Elastic bandage that can be used, in particular, for the treatment and prevention of vein diseases

Abstract

A compression bandage formed by the assembling of a nonwoven based on short conjugate fibers which have been crimped and of a nonelastic material. The compression bandage can be used in a bilayer compression system, in particular for the prevention or treatment of venous pathologies.

Claims

1. A compression bandage comprising a nonelastic material, which exhibits a thickness of greater than 1.8 mm and a nonwoven of crimped fibers obtained from short conjugate fibers, said nonelastic material and said nonwoven of crimped fibers being assembled together and the nonwoven of crimped fibers having a grammage of between 70 g/m.sup.2 and 300 g/m.sup.2, said crimped fibers being uniformly crimped in a thickness direction of the nonwoven of crimped fibers and exhibiting a mean curvature radius between 10 and 200 micrometers, and a surface of the nonwoven of crimped fibers having between 10 and 50 crimped fibers/cm.sup.2.

2. The compression bandage as claimed in claim 1, wherein the short conjugate fibers are bicomponent fibers that are made of two polymer components which exhibit a softening point greater than or equal to 100 C., and which are selected from the group consisting of polypropylene polymers, polyester polymers and polyamide polymers.

3. The compression bandage as claimed in claim 2, wherein the bicomponent fibers are composed of a first polymer which is a polyethylene terephthalate and of a second polymer which is a copolymer of an alkylene arylate with isophthalic acid and/or diethylene glycol.

4. The compression bandage as claimed in claim 2, wherein the two polymer components consist of two different aromatic polyester polymers.

5. The compression bandage as claimed in claim 1, wherein the short conjugate fibers have a mean count of between 1 and 5 dtex and a mean length of between 10 and 100 mm.

6. The compression bandage as claimed in claim 1, wherein the crimped fibers exhibit a mean curvature radius of between 50 and 160 microns.

7. The compression bandage as claimed in claim 1, wherein the nonwoven of crimped fibers has a grammage of between 80 and 200 g/m.sup.2.

8. The compression bandage as claimed in claim 1, wherein the surface of the nonwoven of crimped fibers has between 10 and 35 crimped fibers/cm.sup.2.

9. The compression bandage as claimed in claim 1, wherein the nonwoven of crimped fibers exhibits, in a cross-section taken parallel to the thickness direction thereof, a fiber incurvation ratio greater than or equal to 1.3, and a ratio between a minimum value of the fiber incurvation ratio and a maximum value of the fiber incurvation ratio greater than 75%, wherein said ratio and said fiber incurvation ratio are measured in three parts of the nonwoven of crimped fibers, each part corresponding to one third thereof in a cross-section taken perpendicular to the thickness direction of the nonwoven of crimped fibers.

10. The compression bandage as claimed in claim 1, wherein the nonelastic material is selected in the group consisting of textile materials, cellular materials, films and their combinations.

11. The compression bandage as claimed in claim 1, wherein the nonelastic material is chosen from absorbent textile materials.

12. The compression bandage as claimed in claim 11, wherein the absorbent textile materials comprise knitwear, wovens, nonwovens and their combinations.

13. The compression bandage as claimed in claim 1, wherein the nonelastic material is an absorbent nonwoven having a thickness of between 1.8 and 3 mm.

14. The compression bandage as claimed in claim 13, wherein the absorbent nonwoven comprises a padding.

15. The compression bandage as claimed in claim 1, wherein the nonwoven of crimped fibers and the nonelastic material are assembled by needling, with an adhesive or by ultrasound.

16. The compression bandage as claimed in claim 1, wherein the nonwoven of crimped fibers is composed of bicomponent fibers based on aromatic polyester polymers, the nonwoven of crimped fibers has a grammage of between 90 and 150 g/m.sup.2 and the surface of the nonwoven of crimped fibers has between 10 and 35 crimped fibers/cm.sup.2.

17. The use of a compression bandage as claimed in claim 1 comprising applying the compression bandage to a limb of a patient.

18. A process for the manufacture of a compression bandage as claimed in claim 1, wherein the nonelastic material and the nonwoven of crimped fibers are assembled together by needling, without prestressing the nonwoven of crimped fibers.

19. The compression bandage as claimed in claim 1, wherein the short conjugate fibers have a mean count of between 1.5 and 3 dtex and a mean length of between 40 and 60 mm.

20. The compression bandage as claimed in claim 1, wherein the crimped fibers exhibit a mean curvature radius of between 70 and 130 microns.

21. The compression bandage as claimed in claim 1, wherein the nonwoven of crimped fibers has a grammage of between 90 and 150 g/m.sup.2.

Description

EXAMPLES: COMPRESSION BANDAGES

(1) Different materials were used to manufacture bandages.

(2) 1. Materials Used

(3) a) Nonelastic Material

(4) The nonelastic material used is the Ks ft padding sold by Urgo Limited.

(5) It exhibits a grammage of 75 g/m.sup.2. It is manufactured by the conventional carding, napping and preneedling process from viscose fibers and polyester fibers in the proportion of 60%/40% by weight.

(6) These fibers have the following characteristics: Viscose fibers of 1.7 dtex and with a length of 50 mm Polyester fibers of 3.3 dtex and with a length of 60 mm

(7) b) Nonwovens

(8) The examples use two different nonwovens, based on crimped asymmetric bicomponent fibers, manufactured according to the teaching of the patent application WO 2008/015972. They respectively carry the references SJJ 142 for nonwoven A and SJJ 146 for nonwoven B from Kuraray.

(9) These two nonwovens are produced from the fiber, of side by side type, based on polyester copolymers from Kuraray, the reference of which is PN-780.

(10) These two nonwovens exhibit the following properties and characteristics:

(11) TABLE-US-00001 Nonwoven A Nonwoven B Grammage (standard EN 9073-1) 96 g/m.sup.2 134 g/m.sup.2 Thickness (standard EN 9073-2) 1.13 mm 1.14 mm Elasticity (standard EN 14704-1) 86% 87% Longitudinal lengthening (standard 117% 104% EN 9073-3) Transverse lengthening (standard 111% 65% EN 9073-3) Self-adhesion* 0.03 N/cm 0.03 N/cm Number of crimped fibers 19/cm.sup.2 27/cm.sup.2 at the surface of the nonwoven** *measured according to the method described above **measured according to the method described above

(12) 2. Assembling

(13) The bandages were assembled by needling.

(14) The tests on assembling by needling were carried out on a Fehrer needling machine using a board comprising 2500 needles per linear meter.

(15) The implementational conditions on the needling line are as follows: Output rate on the needling line: 1 meter/minute Penetration of the needles: 13 mm Needling density: 20 punches/cm.sup.2 with nonwoven A and 40 punches/cm.sup.2 with nonwoven B.

(16) The padding and nonwoven B or nonwoven A are combined before needling without prestressing the nonwoven.

(17) Example 1 corresponds to the needling of nonwoven B and the padding and example 2 to the needling of nonwoven A and the padding.

(18) The longitudinal lengthening properties, measured according to the standard EN 9073-3, of the bandages according to the invention, before and after needling, were compared with those of the first bandage Ktech, which corresponds to the needling of a knitwear and of the same padding, of the K2 compression system.

(19) The results are collated in table 1.

(20) TABLE-US-00002 TABLE 1 Example Lengthening in % Knitwear alone, comparative 180 Ktech, comparative 93 Nonwoven B 104 Example 1 124 Nonwoven A 117 Example 2 118

(21) The analysis of the table clearly shows the advantages of the combination of this type of nonwoven with a nonelastic material, such as the padding.

(22) For the Ktech bandage, 50% of the lengthening of the starting knitwear is lost after needling, whereas, for nonwoven A, the lengthening virtually does not change and, for nonwoven B, it is improved by 19%.

(23) By way of comparison, nonwoven B was needled with two other nonelastic nonwovens, the product Sontara 8004 from DuPont, the thickness of which is 0.25 mm and the elastic recovery of which is 25%, and the product Jettex1005 from Orma, the thickness of which is 0.37 mm and the elastic recovery of which is 18%.

(24) It is found that these two materials do not make it possible to obtain an elastic bandage. This is because it is found that their combination, after needling with nonwoven B, results in a compression bandage which breaks, when the standard EN 14704-1 is applied, before reaching the elongation of 30%. The elastic recovery of the padding is lower, 17%, but, surprisingly, by virtue of its thickness of 2.5 mm, it makes it possible to obtain an elastic bandage.

(25) 3. Performance of the Compression Bandages

(26) The performance of the bandage of example 1 was compared with that of the first compression bandage of the K2 system, the Ktech bandage.

(27) The performances of both these compression bandages were evaluated in terms of working and resting pressures and of difference in pressure over time.

(28) The in vitro testing device and method described in the patent application WO 2007/113430, page 17, line 26, to page 19, line 18, was used. According to this method, the bandage is put in place around a cylinder with a total cover of 100% and then the circumference of the cylinder is continuously varied at a set rate between a resting position (smallest diameter) and a working position (greatest diameter), in order to mimic muscle contraction. Pressure sensors measure, over time, the values of the resting pressures and working pressures.

(29) The time difference between the working pressure and resting pressure measurements is 5 seconds and the frequency of the measurements of these two successive parameters is 0.2 Hz.

(30) In order to test the compression bandage of example 1, the elongation at the putting in place of the bandage was determined as a function of the desired working pressure, for example using the tension/break curve as defined on the basis of the standard EN 9073-3. According to Laplace's law, the elongation to be carried out corresponds to the desired pressure.

(31) In order to appropriately put the bandage of example 1 in place, the bandage was calibrated using a stencil, as described in the patent application WO 2007/113430, page 13, line 18, to page 14, line 6. If necessary, the value of the percentage of elongation at being put in place was refined by a few successive tests.

(32) The Ktech bandage of the K2 commercial product is already calibrated.

(33) Each of the bandages was put in place at a given elongation, expressed as percentage, which is shown in table 2.

(34) The Max. Pressure at T0 value corresponds to the first working pressure recorded immediately after putting in place and Delta at T0 corresponds to the difference in pressure between the first working pressure and the first resting pressure which are recorded immediately after putting in place. The Max. Pressure at T24 and Delta at T24 values correspond to the measurements recorded 24 hours after putting in place.

(35) The difference in each of these two values between T0 and T24 hours, Max. Pressure (T0-T24) and Delta (T0-T24), was then calculated.

(36) The loss in working pressure at 24 hours, Loss in Max. Pressure T24, with respect to the working pressure at being put in place, was also calculated by determining the ratio of the variation Max. Pressure (T0-T24) to the Max. Pressure at T0.

(37) The combined results obtained are collated in table 2.

(38) TABLE-US-00003 TABLE 2 Ktech, comparative Example 1 Elongation at being put in place 55% 15% Max. Pressure at T0 31 30 Delta at T0 15 14 Max. Pressure at T24 23 27 Delta at T24 12 16 Delta (T0 T24) 3 2 Max. Pressure (T0 T24) 8 3 Loss in Max. pressure at T24 25.8% 10%
Interpretation of the Results

(39) The analysis of the results of table 2 demonstrates another advantage, apart from the ease of industrial manufacture by virtue of the absence of decrease in the lengthening of the nonwoven after needling with the padding: this is the remarkable improvement in the performance of this bandage with respect to the Ktech.

(40) It is thus found that there is a loss in working pressure at 24 hours of only 10%, versus 25.8% for the Ktech.

(41) It is also found that the difference in pressure between working pressure and resting pressure does not decrease over time. It changes from 14 immediately after being put in place to 16 mm of mercury after 24 hours, versus 15 to 12 mm of mercury for the Ktech.

(42) On the contrary, it unexpectedly increases.

(43) Thus, for the bandage of example 1, the difference in Delta between putting in place and 24 hours is negative: 2.

(44) This result is all the more remarkable as it is obtained by a slower fall in the working pressure (which guarantees the effectiveness of the system) than that in the resting pressure.

(45) The compression bandage according to the invention thus improves its effectiveness over time.

(46) The compression bandages according to the invention thus make it possible to advantageously replace the first bandage in a bilayer compression system and to improve the effectiveness of this system while being easier to manufacture.