HK1112831B - Material for producing a support bandage - Google Patents

Description

Material for producing support bandages

The invention relates to a material for producing a support bandage, comprising a textile support which is coated and/or impregnated with a curable synthetic material and which is formed at least partially as a leno fabric having two warp threads which intersect one another between two parallel weft threads.

Materials having textile supports coated and/or impregnated with curable synthetic materials are used as a substitute for plaster bandages which are uncomfortable to wear due to their large weight. Such alternative materials can be manufactured as rigid synthetic bandages by selecting suitable synthetic materials and carriers having a substantially reduced weight and the same stiffness or rigidity, while ensuring a sufficient degree of breathability. Furthermore, if curable synthetic materials with suitable properties are used, such materials can also be used to manufacture bandages which remain slightly malleable after curing.

Existing synthetic rigid bandages are available in the form of a linear, bandage-like material and are wrapped around the body part to be supported to form a supporting bandage, with the hardening of the synthetic material being carried out using suitable steps before, during and/or after the application of the bandage. Depending on the type of synthetic material, the hardening can be carried out by UV treatment, thermal curing or solvent-assisted curing. Cold water has proven particularly effective as a solvent-assisted hardening, since it avoids skin reactions, such as skin pricks caused by elevated temperatures of the synthetic material.

In order to adapt the existing material to the body part, a textile support that is extensible in length or width can be used, the shape of the support that is produced during the application of the bandage being fixed when the synthetic material hardens. In order to maintain the desired stretchability, in the case of the known synthetic rigid bandages, the stretchability of the woven glass fiber carrier in the transverse direction, i.e. the filling direction of the carrier, comes from the network of woven material, while the extensibility of the linear bandage-type material in the longitudinal direction, i.e. the direction of the warp threads of the woven carrier, is due to the rigidity of the glass fibers, so that the individual meshes of the woven carrier also remain extensible in the direction of the warp threads.

Materials made using such textile supports as described above are described, for example, in US-PS-3,787,272.

The use of such materials is however problematic in that glass fibre dust which is suspected to be harmful to health is produced when cutting such support bandages.

In view of these problems, it has been envisaged to manufacture textile carriers from other synthetic fibres, such as polyester yarns and polyamide yarns. However, these yarns have a rigidity which is much less than that of the glass fibers, so that when these yarns are used, the material used for the support bandage is generally sufficiently extensible in the transverse direction, i.e. in the filling direction of the woven textile carrier, while retaining only a very small extensibility in the longitudinal or warp direction. For this reason, materials made using such carriers are difficult to fit the body shape. As a solution to the above-mentioned problems, a woven carrier is proposed in european patent EP 0356446B 1 as a material for the production of support bandages, wherein the longitudinal warp threads are made of a heat-shrinkable material. The carriers described in the above publications are first woven with yarns, typically a plurality of long yarn filaments, followed by a heat treatment. This heat treatment leads to a shrinkage of the warp threads in the longitudinal direction of the carrier, which imparts a change in the structure of these warp threads and of the entire carrier, which in turn makes it possible for the warp threads to extend, and thus for the entire carrier to extend in the longitudinal direction.

Although satisfactory adaptation of the bandage material to the body shape can be achieved with the above-described carriers, the manufacture of these carriers has problems.

In view of these problems of the prior art, a support bandage carrier of the above-mentioned kind is described in german patent DE 20011824. By using a leno fabric which is simple to manufacture in relation to the weave structure, the above-mentioned manufacturing problems can be solved, while at the same time a satisfactory structural stability of the carrier material is obtained. In this process, the manufacture of the existing material with a carrier in the form of a leno fabric is simplified, with the result that: one intersecting warp thread passes under a weft thread and the other intersecting warp thread passes over a weft thread, wherein the warp thread passing under the weft thread is located above the warp thread passing over the weft thread at the point of intersection.

Although such materials are easy to manufacture and ensure structural stability, and yet ensure the extensibility necessary to fit the body shape, it has been found that the long term stability of these materials can compromise certain desirable properties.

In view of these problems of the prior art, the object of the present invention is to describe a further refinement of the usable materials which maintain stability and even allow an extended period of use.

This object is achieved according to the invention by a further elaboration of the existing material, which is characterized in that the leno fabric has at least one further warp thread which is located between two pairs of intersecting warp threads and does not cross other warp threads.

The invention is based on an understanding of the following facts: although a particularly stable structure can be obtained by a good fixation of the weft threads by the crossing warp threads of a leno fabric in relation to conventional fabrics, the structural integrity of the material in the thickness direction (i.e. perpendicular to the plane defined by the warp and weft threads) is unsatisfactory, since the single warp thread of existing leno fabrics usually passes over only one side of the weft thread. This leads to inadequate adhesion of the synthetic material applied to the support; in addition, it also causes a single warp thread to slip off the edge of the material. These effects lead to the problems observed and described above relating to the long-term stability of existing materials. These effects are eliminated by the use of additional warp threads, which are further elaborated according to the invention; on the one hand, they form the structural integrity of the material in the direction of the thickness of the material, and on the other hand they simultaneously ensure good anchoring of the weft and warp threads of the material.

With regard to the process aspect of the production, it has proved particularly advantageous if at least one further warp thread has at least one second section which passes over the weft thread on one side and which is diverted from the first section of the warp thread, wherein the transition from the first section to the second section preferably takes place between those parallel weft threads between which the warp threads of at least one pair of intersecting warp threads also intersect one another. If there are two additional warp threads on opposite sides of a pair of intersecting warp threads, one of the additional warp threads being on the side of the weft thread in the weft region, which turns away from the other additional warp thread, the structural integrity of the material is further improved in its thickness direction. In order to prevent individual warp threads from slipping out at the edge of the material, which leads to material abrasion at this edge, it has proven to be particularly advantageous if at least one further warp thread and/or at least one weft thread is textured.

As can be seen from the above description of the prior art material, in the case of the material according to the invention at least one warp thread and/or at least one further warp thread and/or at least one weft thread of a pair of intersecting warp threads is preferably extensible, more preferably elastically extensible, and particularly advantageous if composed of an elastically extensible material, such as an elastic polyurethane. The warp threads, which consist at least partially of an elastic material, can have a core of an elastic thread, for example a polyurethane thread, preferably double-wrapped around it with a further thread, for example a polyester thread.

With prior art materials of the above kind, a structure of tension-induced shrinkage and/or bulging creases is found. In the case of a rigid bandage for shorter legs, such bulging folds develop into a ring around the ankle and on the forefoot, which ring is parallel to the warp direction of the carrier material.

According to a further aspect of the invention, a material is proposed with a carrier in the form of a leno fabric, at least one weft thread of which (at least in certain sections) consists of a high-strength yarn, for example a polyester yarn.

This solution to the problem is based on the following recognition: the above-described structure of the shrinkage and bulge-like folds is caused by the insufficient lateral stability of the existing materials used in the carrier. According to one aspect of the invention, this deficiency can be compensated for by using high strength weft yarns, since high strength weft yarns, such as polyester yarns, impart increased cross-directional stiffness to the carrier material.

To maintain the desired extensibility, the heat-shrinkable warp and/or weft yarns may be heat treated to maintain the flexible structure before or after the weaving process. Additionally or alternatively, the fabric of material according to the invention may also have warp or weft threads made of an elastic material, the extensibility of which comes from the nature of the material itself and not from the structure of the yarns.

With regard to sufficient stability of the material and at the same time ensuring satisfactory adaptation to the body shape, it has proven to be particularly advantageous if, before the synthetic material has hardened, the material has an extensibility of at least 20%, preferably at least 30%, particularly preferably from 65% to 95%, in the warp direction of the fabric, wherein the material advantageously has a tensile strength of at least 10N/cm, preferably at least 20N/cm, particularly preferably from 30 to 60N/cm, in the unstretched state in the warp direction of the fabric.

From the same point of view of advantages (adaptability to body shape and stability of the material), it has proven to be particularly advantageous if, before the synthetic material has hardened, the material has an extensibility of at least 30%, preferably at least 40%, particularly preferably from about 50% to 100%, wherein the material advantageously has a tensile strength of up to 10N/cm, preferably at least 20N/cm, particularly preferably from about 30 to 50N/cm, in the unstretched state in the weft direction of the fabric.

If the fabric has about 50 to 250g/m in the unstretched state²Preferably about 100 to 200g/m²Weight per unit area ofThe weight of the material according to the invention can be kept low while ensuring a sufficiently high stability.

The weft and/or warp of the fabric of the material according to the invention may consist, for example, of natural fibers. Particularly good properties can be achieved, however, if the weft and/or warp of the fabric additionally or alternatively consist of synthetic fibers, for example polyamide fibers, polyester fibers, polypropylene fibers or the like, since these synthetic fibers can achieve particularly good degrees of extensibility, tensile strength, and other mechanical properties. Additionally, at least a portion of the weft and/or warp may be textured to ensure extensibility. The texture may be obtained by heat treatment of the fibers or by treating the fibers with a solvent.

In the prior art material according to DE 20011824, a leno fabric of the material according to the invention can be produced in a particularly simple manner while ensuring a particularly high stability if one of the intersecting warp threads of at least one pair of intersecting warp threads passes under a weft thread and the other intersecting warp thread passes over a weft thread, and the warp thread under the weft thread is located above the warp thread above the weft thread at the point of intersection. In addition, a particularly high stability of the carrier in the form of a leno fabric can be achieved if at least two weft threads are located between the intersections of successive warp threads and/or between the transition points of at least one further warp thread which is successive. In this connection, it has proved particularly advantageous if at least one of the weft threads located between successive intersections and/or between successive intersections is textured and the other of these weft threads is formed from a high-strength and preferably smooth yarn, in particular a polyester yarn, with regard to both achieving the desired increased transverse rigidity and ensuring the structural integrity also required. The use of this high strength yarn ensures the required cross-directional stiffness while the use of textured weft yarns improves the required structural integrity.

In the present description, each line segment that is substantially straight and perpendicular to the warp is referred to as a "weft". In order to achieve a particularly good stability of the carrier fabric of the material according to the invention, it has proved to be particularly advantageous if the individual weft threads are in the form of thread segments, wherein at least two weft threads are connected to one another by a connecting segment at the edge of the fabric, wherein the connecting segment can be part of the thread segment forming the weft thread. Tearing or other damage to the fabric edge can be avoided if at least one connecting section, which connects two weft threads to one another, is wrapped around at least one, preferably at least two, of the aforementioned weft threads in such a way that the fabric edge is formed outside the connecting fiber section.

With regard to obtaining as high a stability and extensibility as possible of the material according to the invention while ensuring as low a weight as possible, if the fabric in the unstretched state has about 40 to 80, preferably about 66, warp threads per 10cm of fabric length and/or width, i.e. about 20 to 40, preferably about 33, double threads in the warp direction as with a leno fabric; and/or about 80 to 150, preferably about 132, picks, i.e. about 40 to 75, preferably about 66 double picks as with the leno fabric, have proven particularly advantageous.

Although explained above, the hardenable synthetic material may comprise a thermally or UV hardened synthetic material. For better certainty, the manufacture of the material according to the invention preferably comprises the use of a solvent-cured synthetic material, in particular cold water as solvent. With regard to achieving maximum skin suitability and at the same time ensuring the desired mechanical properties, it has proven particularly advantageous to use synthetic materials comprising moisture-curing polyurethane prepolymers. Such synthetic materials are described, for example, in EP 0093780B 1, the disclosure of which relating to curable synthetic materials is incorporated herein by direct reference. The composite material according to the invention may suitably represent 30% to 70% of the total weight of the material according to the invention.

From the above description according to the invention it has been deduced that the carrier for manufacturing such a material according to the invention is essentially characterized in that it has a woven structure, said carrier being in the form of a leno fabric and having further warp threads which do not cross other warp threads. With the aid of such a carrier, the material according to the invention can be manufactured with a process according to the invention, in which the carrier is coated and/or impregnated with a curable synthetic material and the carrier is subjected to a heat treatment before or after the coating and/or impregnation with the curable synthetic material, in order to impart the desired ductility to the material as a whole.

In the following, the invention is described with reference to the accompanying drawings, which clearly indicate to the reader all the essential details related to the invention which are not described in more detail in the description. One figure of the drawing shows a schematic view of an embodiment of the inventive carrier for manufacturing a material according to the invention.

The figure shows a part of a carrier according to the invention for the material from which the support bandage is made, in the form of a leno fabric with four warp thread pairs (10) of intersecting warp threads (12 and 14), a total of four weft thread pairs (20) and three further warp threads (30). Each warp thread pair (10) comprises one warp thread (12) passing below the weft thread pair (20) and one warp thread (14) passing above the weft thread pair (20). In the warp yarn pair (10), a warp yarn (12) passing below the weft yarn pair (20) and a warp yarn (14) passing above the weft yarn pair (20) cross at a crossing point (16). At these intersections (16), the warp threads (12) passing below the weft thread pairs (20) are located above the warp threads (14) passing above the weft thread pairs (20). A pair of weft pairs (20) is located between each two consecutive intersections (16) of the warp pairs (10), wherein the intersections of a single warp pair (10) are located substantially on a straight line parallel to the weft pairs (20). With a leno weave construction as shown in the drawing, the weft pairs (20) are firmly held, thereby preventing the individual threads from slipping off during coating or impregnation with a curable synthetic material, for example a polyurethane prepolymer.

Each pair of weft yarns (20) comprises a smooth weft yarn (22) of high strength polyester yarn and a textured weft yarn (24) also made of polyester yarn.

Further warp threads (30) which do not cross other warp threads are located between the warp thread pairs (10); individual segments of these additional warp threads pass over the weft threads and other segments pass under the weft threads. The transition between the section above the passage weft and the section below the passage weft is performed between the weft between which the warp threads (12) and (14) of the pair of warp threads (10) also cross each other. The figures show two further warp threads (30) on opposite sides of the intersecting warp thread pair (12 and 14), the two further warp threads (30) being located above and below the parallel weft thread pair (20), respectively.

The invention is not limited to the leno fabric described in the figures. Indeed, the carrier according to the invention can be made with yarns comprising natural fibers, polyamide fibers, polypropylene fibers and other similar fibers. The extensibility of the carrier made of polyamide fibres reaches 80% to 90% in the warp direction in a predetermined state (i.e. in the unstretched state and treated with synthetic material). This means that the unextended fabric may extend from 100 to 180 to 190% in the warp direction. In the weft direction, the ductility of the carrier made of polyamide fibers can be up to 120% to 130% in the treated (unstretched) state. This means that the fiber can be stretched from 100 to 220 or up to 230%. In the extended state, the coating weight per unit area thus amounts to from 50 to 55g/m². When polyamide fibres are used for making the warp and weft, warp sizes of 40 to 60 counts (tex), preferably about 46.8 counts, can be used, while weft sizes are from 20 to 40, preferably about 31.2 counts.

In addition, it is also possible within the scope of the present invention to use novel synthetic materials, in particular in the form of moisture-curable polyurethane prepolymers suitable for polyamides.

Claims (41)

1. Material for the manufacture of a support bandage, comprising a carrier which is coated and/or impregnated with a curable synthetic material and is at least partly in the form of a leno fabric with at least two pairs of crossing warp threads (10) and at least two pairs of parallel weft threads (20), the two crossing warp threads (12, 14) of each pair of crossing warp threads (10) crossing between two pairs of parallel weft threads (20), characterised in that the leno fabric also has at least one further warp thread (30), which at least one further warp thread (30) is located between two pairs of crossing warp threads (10) and does not cross other warp threads.

2. A material as claimed in claim 1, characterized in that at least one further warp thread (30) has at least a second section passing over one side of the pair of parallel weft threads (20), which turns from a first section of the at least one further warp thread (30), wherein the transition point between the first section and the second section occurs between the two pairs of parallel weft threads (20), the intersecting warp threads (12, 14) of at least one intersecting pair of warp threads (10) between the two pairs of parallel weft threads (20) also intersecting.

3. A material according to claim 1, characterized in that two further warp threads (30) are located on opposite sides of the crossing warp thread pair (10), and that the two further warp threads (30) are located above and below the parallel weft thread pair (20), respectively.

4. A material as claimed in claim 1, characterised in that at least one further warp thread (30) is textured.

5. The material according to claim 1, characterized in that at least one crossing warp thread (12, 14) of the crossing warp thread pairs (10) and/or at least one further warp thread (30) and/or at least one weft thread (22, 24) of the parallel weft thread pairs (20) is/are extensible.

6. Material according to claim 5, characterized in that at least a part of at least one crossing warp thread (12, 14) of the crossing warp thread pairs (10) and/or of at least one further warp thread (30) and/or of at least one weft thread (22, 24) of the parallel weft thread pairs (20) consists of an elastic polyurethane.

7. A material as claimed in claim 5, characterized in that at least one intersecting warp thread (12, 14) of the pair of intersecting warp threads (10) is at least partly made of an elastic material and has a core of elastic yarn.

8. A material as claimed in claim 7 in which the elastic yarns are polyurethane yarns.

9. The material of claim 7 wherein said core further comprises additional yarns double wrapped therearound.

10. A material as claimed in claim 9 in which the other yarns are polyester yarns.

11. The material of claim 1 wherein the leno fabric has at least one weft comprising high strength yarns.

12. The material of claim 11, wherein said high strength yarn is a polyester yarn.

13. A material as claimed in claim 1, wherein the leno fabric has heat-shrinkable warp and/or weft threads.

14. A material as claimed in claim 1, characterised in that the leno fabric has warp and/or weft threads made of an elastic material.

15. A material as claimed in claim 1, characterised in that it has an extensibility of at least 20% in the direction of the warp threads (12, 14, 30) of the leno fabric.

16. The material of claim 15, wherein the ductility is 65% to 95%.

17. A material as claimed in claim 1, characterized in that the material has a tensile strength of at least 10N/cm in the unstretched state in the direction of the warp threads (12, 14, 30) of the leno fabric.

18. A material as claimed in claim 17, in which the tensile strength is from 30 to 60N/cm.

19. A material according to claim 1, characterised in that it has a extensibility of at least 30% in the direction of the weft threads (22, 24) of the leno fabric before the synthetic material has solidified.

20. The material of claim 19, wherein the ductility is 50% to 100%.

21. A material according to claim 1, characterised in that it has a tensile strength of at least 10N/cm in the unstretched state in the direction of the weft threads (22, 24) of the leno fabric.

22. A material as claimed in claim 21 in which the tensile strength is from 30 to 50N/cm.

23. A material as claimed in claim 1, in which the leno fabric has a thickness of 50 to 250g/m in the unstretched state²Weight per unit area of (a).

24. A material as claimed in claim 23 in which the leno fabric has 100 to 200g/m in an unstretched condition²Weight per unit area of (a).

25. Material according to claim 1, characterized in that the weft threads (22, 24) and/or the warp threads (12, 14, 30) of the leno fabric are of natural fibers.

26. Material according to claim 1, characterized in that the weft threads (22, 24) and/or the warp threads (12, 14, 30) of the leno fabric comprise synthetic fibers.

27. The material as claimed in claim 26, characterized in that the weft threads (22, 24) and/or the warp threads (12, 14, 30) of the leno fabric comprise polyamide, polyester or polypropylene fibres.

28. A material as claimed in claim 1, characterised in that the weft (22, 24) and/or warp (12, 14, 30) of the leno fabric are at least partially textured to maintain extensibility.

29. The material according to claim 1, characterized in that one intersecting warp thread (12) of at least one pair of intersecting warp threads (10) passes below a parallel weft thread pair (20), the other intersecting warp thread (14) passes above the parallel weft thread pair (20), and the intersecting warp thread (12) passing below the parallel weft thread pair (20) is located above the intersecting warp thread (14) passing above the parallel weft thread pair (20) at the intersection point (16).

30. A material as claimed in claim 2, characterized in that at least one pair of parallel weft threads (20) is located between successive points of intersection (16) of intersecting warp threads (12, 14) and/or between successive transition points of at least one further warp thread.

31. The material according to claim 30, characterized in that one parallel weft thread (22, 24) of at least one pair of parallel weft thread pairs (20) located between said consecutive intersection points (16) and/or between consecutive transition points is textured and the other parallel weft thread (22, 24) of the at least one pair of parallel weft thread pairs (20) is made of a high-tension yarn.

32. The material of claim 31, wherein said high tension yarn is a polyester yarn.

33. The material according to claim 1, characterized in that the weft threads (22, 24) are formed by thread segments, at least two of which are connected to one another by connecting segments at the edges of the fabric.

34. The material of claim 33 wherein at least one connecting segment connecting two weft yarns is wrapped around at least one of said weft yarns.

35. A material as claimed in claim 1 in which the leno weave has 40 to 80 warp threads and/or 80 to 150 weft threads per 10cm of fabric length and/or width in the unstretched state.

36. A material as claimed in claim 35 in which the leno weave has 66 warp threads and/or 132 weft threads per 10cm of weave length and/or width in an unstretched condition.

37. The material of claim 1, wherein the synthetic material is solvent curable.

38. A material according to claim 37, wherein the solvent is water.

39. The material of claim 37 wherein the synthetic material comprises a moisture-curable polyurethane prepolymer.

40. A material as claimed in claim 1, characterised in that the synthetic material constitutes 30% to 70% of the total weight of said material.

41. Carrier coated and/or impregnated with a curable synthetic material and at least partly in the form of a leno fabric with at least two pairs of crossing warp threads (10) and at least two pairs of parallel weft threads (20), the two crossing warp threads (12, 14) of each pair of crossing warp threads (10) crossing between two pairs of parallel weft threads (20), characterized in that the leno fabric also has at least one further warp thread (30), which at least one further warp thread (30) is located between two pairs of crossing warp threads (10) and does not cross other warp threads.