Compression textiles

Abstract

The present invention relates to a compression textile, e.g. a compression bandage or garment, which comprises at least one chitosan-containing fiber. The compression textile is suitable for medical applications, but also for non-medical applications in the field of wellness and sport.

Claims

1. A compression garment comprising at least one fiber coated with chitosan, wherein the fiber is a cellulose-based fiber selected from the group consisting of viscose, modal, polynosic and lyocell fiber, wherein the surface of said fiber is at least partially coated with chitosan, and wherein said fiber coated with chitosan is spun onto an elastic yarn.

2. The compression garment according to claim 1, wherein said garment is selected from the group consisting of a stocking, arm sleeve, calf sleeve, glove, sock, leggings, top and shorts.

3. The compression garment according to claim 1, wherein said garment is capable of compression suitable for a medical garment.

4. The compression garment according to claim 3, wherein said compression is sufficient for phlebologic or lymphologic applications, for scar formation reduction or for diabetes patients.

5. The compression garment according to claim 1, wherein said garment is capable of compression suitable for wellness or sport applications.

6. The compression garment according to claim 1, wherein the fiber has a content of 0.1-25% by weight of chitosan.

7. The compression garment according to claim 1, wherein at least one fiber which is coated with chitosan covers an elastic yarn.

8. The compression garment according to claim 7, wherein the elastic yarn is selected from the group consisting of a synthetic yarn, a spandex yarn, and a natural elastic yarn.

9. The compression garment according to claim 8, wherein said synthetic yarn is made of a polyester-polyurethane copolymer, or said natural elastic yarn is made of rubber.

10. The compression garment according to claim 1, wherein the at least partially chitosan-coated fiber is blended with a further component selected from the group consisting of bamboo, wool, cotton, linen, silk, polyamide, polyester, polyacrylnitrile, polypropylene, viscose, modal, micro modal with elastane and elastodien.

11. The compression garment according to claim 10, wherein the amount of the at least partially chitosan-coated fiber in the blend is at least 3% by weight, based on the total-weight of the blend.

12. The compression garment according to claim 11, where the amount of the at least partially chitosan-coated fiber in the blend is at least 10% by weight, based on the total-weight of the blend.

13. The compression garment according to claim 12, where the amount of the at least partially chitosan-coated fiber in the blend is at least 20% by weight, based on the total-weight of the blend.

14. The compression garment according to claim 13, where the amount of the at least partially chitosan-coated fiber in the blend is at least 30% by weight, based on the total-weight of the blend.

15. The compression garment according to claim 14, where the amount of the at least partially chitosan-coated fiber in the blend is at least 40% by weight, based on the total-weight of the blend.

16. The compression garment according to claim 15, where the amount of the at least partially chitosan-coated fiber in the blend is at least 50% by weight, based on the total-weight of the blend.

17. A method for improving microbial skin flora, comprising applying a compression garment according to claim 1 to a subject in need of such improvement.

18. A method for improving compliance and wearing comfort of medical garments comprising applying a compression garment according to claim 1 to a subject in need of such improvement in compliance and wearing comfort.

19. A method for improving the regulation of skin moisture, comprising applying a compression garment according to claim 1 to a subject in need of such improvement in the regulation of skin moisture.

20. The method according to claim 18, wherein said compression garment is applied as an under-article which is in direct contact with the skin.

21. The method according to claim 20, wherein said under-article is selected from the group consisting of socks, stockings, knee socks, and tights.

22. A method for treating and/or preventing oedema in patients suffering from diabetes comprising applying a compression garment according to claim 1 to a subject in need of such treatment or prevention.

23. A method for improving skin thermoregulation, comprising applying a compression garment according to claim 1 to a subject in need of such improvement in skin thermoregulation.

24. A method for improving skin healing and protection, comprising applying a compression garment according to claim 1 to a subject in need of such improvement in skin healing and protection.

25. The method according to claim 18, where said subject is suffering from aging, sensitive and/or dry skin.

26. The compression garment according to claim 1, wherein said fiber coated with chitosan is spun onto an elastic yarn by wrap spinning.

Description

EXAMPLE 1

(1) Test for Moisture Regulation In Vitro

(2) The moisture management properties of textile samples were determined by micro computer tomography measurements.

(3) Samples:

(4) Sample 1:

(5) Tubing (19.5 cm. times 10.8 cm) consisting of a loop yarn (LYCRA (spandex, polyurethane fiber) double covered with polyamide 6.6) and an inlaid yarn (LYCRA (spandex, polyurethane fiber) double covered with PA 6.6 and the chitosan-containing fiber TENCEL C2(lyocell with chitosan)).

(6) Total components: 34% elastane, 52% PA 6.6, 14% Tencel C2 (based on the total weight). Sample 2:

(7) Tubing (19.5 cm. times. 10.8 cm) consisting of a loop yarn (LYCRA (spandex, polyurethane fiber) double covered with PA 6.6) and an inlaid yarn (LYCRA (spandex, polyurethane fiber) double covered with PA 6.6 and cotton).

(8) Total components: 34% elastane, 52% PA 6.6, 14% cotton (based on the total weight).

(9) In FIG. 1, microscopic photographs (magnification >20 times) of Sample 1 (A) and Sample 2 (B) are shown. The Tencel C or cotton, respectively, containing inlaid yarns and the polyamide containing loop yarn are indicated.

(10) Test Performance:

(11) Computerised tomography (CT) is a layer-selective radiographic process by which a three-dimensional image can be reconstructed with the aid of a number of sectional photographs corresponding to process one-dimensional projections at different angles. Each projection corresponds to the integration of the attenuation coefficient along the X-ray beam, and by combining the data from different angles, it is possible to reconstruct the two- or three-dimensional image of a sample. The tomograph used is a CT 80 from Scanco Medical AG, Bassersdorf, Switzerland. The X-ray anode voltage was 55 kV. For objects up to 74 mm in diameter, this device allows one to scan around the object with either 37 or 74 m resolution, but with different imaging times. The lower resolution was chosen (in all three directions) for faster skin speed to allow a sufficient temporal resolution. A total of 104 projections per 180 were taken and each projection required an X-ray exposure of 200 ms. The two-dimensional detector of the CT 80 gives 52 slices in a single term, resulting in a image time of 3 min/stack of 50 slices and two stacks were measured per time point, giving a total imaging time of 6 minutes.

(12) The described method is also suitable for representing and quantifying the moisture content in tissues. In order to simulate sweating, the structure according to M. Weder et al., Textile Research Journal, vol. 76(1), 18-26, has been chosen.

(13) The samples were introduced into a holder and adjusted to 35 C.

(14) In order to simulate sweating, water was introduced from a reservoir at two different rates, i.e. 1.25 g/h (low sweating rate corresponding to normal activity) and 2.25 g/h (high sweating rate corresponding to sport activity).

(15) The measurements were carried out in three phases: acclimatisation (without sweating) physical activity (with sweating) recovery (without sweating)

(16) The results at a low sweating rate are shown in Table 1:

(17) TABLE-US-00001 TABLE 1 Low sweating rate (a) Sample 1: made with Tencel C2 2: made with cotton Supplied water (g) 1.28 1.28 Outer side (mg) 45 60 Inner side (mg) 70 50 Total (mg) 120 115 Max water (vol %) 11 11

(18) It can be seen that the Tencel C2 containing fibre stores water closer to the skin, i.e. at the inner side of the tubing than cotton. Thus, Tencel C containing fibres provide an increased skin hydration at a low sweating rate.

(19) The results at a higher sweat rate are shown in Table 2:

(20) TABLE-US-00002 TABLE 2 Higher sweating rate (b) Sample 1: made with Tencel C2 2: made with cotton Supplied water (g) 2.52 2.53 Outer side (mg) 285 340 Inner side (mg) 235 240 Total (mg) 520 580 Max water (vol %) 52 55

(21) At a high sweating rate water is sucked away from the inner side and deposited on the outer side for both samples. The skin side is rather dry. Sample 1 (Tencel C) has a lower drying time.

(22) From Tables 1 and 2 it can be gathered that the presence of a chitosan-containing fibre such as Tencel C in a compression textile results in differential moisture regulation properties depending on the sweat rate.

EXAMPLE 2

(23) Test for Moisture Regulation in Human Test Persons

(24) The moisture regulation properties of textile samples were determined by corneometry and tewametry.

(25) Samples:

(26) Sample 1: compression stocking comprising a chitosan fibre, i.e. Tencel C2 (colour white) Sample 2: compression stocking comprising a cotton fibre (colour beige)
Methodology:
Corneometry

(27) A CM 825 PC Corneometer (Courage+Khazaka, Cologne, Germany) is used to measure the water content.

(28) The face of the sensor is coated with a special glass, which allows axial movement and it has a range of at least 3 mm. The principle of measurement requires that the surface of the measuring device sits evenly at a constant pressure on the skin. To ensure that this is as reproducible as possible, the face of the measuring head is very small with an area of 77 mm.sup.2. The inner movable partthe active faceis pressed onto the skin with a pressure of 3.5 N by means of a spring. This guarantees standardised measurements, irrespective of the investigator.

(29) In order to carry out a measurement, the measuring head is pressed onto the required part of the skin. After one second the measured value is recorded and processed by the computer.

(30) The value measured by the CM 825 Corneometer specifies the degree of moisture of the skin surface.

(31) Tewametry

(32) A Tewameter (Courage+Khazaka, Cologne, Germany) is used for measuring the transepidermal water loss which is a reliable tool for judging the integrity of the skin barrier. The measuring method is based on Fick's law saying that the concentration of water vapour at various distances above a surface is directly related to the quantity evaporated by area and time:
dm/dt=DAdc/dx dm/dt=diffusion current (water transported per time) dc/dx=density gradient D=diffusion constant or water vapour in air A=surface

(33) The most important part of the Tewameter is the probe, consisting of a cylindrical tube, which is open at the top and bottom and which is placed on the surface to be measured. Two capacitive moisture sensors installed in the cylindrical tube measure the moisture of the air at two defined distances above the surface. The water vapour is given in g/m.sup.2 h. Evaporation rates from 0 to 300 g/m.sup.2 h can be recorded by this device.

(34) Test Performance:

(35) The stockings were worn by 31 test persons for 14 days for about 10 hours per day. The stockings were randomly distributed. Each test person wore a cotton stocking on one leg and a Tencel C stocking on the other leg.

(36) Results:

(37) It was found that the chitosan fibre-containing stocking exhibited advantageous properties even after a short time of wear. These advantageous properties were as follows:

(38) In 41% of the test persons the skin showed a marked improvement with Tencel C compared to cotton, e.g. less ragades, wrinkles and hyperkeratoses (in 31% of the test persons there was no difference between both stockings and in 16% of the test persons, the cotton stocking led to skin improvements).

(39) In both stockings, the skin hydration was decreased. The respective results of corneometric measurements are shown in FIG. 2. The decrease in skin hydration for the stocking containing Tencel C, however, was lower (12.4%) than with cotton (14.8%). Thus, Tencel C2 improves skin hydration compared to cotton.

(40) In a further experiment the transepidermal loss of water after removal of the stocking was determined directly on the skin by tewametry. The results are shown in FIG. 3. It can be seen that the transepidermal water loss with the compression stocking containing Tencel C is markedly lower (about 8%) compared to the transepidermal water loss with the compression stocking containing cotton (10.8%). Thus, wearing of a Tencel C containing stocking leads to a decreased water loss of about 0.5 g/m.sup.2 skin.

(41) Further, it was found that wearing of compression stockings containing Tencel C leads to a smoothing of skin of about 2% compared to the starting value. The wearing of compression stockings containing cotton did result in a smoothing of the skin.

(42) The results demonstrate that wearing of compression stockings containing Tencel C leads to an improvement in skin quality, particularly higher water retention and higher smoothness of the skin.

EXAMPLE 3

(43) Test for Skin Roughness (FOITS)

(44) The skin roughness was evaluated by fast optical in vivo topometry of human skin (FOITS).

(45) Samples:

(46) Sample 1: Compression stocking comprising Tencel C2 (colour white) Sample 2: Compression stocking comprising a cotton fibre (colour beige)
Test Performance:

(47) The stockings were worn by 31 test persons for 14 days for a minimum of eight hours per day. The stockings were randomly distributed. Each test person wore cotton stockings on one leg and a Tencel C stocking on the other leg. Creaming of the legs was not allowed one week before the start of the study and during the study.

(48) Methodology:

(49) FOITS is an optical measurement procedure which uses a combination of gray code and phase shift technique (Breuckmann B. (1993), Bildverarbeitung und optische Messtechnik in der industriellen Praxis, Franzis, Mnchen). In less than one second, one can measure the absolute space coordinates of all object points in the selected image area with great exactitude. The FOITS-measurement system consists of a projection unit and a CCD camera. Both are fixed under a so-called triangulation angle. Concerning the gray code method, grids with a rectangular brightness distribution by different numbers of lines are projected. The number of lines is doubled at each new projection. This gives a clearly defined hierarchy of lines for each image point. Regarding the phase shift technique, only one grid with a sinus-like intensity distribution is projected several times with different phase positions. A detailed description can be found in Breuckmann B., Bildverarbeitung und optische Messtechnik in der industriellen Praxis, Franzis, Mnchen, 1993, and Rohr M., Schrader K. 1998, Fast optical in vivo topometry of human skins (FOITS), SFW-Journal 124, 52-59. A CCD camera with a horizontal and vertical resolution in x and y direction of about 30 m is used. The measurement has been carried out via contactless direct skin measurement of an area of inspection of 1200 mm.sup.2. The area of measurement (depth-sharpness) was 20 mm. The dissolution in x and y direction was each approx. 30 m. The dissolution in z direction was 4 m. The time to digitise the fine structure was about 300 ms.

(50) The roughness parameters Rz and Ra (according to DIN 4768) were determined using twelve separate lines of a length of 20 mm for the analysis.

(51) Rz means average depth of roughness and is the arithmetic means of Rmax in five successive single measuring sections of the total length of measurement.

(52) Ra means the arithmetic mean roughness and specifies the absolute amounts of all variances in the roughness profile from the centreline over the total distance.

(53) Results:

(54) The results of the skin roughness measurements via FOITS are shown in FIG. 4. Using the Tencel C2 stocking, the average depth of roughness Rz as well as the arithmetic mean roughness Ra showed a difference of about 2.3%-points compared to the starting value, which indicates a reduction of the skin roughness. In case of the cotton stockings, a reduction of the skin roughness of only about 0.5%-points was observed. These results show that Tencel C2 stockings considerably reduce the skin roughness compared to conventional cotton stockings.

EXAMPLE 4

(55) Test for Skin Elasticity

(56) The effects on skin elasticity of the textile samples were determined by cutometry.

(57) Samples:

(58) see Example 3

(59) Test Performance:

(60) see Example 3, except that the study included only 30 test persons.

(61) Methodology:

(62) The Cutometer (Courage and Khazaka, Cologne, Germany) is a vacuum generator with electronic control elements to which the actual measuring probe is connected. Pressure tubing connects the probe and the vacuum generator. The head of the probe is pressed onto the skin. A spring loaded part ensures that constant pressure to the skin is applied.

(63) The displacement of the skin into the probe due to the vacuum is measured optically and transmitted to a PC that is connected to the set-up. The Cutometer sucks an area of skin of approximately 2 mm in diameter in a defined vacuum and then, without friction, optically measures the depth of the skin penetrates into the probe. For a standard test, the instrument generates a vacuum of 300 mbar which is applied to the skin as a sudden jump function. The vacuum is turned off after 5 seconds (on time), also as a sudden jump function and is applied again after another 5 seconds (off time). One measuring cycle is performed in this way.

(64) The standard parameters R.sub.0 to R.sub.7 can be calculated from the measuring curves. The parameters result from the below calculations.

(65) R.sub.0

(66) R.sub.0 shows the maximum displacement of the skin after the first suck. It incorporates the elastic stretch of the skin, as well as the plastic portion, which is characterized by a non-linear curve shape.

(67) An improvement in skin firmness is indicated by a decrease of R.sub.0.

(68) R.sub.1

(69) R.sub.1 shows the remaining displacement of the skin when the vacuum has been turned off for five seconds after the first suck. This parameter therefore shows the remaining plastic deformation of the skin after the first suck. It gives information about the ability of the skin to come back in its original state.

(70) R.sub.2

(71) The R.sub.2 firmness parameter is a combination of R.sub.0 and R.sub.1.
R.sub.2=(R.sub.0R.sub.1)/R.sub.0

(72) This parameter reflects the ratio of the decrease in displacement after the first suck and the total displacement in the first suck (Gross Elasticity).

(73) The greater R.sub.2 is, the less plastic deformation remains.

(74) R.sub.3

(75) R.sub.3 reflects the maximum displacement of the skin after the last suck. It, therefore, incorporates an additional effect compared with R.sub.0, namely a wear effect caused by repeated displacement of the skin.

(76) This parameter equals R.sub.0 if the measuring cycle is carried out only once.

(77) R.sub.4

(78) R.sub.4 reflects the remaining displacement after the last suck, and therefore corresponds to R.sub.1 plus the wear effect from repeated suction. R.sub.4 equals R.sub.1 if one measuring cycle is done.

(79) R.sub.5

(80) The R.sub.5 parameter (Net Elasticity) reflects the elastic portions of the first curve.
R.sub.5=U.sub.R/U.sub.E

(81) R.sub.5 comprises UE, the linear proportion of the first curve, and UR, the linear decrease when the vacuum has been turned off after the first suck. The closer R.sub.5 to 1 (100%), the more elastic the skin is.

(82) R.sub.6
R.sub.6=U.sub.v/U.sub.E

(83) Here UV is the plastic portion of the first curve. R.sub.6, therefore, represents the inelastic portion of stretch versus the elastic portion of stretch in the first curve. The higher R.sub.6, the more plastic the skin. The lower R.sub.6, the more elastic the skin.

(84) R.sub.7

(85) Parameter R.sub.7 represents a kind of spontaneous elasticity. Namely, the elastic portion after the vacuum has been turned off for the first time is related to the total displacement of the first suck. The closer R.sub.7 to 1 (100%) the more elastic the skin. The lower R.sub.7, the more inelastic the skin.
R.sub.7=U.sub.R/R.sub.0

(86) In this study, parameter R.sub.0, R.sub.1, R.sub.2, R.sub.5 and R.sub.7 are analysed on a statistical basis. A positive product effect is documented by a decrease of parameter R.sub.0 and R.sub.1 and an increase of parameter R.sub.2, R.sub.5 and R.sub.7.

(87) Results:

(88) In FIG. 5, the results of the Cutometry measurements are shown. In all experiments, the values of the parameters R.sub.2, R.sub.5 and R.sub.7 are reduced compared to the starting value. As can be seen from the legs treated with Tencel C2, the R.sub.2, R.sub.5 and R.sub.7 parameters only varied slightly with respect to their starting value as compared to the experiments done with cotton-treated legs. These results show that the Tencel C2 stockings almost maintain the skin elasticity during wearing, whereas skin elasticity is markedly reduced when wearing conventional cotton stockings. Thus, using Tencel C2 stockings, a higher skin elasticity can be maintained as it is the case when using cotton stockings.

EXAMPLE 5

(89) Test for Skin pH

(90) The skin pH value was determined by a pH meter.

(91) Samples:

(92) see Example 3

(93) Test Performance:

(94) see Example 3

(95) Methodology:

(96) The skin pH meter pH 905 (Courage and Khazaka, Cologne, Germany) is used for pH measurements directly on the skin surface. Due to the excretions of skin, skin surface represents almost an aqueous solution. The measurement of skin pH is performed with a glass electrode that reacts on the activity of [H+] ions. The potential of the glass electrode is linearly dependent on the pH value of the measuring solution.

(97) The pH value of healthy skin is about 4.4 to 5.5 at room temperature (20 C. and 40-60% air humidity).

(98) Results:

(99) In FIG. 6, the -deviation from the skin pH value before and after wearing Tencel C2 or cotton stockings is indicated. As can be seen from the Figure, there is almost no difference in pH value in case of Tencel C2-treated skin and cotton-treated skin.

EXAMPLE 6

(100) Test of skin trophy, skin microclimate and wearing comfort of Tencel C2 containing stockings in comparison to conventional cotton stockings.

(101) Test Performance

(102) 12 healthy test persons wore the Tencel C2 (chitosan) medical compression stocking on one leg and the cotton-containing comparison stocking on the other leg. The test persons completed a defined physical stress on the treadmill (treadmill ergometry). In connection with the treadmill ergometry, different measurements regarding the skin climate and the evaluation of the skin barrier function, e.g. a measurement of the skin moisture, evaporation of water, and skin temperature, were carried out.

(103) All experiments were carried out in an air-conditioned testing room (20-24 C., average humidity of 60%). The test persons first of all completed a 20-minute acclimatization phase. The test persons walked 15 minutes on the treadmill at a speed of 3 km/h and a slope of 12.

(104) The abbreviations 1 to 5 used below refer to the respective examination times: U1: before treadmill, without stocking U2: before treadmill, with stocking U3: after treadmill, with stocking U4: after treadmill, without stocking U5: 5 minutes after treadmill, without stocking.
Transepidermal Water Loss (TEWL, Courage and Khazaka, Cologne)

(105) The transepidermal water loss (TEWL) provides information regarding the skin permeability and its barrier function. TEWL was measured using a Tewameter TM300 (Courage and Khazaka) as described above.

(106) The obtained TEWL values are summarised in Table 3.

(107) TABLE-US-00003 TABLE 3 Describing statistic of the examined TEWL values Stocking Size U1 U2 U3 U4 U5 Cotton Minimum 2.40 2.30 7.00 9.30 7.00 l.q. 4.70 5.98 14.38 17.45 9.05 Median 6.75 7.85 19.10 28.05 13.95 u.q. 9.23 11.40 24.28 38.40 25.25 Maximum 10.00 16.60 34.90 55.20 37.30 Tencel C Minimum 4.20 3.30 11.40 9.90 6.70 l.q. 5.18 6.28 13.53 24.38 8.10 Median 8.20 10.55 18.45 30.80 13.25 u.q. 11.88 14.00 20.23 38.40 23.50 Maximum 13.20 18.40 25.70 48.70 37.50 l.q. = lower quartile; u.q. = upper quartile

(108) FIG. 7 shows a correlation between the TEWL value U2 before treadmill treatment and the TEWL value U3 after treadmill treatment. FIG. 7 indicates that the physical stress caused by treadmill treatment results in increased perspiration (perspiratio sensibilis) and an increased TEWL value in case of both compression stockings.

(109) There is a higher increase of the TEWL value for the cotton stockings than for the Tencel C stockings. This can be explained by the fact that Tencel C can partially absorb and retain moisture such that the water vapour emission measured at the outer surface of the compression stocking is lower in Tencel C2 stockings as compared to cotton stockings.

(110) Measurement of the Skin Moisture (Corneometry, Courage and Khazaka, Cologne)

(111) The moisture content of the stratum corneum is measured via corneometry as described above. The stratum corneum is a suitable indicator due to its specific storage capacity.

(112) The values for the skin moisture in the stratum corneum are shown in Table 4.

(113) TABLE-US-00004 TABLE 4 Skin moisture parameters Stocking Size U1 U4 U5 Cotton Minimum 33.40 31.50 34.80 l.q. 38.95 42.85 43.00 Median 41.00 45.65 45.05 u.q. 47.33 56.00 50.53 Maximum 56.10 60.30 57.30 Tencel C Minimum 25.20 32.30 34.40 l.q. 38.38 43.83 40.83 Median 40.65 45.05 43.50 u.q. 44.63 51.98 52.03 Maximum 49.90 57.20 59.80

(114) A correlation between U1 and U4 shows that an increase in skin moisture is observed in both types of stockings, However, the increase of the skin moisture is lower when wearing Tencel C2 stockings than when wearing cotton stockings.

(115) When comparing the values measured at the time points U1 and U5, a similar result is obtained.

(116) The corneometry data, thus, confirm the result of the TEWL measurements that Tencel C tends to cause less perspiration/skin moisture.

(117) Temperature

(118) The sensors were applied onto the skin, below the stocking. The measured temperatures are shown in Table 5.

(119) In FIG. 8, the relationship between U2 and U5 is schemattically displayed. Therein the slope of temperature increase is lower when wearing Tencel C2 stockings compared to the temperature increase when wearing cotton stockings.

(120) The lower increase of the body temperature when wearing Tencel C2 stockings correlates with the lower TEWL value and the lower moisture increase (FIG. 8).

(121) TABLE-US-00005 TABLE 5 Describing statistic of the temperature parameters Stocking Size U1 U2 U3 U4 U5 Cotton Minimum 30.3 29.8 29.8 30.8 30.9 l.q. 30.6 30.95 30.78 31.2 31.25 Median 31.3 31.25 31.95 31.8 32.35 u.q. 31.7 31.73 32.63 32.33 32.88 Maximum 32.7 32.9 33.4 34.1 33.8 Tencel C Minimum 29.8 29.8 29.8 30.6 30.8 l.q. 30.73 30.85 30.75 31.25 30.98 Median 31.1 31.15 32 31.75 32.1 u.q. 31.63 31.48 32.23 32.33 32.4 Maximum 31.8 31.8 32.7 32.8 33.2
Gravimetric Examination

(122) The weight of the medical compression stockings has been determined before and after the treadmill treatment. The measurements have been carried out in closed plastic bags (to avoid moisture loss by evaporation) and by means of highly precise laboratory scales.

(123) In FIG. 9, a correlation between the moisture increase of the Tencel C2 stockings (weight) and conventional cotton stockings after physical stress (treadmill) is shown. There is a clear deviation from the diagonal (weight tencel=weight cotton) suggesting that Tencel C absorbes more moisture.