A SPLINT-ARMORED BANDAGE AND A METHOD FOR ITS PRODUCTION

Abstract

A bandage for fixation of a limb is disclosed, the bandage comprising at least one flexible, thermoplastic polymer splint which is shaped and in plasticized condition attached to the surface of a longitudinal strip of fabric which is elastic in its length direction, the fabric and splint having a length sufficient for wrapping in layers about a limb. The splint is formed to the shape of a wave wherein adjacent splint ribs are interconnected at a wave crest or a wave trough respectively, wherein at least one of the wave crests and the wave troughs is located near, i.e. in the region of, a longitudinal edge of the strip of fabric. A method for manufacture of the splint-armored bandage is likewise disclosed.

Claims

1. A bandage for fixation of a limb, the bandage comprising: a longitudinal strip of fabric that is elastic in its length direction; and at least one flexible, thermoplastic polymer splint which is shaped and, in plasticized condition, attached to a surface of the longitudinal strip of fabric, wherein the fabric and splint having a length sufficient for wrapping in layers about a limb, wherein the splint comprises a portion that is formed to the shape of waves wherein the waves comprises adjacent splint ribs that are interconnected to each other at wave crests and wave troughs respectively, wherein at least one of the wave crests and the wave troughs is located adjacent to a longitudinal edge of the strip of fabric.

2. The bandage of claim 1, wherein the wave-shape of the splint is one of pointed, sinus, square trapezoid shaped.

3. The bandage of claim 1, wherein the splint ribs of the splint is a continuous distributed in the length direction of the fabric.

4. The bandage of claim 1, comprising a series of splints located adjacent to each other on the fabric and separated by non-armored portions of the fabric.

6. The bandage of claim 1, wherein the splint is anchored to the fabric by being fused or bonded to fibers or threads in the fabric.

6. The bandage of claim 1, wherein the splint is located between first and second superimposed layers of fabric.

7. The bandage of claim 1, wherein a sectional profile of the splint comprises a width (w) and a height (h), wherein the height (h) is a normal to a plane of the surface of the strip of fabric, and wherein a width to height ratio (w/h) in the sectional profile of the splint is formed based on a controlled result from subjecting the splint to adjustable compression from a shaping roll when the splint is in plastic state.

8. The bandage of claim 7, wherein the width to height ration (w/h) of the sectional profile of the splint is in the range of about 0.5/1 to about 10/1.

9. The bandage of claim 8, wherein the width to height ration (w/h) of the sectional profile of the splint is in the range of about 1.5/1 to about 4/1.

10. A method of producing an armored bandage for fixation of a limb, the method comprising a. heating a thermoplastic polymer material for discharge via a hot extrusion nozzle in molten or semi-molten state; b. feeding a first strip of fabric beneath the hot extrusion nozzle U; c. forming a wave-shaped splint on the first strip of fabric by extrusion from the extrusion nozzle while moving the extrusion nozzle back and forth transversely to a direction of feed of fabric, thereby forming a series of splint ribs distributed in a length direction of the strip of fabric, where adjacent splint ribs are interconnected at their ends by wave crests and wave troughs respectively; and d. positioning at least one of the wave crests and the wave troughs adjacent to a longitudinal edge of the strip of fabric.

11. The method of claim 10, further comprising controlling a width to height ratio (w/h) in a sectional profile of the splint by subjecting the splint to adjusted compression when the splint is passed in plastic state under a shaping roll.

12. The method of claim 11, further comprising forming, by pressure adjustment, the sectional profile of the splint with a width to height ratio (w/h) in the range of about 0.5/1 to about 10/1.

13. The method of claim 12, further comprising forming, by pressure adjustment, the sectional profile of the splint with a width to height ratio (w/h) in the range of about 1.5/1 to about 4/1.

14. The method of claim 10, further comprising solidifying the splint by feeding the strip of fabric through a cooling region.

15. The method of claim 10, wherein the polymer material is selected from thermoplastic or thermosetting, petroleum or cellulose based polymers, with a melting point temperature in the range of 60° to 300° C., and which remains flexible and elastic at temperatures of −20° C. or lower.

16. The method of claim 10, wherein the fabric selected is an elastic web including synthetic or natural fibers, or a mixture or composition thereof, the fabric having a tacky surface.

17. The method of claim 10, further comprising applying a second strip of fabric onto the first strip of fabric and splint.

18. The method of claim 17, further comprising applying an adhesive to an exposed side of the first or second strip of fabric, wherein the adhesive is chosen to provide adhesion between overlapping layers of fabric.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In the drawings,

[0041] FIG. 1 is a schematic setup of a production line for the manufacture of a splint-armored bandage according to embodiments of the present invention,

[0042] FIG. 2 is a cut-out detail and sectional view of the production line of FIG. 1 shown on a larger scale,

[0043] FIG. 3 shows a first embodiment of a splint for the splint-armored bandage,

[0044] FIG. 4 shows the first embodiment of the splint in modified design,

[0045] FIG. 5 shows the splint of the first embodiment expanded in longitudinal direction,

[0046] FIG. 6 is a schematic representation of overlapping layers of splint-armored bandage,

[0047] FIG. 7 is an elevation view showing the splint-armored bandage of the present invention dressed about a human foot and ankle,

[0048] FIG. 8 shows an alternative splint design,

[0049] FIG. 9 shows another alternative splint design,

[0050] FIG. 10 shows yet another design of the splint,

[0051] FIG. 11 shows an alternative application of splints, and

[0052] FIG. 12 shows yet an alternative design of the splint-armored bandage.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

[0053] With reference to FIG. 1, a production line for the manufacture of a splint-armored bandage by application of a splint to a longitudinal strip of fabric comprises a hot extrusion station 1 and a fabric feeding path 2.

[0054] The hot extrusion station 1 includes a container 3 for a thermoplastic polymer material, equipped with a heater 4 and a hot extrusion nozzle 5. One or more additional heaters 4′ may be installed along the fabric path 2 in order to maintain or return the splint into plastic state.

[0055] The hot extrusion nozzle 5 is suspended movable above the fabric feeding path 2 and controlled in back and forth movements, transversely to the fabric feeding path 2, by means of a nozzle control 6. Nozzle control also involves controlling the discharge rate of polymer product via the nozzle, The specification of components in the hot extrusion station 1 may correspond generally to those conventionally applied in extrusion of polymer and co-polymer materials.

[0056] The fabric feeding path 2 defines a feed direction F from a fabric supply reel 7 to a reel 8 for a splint-armored fabric. The reel 8 is driven for feeding, continuously or intermittently as the case may be, a strip of fabric 9 from the supply reel 7 to pass underneath the nozzle 5 from which a string of molten or semi-molten polymer product 10 is discharged so as to form a splint 10 on the fabric. The path length from the nozzle 5 to the reel 8 is long enough to permit cooling and solidification of the splint, until the fabric with splint is rolled onto the reel 8. For the purpose of accelerating solidification, the fabric feeding path 2 may include a cooling region 11 through which the fabric and splint passes before it reaches the reel 8. The cooling region may include a cooling fan, or a cooling plate 12, e.g., over which the fabric and splint is passed in the feed direction F.

[0057] A fabric suitable for production of a splint-armored bandage according to the present invention can be comprised of synthetic fibers or natural fibers, or a mix or composition of synthetic and natural fibers. A composite fiber may include a cotton fiber or thread coated with an elastomeric compound, e.g. The fibers may be formed into threads that are woven, knitted or interlaced to produce the fabric. At least the warp or yarn of the fabric is elastic. The elasticity may result from intrinsic properties in a synthetic, composite or rubber thread, and may alternatively be the result of appropriate knitting or weaving technique.

[0058] A suitable fabric is a fabric comprising fibers or threads that provide a tacky effect. The character of tackiness which is aimed for results in self-adhesion between superimposed layers of fabric in a dressing about a limb. Fabric which meets the desired tackiness and elasticity can be found commercially, such as the brands of fabric which are conventionally used in adhesive bandages and wound dressings.

[0059] A polymer suitable for production of a splint-armored bandage according to the present invention is a thermoplastic or thermosetting polymer with a melting point temperature that is well above the upper temperatures prevailing in normal use of the bandage. At the other end of the scale, the temperature of the polymer splint in molten or semi-molten state must not deform or damage the fibers or threads in the fabric. Particular attention should be paid to specifications, such as melting point temperature, for synthetic fibers included in the fabric. It is also essential that the splint material stays flexible, i.e. does not become brittle, at the lower temperatures prevailing in normal use of the bandage. A thermoplastic or thermosetting polymer which has a melting point temperature within a range of 60° to 300° C., and which remains flexible and elastic at temperatures of −20° C. or lower, is considered to meet the purpose for a wide range of embodiments.

[0060] Without excluding other alternatives, a splint material according to specifications may be found among, e.g., polyethylene, polypropylene, polyvinyl chloride, polyamide, or among thermoplastic cellulose derivatives such as cellulose acetate e.g., with or without plasticizer added to the polymer composition.

[0061] The manufacturing process can include a pelletized or granulated polymer material which is heated to melting temperature for discharge via the nozzle 5.

[0062] Alternatively, the manufacturing process can include discharge of a solid polymer thread 13 (see FIG. 1) which is heated to a temperature below melting temperature (semi-molten) at which the thread can be plastically deformed and its applied shape on the fabric be maintained after cooling. In one embodiment, the splint is shaped from a solid polymer thread, such as a polyamide or nylon thread, with a

[0063] homogenous section and a diameter of about 0.5-10 mm. However, whether starting from a pelletized material or a thread, in either alternative the splint can be shaped and applied to the strip of fabric in a plasticized condition, and in solidified state attaching to the threads and/or fibers in the fabric, without requiring special preparation or modification of the fabric.

[0064] It shall be noted that the shape and dimensions of the splint can be varied through proper control of fabric feed rate and polymer discharge rate at the hot extrusion nozzle 5. With reference to FIG. 2, which is a cut-out detail and sectional view of the production line of FIG. 1 shown on a larger scale, a transverse section of a splint 10 is formed with a width w and a height h, the height h being a normal to the plane and surface S of the strip of fabric.

[0065] The width to height ratio in the sectional profile of the splint 10 is the result from subjecting the splint to a controlled compression applied in a compression region 14, arranged in the production line (see FIG. 1) at a position where the splint 10 is still in plastic state. The compression region comprises a shaping roll 15 under which the fabric and splint is passed in the feed direction. By adjustment of the pressure applied from the shaping roll 15 there is accomplished control of stiffness of the splint in the directions w and h. That is, a wider splint in the w direction will be stiffer in the longitudinal plane of the fabric (i.e., in the circumferential direction of a dressing about a limb), whereas a splint wider in the h direction will be stiffer transversely to the plane of the fabric (i.e. in radial direction of a dressing about a limb).

[0066] According to this aspect of the present invention, and more precisely by properly adjusting the height of a gap between the shaping roll 15 and the fabric 9, the section of the splint 10 can be formed with various w/h ratios,

[0067] It is possible and lies within the scope of the invention to arrange the mouth of the nozzle 5 such that a polymer string is deposited onto the fabric, wherein the width w of the splint section is less than the height h of the splint section. This can be achieved, for example, using a rectangular nozzle mouth which is tilted at an angle of about 45° from the plane of the fabric. The w/h ratio may this way be extended to a lower range limit of about 0.5/1, at least. An upper range limit, up to which the splint will still provide adequate radial support in a dressing, is for this practical reason defined at a w/h ratio of about 10/1.

[0068] The applicant has found that a width to height ratio within the range of about 1.5/1 to about 4/1 provides a most beneficiary balance between elasticity and radial and circumferential rigidity in a dressing, and is therefore preferred in a bandage which is armored by means of a wave-shaped polymer splint.

[0069] One embodiment of a splint-armored bandage produced in a production line substantially as recited above is shown in FIG. 3. In this embodiment, the splint 10 includes a continuous series of splint ribs 16 and 17 distributed in the length direction L of the strip of fabric 9, and interconnected at their ends by wave crests 18 and wave troughs 19 respectively.

[0070] More precisely, a discrete length of the splint-armored bandage may include one singular wave-shaped splint 10 extended the full length of the bandage, as illustrated in FIG. 3.

[0071] In one embodiment, a splint-armored bandage may include a series of splints 10 of shorter lengths, wherein adjacent splints are separated in the longitudinal direction L by a non-armored length 20 of the bandage, as illustrated in FIG. 4.

[0072] In particular, the shortest wave-forming element wl available in a splint-armored bandage according to the present invention is one wavelength long, including a pair of adjacent splint ribs 16 and 17, in one of their ends interconnected by a wave crest 18 or a wave trough 19 respectively.

[0073] With reference to FIG. 5 a splint 10, whether produced in a petroleum based or cellulose based thermoplastic polymer, provides in solidified state a flexible and elastic armor that follows in elongation E and contraction C of the fabric which is elastic in its length direction L. The elastic connection between adjacent splint ribs, i.e. at wave crests and wave troughs, results in a splint acting like a tension spring element which operates in the length direction of the fabric, permitting elongation and adding to contraction of the fabric from an expanded state,

[0074] In a splint-armored bandage according to the present invention, the strip of fabric 9 and the splint 10 have a length L sufficient for wrapping in layers about a limb. Without limiting the invention to a specified length, but rather to indicate the art and character of the subject of the present invention, a length L in the range of 0.5 to 10 meters is considered to cover most practical cases. If appropriate, a length of fabric in one or both ends of the fabric may be left without the splint in order to facilitate the foundation and/or finishing of a dressing about a limb. Excessive lengths of the splint-armored bandage can be cut off from a dressing by using knife or scissors

[0075] The strip of fabric 9 may be formed with transverse widths in the order of about 10 mm up to the order of about 400 mm, covering various needs for fixation of body portions the size of an upper body down to finger size.

[0076] In one embodiment of the present invention, the splint ribs are formed with a w/h ratio which differs from the w/h ratios of the splint waves or the splint crests. For example, by applying pressure only in the longitudinal edge regions of the splint-armored fabric, the wave crests 18 and/or the wave troughs 19 can be flattened to a higher w/h ratio, such as 1.5/1 or higher, whereas the splint ribs 16 and 17 are left at a comparatively lower w/h ratio, such as 0.5/1 or higher. This way, elasticity in the length direction of the splint-armored fabric can be altered without affecting the radial stiffness transversally to the fabric.

[0077] The frequency of waves in a dressing, and thus the density of armor, can also be adjusted and adopted to need and anatomy in the treated limb by more or less stretching of fabric and splint.

[0078] With reference to FIG. 6, the radial and circumferential rigidity in a dressing can also be enhanced locally by arranging crossing splints in overlapping layers of fabric, such as at the location of a suspected fracture, e.g.

[0079] FIG. 7 shows the splint-armored bandage of FIGS. 3-6 dressed about a human ankle. From the drawing of FIG. 7 it can be appreciated that in applied state the splint-armored bandage forms an overlapping and crosslinked network of splints that provide all-around support, in appearance similar to scales in the panzer of a fish or reptile. Yet, the armor is still flexible to avoid discomfort caused by pressure or chafing, and permits adaptation to protrusions on the limb, such as heel and fibula e.g., which can be positioned between splint ribs 16, 17.

[0080] In the manufacturing process, feeding the strip of fabric as well as nozzle movement and polymer discharge rate may be controlled for continuous or intermittent operation. Different splint shapes and patterns can this way be formed onto the fabric.

[0081] A sample of splint shapes and embodiments made available by the present invention are illustrated in FIGS. 8-11. In FIG. 8 the splint has a pointed wave shape, whereas in FIG. 9 the wave shape is sinusoidal. FIG. 10 illustrates a splint having the shape of a square or trapezoidal wave. With respect to its shape, a common feature of disclosed embodiments is that the splint is shaped as a wave extended in a plane parallel to the plane of the fabric, the splint changing its run direction, uninterrupted, in a wave crest or a wave trough respectively.

[0082] The manufacturing process can be modified. For example, the feed direction of the fabric may be reversed in a process of applying one or more additional splints. In a set of splints, the splints may be arranged to run in parallel side-by-side while displaced laterally in the width direction of the strip of fabric, or the splints can be arranged intersecting each other. Alternatively, two or more hot extrusion stations may be arranged in succession in the production line to produce parallel or intersecting splint patterns, such as the one illustrated in FIG. 1, e.g.

[0083] The distribution of the splint 10 extends generally in longitudinal direction of the strip of fabric, the wave crests and troughs located near the longitudinal margins M of the strip of fabric (see FIG. 12).

[0084] However, the transverse width or amplitude of the splint need not cover the full width of the strip of fabric: in fact, a portion N of the width of the fabric may be left without armor in the length of the fabric, substantially as illustrated in FIG. 12. Although not illustrated in the drawings, it will be understood that the splint or splints may alternatively be centered on the strip of fabric, leaving unarmored corridors along both edges of the fabric. Preferably though, at least one of the wave crests and the wave troughs is located near, i.e. in the region of, a longitudinal edge M of the strip of fabric as illustrated in FIG. 12.

[0085] It serves to be noted, still with reference to FIG. 12, that the inclinations a, b of the splint ribs 16 and 17 with respect to the longitudinal direction of the strip of fabric 9 need not be the same for the full length of the strip of fabric. By adjusting the feeding speed of the fabric and/or speed of movements of the hot extrusion nozzle, the ribs 16, 17 following each other in succession may be given different inclinations with respect to the fabric longitudinal direction. By varying the inclination of splint ribs there is achieved a possibility of concentrating the stabilizing forces in a desired direction in a bandage dressing. This feature can be of advantage, e.g., in the fixation of a joint at an angle between upper and lower limb portions.

[0086] In a splint-armored bandage produced and composed substantially as described above, the splint may be anchored to the fabric through bonding at the interface between the splint and the fabric. In this context,“bonding” is used as a definition of a connection between splint and fabric that arises upon solidification of splint material which in molten or semi-molten phase has adhered to threads or fibers in the fabric. Bonding can also comprise penetration of molten splint material into and/or between threads or fibers in the fabric. If appropriate, bonding may also include fusion between the splint material and any synthetic component in the fabric. Bonding between splint and fabric can be enhanced when splint material is forced into the fabric during the step of compressing the splint while in plastic state as mentioned above.

[0087] However, a splint may be anchored and affixed to the fabric in other ways beside bonding.

[0088] With reference again to FIG. 1, finishing of the splint-armored bandage optionally involves application of an additional second strip of fabric 9′ which is arranged superimposed on the first strip of fabric and splint. The second strip of fabric can be introduced in the fabric feeding path 2 at a position downstream of the shaping roll 15 as illustrated, or at a position (not illustrated) upstream of the shaping roll 15.

[0089] The resulting bandage forms a laminate wherein the splint is anchored in the bandage by being sandwiched between layers of fabric.

[0090] The layers of fabric may be secured to each other simply through the adhesion between tacky fabric surfaces being laid or pressed together. Alternatively, or in addition thereto, stitches of thread may be applied through the layers of fabric.

[0091] Stitching may also serve for fixation of the splint in a laminate of superimposed layers of fabric. Other alternatives include application of heat and/or pressure to achieve connection between the layers of fabric. If appropriate, a lamination station (not shown in the drawings) performing sewing, heating or compression may be included in the production line of FIG. 1.

[0092] Beside the embodiments presented above, the invention can be modified and realized in other ways without abandoning the scope of the invention.

[0093] One modification of the invention comprises an additional step in the production process, wherein an external layer, or string, of adhesive is applied to the outer and exposed side of the second strip of fabric 9′. The purpose of the added adhesive layer is to improve adhesion between overlapping layers of fabric, this way even further increasing the integrity of a dressing applied to a limb. With reference again to FIG. 1, the laminate of the first and second fabric with the splint positioned there -between can be fed through an adhesive transfer station 21, comprising an adhesive transfer roll or an adhesive spray curtain, e.g. At a position downstream of the location of the station 21, the laminate can be arranged to receive a protective film or paper 22 before the finished product is wound onto the reel 8.

[0094] It will be realized that a splint of wave-shape may alternatively be prefabricated in a heat extrusion process and stored on a reel. A splint of wave-shape may also alternatively be prefabricated from a sheet of material by punching, or even produced from a solid thread that is bent into wave-shape. The prefabricated splint is then, in solid state, rolled off onto a strip of fabric moving down the fabric feeding path. By heating the splint to thermoforming temperature the splint is set in plastic state, its sectional profile shaped and bonded to the fabric by application of pressure from a shaping roll as previously explained.

[0095] Accompanying claims define the invention as described and explained, including disclosed embodiments and others which would be readily derivable from the disclosure although not explicitly illustrated and specified herein.