Latex Water. Air per- Without after after after afte: after after after holding meability ageing 1 2 3 4 5 6 7 capacity 101/sec year- years years years years years years Bandage 600 basic product 200 0 134 7.0 Bandage 600 application process 180 15 120 7.5 475 390 243 527 664 541 556 427 Bandage 600 according to QAS 1,491.205 150 17 105 9.9 435 198 319 402 589 490 478 389 Bandage 600 dipping process 115 42 50 12.5 490 257 226 196 213 118 117 107 c r -lal 28 The water holding capacity of such a bandage is 134%. When cohesively finished by the process according to the invention, the same bandage only reveals an extensibility Loss of the extensibility drops from 200 to 180%. The latex percentage is 15% and the water holding capacity drops from 134 to 120%, while the air permeability rises only from 7.0 to seconds. The adhesiveness without aging is 475 cN, after 1 year 390 cN, after 2 years 342 cN, after 3 years 527 cN, after 4 years 664 cN, after 5 years 541 cN, after 6 years 556 cN, and after 7 years 427 cN.

SThe type 600 bandage cohesively finished according to DE-AS ooo No. 1,491,205 has a 50% extensibility loss, the extens, g sibility has dropped from 200 to 150%. The water holding caooa pacity is only 105% compared with the basic article with 134%.

oo0 ooac 15 Whereas the air permeability of a type 600 bandage cohesively 0 oo a finished according to the process of the invention rose from 0 o 7.0 to 7.4 seconds, the time taken to force 10 liters of air through a bandage finished according to the DE-AS No.1,491,205 under the same physical conditions was 9.9 seconds, i.e., there is a considerable increase due to the method. With a S g Latex proportion of 17%, the adhesiveness of a bandage produced according to DE-AS No. 1,491,205 without aging was 435 cN, after 1 year 189 cN, after 2 years 319 cN, after 3 years 402 cN, after 4 years 589 cN, after 5 years 490 cN, and after 7 years 0 389 cN.

In the case of a type 600 bandage cohesively finished accor- O ding to the dipping process, the extensibility was found to be only the extensibility drops from 200 to 115% as a result of the cohesive finish. The water holding capacity dropped to the insignificant value of 50%, while the air 4 A 29 permeability dropped from 7.0 to 12.5 seconds. Although the Latex proportion was 42%, the adhesiveness without aging was 498 cN, after aging for 1 year was only 257 cN, after 2 years 226 cN, after 3 years 196 cN, after 4 years 213 cN, after years 118 cN, after 6 years 117 cN, and after 7 years 107 cN.

It should be noted that from the fourth year on, the cohesive character, the individual turns only adhering to one another and not to the skin, hair or clothing, was Lost because at that time, the adhesive became greasy and started to 10 stick to the skin, hair ard clothing. Thus, with such a permanent elastic compression and support bandage, the cohesive finish thereof by the process of the invention only has an insignificant influence on the water holding capacity, air permeability, etc. The extensibility loss of 200 to 180% is in- 15 significant and, despite pronounced aging, the adhesiveness values are in very favorable ranges.

o o 0o a a g i a 09 *oo 0 u 000o 6 o a 000 0or 040 In summarizing, it can be said that based on the present examples of types 103,181 and 600 bandages, it is shown that the cohesive finishing thereof by the process of the invention, 20 the macroscopic values such as extensibility, elastic behavior, water holding capacity and air permeability only dropped insignificantly. These macroscopic values confirm the microscopic values obtained. As a result of the cohesive finish according to the present process, regardless of the type 25 of bandage involved, the individual particles scarcely impaired the indication range, the individual particles are located in almost droplet-Like manner.on the surface of the fabric, especially on the fiber ends 'of the bandages, and claw into one another between the individual turns. Unlike the bandages produced by the known processes, the individual rubber particles do not cause the weft and warp threads to stick together.

4 90 00fr0 30 Thus, the breathing activity is not impaired and, consequently, there is no narrowing of the indication range. As a result of the very fine particles and the uniformity of distribution, the formation of heat and moisture chambers between the skin and the bandage, which are the prerequisite for inflammation foci, is avoided.

:0 10 6S00 e.Ot, a a 6-09 0 090 Q 0 15 a 0 With respect to the above-mentioned bandage types 103,181 and 600, it is pointed out that bandage type 103 is a compression bandage, whose extensibility is 90% as a result of elastic, twisted crepe threads. The twisting of these threads of Nm 50/2 is approximately 2.150, and the threads are arranged in such a way that a thread with an S-twisting direction is followed by a thread with a Z-twisting direction, or two threads with an S-twisting direction are followed by two threads with a Z-twisting direction. The elastic element of the elastic fixing bandage of type 181 is a textured, polyfilic, synthetic thread, followed by two rigid staple fiber or cotton threads.

'0 0 0 C0 a0 00 #oo 60000 The type 600 permaneri, elastic compression bandage contains covered polyurethane or rubber threads, as well as rigid cotton or staple fiber threads in a ratio of 1:1, 1:2, 1:3 1:4, etc.

The results of the size and percentage distzribution of the particles appplied to the surface of the bandage are given in 25 Tables 4 to 22.

Figures 5 and 6 show the size and percentage distribution of the particles applied to a type 103 bandage by the process of the invention and Table 2 shows the percentage area coverage.

Figures 7 and 9 show the size and percentage distribution of the perticles applied to a type 181 bandage by the process of the invention and Table 6 shows the percentage area coverage.

-31- FIGS. 9 and 10 show the size and percentage distribution of the particles applied by the process of the invention to a type 600 bandage and Table 7 shows the percentage area coverage.

FIGS. 11,12 and 13 show the size and percentage distribution of the particles applied to a type 103 bandage produced according to DE-AS No. 1,491,205 and Table 8 shows the percentage area coverage.

FIGS. 14,15,16 and 17 show the size and percentage distribution of the particles applied to a tyoe 181 bandage produced according to DE-AS No. 1,491,205 and Table 9 shows the percentage area coverage.

0 4B aaoo The different cohesive finishing of bandages of type 103,181 Sa and 600 is explained in greater detail by means of FIGS, 0 o 15 to 17 and Tables 5 to 9 0 6 0 .4 oo oo a 6 o D 0 00 7-1a TABLE 4 Quanti.ty and percentage distribution of particles/image surface according to size, as a function tuf tb:a application process Bandage type 103 Percentage coverage of the microscopically visible image surface 'of 50 .24 mun' determined by graph paper.

Calculation Example: particle dia. calculated particle size coverage mm 2 1/100 1/200 x 1/200 x 3.14 0.0000785 x 13 0.0010 mm 2 1/80 1/160 x 1/160 x 3.14 0.00012 x 31 0.0037 mm 2 1/60 1/120 x 1/120 x 3.14, 0 0.00022 x 44 0.0097 mm 2 1/40 1/80 x 1/80 x 3.14 0.00040 x 75 0.03 mM 2 1/20 1/40 x 1/40 x 3.14 0.00196 x 120 0.235 mm 2 1/10 1/20 x 1/20 x 3.14 0.0078 x 72 0.562 MM 2 2/10 1/10 x 1/10 z 3.14 =0.03 x 6 0.8 £taZo 3/10 3/20 x 3/20 x 3.14 0.07 x 1 0.p7M 1.0214 mm 2 image surface 50.24 mm 2 2 All graphs were based on this calculation example.

0 Op p 0004 0040 4 00 po P 0 on p 0 0 0400 0040 0 0000 0 Oppppp 0 p qk4 4 4 0090 Ta sf ar a a0tud TABLE Application Process Bandage Type 103 2 2 Total surface area of 123 measurements for a magnitude of 0.0000785 mm 0.0967 mm 2 2 Total surface area of 288 measurements for a magnitude of 0.0001200 mm 0.03456 mm2 2 2 Total surface area of 412 measurements for a magnitude of 0.0002200 mm 0.09064 mm Total surface area of 847 measurements for a magnitude of 0.0004000 mm 0.33880 mm 2 2 2 Total surface area of 964 measurements (34.76%) for a magnitude of 0.0019600 mm 1.88940 mm 2 2 Total surface area of 358 measurements (51.37%) for a magnitude of 0.0078000 mm 2.79240 mm 2 2 Total surface area of 7 measurements for a magnitude of 0.0300000 mm 3.86000 mm 2 2 Total surface-area of 1 measurements for a magnitude of 0.0700000 mm 0.07000 mm 2 Total coverage: 3000 particles Total surface area: 5.43547 mm 2 Size of complete stereo image surface of 8 stereo images: 401.92 mm Percentage of covered surface of total surface area: 1.35%

T--

*L 0 0 0900 0p *a o 9 a 0 Ci 99 0 a 00 0 a a 000r 4 0 00e 0 TABLE 6 Application Process Bandage Type 181 Total Total Total Total Total Total 2 2 surface area of 145 measurements for a magnitude of 0.0000785 mm 0.01138 mm 2 2 2 2 surface area of 485 measurements for a magnitude of 0.0002200 mm 0.10670 mm 2 2 surface area of 655 measurements (16.67%) for a magnitude of-0.0004000 mm 0.26200 mm 2 2 surface area of 432 measurements (53.87%) for a magnitude of 0.0019600 mm 0.84672 amm 2 2 surface area of 39 measurements (19.36%) for a magnitude of 0.0078000 mm 0.30420 mm 2 Total coverage: 2095 particles Total surface area: 1.57168 mm 2 Size of complete stereo image surface of 10 stereo images: 502.40 mm Percentage of covered surface of total surface area: 0.31%

ILW

O 0 00 -i 4 0 a ~C 000O 0 i 0i 0r 0 000 0 04 0 00 0e TABLE 7 Application Process Bandage Type 600 Total Total Total Total Total Total Total Total 2 2 surface area of 87 measurements for a magnitude of 0.0000785 0.00683 mmn surface area of 202 measurements for a magnitude of 0.0001200 no 2 0.02424 mm 2 2 2 surface area of 202 measurements for a magnitude of 0.000200 0.063582424 mm 2 2 surface area of 803 measurements for a magnitude of 0.0004000 mm 2 0.32120 mm 2 surface area of 702 measurements (32.21%) for a magnitude of 0.0019600 mm 1.37592 mm 2 2 surface area of 803 measurements (7.5293%) for a magnitude of 0.0078000 mm 0.3212.09040 mm 2 2 surface area of 6 measurements for a magnitude of 0.0300G6 mm 0.18000 mm 2 2 surface-area of 3 measurements for a magnitude of 0.0700000 mm 0.21000 mm Total coverage: 2360 particles Total surface area: 4.27217 mm 2 Size of complete stereo image surfac- of 10 stereo images: 502.40 mm Percentage of covered surface of total surface area: 0.85%

CA

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F

vy j 0 0 p a0: a-~ o fr O 0 00 *o a 0 0 4 0 0- 000 0 00 0 a *r 000 .4 00dB 0 0 O *0 TABLE 8 According to DE-AS 1,491,205 Bandage Type 103 Total Total Total surface area surface area surface area Total surface area Total Total Total Total Total Total Total Total Total Total Total Total surface surface surface surface surface surface surface surface surface surface surface surface area area area area area area area area area area area area 2 2 9 measurements (0.028%) for a magnitude of 0.00001 mm 0.009 mm 2 2 28 measurements (0.216%) for a magnitude of 0.0025 mm 0.070 mm 2 2 51 measurements (0.785%) for a magnitude of 0.0050 mm 0.255 mm 2 2 83 measurements (2.556%) for a magnitude of 0.01 mm 0.830 mm 2 2 56 measurements (3.449%) for a magnitude of 0.02 mm 1.120 mm 2 2 49 measurements (4.527%) for a magnitude of 0.03 mm 1.470 mm 18 measurements (2.217%) for a magnitude of 0.04 mm 2 0.720 mm 2 2 2 24 measurements (3.695%) for a magnitude of 0.0 mm 1.200 mm 2 2 33 measurements (10.162%) for a magnitude of 0.1 mm 3.300 mm 2 2 27 measurements (16.629%) for a magnitude of 0.2 mm 5.400 mm 2 2 18 measurements (16.629%) for a magnitude of 0.3 mm 5.400 mm 2 2 4 measurements (4.927%) for a magnitude of 0.4 mm 1.600 mm 2 2 6 measurements (9.238%) for a magnitude of 0.5 mm 3.000 mm 2 2 1 measurements (1.848%) for a magnitude of 0.6 mm 0.600 mm 2 2 6 measurements (18.476%) for a magnitude of 1.0 mm 6.000 mm 2 2 1 measurements (4.619%) for a magnitude of 1.5 mm 1.500 mm 2 Total coverage: 414 particles Total surface area: 32.474 mm 2 Size of complete stereo image surface of 9 stereo images: 452.16 mm Percentage of covered surface of total surface area: 7.18% W L

Y

L

r 0 000 00 C a a 0 V 0 o 000 0 L 0 0 C 0 P a a, a p. a a O a TABLE 9 According to DE-AS 1,491,205 Bandage Type 181 Total Total Total Total Total Total Total Total Total Total Total surface surface surface surface surface surface surface surface surface surface surface area area area area area area area area area area area 2 2 9 measurements for a magnitude of 0.01 mm 0.08 mm 2 2 16 measurements for a magnitude of 0.02 mm 0.32 mm 16 measurements for a magnitude of 0.03 mm 2 0.48 mm 2 2 2 15 measurements for a magnitude of 0.04 mm2 0.60 mm 40 measurements (10.74%) for a magnitude of 0.05 mm 2 2.00 mm 2 Smeasurements fr a magnitude of 0. mm 2 0.

measurements for a magnitude of 0.08 mm 0.40 mm 2 2 2 64 measurements (34.35%) for a magnitude of 0.10 mm 6.40 mm 2 2 21 measurements (22.54%) for a magnitude of 0.20 mm 4.20 mm 2 2 1 measurements for a magnitude of 0.25 mm 0.25 mm 2 2 1 measurements for a magnitude of 0.30 mm 0.30 mm Total.coverage: 211 particles Total surface area: 16.962 mm 2 Size of complete stereo image surface of 10 stereo images: 502.4 mm Percentage of covered surface of total surface area: 3.38% L Edo= 33 J As can be gathered from the graphs of Table 4 and FIGS. 5 and 2 6, the number of counted particles per image detail (50.24 mm is between 350 and 450. 3,000 particles were recorded for 8 2 2 image details 8 times 50.25 mm 401.94 mm Most of the partides and specifically approximately 86% were between 20/10,000 2 anJ 78/10,000 mm The calculation of the surface area of 3,000 2 particles gave 5.43 times 8 401.9 mm representing a percentage area coverage of This refers to a type 103 bandage.

However, the same applies to a type 181 bandage. FIGS. 7 and show that the number of particles was about 200, so that the 2 total number of particles of the ten image areas of 502.4 mm S0° is 2095. The greatest percentage of the particles were between 20/10,000 and 78/10,000. The particles of a magnitude of 10,000 mm represented 53.9%. Thus, from the total number of a a 15 particles, a coverage of 1.57 mm corresponding to a percen- 2 tage area coverage of 0.31 is calculated for 502.4 mm pots The same picture is obtained for an identical cohesive finish with a type 600 bandage according to FIGS. 9 and 10, where the number of particles per image detail is between 51 and 400. 2,360 particles were counted for the 10 image details, 2 the largest proportion being at 20/10,000 mm and 78/10,000 S2 2 A, mm Thus, there is an overall coverage of 4.3 mm correso ponding to a percentage surface coverage of 0.85% of the .oo 2.360 particles with a total image surface of 10X50.24 mm 2 0 2 25 502.4 mm 2 The same values are shown in the technical-physical data of Tables 1 to 3. They sh-w that the extensibility of a finished type 103 bandage has only dropped by 10% com- 0 00 pared with the basic articles, from 95 to 85%. The water holding capacity dropped from 70% in the basic article to 66%, while the air permeability for the same bandage rose from 7 seconds to 8.6 seconds. In the case of a latex ~la~ l r~ l illri~.-ii -_1~I 34 proportion of only 15%, the energy of adhesion both with and without aging, no matter whether it was after 1 year or after 7 years, was much higher than in the cohesive bandages treated by the dipping process or DE-AS No. 1,491,205.

The same picture is repeated for type 181 bandages. As a result of the fine particles, the water holding capacity only dropped from 152 to 140%, compared with the basic article. The air permeability for forcing 10 Liters of air through the fabric under identical physical conditions only rose by With regard to the adhesiveness, both with and without aging, with Sthe cohesive finish according to the present process, much hio oa° gher values are obtained than with the previously described So cohesively finished banda es according to the dipping process o 10 or according to DE-AS No. 1,491,205. The order of magnitude o 15 and distribution are also shown in the technical-physical data on of a type 600 bandag. Thus, the extensibility only dropped from 200 to 180% compared with a non-cohesively finished bandage. The water holding capacity dropped from 137 10 120%, while the air permeability rose from 7.0 to 7.5 seconds. In the case of a latex proportion of 15%, values were obtained Sfor the adhesiveness both with and without aging which are t, well above the values obtained with a cohesive finish by the dipping or roller application process.

0000 0 o,1 Admittedly, with a bandage having a cohesive finish according to DE-AS No. 1,491,205, the indication range is not limited to the same extent as with bandages cohesively finished by So*o the dipping process, but in a number of areas of said bandage, the breathing activity of the groups 'of fibers is negatively affected to a considerable extent, the bridge formation between skin and external air is reduced. The number of particles and the percentage distribution thereof on the bandage surface are determined according to FIGS. 14,15 and 16. The percentage coverage is determined by adhesive particles for measurements and therefore, for a natural otal surface 2 area of 502.4 mm according to classes in 211 measurements (FIG. 17), together with the percentage area coverage for a 2 natural surface of fibers 502.4 mm (Table FIGS. 14 and show that the number of particles per image area is approximately 20. The size of the particles is mainly 10/100, 2 15/100 and 20/100 mm Thus for a total natural surface of 2 502.4 mm and 211 measurements, there is a total coverage of 2 16.9 mm corresponding to a percentage coverage of 3.38%.

S0 *The same picture is obtained for a type 103 bandage cohesio vely finished according to the process of DE-AS No. 1,491,205.

o °Although the number of particles per surface is somewhat higher, oo 15 the distribution is of a very random nature, which is apparent o, from the strip arrangement of the adhesive coating (FIGS. 11 and 12). The total number of particles was 414 for a natural image size of 452.16 mm Here again and in accordance with FIG. 13, most of the particles were of sizes of 10/100, 20/100, 30/100, 40/100, 50/100 and 60/100 and even 1 mm. Thus, as is shown by FIG. 17, there is a total coverage area of 32.47 mm corresponding to a percentage coverage of 7.18%.

Thus, the particles applied to the bandage by the aerosol m^ process according to the invention are 100 to 1,000 times smaller than the particles of a bandage cohesively finished according to DE-AS No. 1,491,205. It can be concluded from the particle size of bandages according to the present process and according to that of bandages with a cohesive finish according to the DE-AS No. 1,491,205 that the number of particles according to the present process is 10 times higher than with the known construction. Despite the large number of 36 particles after the cohesive finish of the bandages according to the present process, the percentage area coverage is 6 to 7 times lower as compared with a bandage procuced according to DE-AS No. 1,491,205, while the adhesiveness is greater. It is also pointed out and this is shown by the graph, that the distribution of the particles is extremely uniform. Referring to the technical-physical data of Tables 1 and 3 and comparing said data, it is clear that the individual bandages of the types 103,181 and 600, have been detrimentally affected with regard to the extensibilit>, water holding capacity, air permeability and aging. This deterioration, compared with the oS basic article, is least in the ca .e of bandages cohesively fi- Sto* nished according to the present process and with maximum adhesiveness, but increases to a very considerable extent in the S 15 case of bandages according to DE-AS No. 1,491,205, with the oa same latex percentage. The data for the water holding capacity 1 and air permeability were of a very inferior nature in the case of bandages cohesively finished by the dipping process and, in fact, the water holding capacity was 2 to 3 times Lower than with the basic article. Much the same applies regarding the air permeability which dropped very considerably due to the high rubber percentage and, in fact, the passage time rose from 7.0 to 12.5 seconds. Although the rubber percentage for the dipping process was 4 to 5 times higher than in the process according to the invention, the adhesiveness data are much lower.

J In summary, it can be stated that as a result of the cohesive finish according to the present proce'ss, the particles are so finely and uniformly distributed that in spite of the high adhesiveness, the factors necessary for the healing process, such as the breathing activity, etc., are in no way impaired i i-- 37 and no hot or moist chambers were found. Thus, the superiority of a bandage produced according to the inventive process is established.

As a result of the Longitudinal, transverse and Longitudinal/ transverse elasticity of the bandages and due to the uLtrafine arrangement of the rubber particles, it is possible to produce plastic and slide-proof, as well as elastic fixing dressings for all parts of the body, even when they have a very small radius, without losing air circulation, moisture absorption and the bridge formation for moisture and water, so that there o is no build-up of heat and moisture which could provide foci of infection.

With the present invention, a rigid or elastic bandage is obatained, wherein both sides are covered extremely finely and S 15 uniformly with rubber particles. These result in a high coheo sive force so that the individual layers of the bandage are held together and slipping is minimized.

Even so, however, the bandage layers adhere only to themselves and not to the skin, hair and clothing. Moreover, a bandage prepared in such a way possesses water vapor permeability and air permeability, as well as the ability to absorb secretions.

Also, if the fabric of the bandage is elastic, the adhesive does not interfere with the elastic properties. Thus, for example, the accumulation of heat and moisture chambers which generally are feared because thay can cause infection, are avoided with the present invention. Due to this cohesive em- S a bodiment of the bandage of the present invention, after the bandage has been placed, the individual layers of the bandage are securely held and do not slip until they are removed.

The use of an application quantity of rubber which is as small as possible, in the order of magnitude of to to 38 g/m 2 is sufficient. The individual particles should be very finely and uniformly distributed over both sides of the bandage surface so that a strong cohesiveness results between the individual layers, regardless of how they are arranged. Additionally, the fiber groups should not adhere to themselves or to one another. The uniformly distributed small particles provide a genuine tooth-Like connection without significantly reducing the breathing activity of the fabric. The rubber particles which are applied to the bandage surfaces do not form a continuous sticky coating which penetrates into the interior of the bandage. Thus, the individuat particles do not affect the physical behavior of the bandage, such as, for instance, elasticity, reversible energy o° capacity or breathing activity and the Like. In addition, a 15 there is no impairment of the elastic behavior of the bandage.

A cohesive adhesive is applied to the surface of the fabric P in the finest distribution in accordance with an aerosol method, so that the permeability to air and water does not suffer from the cohesive design of the bandages. Only woven or knitted, highly elastic bandages are used as carrier material.

Non-woven fabrics are not used. Cohesively designed bandages 1 do not adhere to skin and hair as do adhesive bandages; rather; the individual bandage Layers adhere to each other.

0 r9 a According to a further embodiment, the bandage consisting of a fabric 10 is provided with weft threads 20 and warp threads On both sides of the exposed surface sections of the weft- 0ow warp threads 20,30, ultrafine particles identified with of rubber, such as latex, are applied', to which, in an order of magnitude of 3% by weight to 15% by weight relative to the solid substance, acrylic acid or butadiene styrene derivatives or rubber-like polymerisates are admixed according to the 39 known aerosol method. At 51, a puLLed-apart small rubber particle is rendered visible between rolled-jp and already unrolled fabric portions. These ultrafine particles 50 are likewise applied in a distribution of approximately 1,00 to 5,000 2 particles to 500 mm 2 the application quantity in this case consisting at a magnitude of 10 to 40 g/m 2 The present process, in which, to the adhesive, such as e.g.

a latex dispersion, further additives are admixed, is explaio ned with the aid of the following embodiment: "0 o 10 On a first section of a longitudinally elastic web of fabric 0000 of the type 103, which is employed for compression and support I o o bandages and in which the warp threads consist of highly-twis- GO0 o .o ted S and Z crepe yarn threads, in which the threads are aroo 0ranged in such a way that a thread with an S-twisting direco 15 tion is followed by a thread with a Z-twisting direction, or two threads with an S-twisting direction are followed by two threads with a Z-twisting direction, an aqueous latex dispersion is applied. The quantity of the aqueous latex dispersion o 2 S, is 10 g per m on one side, so that, with a percentage solids .o"o 20 proportion of 60% latex, 12 g solids proportion in the form of ultrafine particles remains. By atomizing the aqueous latex dispersion, to which, in an order of magnitude of 3% to too relative to the solid substance, acrylic acid or butadiene styrene derivatives or rubber-like polymerisates are admixed 25 in an eddy current field (aerosol method) and a residence time GOOD of approximately 1 minute and at 80 C, the ultrafine particles adhere to the surface of 'the fabric, as a result of which said surface is only covered 1.53% and, due to this, the breathing activity, absorptivity, bridge formation between skin and external air are fully preserved.

I: iL1 i I- i 40 The fabric surface was provided on both sides with particle agglomeration of the Latex dispersion so that, when two fabric sections impact upon each other, a sticking together of the particle agglomeration and, consequently, an adhering on top of one another of the two fabric sections cannot take place.

With the aid of the following example, the superiority, i.e., the adhesiveness of two bandage layers on top of each other and the unrolling force of a bandage according to the DE-OS 29 12 129 is compared with that of a bandage produced according to the inventive process.

Adhesion of two superimposed bandage layers o0 o 10 0 0 0 6 00 0o a 0 0 0 *a t I t 1 20 0 Bandage according to DE-OS 29 12 129 New Bandage After 1 application 95 cn 85 cn After 2 applications 68 cn 79 cn After 5 applications 44 cn 65 cn After 10 Applications 29 cn 50 cn (Adhesiveness/cm bandage width, measured in cn/cm) Unrolling Force Bandage according to New Bandage DE-OS 29 12 129 0 04 o o od 0 0 B 0 444 Outside Center Inside 61 cn 80 cn 104 cn 51 cn 63 cn 65 cn (Unrolling force/cm bandage width, measured in cn/cm) Used as additives are acrylic acid or butadiene styrene derivatives, acrylic acid or butadiene styrene polymers or 41 rubber-Like poLymerisates possessing the same properties and this preferably in the form of aqueous dispersions, in which connection, by derivatives of acrylic acid, the monomeric derivatives in the form of esters, amides or nitrile are understood. Thus, by way of example, it is also possible for an aqueous, coLLoidaL dispersion of a styrene-butadienecopolymerisate containing a carboxyL group to be used.

0 04 O6 00 0 0 00 o 00000 oa 6 0 0400

Claims (8)

1. A method for the manufacture of a cohesive, elastic bandage for medical purposes, which bandage adheres solely to itself but does not adhere to skin, hair or items of clothing and comprises a fabric in the form of a coarse or fine knit, the fabric having projecting fibre ends, said method being characterized in that an adhesive in the form of superfine particles is admixed with from 3% to 15%, by weight of adhesive solids, of acrylic acid or butadiene styrene derivatives or rubber-like polymerisates which possess the same properties and the admixture is uniformally applied to both surfaces of the fabric in a quantity of 1000 to 5000 particles of adhesive on approximately 500 mm2 of fabric, the application being by atomization in an eP eddy current field whereby the adhesive is only applied o to the projecting fiber ends in an application quantity 0 0 of 10 to 40g/m whilst preventing a group of fibers from adhering to one another.

2. The method of claim 1 whereia the derivative is goo in the form of an ester, amide or nitrile, an acrylic 00 acid or butadienestyrene polymer, or rubber-like o polymerisate possessing the same properties.

3. The method of claim 1 or 2 wherein the particle size of the adhesive is 0.0000785 to 0.07 mm 2

4. The method of any one of claims'l to 3 wherein the adhesive is applied in a quantity of 15 to g/m 2 43 The method of any one of claims 1 to 4 wherein the adhesive is rubber.

6. The method of any one of claims 1 to 5 wherein the adhesive is an aqueous latex dispersion.

7. The method of any one of claims 1 to 6 wherein atomization is conducted in an eddy current field at a residence time of 1 minute at 80 0 C.

8. A bandage whenever prepared by the process of any one of claims 1 to 7. DATED This 20th day of December 1994 KARL OTTO BRAUN KG Attorney: RUTH M. CLARKSON Fellow Institute of Patent Attorneys of Australia of SHELSTON WATERS o* 0 Q 0 0o 0o00 0e 6 o o 00 6 f A' ABSTRACT The invention relates to a ,,-ocess for preparing a cohesive, self-adhesive bandage, which does not adhere to the skin, hair and articles of clothing and which is rigid or elastic for fixing, compression anid support dressing for medical purposes and a bandage prepared by the process. 0 O~2 0 0 9 0000 9

94. o ~0 44 4 0~0o 0004 0990 000 .00 a 4.4 0 44 40 4) 04 9 49 44 443 0 0400 94490 0 01 044p~