Self-adhesive elastic bandage that can be used, in particular, for the treatment and prevention of diseases of the veins

Abstract

A self-adhesive compression bandage, in particular for the treatment and prevention of pathologies of venous origin and lymphedema. This bandage is manufactured by the assembling of two self-adhesive nonwovens based on short conjugate fibers which have been crimped. The fibers are preferably made of polyester. The bandage can in addition comprise a supplementary layer.

Claims

1. A compression bandage comprising two nonwovens of crimped fibers obtained from short conjugate fibers, in which: the two nonwovens are assembled together and have, independently of one another, a grammage of between 70 g/m.sup.2 and 300 g/m.sup.2, the crimped fibers are uniformly crimped in a thickness direction of the nonwovens, and exhibit a mean curvature radius of between 10 and 200 micrometers, and a surface of each of the nonwovens 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 each nonwoven has, independently of one another, a grammage of between 80 and 200 g/m.sup.2.

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

9. The compression bandage as claimed in claim 1, wherein each nonwoven 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 nonwovens, each part corresponding to one third thereof in a cross-section taken perpendicular to the thickness direction of the nonwovens.

10. The compression bandage as claimed in claim 1, further comprising a supplementary layer selected from the group consisting of a textile material, a cellular material, a film, and their combinations.

11. The compression bandage as claimed in claim 10, wherein the supplementary layer is a textile material that is a nonelastic nonwoven which exhibits a thickness greater than 1.8 mm.

12. The compression bandage as claimed in claim 11, wherein the nonelastic nonwoven is an absorbent nonwoven which exhibits a thickness between 1.8 and 4 mm.

13. The compression bandage as claimed in claim 11, wherein the nonelastic nonwoven is an absorbent nonwoven which exhibits a thickness between 2 and 3 mm.

14. The compression bandage as claimed in claim 10, wherein the supplementary layer is a hydrophilic polyurethane foam or a padding.

15. The compression bandage as claimed in claim 10, wherein the two nonwovens are needled with the supplementary layer which is a padding exhibiting a thickness between 2 and 3 mm.

16. The compression bandage as claimed in claim 1, wherein the nonwovens are assembled by needling, with an adhesive or by ultrasound.

17. The compression bandage as claimed in claim 1, wherein the nonwovens comprise bicomponent fibers that are based on aromatic polyester polymers, each nonwoven having a grammage between 90 and 150 g/m.sup.2 and the surface of each nonwoven having between 10 and 35 crimped fibers/cm.sup.2.

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

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

21. The compression bandage as claimed in claim 1, wherein each nonwoven has, independently of one another, 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) Nonwovens

(4) 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.

(5) 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.

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

(7) 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 117% 104% (standard EN 9073-3) Transverse lengthening 111% 65% (standard 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

(8) b) Supplementary Layer

(9) The materials used for the supplementary layer are commercial products, the names or references of which are as follows and which are shown abbreviated in table 1. hydrophilic polyurethane foams sold under the reference MCF.03 by AMS, with a thickness of 4.5 mm (abbreviated to foam 4.5 mm) and with a thickness of 2.5 mm (abbreviated to foam 2.5 mm) Ksoft padding sold by Urgo Limited (abbreviated to padding) hydrophobic foam sold by Alveo under the name Alveolit TEE.1000.8 (abbreviated to Alveo foam) polyurethane foam sold by Scapa under the name MDifix 4005 (abbreviated to Scapa foam) 3D knitwear sold by Louis Vuidon under the reference 9315 (abbreviated to 3D knitwear) polyurethane film sold by Leygatech under the reference PU 55 IMPER 01 with a thickness of 55 micrometers (abbreviated to PU film)

(10) 2. Assembling

(11) Different assembling techniques were used to manufacture the bandages: needling, application of an adhesive by points or assembling by points by ultrasound.

(12) a) Conditions for Assembling by Needling

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

(14) The tests were carried out in two passes on the needling machine, except for example 6, which does not comprise a supplementary layer.

(15) Three different types of needling were employed to prepare the compression bandages of the invention.

(16) Needling 1

(17) The implementational conditions on the needling 1 line are as follows: Output rate on the needling line: 1 meter/minute Penetration of the needles: 10 mm Needling density: 50 punches/cm.sup.2

(18) The foam and the nonwoven are combined before needling 1 without prestressing the nonwoven.

(19) Needling 2

(20) The implementational conditions on the needling 2 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

(21) The padding and nonwoven B or nonwoven A were combined before needling 2 without prestressing the nonwoven.

(22) Needling 3

(23) The implementational conditions on the needling 3 line were as follows: Line speed=1 m/min Penetration of the needles: 13 mm, except for example 10, where it is 18 mm Needling density: 50 punches/cm.sup.2

(24) The supplementary layer and the nonwoven were combined or the nonwoven was combined with itself before needling 3 without prestressing the nonwoven.

(25) b) Conditions for Assembling by Application of Adhesive by Points Under Hot Conditions with Engraved Cylinder

(26) Assembling with an adhesive was used when the application temperature of the adhesive necessary for its deposition is compatible with the thermal resistance of the nonwoven. When the bandage comprises a supplementary layer, the surface of the supplementary layer has to be sufficiently even for the adhesive to be able to be uniformly distributed.

(27) The product was produced on a Cavimelt apparatus for laminating by an engraved cylinder (left-hand part). Cylinder used=cylinder No. 6 Engraving Net 1 Test conditions of the apparatus:

(28) Operating speed=2 m/min

(29) Rolling slot=0.3 mm

(30) Rolling cylinder pressure=3 bar

(31) Anvil roll pressure=2.5 bar

(32) Heating temperature=188 C.

(33) Temperature of the adhesive=180 C.

(34) The supplementary layer of foam was spread with adhesive and then the nonwoven was laminated. The hot melt adhesive used was a polyester adhesive having the Griltex D 2116 E trade name from EMS.

(35) c) Conditions for Assembling by Ultrasound

(36) Assembling is carried out by points which correspond to the number of pins on the surface of the roller facing the sonotrode which are used to produce the point bonding between the 2 nonwovens.

(37) This assembling is carried out on a conventional device from Herrmann Ultraschalltechnik.

(38) The parameters were as follows: Roller with a diameter of 190 mm, the reference of which is H 058 Uncoated flat titanium sonotrode with a width of 161 mm Frequency of the ultrasound: 20 kHz Amplitude 100% Rate of passage of the order of 5 m/min.

(39) All of the bandages produced and the assembling techniques are collated in table 1.

(40) TABLE-US-00002 TABLE 1 Nonwovens Supplementary Example used layer Assembling 1 B/B Foam 4.5 mm Needling 1 2 B/B Foam 4.5 mm Adhesive 3 B/B Padding Needling 2 4 A/B Padding Needling 2 5 A/A Padding Needling 2 6 B/B Without Needling 3 7 B/B Foam 2.5 mm Needling 3 8 B/B Scapa Foam Needling 3 9 B/B Alveo foam Needling 3 10 B/B 3D knitwear Needling 3 11 B/B PU film Needling 3 12 B/B Without Ultrasound

(41) 3. Performance of the Compression Bandages

(42) The performance of the compression bandages of examples 1 to 12 were evaluated in terms of working and resting pressures and of difference in pressure over time.

(43) 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.

(44) 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.

(45) In order to test the compression bandages according to the invention, 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 in the standard EN 9073-3. According to Laplace's law, the elongation to be carried out corresponds to the desired pressure.

(46) In order to appropriately put the bandage in place, the bandages were 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.

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

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

(49) 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.

(50) The performance of the bandages according to the invention was compared with the bilayer compression systems sold by Urgo Limited under the K2 and K2 Lite names. The bandages of these commercial products were already calibrated.

(51) The combined results have been given in table 2.

(52) TABLE-US-00003 TABLE 2 Max. Max. Loss in Elongation at Max. Delta at Pressure at Delta at Delta Pressure Max. being put in Pressure at T0 T24 T24 (T0 T24) (T0 T24) Pressure Bandage used place T0 (mmHg) (mmHg) (mmHg) (mmHg) (mmHg) (mmHg) T24 K2 55% + 50% 44 19 35 17 +2 9 20.4% K2 Lite 50% + 50% 33 10 25 8 +2 8 24.2% Example 1 30% 93 23 81 27 4 11 11.8% Example 2 30% 67 21 58 22 1 9 13.4% Example 3 20% 77 30 71 34 4 6 7.8% Example 4 20% 39 17 37 20 3 2 5.1% Example 5 20% 39 17 33 19 2 6 15.3% Example 6 30% 54 17 47 20 3 7 13% Example 6 20% 48 15 46 18 3 2 4.2% Example 6 15% 33 12 29 14 2 4 12.1% Example 12 20% 52 13 50 15 2 2 3.8% Example 7 30% 66 17 59 21 4 7 10.6% Example 8 30% 82 24 68 28 4 14 17% Example 9 10% 76 29 70 39 10 6 7.9% Example 10 30% 71 22 61 27 5 7 14% Example 11 10% 70 25 63 30 5 7 10%

(53) Interpretation of the Results

(54) The analysis of the results of table 2 demonstrates the performance of the compression bandages according to the invention.

(55) Generally, these results show that it is possible to treat all the pathologies described above with just one latex- or adhesive-free self-adhesive compression bandage as there exists, depending on the products or their elongation at being put in place, a value range for the working pressure at 24 hours which varies from 29 to 81 mm of mercury.

(56) It is also found that all these compression bandages exhibit an excellent retention, after 24 hours, of the pressure applied at being put in place.

(57) The large fall which is generally found for short-stretch bandages, of the order of 30 to 40% after 24 hours, and of the order of 20 to 25% for the bilayer systems which are the most effective, is here much lower. It is always less than 20% and generally between 10 and 15%, indeed even less than 10% for examples 3, 4, 6 (put in place at 20%), 9 and 12.

(58) To be able to apply a high pressure and to retain it over time is a very important parameter for the treatment of lymphedemas, in particular leg lymphedemas, for which a pressure of greater than 60 mm of mercury and preferably between 70 and 100 mm of mercury is desired at 24 hours.

(59) Examples 1, 3, 8, 9, 10 and 11 are particularly well suited to the treatment of this pathology.

(60) Likewise, it is found that the value for the differences in pressure at 24 hours varies between 14 and 39 mm of mercury, which makes it possible to be appropriate for all the categories of leg ulcers indicated above.

(61) It is also found that the difference in pressure between working pressure and resting pressure does not decrease over time but on the contrary, unexpectedly, increases. Thus, for all the bandages of the invention, the difference between the Delta after putting in place and the Delta at 24 hours is negative.

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

(63) The compression bandages according to the invention are thus the first to improve their effectiveness over time.

(64) It may also be observed that these results are obtained with products based on different materials or assembled according to different technologies.

(65) Thus, if a bandage is targeted which exhibits a difference in pressure at 24 hours of the order of 15 to 25 mm of mercury, the compression bandages of examples 2, 4, 5, 6, 7 and 12 can meet these specifications.

(66) In particular, example 6, which corresponds to the needling of two nonwovens B, is particularly advantageous as, put in place at 20%, it gives equivalent results, indeed even better results, in terms of delta and of pressure at 24 hours than the product K2 using just one bandage. It also exhibits one of the smallest falls in working pressure at 24 hours, at 4.2%.

(67) Likewise, examples 4 and 5, respectively composed of the nonwovens A and B with a padding and of two nonwovens A with a padding, give, put in place at 20%, at 24 hours, excellent differences in pressure of 20 and 19 mm of mercury, while immediately applying, after being put in place, low working pressures of the order of 39 mm of mercury. These bandages will thus be easily endured and accepted by patients in the treatment of classic leg ulcers. Furthermore, the presence of the padding makes it possible, if necessary, to increase the dampening effect of the bandage and its absorption capability.

(68) Example 6 is also advantageous as it is found that, with just one bandage put in place at different elongations, it is possible to cover several pathologies.

(69) In order to be able to treat mixed arterial and venous ulcers, what are desiredbecause of the arterial componentare low working pressures (of the order of 30 to 35 mm of mercury) while retaining a high difference in pressure. In order to obtain this result, it had been necessary to develop a specific bilayer compression system, K2 Lite.

(70) It is found that the bandage of example 6, put in place at 15% elongation, makes it possible to obtain pressure values in the desired range and of the same order as K2 Lite while retaining a greater difference in pressure than that of K2 Lite.

(71) It is thus found that, with just one bandage, by varying its elongation at being put in place, it is possible to obtain both a system which is equivalent to or superior to the K2 system but also a system which can be used for the pathology of mixed ulcers and that this system is more effective than the K2 Lite system.

(72) All the results obtained demonstrate that, finally, a compression bandage has been produced which exhibits the advantages of the short-stretch bandages (strong difference in pressure) and of the long-stretch bandages (low fall in pressure) without their disadvantages with a single bandage. This bandage is more effective than the best known bilayer compression systems.