US3482570A - Surgical dressing and method of producing the same - Google Patents

Description

Dec. 9, 1969 w. SCHUSTER 3,482,570

SURGICAL DRESSING AND METHOD OF PRODUCING THE SAME Filed Jan. 18, I967 Inventor 4%% W United States Patent T Int. Cl. A611 15/ 01; A61f 13/00 US. Cl. 128-156 5 Claims ABSTRACT OF THE DISCLOSURE A surgical textile dressing consisting of one or more layers of non-woven fabric which is needled vertically to its plane so that Wicklike fiber bundles extend through the fabric, and wherein the entry side of the needles into the fabric which engages with the wound is provided with a thin coating of adhesive which connects the uppermost fibers but leaves intermediate spaces through which the moisture of the wound will be absorbed.

Background of the invention The present invention relates to a surgical dressing of a textile material which is made of a non-woven fabric or fleece material.

The general requirements of a good textile dressing are that it be highly absorbent, have a sufficient capacity for absorbing secretions, and allow air to penetrate easily. Furthermore, it should rest on the wound without folds, be nonirritant, and not stick to or grow together with the wound.

There is a known kind of surgical dressing which consists of a fabric which has the disadvantage that, due to its type, thread count, thread thickness, and degree of twist, some of its threads shrink differently from others when absorbing moisture. This causes the fabric to move of its own accord and it contracts to a wavy condition. Although, if there is only a slight secretion from the wound, this dressing will not stick to the wound, the wound will not be kept absolutely quiet and if a strong secretion occurs, the absorptive capacity of the dressing is often insuflicient.

Another known kind of surgical dressing comprises a fleece material in which the gaps between the fibers are reduced by compression and the contact surface of which is treated with aluminum by vapor-deposition in order to prevent the dressing from sticking to the wound. A similar effect is supposed to be attained by another .kind of dressing which consists of a sheet of polypropylene into which numerous small holes are punched and upon the upper side of which a wide-mesh gauze is glued.

Both of these surgical dressings have very little, if any, absorptive properties and therefore require an additional layer of an absorbent material.

Summary of the invention It is an object of the present invention to provide a surgical dressing of a textile material which complies with all of the requirements as outlined at the beginning and has a considerably higher absorptive capacity than the conventional dressings and also a sufliciently smooth contact surface in order to prevent it from sticking to the wound.

According to the invention, this object is attained by needling the non-woven fabric or fleece material and applying a thin coating of adhesive upon the uppermost fiber layer on the entry side of the needles which is ap- 3,4825% Patented Dec. 9, 1969 ICC plied upon the wound so as to connect the fibers of this layer to each other.

Although by applying an adhesive upon the fibers of the uppermost fiber layer of a non-woven fabric at the entry side of the needles, these uppermost fibers will be connected to each other and thinly coated with the adhesive, the funnellike recesses which are produced by the needling operation and the surfaces of which are located underneath the uppermost fibers will remain uncoated. The surgical dressing which is thus produced therefore has a sufficiently smooth contact surface and since the fibers on this surface are firmly connected to each other, they cannot grow into the wound. Such a nonwoven fabric or fleece has the further advantage that, while having the same weight as a woven fabric, it has a much higher absorptive capacity. This is due to the fact that in a needled fleece the individual fibers are spaced at practically the same distance from each other and, contrary to a woven fabric, none of the gaps between the fibers are too large for accumulating moisture therein. By the needling operation, a considerable number of the fibers of the fleece are bent and aligned in a direction substantially vertical to the longitudinal plane of the fleece and these fibers also extend vertically to the liquid level of the wound Which is covered by the dressing. Consequently, a Wicklike effect is produced by these vertical fibers which further increases the absortive capacity of the dressing.

Another feature of the invention consists in providing a supporting fabric within the needled fleece, for example, in the form of absorbent gauze. The combination of this supporting fabric with the needling of the non-woven fabric or fleece results in a relatively solid surgical dressing of stable dimensions.

Recent investigations have shown that white and metalcoated surgical dressings due to their high heat-reflecting capacity may cause an increase in the wound temperature of more than 4 C., while a violet-colored textile dressing of the same thickness only produces a temperature increase of about 0.6" C. In order to prevent such an undesirable increase in the wound temperature, the present invention further provides that the adhesive is preferably died to a heat-absorbing color.

Aside from its object of attaining a new and improved type of surgical dressing, the present invention is further directed to provide a method of producing this dressing. This method consists of the steps of needling the nonwoven fabric or fleece and thereafter passing it through a pair of revolving coating rollers upon one of which a uniform layer of adhesive of a thickness of about 25 to 50 ,um. is applied by a doctor blade. This adhesive is then transferred from this roller upon the needle-entry side of the fleece. Before the adhesive dries, the coated fleece is then compressed, for example, between a pair of revolving rollers. The method according to the invention may be carried out continuously and therefore permits a very economical production of the new surgical dressmg.

In order to tear apart the thin strips of adhesive which after the adhesive has been applied adhere to and connect many fibers and which, if remaining, might reduce the absorptive capacity of the needled fleece, and since the adhesive accumulates especially at the points where the fibers engage with or intersect each other, the invention further provides that, immediately after the needled fleece leaves the coating rollers, its coated side he treated with strong jets of compressed air.

These and additional features and advantages of the present invention will become more clearly apparent from the following detailed description thereof which is to be read with reference to the accompanying drawings, in which FIGURE 1 shows an enlarged cross sectional of a piece of the surgical dressing according to the invention, while FIGURE 2 shows a top view of the piece of dressing according to FIG. 1.

The surgical dressing according to the invention, as illustrated in the drawings, consists essentially of a needled layer of non-woven fabric or fleece material 1, wherein the uppermost fibers 2 on the needle-entry side 3 are connected to each other by an adhesive coating 4.

The fleece itself consists of cotton and/ or rayon staple fibers as employed conventionally, for example, for producing absorbent cotton for medical purposes. This fleece 1 is pierced in a needling machine approximately 150* times per cm. and its structure is thereby changed in the manner as illustrated in FIGURE 1. It then consists partly of fiber bundles 5 which extend substantially vertically to the longitudinal plane of the fleece 1 and partly of fibers 7 which extend substantially parallel to this longitudinal plane. At the points of entry of the needles of the needling machine, these needles form funnellike recesses 6.

After the fleece 1 has left the needling machine, it is passed through a pair of revolving rollers, one of which carries a uniform layer of an inert, polymerous, Waterunsoluble elastic adhesive 4 of a thickness of about 0.05 mm. which is made on a basis of silicon rubber, cellulose acetate, polyisobutylene or polyamide. This adhesive is transferred by the coated roller upon the fibers 2 of the uppermost layer of fibers of fleece 1 on the: entry side 3 of the needles. In transferring the adhesive 4, the coating rollers should, however, compress the needled fleece 1 only very slightly so as to prevent the lower parts of the funnellike recesses 6 in the fiber bundles 5 from being clogged by adhesive. The coating operation should therefore be carried out so that the adhesive 4 only penetrates into the fibers of the uppermost fiber layer at the entry side of the needles. After leaving the coating rollers, the surgical dressing which is thus basically completed is treated by means of strong jets of compressed air so that the small strips of adhesive which connect many of the individual fibers to each other will be torn apart and the adhesive will be deposited primarily on the points of contact and intersection between the uppermost fibers 2. Before the adhesive 4 dries completely, the dressing material is once more compressed between another pair of revolving rollers so that the coated uppermost fibers 2 will engage with and be glued to each other at additional points.

By this strong subsequent compression of the dressing material before the adhesive 4 has been cured completely, the coated side of the material which is to be applied upon the wound is provided with a very smooth contact surface which may therefore be very easily separated from the wound. Furthermore, the adhesive is then no longer capable of combining additional fibers, for example, in the funnellike recesses, so that the absorptive capacity of the needled fleece will not be dimnished. The adhesive 4 of the surgical dressing according to the invention may, in addition, be provided with a heat-absorbing coloring matter so that the side of the dressing facing the wound will absorb the heat of the wound and dissipate it to the outer air. The heat which may be radiated from the outside upon the other side of the dressing will be reflected to the largest extent by the many white fibers. The dressing according to the invention will therefore reduce the temperature of the wound considerably.

Before being treated by the needling machine, the fleece 1 may also be applied upon an additional supporting fabric, for example, absorbent gauze, and thereafter be needled. The light supporting fabric then prevents the fibers from yielding laterally during the needling operation and it solidifies the dressing and maintains its outer dimensions.

Instead of making the dressing of a single thick layer of fleece material, it is also possible to employ a plurality of thinner super-imposed layers in each of which the fibers preferably extend parallel but at substantially right angles to those in the adjacent layer. Such a surgical dressing has the advantage of being of considerable solidity and of maintaining its shape and dimensions in all directions.

Although my invention has been illustrated and described With reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim 1. A surgical dressing of a textile material comprising a needled fiber fleece including an uppermost layer and a coating of adhesive connecting the fibers of the uppermost layer of said fleece to each other at the entry side of the needles into said fleece, adapted to be applied upon a wound,

a plurality of the fibers of said fleece extending in a direction substantially parallel to its plane,

said fleece being needled in a direction vertical to said plane and forming funnel-like recesses in said entry side,

wick-like fiber bundles extending through said fleece substantially vertically to said plane,

said fleece being composed of several layers of straightened fibers substantially parallel to and superimposed on each other, and

said fibers of each layer extending at substantially right angles to those of the adjacent layer.

2. The surgical dressing, as set forth in claim 1, which includes a supporting fabric in said needles fleece.

3. The surgical dressing, as set forth in claim 1, wherein said adhesive is dyed to receive a heat-absorbent color.

4. A method of producing a surgical dressing of a textile material, comprising the steps of needling a fiber fleece in a direction vertical to its plane,

thereby forming wick-like fiber bundles extending through said fleece substantially vertically to said plane and funnel-like recesses in the entry side of said needles into said fleece,

applying a thin coating of adhesive upon said entry side,

in order to cover said side substantially without penetrating into said recesses,

applying said adhesive upon said entry side by passing it through a pair of revolving coating rollers to form a thickness of about 50 to ,um., and then transferred from said roller upon said entry side, and compressing said coated fiber fleece before said adhesive has dried by passing it through another pair of rollers pressing upon the opposite sides of said fleece.

5. The method, as set forth in claim 4, which includes the step of blowing strong jets of compressed air upon the coated side of said fleece immediately after said fleece leaves said coating rollers and before it passes between said compressing rollers.

References Cited UNITED STATES PATENTS 3,292,619 12/1966 Egler 128-156 3,301,257 1/1967 Crowe et a1 128-296 3,307,545 3/1967 Surowitz 128-156 3,400,188 9/1968 Olson 156-148 ADELE M. EAGER, Primary Examiner US. Cl. X.R.

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