Lyocell filament denim

Abstract

The invention relates to a denim fabric for use in clothing (1). The fabric is made of weft yarns (4) and warp yarns (6). At least one of the warp yarns and the weft yarns comprises or consists of lyocell filaments (8). The resulting material combines high mechanical strength against wear and tear with excellent softness, smoothness and gloss. Furthermore, the denim according to the invention is bleachable. In addition to existing cotton denim and denim with silk components, the denim according to the invention represents a new class of denim.

Description

[0001] The invention relates to a denim fabric.

[0002] Denim is a fabric that is usually woven from cotton as a warp-faced textile with a twill weave pattern. A very common denim fabric is indigo-dyed denim, where only the warp yarns are dyed. The weft yarns remain white. However, the core of the warp yarns remains undyed, which results in the characteristic fading properties of denim. Due to the warp-faced weave, the outside of the denim is colored (usually indigo) and the inside is white (uncolored).

[0003] Although cotton is a highly resistant fiber which can therefore undergo even aggressive finishing, its mechanical properties and its tactile qualities are not ideal, thereby imparting only a small range of properties to denim.

[0004] Therefore, attempts have been made in the past to improve the quality of denim by at least partially replacing cotton with silk and / or rayon and filaments. One such example is the addition of elastane to increase elasticity. Typically up to 3% of elastane can be added; more elastane is detrimental to longevity.

[0005] Man-made continuous filament yarns are widely used in the textile industry to produce fabrics with distinctive characteristics compared to fabrics produced from yarns made from cut fibers. Continuous filament yarns are yarns in which all the fibers are continuous over any length of the yarn. Continuous filament yarns will typically consist of 20 to 200 or more individual fibers, which are all parallel to each other and to the axis of the yarn when produced. The yarn is produced by extruding a solution or melt of a polymer or polymer derivative and then winding the produced yarn onto a bobbin or wire frame, or by centrifugal winding to form a cake.

[0006] Synthetic polymer continuous filament yarns are common. For example, nylon, polyester, and polypropylene continuous filament yarns are used in a variety of fabrics. They are produced by melt spinning a molten polymer through a spinneret having a number of holes corresponding to the number of fibers desired in the yarn being produced. After the molten polymer begins to solidify, the yarn can be stretched to orient the polymer molecules and improve the properties of the yarn.

[0007] Continuous filament yarns can also be spun from cellulose derivatives such as cellulose diacetate and cellulose triacetate by dry spinning. The polymer is dissolved in a suitable solvent and then extruded through a spinneret. The solvent evaporates quickly after extrusion, causing the polymer to precipitate in the form of yarn. The newly produced yarn can be stretched to orient the polymer molecules.

[0008] Continuous filament yarn can be further produced from cellulose using the viscose process. Cellulose is converted to cellulose xanthate by reaction with sodium hydroxide and carbon disulfide, which is then dissolved in a sodium hydroxide solution. The cellulose solution, commonly known as viscose, is extruded through a spinneret into an acid bath. Neutralization of the sodium hydroxide causes the cellulose to precipitate. At the same time, the cellulose xanthate is converted back to cellulose by reaction with the acid. The newly formed fibers are stretched to orient the cellulose molecules, washed to remove the reactants from the fibers, then dried and wound onto bobbins. In early versions of this process, a centrifugal winder - the TophamBox - was used to collect the wet yarn into a cake. The yarn cake was then dried in an oven and then wound onto bobbins.

[0009] Continuous filament cellulose yarn is also produced using the cupro process. Cellulose is dissolved in a cupro hydroxide solution. The resulting solution is extruded into a water bath where the cupro hydroxide is diluted and the cellulose precipitates. The resulting yarn is washed, dried and wound onto bobbins.

[0010] Cellulosic continuous filament yarns produced by the viscose process or the cuprammonium process can be woven into fabrics. The fabrics produced are used in a variety of applications, including linings for women's and men's clothing.

[0011] Fabrics made from continuous filament cellulosic yarns excel in moisture management for increased wearer comfort. They do not build up static electricity as easily as fabrics made from continuous filament synthetic yarns.

[0012] Fabrics made from currently available continuous filament cellulose yarns generally have poor physical properties. Dry strength and tear strength are poor compared to fabrics made from synthetic polymers such as polyester. Wet strength is much lower than dry strength due to the interaction between cellulose and water. Abrasion resistance is low. The interaction with water also softens the cellulose, causing fabrics made from the yarn to be unstable when wetted. This is particularly problematic when these materials are washed in a domestic washing machine.

[0013] Due to these deficiencies, products originally made using continuous filament cellulose yarns are now primarily made from synthetic polymer continuous filament yarns, such as polyester and nylon.

[0014] However, there are problems with synthetic yarns. Fabrics made using them do not have the moisture handling capabilities of fabrics made from cellulose yarns. Synthetic fabrics can generate static electricity. Some people find that fabrics made from synthetic yarns are much less comfortable to wear than silk. In addition, fabrics made from synthetic yarns do not wash well and need to be dry cleaned to avoid excessive shrinkage.

[0015] With regard to the available denim fabrics, there is therefore a need to create a washable and soft denim fabric having high hygroscopicity, which can be finished with a wide variety of even aggressive agents.

[0016] This object is achieved by a denim fabric made of weft yarns and warp yarns, wherein at least one of the weft yarns and the warp yarns comprises or consists of lyocell filaments.

[0017] Such lyocell filament denim is subjected to aggressive finishing agents. Furthermore, the denim comprising or consisting of lyocell filament yarn is even softer and smoother than denim with a silk component. Thus, the lyocell filament denim of the present invention creates a new class of fabrics with a completely new set of properties. This is all the more surprising because from the properties of cotton yarn it would have been expected that denim comprising or consisting of lyocell staple fibers would replace cotton denim, if at all.

[0018] Lyocell is the general name given to a class of cellulosic man-made fibres produced by the direct dissolution process. The Lyocell process is described, for example, in US 4,246,221 and WO 93 / 19230.

[0019] A slurry of wood pulp is formed with a solution of amine oxide in water. The water is then evaporated from the slurry in a thin film evaporator vessel. When the water content drops below a certain level, the cellulose forms a solution in the amine oxide. The resulting viscous liquid solidifies into a glassy solid below about 70°C. If kept above this temperature, it can be pumped through a spinneret to form filaments, which are then immediately immersed in water, where dilution of the amine oxide causes the cellulose to precipitate.

[0020] The spinneret used to extrude the amine oxide cellulose solution has a number of holes corresponding to the number of filaments desired in the continuous filament yarn. After extrusion, the newly formed yarn is washed with countercurrent water to remove the amine oxide. This washing can be done on a self-advancing frame where water is introduced to wash the fibers. A finish can be applied to aid further processing, and the yarn is dried. The washed and dried yarn is wound onto a bobbin.

[0021] In the Lyocell process, cellulose in the form of wood pulp is the only raw material used. The wood pulp used comes from sustainably managed forests. The filaments produced are 100% cellulose and are the only product from the process. The amine oxide solvent is recovered from the wash water and reused to produce further filaments. This recovery rate can be as high as 99.7%. As a result, the environmental impact of the Lyocell process is very low. The process releases virtually no gaseous or liquid emissions and the filaments produced are solvent-free.

[0022] In contrast, the viscose process uses carbon disulfide, sodium hydroxide, sulfuric acid, and zinc sulfate. Unless special care is taken, hydrogen sulfide and carbon disulfide can be released from the process. Sodium sulfate is produced as a by-product of the process.

[0023] The present invention can be further improved by the following additional features, which can be combined independently of each other and each exhibit different technical effects.

[0024] The continuous filament lyocell yarn used to produce the products of the present invention may be in the untwisted state as produced, or may be twisted by rewinding. It may be a doubled yarn. It may be combined with another continuous filament yarn or a staple yarn by twisting the yarns together or by using, for example, air jet interlacing.

[0025] The lyocell denim according to the invention preferably contains at least 10% of lyocell filaments in at least one of the weft and the warp. Preferably, the minimum total content of lyocell filaments in the lyocell denim is higher than 10%. Considering the soft structure of the yarn containing or consisting of lyocell filaments, a content of more than 10% can significantly improve the feel of the fabric. Therefore, a total content of at least 10% of lyocell already produces a tactile impact, regardless of whether the lyocell filaments are used for warp or weft. In addition, blends of at least 10% of lyocell filaments with other synthetic or cellulosic filaments, such as viscose or cupro filaments, or with viscose or cupro staple fibers, or wool and cotton, increase the strength of the yarn. Finally, blends of at least 10% of lyocell filaments and synthetic fibers significantly improve the breathability and moisture management of the fabric.

[0026] The dyeing and finishing process of the denim process is very harsh, as it combines strong chemical impacts with strong mechanical treatments of the fabric. Therefore, viscose and silk fibers cannot be used in these processes, as they cannot withstand the process. This is why in another embodiment, viscose and / or cupro staple fibers and filaments can only be used in combination with lyocell filaments in very small parts, or even need to be replaced by lyocell filaments.

[0027] According to another preferred embodiment, the denim is bleached. Compared to denim with silk content, for example, lyocell filaments can be treated with aggressive finishing agents, such as chlorine bleach. Furthermore, it has surprisingly been found that such aggressive finishing agents, in particular chlorine bleach, soften the yarn comprising or consisting of lyocell filaments, thus actually improving the softness and smoothness of the lyocell denim.

[0028] The lyocell denim according to the invention has superior softness. An indirect measure of softness is the TS7 value determined by the TSA tissue softness analyzer. According to one embodiment, the denim according to the invention has a TS7 value of no more than 8 in the fixed state, i.e. before garment washing. Furthermore, the denim of the invention after garment washing and even after bleaching can obtain a TS7 value of no more than 6.

[0029] TSA also produces another parameter - TS750 value, which is related to smoothness. Preferably, the denim according to the present invention in the fixed state has a TS750 value of no more than 120. After the garment is washed and / or bleached, a TS750 value of no more than 120 can also be maintained.

[0030] The denim according to the present invention having the above-mentioned smoothness and / or softness has a higher smoothness and / or softness than cotton denim, and even a softness and / or smoothness superior to that of a denim portion having silk yarn.

[0031] Preferably, the denim also has high mechanical resilience. For example, in the fixed state, i.e. before garment washing, in the Martindale abrasion test, the denim can score at least 15,000 cycles to hole formation. In another embodiment, the denim can score 8,000 cycles to hole formation after garment washing and / or after bleaching. This shows that the denim according to the present invention can be used for textiles that are subjected to strong wear.

[0032] In another embodiment, the outer surface of the denim, i.e., the warp side of the denim, has a pilling rating of no worse than 5 in the fixed state, i.e., before garment washing, and / or has a pilling rating of no worse than 5 after garment washing, and has a pilling rating of no worse than 5 after bleaching.

[0033] The yarn strength of the denim in the fixed state (conditioned, 20 / 65) is preferably at least 20 cN / tex, more preferably at least 25 cN / tex and / or at least 10 cN / tex, preferably at least 20 cN / tex in the wet state in at least one direction (of the warp and / or weft) in which the lyocell filament yarn is used. After washing of the garment, the yarn strength in at least one direction (of the warp and / or weft) in which the lyocell filament yarn is used is preferably at least 4.5 cN / tex, more preferably at least 5 cN / tex in the conditioned state 20 / 65, and preferably at least 3, preferably at least 7 cN / tex in the wet state. After bleaching, the yarn strength in at least one direction (of the warp and / or weft) in which the lyocell filament yarn is used is at least 2 cN / tex, preferably at least 3 cN / tex in the conditioned state 20 / 65, and preferably at least 2 cN / tex, more preferably at least 5 cN / tex in the wet state.

[0034] The yarn elongation of the weft and / or warp yarns comprising or consisting of lyocell filaments may be at least 4% after fixing and / or at least 2% after garment washing and / or at least 1% after bleaching.

[0035] The hairiness of the denim according to the present invention may have a grade of no worse than 4 after garment washing and a grade of no worse than 3 on the warp side, ie the outer surface of the denim, after bleaching.

[0036] The fiber twist of the denim fabric according to the present invention may have a grade of no worse than 4 before and / or after fixing, and / or a grade of no worse than 4.5 after the garments have been washed, and / or a grade of no worse than 4.5 after bleaching.

[0037] All the above parameters qualify the denim according to the invention as a fabric suitable for an extremely wide range of denim applications. The combination of softness, smoothness and gloss on the one hand, and the set of mechanical properties such as abrasion resistance and yarn strength on the other hand, provides a unique combination for denim.

[0038] The specific hand determined by a fabric hand meter in the direction of the warp yarns and / or weft yarns containing or consisting of lyocell filaments is at least 4 mN·m after the garment is washed. 2 ·g -1 and / or after bleaching is at least 3 mN·m 2 ·g -1 These values ​​indicate the high smoothness and softness of the denim fabric of the present invention.

[0039] The gloss of the warp and / or weft yarns comprising and preferably consisting of lyocell filaments may be at least 20% reflectivity. This allows the production of denim with a high gloss.

[0040] The invention also relates to a garment, in particular a garment for women and / or men, such as a jacket, a coat, a blouse, a dress and trousers, in which a lyocell denim fabric as described above is used.

[0041] Furthermore, the invention relates to the use of yarn comprising or consisting of lyocell filaments in denim fabrics.

[0042] The moisture regain of the fabric measured according to ASTM D 190g is an indicator of the comfort level. Mulberry silk has a moisture regain of 11% and provides one of the best comfort levels of all fabrics in terms of moisture regain. The lyocell filament yarn and / or denim fabric according to the invention preferably has a moisture regain of at least 13%, which results in similar or even better comfort than mulberry silk.

[0043] The lyocell filament denim fabric of the present invention may be any style, weave or finish suitable for production with continuous filament yarn and producing a denim fabric comparable to cotton. Lyocell filament denim fabric may be constructed as plain weave, twill, satin, weft satin, basket weave, ribbed and fancy weave fabrics. The fabric may be woven using any loom suitable for weaving continuous filament yarn, including shuttle looms, rapier looms, projectile looms or ribbon looms.

[0044] Lyocell denim fabric produced using continuous filament lyocell yarn can have similar aesthetics and appearance to fabrics produced from continuous filament viscose yarn, but with significantly better physical properties. The higher strength and modulus of the yarn results in improved fabric breaking strength, tear strength, abrasion resistance and stability. The properties of the wet fabric are also superior.

[0045] Figure 1 Schematically shown is a garment 1, which is at least partially made of lyocell denim 2. The garment 1 is schematically shown as trousers only, but is not limited thereto. The garment 1 may also be a dress, a suit, a costume, a jacket, a shirt or a blouse or parts of these garments and / or parts on these garments.

[0046] The lyocell denim fabric 2 includes a weft yarn 4 and a warp yarn 6 which may be twisted. At least one of the weft yarn 4 and the warp yarn 6 includes or consists of lyocell filaments.

[0047] Examples of warp and / or weft yarns 6, 4 having at least one lyocell filament 8 are Figure 2 Shown in. Figure 3 A twisted warp and / or weft three-ply yarn 4,6 with at least one lyocell filament is shown. At least one of the filaments 8 is a lyocell filament. The twisted filaments may have any number of filaments and any twist direction. Preferably, at least 50% of the yarn 4,6 consists of lyocell filaments 8.

[0048] In order to investigate the qualities of lyocell filament denim according to the invention over silk, samples were prepared and compared with comparative examples made of denim consisting of or containing cotton. For denim, the bottom is the benchmark with which any denim using yarns from man-made fibers or filaments must compete on the market. The lyocell filament denim samples according to the invention were compared with the comparative examples using the following tests:

[0049] test

[0050] - Martindale abrasion test according to DIN EN ISO 12947-2;

[0051] - Martindale pilling test according to DIN EN ISO 12945-2;

[0052] - Washing shrinkage according to DIN EN ISO 5077; the absolute values ​​of the shrinkage in both sample directions are taken as the sum

[0053] is the combined shrinkage ratio;

[0054] - rubbing fastness according to ISO 105 X12;

[0055] - AATCC durable press rating according to DIN EN ISO 15487;

[0056] - Air permeability according to DIN EN ISO 9237;

[0057] - Color fastness according to DIN EN 20105-A02;

[0058] - yarn strength of warp and weft yarns according to DIN EN ISO 2062,

[0059] - Moisture regain according to ASTM D 1909,

[0060] - Gloss of yarn measured at an angle of 45° according to EN 14086-01 / 2003,

[0061] - The gloss of the fabric was measured at an angle of 75° according to TAPPI T480.

[0062] What is important to the end consumer is how the fabric changes appearance after washing. To assess this, surface appearance hairiness, pilling and fiber splicing are determined according to the following tests:

[0063] The test was carried out by 3 persons in a dark room with a Variolux colour evaluation cabinet "Multilight Datacolor" and a fluorescent lamp D65. The lamp was mounted on the upper side of the cabinet.

[0064] To test the hairiness, the tester holds the test sample at an angle and ranks the hairiness as best (grade 5, no hairiness) and worst (grade 1, long protruding fibers up to 2 mm).

[0065] The number of pilling (nubs on the fabric surface) is assessed using reference samples (knitted fabrics K3 or K2, or woven fabrics W3 or W2) similar to DIN EN ISO 12 945-2 according to EMPA standard SN 198525. The reference samples are graded from 1 to 5 and compared with the test samples. Grade 5 corresponds to denim with no pilling. The more pilling there is on the surface of the test sample, the worse the grade obtained. The worst grade is 1.

[0066] If the fibrils are transferred to the surface by scouring, fiber twisting occurs. If the scour sample is analyzed under a microscope, the fibrils are brush-like with protruding ends. To measure the fiber twisting, a microscope SM with an X10 eyepiece from UHL Technische Mikroskope is used. A rating of 5 is given for a smooth surface showing no fibrils. A rating of 1 is given if there is a dense fuzz of long, curved fiber ends that are partially detached from the surface.

[0067] In all three tests, intermediate grades were possible.

[0068] If the samples were subjected to washing, the washing was carried out in accordance with DIN EN ISO 6330. Tests for evaluating parameters in the dry state were carried out in conditioning state 65 / 20. All standards mentioned in this application are incorporated in their entirety by reference.

[0069] The samples were prepared as follows. The weight was determined according to DIN EN 12127. The yarn count in the weft and warp was determined according to DIN 53820-3.

[0070] An overview of the materials and properties of samples 1, 2, 3, 5 and 6 (relating to lyocell filament denim) and comparative samples 4 and 7 (relating to reference cotton) relative to their test samples 1, 2, 3, 5 and 6 is given in Table 1.

[0071] Samples 1, 2, 3, 5 and 6, and comparative samples 4 and 7

[0072] Sample 1 is denim 1857-A, where the warp yarns consist of bright untwisted yarns with dtex 500f300 made from lyocell filaments. The weft yarns consist of cotton yarns with a lycra T400 core. This results in a fabric with 70% lyocell yarn, 20% cotton, 8% elastic polyester and 2% elastane. The weight of the denim is 343 g·m -2 .

[0073] Sample 2 is denim 978-150-814 containing 33% lyocell filaments and 67% cotton. Weight is 143 g·m -2 . The warp yarn is made of cotton ring yarn Z. The weft yarn is made of dtex 150f90 yarn.

[0074] Sample 3 is denim 1857-8, where the warp yarns consist of bright untwisted yarns of 100% lyocell filaments with a linear mass density of dtex 500f300. The weft yarns are 100% polyester yarns with an ELAS core of Lycra T400. This results in a denim with a density of 356 g·m -2 and 70% lyocell, 28% polyester and 2% elastane.

[0075] Sample 6 is denim 1857-CNF containing 70% lyocell, 28% cotton and 2% elastane. The warp yarns consist of 556 dtex lyocell filament yarns. The weft yarns are made of matte cotton ring yarn with an elastane core.

[0076] Sample 5 is a denim fabric 978-100-814 of 45% lyocell and 55% cotton. The warp yarns consist of cotton ring yarn Z and the weft yarns consist of lyocell yarn dtex 100f 60. The material weight is 128 g·m -2 .

[0077] Comparative sample 4 is denim 840-814 made of 59% cotton and 41% silk, in which the warp yarn is made of cotton and the weft yarn is made of silk. This results in a denim with high softness and smoothness, and a glossy finish. The weight is 171 g·m -2 .

[0078] Comparative Sample 7 is denim 435-4047 composed of 98% cotton and 2% elastane. The warp yarn is made of cotton ring yarn, and the filling yarn is made of cotton ring yarn with a matte elastane core.

[0079] Samples 1 to 3 and 6 were benchmarked against Comparative Sample 7 for wash fastness, resistance to finishes, smoothness, softness, and gloss.

[0080] Samples 2 and 5 were benchmarked against Comparative Sample 4 to compare lyocell warp denim and cotton warp denim since both had the same weft material.

[0081] The samples and comparative samples were subjected to the following conditioning steps. After each conditioning step, the samples and comparative examples were tested.

[0082] fixed

[0083] First, samples 1, 3, and 4 and comparative sample 7 were fixed at 195° C. for 45 seconds and then tested. The results of these tests are summarized in Table 2.

[0084] Clothing washing

[0085] Samples 1, 2, 3, 5, 6 and Comparative Samples 4 and 7 were garment washed as follows.

[0086] Fibrillation was performed with 2.5 kg fabric and 150 I liquor at a liquor ratio of 1 :60 at 22 rpm at 60°C for 20 minutes using maximum heating rate in 2 g / l Persoftal L, 2 g / l soda and 0.3 g / l concentrated Lavasperse KDS.

[0087] Then, the liquid was cooled to 40°C and rinsed cold with 300I, then rinsed warm with 150I at 50°C for 5 minutes, wherein heating was started at the beginning of the rinse, and then rinsed cold with 300I again.

[0088] After rinsing, enzyme washing was performed again with 2.5 kg fabric and 150 1 liquor at a liquor ratio of 1:60 at 22 rpm. The liquor contained 2 g / l Persoftal L, 3 g / l Peristal E and 0.3 g / l concentrated Lavasperse KDS. The pH was controlled between pH 4.5-5. After heating to 55°C at the maximum heating rate, the pH was checked. At pH 5.5, 2 g / l Perizym 2000 was added, followed by the enzyme, and the material was then treated at 55°C for 55 minutes. The material was then heated to 85°C and treated at 85°C for 15 minutes.

[0089] The liquid was then drained and the material was rinsed as follows: First, a cold rinse with 300 I, then a warm rinse with 150 I, where the heating started from the filling of the second rinse step. The warm rinse was continued at 50°C for 5 minutes. Finally, a cold rinse with 300 I was performed.

[0090] After heating at maximum rate, regeneration was carried out at 40°C for 15 minutes using 2% Tubingal RGH, 1% Tubingal RWM, 3 g / l Peristal E in a liquor ratio of 1:60 as above.

[0091] The liquid was then drained, and the material was drum dried at 80°C for 50 minutes, and then allowed to cool for 20 minutes.

[0092] The samples and comparative examples were then tested as described above. The results are summarized in Table 3.

[0093] Strong bleaching

[0094] For the final series of tests, bleaching of samples 1, 2, 3, 5, 6 and comparative samples 4 and 7 was performed as follows:

[0095] Pre-scouring was carried out with 2.5 kg of fabric and 150 I of liquor at a liquor ratio of 1:60. For pre-washing, 2 g / l Persoftal L, 0.5 g / l NaOH 100% (1 g / l NaOH 50%) and 0.2 g / l concentrated Lava Sperse KDS were used. Pre-scouring was carried out at 60° C. for 20 minutes (maximum heating rate).

[0096] Afterwards, it was cooled to 40°C and then cold rinsed with 300I.

[0097] Cold bleaching was again carried out with 2.5 kg of fabric and 150 1 of liquor containing 2 g / l soda and 0.4 g / l concentrated Lava Sperse KDS at a liquor ratio of 1:60 and 15 rpm for 30 minutes. The pH value was checked and maintained at pH 10. As bleaching agent, 3 g / l of active chlorine (20 ml / l of bleaching lye solution (150 g / l)) was used.

[0098] The liquid was then drained and the material rinsed with 300I cold and 150I warm as above.

[0099] Dechlorination was carried out at 40°C with 2 ml / l 50% hydrogen peroxide for 30 minutes.

[0100] This was followed by a cold rinse with 300I, a warm rinse with 150I at 50°C for 5 minutes (heating from the start of the rinse), and a cold rinse with 300I.

[0101] The enzyme wash is then carried out as follows, followed by rinsing and regeneration and drum drying:

[0102] After rinsing, enzyme washing was again carried out with 2.5 kg of fabric and 150 I of liquor at a liquor ratio of 1:60 at 22 rpm. The liquor contained 2 g / l of Persoftal L, 3 g / l of Peristal E and 0.3 g / l of concentrated Lavasperse KDS. The pH value was kept between pH 4.5-5. After heating to 55°C at the maximum heating rate, the pH value was checked. The material was then treated at 55°C for 55 minutes before the enzyme was added. The material was then heated to 85°C and treated at 85°C for 15 minutes.

[0103] The liquid was then drained and the material rinsed as follows: First, a cold rinse with 300 I, then a warm rinse with 150 I, where the heating started from the filling of the second rinse step. The warm rinse was continued at 50°C for 5 minutes. Finally, a cold rinse with 300 I was performed.

[0104] After heating at maximum rate, regeneration was carried out at 40°C for 15 minutes using 2% Tubingal RGH, 1% Tubingal RWM, 3 g / l Peristal E in a liquor ratio of 1:60 as above.

[0105] The samples and comparative examples were then tested as above. The results of these tests are summarized in Table 4.

[0106] result

[0107] From Tables 1 to 4, it is apparent that the wet and dry tenacities of the lyocell filaments according to the present invention are significantly higher than the tenacity of the silk denim of Comparative Sample 4, comparing Samples 2 and 5 with Comparative Sample 4. In addition, compared to the non-lyocell filament cotton denim exemplified in Comparative Samples 4 and 7, the dry and wet yarn strength and yarn elongation of all the lyocell filament denim are better.

[0108] Furthermore, it has been demonstrated that lyocell filament denim (like cotton) withstands even aggressive finishing agents such as chlorine bleach which damage the silk.

[0109] With regard to pilling, hairiness and fiber splicing, Lyocell filament denim is at least comparable to (if not a grade better than) cotton denim before and after garment washing and bleaching. In addition, Lyocell filaments do not undergo the fibrillation that occurs with cotton after washing.

[0110] While cotton still has a high yarn strength before and after garment washing and after bleaching, the yarn strength of the lyocell filament denim of the present invention is still very good. In particular, the yarn strength of lyocell filament denim is paired with a gloss, softness and smoothness that are superior to cotton denim and can only be achieved by denim containing silk. However, the latter cannot be bleached.

[0111] This is evident from the following testing where softness and smoothness were analyzed using a Tissue Software Analyzer (TSA Test), a Handleometer and a Hand Panel.

[0112] TSA Testing

[0113] TSA testing was performed to verify that the tactile qualities of the lyocell filament denim fabrics of Samples 1 to 5 were at least equal to the tactile qualities of the silk denim fabric of Comparative Sample 4, if not better.

[0114] The two main tactile qualities that are improved by using silk in denim are softness and smoothness. In order to objectively evaluate these properties, TSA testing is performed.

[0115] The TSA test is described in Schloβer et al., "Griffbeurteilung von Textilien mittelsSchallanalyse", Meilland Textilberichte, 1 / 2102, pp. 43-45, in the emtec publication, Grüner, "A new and objective measuring technique to analyze the softness of tissue" (2012), in the TSA operating instructions and in the avr-Allgemeiner Vliesstoff report 5 / 2015, "Neue und Objektive Messtechnik für Softness-Analyse", pp. 99-101. Originally developed for measuring the softness and smoothness of thin nonwovens (tissue) and nonwovens using sound spectroscopy, it has now been adapted to also evaluate the softness and smoothness of woven fabrics.

[0116] The TSA tests were performed using the TSA Tissue Softness Analyzer device from emtec electronics GmbH, Leipzig, Germany, as well as the software ESM shipped with the TSA. The TSA measures the sound spectrum, which is generated by pressing a star-shaped object with a defined force onto a sample fabric and rotating it. For the test, the fabric is clamped around its periphery and is not supported in any other way, in particular relative to the rotating body. In the TSA tests performed here, this software and its evaluation algorithm were not used. Instead, the sound pressure measured by the TSA at 7 kHz (TS7) was used as an objective indirect measure of softness, and the sound pressure at 750 Hz (TS750) in the sound spectrum measured by the TSA was used as an objective indirect measure of smoothness. The TSA automatically gives the sound pressure as dB·V 2 rms, where V is the rotational speed of the rotor. Using these values ​​directly avoids any problems caused by the EMS algorithm being developed for thin nonwovens rather than woven fabrics. For each sample, TSA testing was performed with a total of four probes.

[0117] For testing, a fabric sample having a diameter of 11 cm was clamped as required by the TSA equipment and tested without tension.

[0118] Lower TS7 values ​​indicate higher softness, and lower TS750 values ​​indicate higher smoothness values.

[0119] Fabric Handle Tester Test

[0120] Handlemeter testing was performed using Handlemeter testing equipment from Thwing-Albert Instruments, West Berlin, NJ, USA. Sample size was 10 cm x 10 cm. A 1 / 4 inch slot was used for the 1,000 g rod and stainless steel surface. Testing was performed on samples in a 65 / 20 conditioning state.

[0121] In the TSA and Handleometer tests, only the right outer side of the denim was considered. The results are summarized in Table 5.

[0122] As a result, the fabric hand meter produces two force measurements, which are assigned to two orthogonal directions: the machine direction MD, which corresponds to the warp direction in the selected setup, and the cross direction CD, which corresponds to the weft direction in the selected setup. These forces are related to the stiffness and smoothness of the measured surface. The forces are normalized by the volume weight of the test sample and are expressed in mN·m 2 ·g -1 The specific feel of the meter.

[0123] As can be seen from Table 5, the cotton denim of Comparative Sample 7 is inferior in smoothness to Samples 1, 3, and 6. Although these lyocell filament denims are stiffer than the cotton denim of Comparative Sample 7 before garment washing, they are softer than Comparative Sample 7 after garment washing.

[0124] The silk denim of Comparative Sample 4 was not as smooth as that of Samples 2 and 5, in which Lyocell endless filaments were used in the weft yarn instead of silk. In addition, before finishing, the Lyocell filament denim was softer than the silk denim of Comparative Sample 4. After finishing, the softness of Samples 2 and 5 corresponded to the softness of Comparative Sample 4.

[0125] Therefore, it can be concluded from the TSA and Handlemeter tests that the lyocell filament denim according to the present invention does combine superior softness and smoothness with the ability to be bleached. In addition, the lyocell filament denim has high tenacity. This combination creates a new class of denim fabrics.

[0126] Feel Group

[0127] In order to verify the results from the TSA and Handlemeter tests, a Hand Panel was used. The panel consisted of ten independent textile experts. The task of the panel was to objectively evaluate the touch of the lyocell filament denim fabric according to the invention compared to the comparative examples.

[0128] In order to obtain reproducible results independent of panel members, the hand feel panel was run as follows:

[0129] All samples to be tested by the Hand Panel were provided in 17cm x 17cm format and were glued to cardboard using double-sided adhesive approximately 2cm from the upper edge border. The fabric sample was glued to the cardboard with the right warp side facing forward. It was oriented so that the weft direction was horizontal and the warp direction was vertical.

[0130] To evaluate the hand, a semantic grid is defined by providing pairs of contrasting descriptive adjectives used to describe the hand. The terms corresponding to the contrasting pairs of the desired qualities are considered "best". Thus, for fabrics where smoothness is a desired quality, a higher rating will be given compared to the relative quality - roughness. The ratings range from 1 (worst) to 10 (best).

[0131] Furthermore, it is specified how the assessment should be carried out, for example, by specifying the movement of the hand on the fabric to assess smoothness.

[0132] Reference sample fabrics of the same construction type (weave) with construction parameters as close as possible and at the same time with significant hand differences are predefined for each word pair. For example, a fabric considered to have a reference roughness and a fabric considered to have a reference smoothness are provided to the hand panel.

[0133] The ratings for the individual reference fabrics are fixed at 2 and 8, respectively. Thus, the poorer quality reference fabric of a word pair is defined as rating 2, and the better quality reference fabric of a word pair is defined as rating 8. Assigning ratings of 2 and 8, respectively, allows for the ratings to be expanded during testing if materials of better or worse quality than the two reference materials are encountered. Thus, in the roughness-smoothness rating, the reference material for roughness is defined as having a rating of 2, and the reference material for smoothness is defined as having a rating of 8. All other materials subsequently tested must be graded by the hand panel relative to the reference materials.

[0134] For testing the denim sample, the following semantic grid was used:

[0135] - For evaluation of touch: cotton-like (rating 2) and silk-like (rating 8);

[0136] - used to assess consistency: loose (grade 2) and compact (grade 8);

[0137] - For evaluation of wearing feeling: stiffness (grade 2) and flexibility (grade 8);

[0138] - For evaluating surfaces: rough (rating 2); and smooth (rating 8).

[0139] As a reference material for level 2, comparative sample 7 was used. As a reference material for level 8, comparative sample 4 was used for all word pairs.

[0140] The group was instructed to assess the above characteristics as follows:

[0141] - To evaluate the touch, the sample card must be picked up with one hand with the fabric turned down. The hand panelists are then asked to hold the fabric to be treated in such a way that the right side (warp side) of the denim is in contact with the palm of their hand.

[0142] -Consistency describes whether the fabric gives the feel of having a looser or more dense weave. The sample cards were placed on a table in front of each hand panelist. The fabric was picked up with both hands and kneaded and stretched.

[0143] - Determine the wearing feel by lifting the sample card again with one hand and letting the fabric turn down. Then shake the sample card to evaluate the falling pattern of the fabric. Then, grab the fabric with your free hand for further evaluation.

[0144] -Finally, to judge the surface feel, lay the cardboard on a table. Evaluate the warp surface by moving your palm in the warp direction and in the weft direction.

[0145] For each sample fabric and each word pair, the average of the individual hand panelists' evaluations and the deviation from the average were calculated. This average was used to evaluate and rank the samples. A summary of the results is given in Table 6.

[0146] luster

[0147] The gloss of individual yarns that can be used in the lyocell denim according to the invention was measured using a gloss meter. The results of the % reflectance of the incident light are given in Table 7. To measure the gloss of the yarns, they were wound on a pleated cardboard and the gloss was measured at 45° according to EN 14086-01 / 2003. The gloss of the fabric was determined at 75° according to TAPPI T480. The viewing angle was oriented along the yarn direction to measure the yarn gloss.

[0148] Samples 1, 3, 7, 8 are yarns made from 100% high gloss lyocell filaments having the linear mass densities shown in Table 7.

[0149] Samples 2, 4, 5, and 6 are comparative samples.

[0150] Sample 3 has better gloss than all other samples and the comparative example. The gloss of samples 1 and 6 is comparable to the denim of comparative sample 7 which contains silk.

[0151] The luster of the yarns useful for denim fabrics is at least 20% reflectance.

[0152] It can therefore be concluded that the lyocell filament denim fabric of the present invention also combines excellent gloss and resistance to aggressive finishing agents.

[0153] Table 1 - Untreated samples and comparative examples

[0154]

[0155]

[0156] Table 2 - Samples and Comparative Examples after Fixation

[0157] Sample 3 Sample 1 Sample 5 Sample 2 Comparison sample 4 Comparison sample 7 Sample 6 Yarn strength-warp cN / tex Adjustment status 20 / 65 26.1 27.6 14.5 14.6 15.6 15.4 25.3 wet 20.9 19.5 16.2 15.9 16 16.7 19.9 Yarn strength-weft yarn cN / tex Adjustment status 20 / 65 22.9 12.4 27.5 32.8 25.5 13.8 12.8 wet 24.1 15.7 13 27.8 18.7 16.7 14.9 Yarn elongation-warp % Adjustment status 20 / 65 8.4 7.9 4.4 5 5.2 5.9 7.5 wet 9.2 10.1 7.7 7.6 7.3 6.6 9.5 Yarn elongation-weft % Adjustment status 20 / 65 31.3 26.1 7.9 9.8 11.5 6.8 6.2 wet 34 34.9 9.3 11.5 13.5 7.7 7.4 Martindale abrasion test Number of cycles - sample not damaged 41250 40000 17000 16000 28750 27500 Cycles to pore formation 51250 48750 19000 18000 36250 32500 Surface appearance after wash cycle - front - original Blue filament Blue filament Blue yarn Blue yarn Blue yarn Blue yarn Blue filament Hairiness 2 2 2 2 4 2.5 4.5 Pilling 5 3 4 3.5 5 3.5 5 Fiber splicing 2.5 3 2 2 2.5 2.5 2.5 Surface appearance after wash cycle - back side - original Black yarn White yarn White filament White filament White filament White yarn White yarn Hairiness 1 1 2.5 3 3 2 1.5 Pilling 3.5 4 4 4 5 3 4 Fiber splicing 3.5 2 2.5 2.5 2 3 2.5

[0158] Table 3 - Samples and Comparative Examples of Clothing After Washing

[0159] Sample 3 Sample 1 Sample 5 Sample 2 Comparative Example 1 Comparative Example 2 Sample 4 Yarn strength-warp cN / tex Adjustment status 20 / 65 5.5 5.1 8.1 5.5 4.5 11.8 4.4 wet 10.3 7.3 9 9 7.5 17 7.9 Yarn strength-weft yarn cN / tex Adjustment status 20 / 65 19.9 8.2 4.7 7.3 19.6 10.2 8.4 wet 23.6 10.4 3.9 5.8 15.5 15.3 11.8 Yarn elongation-warp % Adjustment status 20 / 65 1.6 2.2 4.2 2.7 2.2 4.5 1.6 wet 5.3 4.3 6.9 6.8 5.1 8.6 4.4 Yarn elongation-weft % Adjustment status 20 / 65 25.4 27.5 2.4 2.1 9.4 5.4 5 wet 37.7 32.6 2.9 2.9 13 12.2 10.2 Martindale abrasion test Number of cycles - sample not damaged 6500 6500 11000 Cycles to pore formation 8500 9500 13000 Surface appearance after wash cycle - front side - original Blue filament Blue filament Blue yarn Blue yarn Blue yarn Blue yarn Blue filament Hairiness 3.5 3 3 3 2.5 2.5 2.5 Pilling 4 4 4 3.5 3 4 5 Fiber splicing 1 1 3 2.5 2 1.5 1 Surface appearance after wash cycle - back side - original Black yarn White yarn White filament White filament White filament White yarn White yarn Hairiness 1 2.5 4 4 2.5 3 3 Pilling 3 4 4.5 5 2 4 5 Fiber splicing 4.5 2 1.5 1.5 1 3 2.5

[0160] Table 4 - Samples and Comparative Examples after Strong Chlorine Bleaching

[0161] Sample 3 Sample 1 Sample 5 Sample 2 Comparative Example 1 Comparative Example 2 Sample 4 Yarn strength-warp cN / tex Adjustment status 20 / 65 4.3 3.4 4.9 4.6 No data 9.8 2.1 wet 6 6.4 8.6 7.8 No data 14.9 5.7 Yarn strength-weft yarn cN / tex Adjustment status 20 / 65 21.7 9.2 2.3 3.6 No data 10 8.8 wet 22.8 10.7 2.2 3.8 No data 14.3 11.3 Yarn elongation-warp % Adjustment status 20 / 65 1.5 1.9 2.8 3 No data 4.2 1.3 wet 3.4 3.8 6.8 6.5 No data 6.3 3.4 Yarn elongation-weft % Adjustment status 20 / 65 27.8 31.4 1 1.5 No data 5.4 7.6 wet 33.2 34 1.7 2.4 No data 11 9.9 Martindale abrasion test Number of cycles - sample not damaged 5000 No data Cycles to pore formation 9500 No data Surface appearance after wash cycle - front - original Blue filament Blue filament Blue yarn Blue yarn Blue yarn Blue yarn Blue filament Hairiness 3 3 3.5 3 Not tested 3 3 Pilling 5 5 4 4 4 5 Fiber splicing 1 1 2 2 1.5 1 Surface appearance after wash cycle - back side - original Black yarn White yarn White filament White filament White filament White yarn White yarn Hairiness 1.5 3 4.5 4 Not tested 3.5 4 Pilling 3 3.5 5 5 5 5 Fiber splicing 4.5 2.5 1.5 1.5 2 2

[0162] Table 5 - TSA and Fabric Handle Tester Test Results

[0163]

[0164] Table 6 - Hand feel panel test

[0165]

[0166]

[0167] Table 7 - Gloss

[0168]

Claims

1. A lyocell denim fabric (2) made from weft yarns (4) and warp yarns (6), wherein at least one of the weft yarns (4) and the warp yarns (6) comprises at least 10% of lyocell filaments (8) or consists of lyocell filaments (8), wherein the minimum total content of lyocell filaments (8) in the lyocell denim fabric (2) is higher than 10%, wherein the denim fabric scores at least 15,000 cycles to hole formation in the Martindale abrasion test in the fixed state and scores 8,000 cycles to hole formation in the Martindale abrasion test after garment washing and / or bleaching.

2. The lyocell denim fabric according to claim 1, wherein the denim fabric is bleached.

3. Lyocell denim according to claim 1 or 2, wherein in the fixed state and / or after garment washing and / or after bleaching, the denim has a TS7 value of not more than 6 in the TSA test.

4. Lyocell denim according to claim 1 or 2, wherein the denim has a TS750 value of not more than 100 in the fixed state and / or after garment washing and / or after bleaching.

5. The lyocell denim according to claim 1 or 2, wherein: The yarn tenacity of the yarn comprising or consisting of lyocell is at least 25 cN / tex after fixing and / or at least 4.5 cN / tex after garment washing and / or at least 2 cN / tex after bleaching.

6. The lyocell denim according to claim 1 or 2, wherein: In the Martindale pilling test, the warp yarn side of the denim fabric has a pilling rating of no worse than 5 in the fixed state and / or no worse than 5 after garment washing and no worse than 5 after bleaching.

7. The lyocell denim fabric according to claim 1 or 2, wherein: The yarn elongation of at least one of the warp yarns and the weft yarns comprising lyocell filaments is at least 4% after fixing, and / or at least 2% after garment washing and / or at least 1% after bleaching.

8. The lyocell denim fabric according to claim 1 or 2, wherein: The hairiness rating of the denim on the warp side is no worse than 4 after garment washing and no worse than 3 after bleaching.

9. The lyocell denim fabric according to claim 1 or 2, wherein the grade of fiber twist of the denim fabric is not worse than 4 before and / or after fixing, and / or not worse than 4.5 after garment washing and / or not worse than 4.5 after bleaching.

10. The lyocell denim fabric according to claim 1 or 2, wherein: The specific hand in the direction of the warp yarns and / or weft yarns composed or composed of the lyocell filaments is at least 4 mN·m after the garment is washed. 2 ·g -1 and / or after bleaching is at least 3 mN·m 2 ·g -1 .

11. The lyocell denim fabric according to claim 1 or 2, wherein: The yarn consisting of or comprising lyocell filaments (8) has a luster with a reflectivity of at least 20%.

12. Garment comprising or consisting of the lyocell denim fabric according to any one of claims 1 to 11.

13. Use of a yarn comprising or consisting of at least 10% of lyocell filaments in a denim fabric, wherein the minimum total content of lyocell filaments in the denim is higher than 10%, wherein the denim scores at least 15,000 cycles to hole formation in the Martindale abrasion test in the fixed state and 8,000 cycles to hole formation in the Martindale abrasion test after the garment has been washed and / or bleached.

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