DE1642082A1 - Medical cloth, especially for bandages - Google Patents

Description

Potentaftwfille DfpL-Iiig. E Sciierrmann Dr.-Ing. R. Roger

73 EssHngen (Neckar), Fabrikstrasse % Postfach 348

PA 22 rüba Stuttgart (0711) 356539

Telegrams patent protection Essllngenneckar

THE KENDALL COMPANY. 140 Federal Street, Boston IOj

Mass./USA .: '- - "'" = ■■ - '^;

Medical cloth «insfa. :: for association purposes

The invention relates to a medical towel, the one Inner layer made of absorbent material and one in direct contact with the inner layer and this covering outer layer made of-alehtgeWebi: em "textile, material (non-woven). Here she relates see.; _ especially on absorbent bandages, have absorbent inner layer, which with an> outer Surrounding envelope is *, "" -

The combination of an inner layer made of absorbent material with a cover folded over it and often firmly connected to it is an im ^ medical and sanitary Uses a commonly used primitive. While the main requirement on absorption and uptake.

d. H. Reluctance to use considerable amounts of fluids directed, for example with medical abdominal swabs, Drainage swabs, general swabs, disposable diapers, Compresses for obstetrics, medical dog towels and the like, determines the frequency and amount, with which such Items used that require a cheap absorption material, which is the main one

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Absorption takes over. The cheapest absorbent material are those that are traded in bulk, such as cotton waste, flooded wood pulp, cellulose wadding and the like. The use of such loose absorbent materials makes one this one Coating or enveloping materials • or a top layer required. This top layer comes with the body surface when the bandage is used in contact, so that the properties of this layer

^ as well as the way this layer interacts with the The absorbent inner layer that covers it is largely responsible for that combination of aesthetic properties which can be referred to as "comfort or convenience factors" * It is an object of the invention based on an improvement with regard to such covers and their interaction with an absorbent one To achieve inner layer. Although the invention is based on a large variety of absorbent dressings and bandages is applicable, the easiest way to do this is to use the

™ Application to a medical mouth towel will be explained *

The usual covering or top layer existed for years for medical mouthcloths made from woven cotton gauze. This was seen from the standpoint of tear strength more than suitable for it, but it was rough and had it not a particularly pleasant grip. With continued use, the threads of a gauze cover tend to fray and clump together, causing chafing and skin irritation may occur.

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! ■ lightly woven textile materials (non-woven) have In In many cases, the gauze displaces because they have a smoother surface and are softer to the touch. They can consist of a continuous piece of a web, but various methods have also become known, to make holes in them.

Regardless of whether they are made in one piece or perforated, the known nonwoven materials have a distinct and well-known disadvantage. By well-known non-woven Liquids flowing through materials are in fact to a considerable extent in the cover or Top layer held back? They are distributed by capillary action in the cover, with the result that the surface area of the cover that is in contact with the body becomes uncomfortably moist, so that the Bandage wet or clammy to the touch. Obviously, this unwanted wetness is related to the popular theory that that an absorbent fiber (cotton, viscose rayon) essential for coverage. Such in high Cheese absorbent fibers show little when wet specific dimensional stability values on, so that if they when they are wet they begin to swell nlchtp-.woven networked structure completely: collapses and settles in the wet areas of the cover Liquid accumulations form from which the liquid relatively quick to previously dry areas of the body lengthened. -

BATH ORIGINAL

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Trying to find a better, more tolerable mouth towel cover Manufacture from non-woven material has already been proposed have been to use a composed of a number of conductor tracks cover, the outer It consists of cellulose acetate or other cellulose ester fibers, as described in US Pat. No. 3,088,463 is described. This acetate fiber layer is bound by means of a binder, which is applied in discrete areas is distributed in such a way that the individual different fiber £ _ lay to be bound together. Such a cellulose ester layer, which may feel more pleasant to the touch when dry, but becomes clammy to an undesirable extent when she gets wet.

The invention has now recognized that, contrary to all expectations, a medical cloth with significantly improved Properties can be produced from such synthetic fibers j which are considered to be hydrophobic. Under such fibers are understood here as those whose main structure ^ Artificially proportionately through the controlled polymerization simple monomer was synthesized. They stand unlike fibers, which are the result of a chemical Modification of a naturally occurring polymer.

The medical cloth according to the invention is characterized in that it covers the absorbent inner layer Outer layer one made of intertwined unspun Fibers composed fiber structure, the predominant part of synthetic, in a number

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discrete and of spaced apart surface regions interconnected fibers having eiiien stiffness value of not 2.D under g per denier and a humidity of not more than 2 saufnähme ■ $ at 65% relative humidity and 21 ° C.

Generally vmrde found that the fibers are am.zweckmäßigsten that apply in the sense to be hydrophobic, that they are still limp when immersed in water, neither swell. They are characterized by the mentioned |

low moisture absorption of less than about 2 % at 65 % relative humidity and 21 ° C, compared to a moisture absorption for cotton of 8 % , for viscose rayon of 13 % or more and for cellulose acetate of 6 ^ or more * Suitable for the invention .Fibers are also characterized by a high • stiffness value in the wet state, which can be calculated from the stress-strain data, which result in the respective fibers in the wet state «This specific value, which can be called the wet stiffness index, is calculated by dividing the Tear strength (in grams per denier) due to the elongation occurring under a certain tensile load. Under moderate stress, as occurs in applications of this type, the wet stiffness index is measured at about 3% elongation. This wet stiffness index can be viewed as the average slope of the stress-elongation curve from the origin to the selected elongation. The experience has shown 1 - "

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that it has the physical properties of an outer layer or cover of a medical drape reproduces, wherein a high index closely with a pleasant dry and im wet condition is not connected to crumpling cloth.

In short, the wet stiffness index can be used as a value ■ be considered, which indicates up to z, which I let in nonwoven fabric composed of such fibers collapses and soaks when wet and φ becomes clammy. In such a measurement, viscose rayon has • has a wet stiffness of about 4 g per denier; Cellulose acetate 9 g per denier cotton 10 g per denier

per denier polyester fibers (polyethylene terephthalate) 28 g ^. Polyolefin fibers 40 g per denier and Pol.lyacrylfase.rn (polymer of acrylonitrile or acrylonitrile modified with not more than 15% of another ethylenically unsaturated monomer) about "4-7 g per denier. It has been found that the use of synthetic fibers with a moisture absorption of not more than about 2 % under normal conditions and a wet stiffness of not less than about 20 g per denier is particularly and unpredictably a measure favorable for purposes of the invention. In known covers of absorbent bandages, the use of such synthetic fibers has been avoided, because they are generally considered to be non-absorbent or even hydrophobic.

In the case of a medical wipe, the absorbent Function correctly the internal absorbent

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Core layer are assigned to the association, while the outer or covering layer, d _a h. the cover, preferably the task of preventing the inner core layer, which is only loosely holding together, from falling apart. From this point of view, the outer or cover layer should serve for the forwarding of the liquid, this forwarding ideally being done in such a way that only a minimum of liquid is retained in the outer or cover layer. In this respect, the medical wipes according to the invention are a fundamental improvement: compared to all medical wipes that have hitherto become known in practice

For proper functioning of the invention medical towel it is necessary that the top layer made of synthetic non-absorbent fibers is porous and allows liquid to pass through quickly. Such a porosity is due to an air permeability of not less than Hl, 16 cbm air per minute and per 12.7 mm water pressure difference marked, measured with a Frazier porosity meter. It is also important that the external or Top layer in direct contact with the absorbent Inner or core layer of the cloth stands so that the Liquid is quickly withdrawn from the cover layer and this is relatively dry, pleasant and not soaked through remain.

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Accordingly, there is a great advantage of the new medical one Tuches, to be achieved with a goal of creation ^ rar ^ in that it is possible to use an absorbent bandage to create; but an outer cover layer made of -nonwoven Has textile material, let the liquid through quickly can "while she herself remains drier" than this at known / facings or coverings made of nonwoven Material the case 1st. With the new medical Tttch 1st According to the invention it is possible to achieve the top layer not soaked and clammy when in use

• In the drawing are examples of the object : illustrated of the invention ·. Show it:

FIg, 1 an inventively i & s medical tuc-h in

Shape of a bandage compress In : Dare division ;, -part wise aöfge cuts and

* '· "- ■ - 3" and M three divided according to the invention

; for medical machiners each in:

'• ι ■ "- · ■"' _- representation · In about 3 "5 £ & cifaeä? Enlargement Im

.- ,; ■ "■. ■■ ■ - - ' ^: " -'...-. Cutout *; '. - - ".

In Flg., 1 1st a medical cloth 1Θ is shown in föesfcalt Vect * bändskompiresse., Which is made of material Ijesfcehenöe inft- ^ over ^ core layer and "over a measure- or iDecicsiehicht I ¹ I; from iRMiffl & tem Ö? Extllmaterlai i ^ added _{: f} which covers the inside and is in direct contact with it

Shape and strength as well as composition and structure of the inner layer 12 are of the usual type. what in same) Dimensions also for the size of the overlap of the covering non-woven textile material and the method for Sealing or defining the overlap applies * if one such sealing or fastening may be necessary

Should. ; ; :.

In FIGS. 2, 3 and A, nonwoven materials produced according to the invention are shown which can be used as an outer layer for medical drapes Layers in a number of discrete spaced apart surface areas; is attached in such a way "that the vast ¹ Rope of the fibrous outer layer unattached bleibt.VDadurch., that the fiber structure is bonded only in certain surface areas and not by a uniform saturation or impregnation, the softness _s convenience and aesthetic overall impression of the Außensehicht be" significantly improved. ■, /

In Fig. 2 synthetic fibers 20 are illustrated, which are joined together to form a structure of superimposed and intersecting fibers, as it is echaracteristis'ch for the "of a card, a junk or Air-lay-machine supplied nonwoven. The fibers are autogenous in a number of discrete spaced apart

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Surface areas 22 bound, these surface areas preferably making up less than 35% of the total area of the fiber structure, so that maximum flexibility and porosity can be achieved. Is under autogenous bond . ■ '_ understood here that the never woven material. forming fibers are only bound to one another by means of fiber material, without the addition of foreign binders. A method for producing such a point binding consolidate For example, in US Patent Application 52 * 1931 from February 3, 1966 in connection with- · US Patent Application 492 6HH from H "in October 1965 the Änmelderln. explained. In this case, pressure and tears are applied to a fleece consisting of intertwined non-spun and non-twisted fibers at points lying apart, around the fibers. to connect predetermined surface areas to a non-woven cohesive iiaterlal. Synthetic fibers made from polypropylene, polyethylene or vinyl fibers, for example, as well as fibers made from plasticized cellulose acetate and the like can be used to form the non-woven material. can be used for this autogenous binding process. In order to obtain the crucial function of these nonwoven materials as the outer layer for medical drapes, it is desirable that the synthetic fibers make up the greater part - i.e. more than 5.0 % and preferably more than 75 % "of the cover layer

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If higher pressures are used * then 'medium'. this method, as also stated in the mentioned patent application 524 931 * produce perforated non-woven materials * which form a modification within the scope of the present invention. As illustrated in Fig * 3, it is possible ;, to be generated by the combination of ■ the action of pressure and a seitliehe displacement by means of the method mentioned in the fiber "30" a number of holes or fiber-free areas 32nd, VÖH each hole ⁵ of a The hand 3 is bordered on melted, displaced fiber material. The fiber material displacement only extends to the edges surrounding the holes; it has no mechanical influence on the fiber segments 36-, these lying between the holes segments substantially -iim normally remain to be weighed length portion of the individual ^ aserii ausmacheti :,. in configuration are in which they "distribution in the Hears the 'bevel rgebi ^ ^ ^ Laes were stored

An alternative method of binding the fiber structure to individual discrete objects is illustrated in FIG. 1 Here the fibers are attached by means of an upper binding material The% wä silier polymeric emulsion or * spray dispersion ^ - pre * - defined areas 42 to each other Eebunffleri "Normally * this is denoted as a point * - otter island-binding. The same is generally known in the case of non-woven materials, so that no further explanation is required.

A corresponding method is for example in the -US -P afc ent writing 2 5II5 952 explains.

Nonwoven textile materials used as outer layers can be used for invention & proper medical wipes are characterized by two features. First they have a high porosity, so that on them to ' Incoming liquids quickly to the absorbent Inner or core layer are passed on. This porosity depends on the proportion that is open or empty Clear in the outer layer what qualitatively by measurement der'Luftporösität the outer layer can be determined. It was found that an air permeability of not less than 1 Jf-, 16 ebm air per minute per 9.29 dm and per 12.7 ram WS differential pressure, measured with the Frazier porosity meter, represents an acceptable lower limit for the porosity and works well with the liquid transfer can be related.

The second feature that characterizes these synthetic fiber outer layers is ^ _t what the applicant for lack of a better term "missing Rückieitung ^'names?' 'Although they are composed of synthetic fibers ,, the inventive materials can retain several times their weight in water when they submerged in water and then drained if only tested alone * Any arrangement of fibers

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becomes because of the capillary expansion ■ as well as the interfacial tension of the water film retain water, even if it is obvious that the individual fibers as such actually do not absorb any water - as evidence, the behavior becomes a structure of joined glass and metal fibers referenced -. .-. However, it will be made of non-woven material Outer layer of a Tuehes according to the invention submerged in water to saturation and then with a dry, absorbent cellulose surface. brought, so is the one absorbed by the outer layer A large part of the liquid is quickly drawn away from the outer layer into the absorbent material, where it is more eager to be held. Becomes a layer; the end Rayon fibers subjected to an appropriate test, so there is only a balance of its liquid content with that of an adjacent absorbent cellulose surface on, with the Rayonaussenenschioht wet and drenched as well remains able to j

"rewet dry surface The same considerations apply now when the nonwoven Außensehichten _e are brought rfindunesgemäßen dressing materials in direct contact with an absorbent Innenschieht. The liquid is rapidly passed through the outer layer to the inner layer, where it is held more avidly than it could be held by the outer layer. This combination of competing surface tensions has the consequence that once it has passed through the outer layer

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Liquid - except for a negligible and on individual points limited 'hatred - not directed back again if using a fresh dry absorbent surface the V-er bands st off is brought into contact.

So while the non-woven outer layer of the medical drape according to the invention is done on its own Examination of properties related to liquid capillarity as well as the liquid retention capacity, which has the corresponding properties of cellulosic non-woven outer layers, the combination of the new results non-woven looks with in the immediate vicinity ■■> "■■■ touching cellulose inner layer to unexpected amazingly favorable results. The synthetic non-woven External appearance of the medical device according to the invention Tuches directs the liquid quickly with a hinimum capillary expansion within the exterior continues, so that they themselves are relatively dry and handsome remains in use.

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Claims (1)

■ - 15 «'■", ■ ■ ^; ·. ■ Patents 1. Medical cloth »especially for bandage purposes, with an inner layer consisting of absorbent material and an outer layer which is in direct contact with the inner layer and covers it, made of non-woven textile material (non-woven), characterized in that its outer layer covering the absorbent inner layer has a fiber structure composed of intertwined non-spun fibers, which consists predominantly of synthetic fibers connected to one another in a number of discrete and spaced-apart areas, which have a stiffness value (index) of not less than 20 g per denier and a moisture absorption of not more than 2 % at 65 % relative humidity and 21 ° G * 2. Cloth according to claim l _f characterized in that the synthetic fibers are autogenously bound without any foreign binding agent: 3V cloth according to claim 1, characterized in that _t the surface regions in which the fibers are bonded together ^ "represents less than 35% of the total area of the outer" layer. k. Cloth according to claim _14, characterized in that the fibers forming the predominant part of the non-woven outer layer are made of the fibers made of polyethylene- ^ olypropylene- ^ 1 0S85 3/139 7 -. ± 6 - BATHROOM ORIGlNAt Polyester-polyvinyl-polyacrylic and modified acrylic fibers existing class are taken. 5. A cloth according to claim 1, characterized in that the fibers forming the non-woven outer layer are bound with a polymeric binder which is present in a number of discrete and spaced-apart surface areas which make up less than 35 % of the total area of the non-blown outer layer, 6. Medical cloth, especially for association zxveeke, with an inner layer made of absorbent material and an outer layer which is in direct contact with and covers the inner layer Made of non-woven textile material (non-woven), characterized in that its covering the absorbent inner layer Outer layer consists of a fiber structure composed of non-spun fibers lying inside one another, mostly made of synthetic fibers 'consists locally with the formation of a number of discrete spaced openings, each surrounded by an edge of molten fiber material, are ordered, and that the synthetic fibers have a stiffness value "of not less than 20 g per denier and a moisture absorption • not exceeding 2 % at 65 % relative humidity and 21 ° C. ~ 1098537 1397