KR20200057764A - Lyocell filament denim - Google Patents

Abstract

The present invention relates to denim fabrics such as those used for clothes (1). The fabric is made from weft yarn 4 and warp yarn 6. At least one of the warp yarn and weft yarn contains or consists of lyocell filaments 8. The resulting material combines high mechanical strength against wear and tear with good flexibility, smoothness and luster. In addition, the denim according to the present invention can be bleached. Denim according to the present invention represents a new class of denim in comparison with existing cotton denim and denim with silk components.

Description

Lyocell filament denim

The present invention relates to a denim fabric (Denim fabric).

Denim is a warp-faced textile, usually with a twill pattern, and is a woven fabric from cotton. A very common denim fabric is indigo-dyed denim, where only the warp is dyed. The weft remains white. However, the inclined core remains undyed, which causes fading characteristics typical for denim. Due to the warp-faced weaving, the denim is usually colored with indigo on the outside and remains white so as not to be colored on the inside.

As a fiber that has a high resistance to cotton and can thus be treated with a much more aggressive finishing, its mechanical properties and its haptic quality are not ideal, providing only a small range of capabilities to denim. .

Accordingly, in the past, attempts have been made to improve the quality of denim by at least partially replacing cotton with silk and / or man-made fibers and filaments. One such example is the addition of Elastane to increase elasticity. Typically, up to 3% of elastane can be added, more elastane being detrimental to longevity.

Artificial continuous filament yarns are widely used in the textile industry to produce fabrics with unique characteristics compared to fabrics produced from yarns made using staple fibers. A continuous filament yarn is one in which all fibers are continuous over any length of the yarn. Continuous filament yarns will typically consist of 20 to 200 or more individual fibers, which, when produced, are parallel to each other and to the axis of the yarn. The yarn is produced by extruding a solution or melt of a polymer or polymer derivative and then winding the produced yarn on a bobbin or reel, or by forming a cake by centrifugal winding.

Synthetic polymer continuous filament yarns are common. For example, nylon, polyester and polypropylene continuous filament yarns are used in a wide variety of fabrics. This is produced by melt spinning the molten polymer through a spinneret having a number of holes corresponding to the number of fibers required in the produced yarn. After the molten polymer begins to solidify, the yarn can be withdrawn to orient the polymer molecules and improve the properties of the yarn.

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 rapidly after extrusion, and the polymer precipitates in the form of a yarn. The newly produced yarn can be drawn to orient the polymer molecules.

Continuous filament yarns can be further produced from cellulose using the Viscose process. Cellulose is converted to cellulose xanthate by reaction with sodium hydroxide and carbon disulphide, and then dissolved in a solution of sodium hydroxide. Cellulose solution, commonly referred to as viscose, is extruded through a spinneret into an acid bath. Sodium hydroxide neutralizes and precipitates cellulose. At the same time, cellulose xanthate is converted back to cellulose by reaction with an acid. The newly formed fibers are drawn out to orient the cellulose molecules, washed to remove reactants from the fibers, and then dried and wound on a bobbin. In previous versions of this process, the wet yarn was collected as a cake using a centrifugal winder, Topham Box. The yarn cake was then dried in an oven before being wound onto a bobbin.

Continuous filament cellulose yarns are also produced using the cupro process. Cellulose is dissolved in a solution of cuprous ammonium hydroxide. The resulting solution is extruded into a water bath, in which cuprous ammonium hydroxide is diluted and cellulose is precipitated. The resulting yarn is washed, dried and wound on a bobbin.

Cellulose continuous filament yarn produced by the Viscose or Kupro process can be made into a fabric by weaving. The fabrics produced are used for a variety of applications, including lining for women's and men's clothing.

Fabrics made from continuous filament cellulose yarns are good for moisture handling to improve wearer comfort. This does not generate static electricity as easily as fabrics made using continuous filament synthetic yarns.

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. Wear resistance is low. The interaction with water also softens the cellulose, making the fabric made from the yarn unstable when wet. This is a particular problem when washing such materials in household washing machines.

Due to these drawbacks, products originally made using continuous filament cellulose yarns are mainly made by synthetic polymer continuous filament yarns such as polyester and nylon.

However, problems exist with synthetic yarns. Fabrics made using them do not have the ability to handle moisture from fabrics made from cellulose yarns. Synthetic fabrics can generate static electricity. Some people find that fabrics made from synthetic yarn can be much less comfortable to wear than silk. In addition, fabrics made from synthetic yarns have poor washability and require dry cleaning to avoid excessive shrinkage.

Accordingly, with regard to available denim fabrics, there is a need to create a denim fabric that is washable and has a high moisture absorption and can be finished with a wide variety of much more aggressive formulations.

This purpose is a denim fabric made from weft yarn and warp yarn, wherein at least one of the weft yarn and warp yarn is resolved by a denim fabric containing or consisting of lyocell filaments.

This lyocell filament denim withstands aggressive finishing agents. In addition, denim comprising or consisting of lyocell filament yarn is much softer and smoother than denim with silk. Accordingly, the lyocell filament denim of the present invention creates a new class of fabric with a completely new set of properties. All of this is at least as surprising as can be expected from the properties of cotton yarns, which denim, which contains or consists of lyocell staple fibers, is a substitute for cotton denim.

Lyocell is a generic name given to one type of cellulose artificial fiber produced by a direct dissolution process. The lyocell process is described, for example, in US 4,246,221 and WO 93/19230.

The slurry of wood pulp is formed from a solution of amine oxide in water. Thereafter, water is evaporated from the slurry in the thin film evaporator container. When the water level decreases below a certain level, cellulose forms a solution in amine oxide. The resulting viscous liquid solidifies to a vitreous solid below about 70 ° C. When maintained above this temperature, it can be pumped through a spinneret to form a filament, which is then impregnated immediately in water, where dissolution of the amine oxide causes the cellulose to precipitate.

The spinneret used for the extrusion of the amine oxide cellulose solution has a number of holes corresponding to the number of filaments required in the continuous filament yarn. After extrusion, the newly formed yarn is washed to remove amine oxide with countercurrent water. This washing can be carried out on a self advancing reel, on which water is introduced to wash the fibers. Finishing can be applied to aid further processing, and the yarn is dried. The washed and dried yarn is wound on a bobbin.

In the lyocell process, cellulose in the form of wood pulp is the only raw material used. The wood pulp used is produced from a sustainable managed forest. The filament produced is 100% cellulose, the only output from the process. The amine oxide solvent is recovered from the wash water and reused to produce additional filaments. This recovery can be as high as 99.7%. Consequently, the environmental impact of the lyocell process is very low. There is almost no gas evolution or liquid evolution from the process, and the filament produced is solvent-free.

Conversely, the Viscose process uses carbon disulfide, sodium hydroxide, sulfuric acid and zinc sulfate. Hydrogen sulfide and carbon disulfide can be released from the process without much attention. Sodium sulfate is produced as a by-product of the process.

The present invention can be further improved by the following additional properties, which can be combined independently of each other, each showing a different technical effect.

The continuous filament lyocell yarn used to produce the product of the present invention can be as produced yarn in the production of an untwisted state or can be twisted by rewinding. It can be double yarn. It can be combined with other continuous filament yarns or staple fiber yarns by twisting the yarns together or intermingling, for example with an air jet.

The lyocell denim according to the present invention preferably contains at least 10% lyocell filaments in at least one of weft yarn and warp yarn. Preferably, the minimum total content of lyocell filaments in lyocell denim is greater than 10%. A content greater than 10% can significantly improve the handfeel of the fabric as long as it provides a soft structure of yarn containing or consisting of lyocell filaments. Consequently, the total content of lyocells of at least 10% already has a haptic impact, regardless of whether the lyocell filaments are used in warp or weft yarns. In addition, blends of at least 10% lyocell filaments with other synthetic or cellulosic filaments, such as viscose or cupro filaments, or viscose or cupro staple fibers, or wood and cotton, improve the strength of the yarn . Finally, a blend of at least 10% lyocell filaments and synthetics significantly improves the fabric's breathability and moisture management.

The dyeing and finishing process of the denim process is very demanding because it combines the strong mechanical treatment of the fabric with the strong chemical effects. As a result, viscose and silk fibers may not be used in these processes, as these cannot withstand this procedure. This is why viscose and / or coupro staple fibers and filaments can only be used in very small proportions in combination with lyocell filaments or even need to be replaced by lyocell filaments in other embodiments.

According to another preferred embodiment, the denim is bleached. For example, as opposed to denim with silk content, lyocell filaments can be treated with aggressive finishing agents such as chlorine bleach. It has also been surprisingly found that this aggressive finishing agent, in particular chlorine bleach, softens the yarn containing or consisting of lyocell filaments, thereby actually improving the flexibility and smoothness of lyocell denim.

The lyocell denim according to the present invention has excellent flexibility. The indirect measure for flexibility is the TS7 value when measured by a TSA tissue flexibility analyzer. According to one embodiment, the denim according to the invention has a TS7 value of 8 or less in a fixed state, ie before washing the garment. In addition, TS7 values of 6 or less can be obtained with the inventive denim after washing clothes and even after bleaching.

The TSA also produces TS750 values that are related to other parameters, smoothness. Preferably, the denim according to the invention in the fixed state has a TS750 value of 120 or less. TS750 values below 120 may also be maintained after garment washing and / or after bleaching.

With regard to the smoothness and / or softness specified above, the denim according to the invention has a higher smoothness and / or smoothness than cotton denim and even partially good softness and / or smoothness compared to denim with silk yarn.

Preferably, denim also has a high mechanical elastic force. For example, denim can record at least 15,000 cycles from a stationary state, i.e., from Martindale abrasion testing to hole formation prior to garment washing. In another embodiment, denim can record 8,000 cycles after garment washing and / or after bleaching to hole formation. This indicates that the denim according to the invention can be used for strongly abrasive textiles.

The outer surface of the denim, i.e., the inclined surface of the denim, in another embodiment is fixed, i.e., a pilling grade no worse than 5 before garment washing, and / or no worse than 5 after garment washing, and After bleaching it can have a peeling grade no worse than 5.

The yarn strength of the denim in at least one, warp and / or weft direction in which lyocell filament yarn is used is cond. At 20/65, it is preferably at least 20 cN / tex, more preferably at least 25 cN / tex, and / or in a wet state at least 10 cN / tex, preferably at least 20 cN / tex. After washing the garment, the yarn strength in at least one, warp and / or weft direction in which lyocell filament yarn is used is preferably at least 4.5 cN / tex, more preferably at least 5 cN / tex cond. 20/65, and preferably, at least 3, preferably at least 7 cN / tex wetting. After bleaching, the yarn strength in at least one, warp and / or weft direction in which lyocell filament yarn is used is at least 2 cN / tex, preferably at least 3 cN / tex. cond. 20/65, and preferably, at least 2 cN / tex, more preferably, at least 5 cN / tex.

The yarn elongation of weft yarns and / or warp yarns containing or consisting of lyocell filaments can be at least 4% after fixing and / or at least 2% after washing of clothing and / or at least 1% after bleaching.

The denim's hairiness according to the invention may have a grade no worse than 4 after washing the garment and a grade no worse than 3 after the bleaching on the inclined surface, ie the outer surface of the denim.

The fiber splices of the denim according to the invention can have a grade no worse than 4 before and / or after fixing and / or a grade no worse than 4.5 after washing the garment and / or a grade no worse than 4.5 after bleaching.

All of the above parameters make it suitable for being a denim according to the invention as a fabric suitable for a very wide range of denim applications. On the one hand, a combination of softness, smoothness and gloss, and on the other hand, mechanical properties such as abrasion resistance and yarn strength represent a unique combination for denim.

When measured by a Handle-O-Meter in the direction of warp yarns and / or weft yarns containing or consisting of lyocell filaments, a specific hand is at least 4 mN m ² after washing the garment g- ¹ and / or at least 3 mN m ² g- ¹ after bleaching. These values indicate the high smoothness and flexibility of the denim of the present invention.

Preferably, the gloss of the warp yarns and / or weft yarns made of them containing lyocell filaments can have a reflectivity of at least 20%. This can produce denim with high gloss.

The present invention also relates to garments, in particular women's garments, and / or men's garments, such as jackets, coats, blouses, dresses and trousers, in which lyocell denim as described above is used.

The present invention also relates to the use of yarns containing or consisting of lyocell filaments in denim fabrics.

When measured according to ASTMD 1909, the moisture regain of the fabric is an indicator of comfort level. Mulberry silk has a moisture content of 11% and provides one of the best comfort levels of any fabric in terms of moisture content. The lyocell filament yarn and / or denim according to the invention preferably has a moisture content of at least 13%, which results in a similar or even better comfort than mulberry silk.

The lyocell filament denim of the present invention is suitable for production with continuous filament yarns and can be processed in any style, weaving or finishing that results in cotton-like denim. The lyocell filament denim can be structured as plain weave, twill, satin, parameter, hop color, cord and fancy weave. The fabric can be woven using any loom suitable for weaving continuous filament yarns, including shuttle looms, rapier looms, projectile looms or ribbon looms.

Lyocell denim fabrics produced using continuous filament lyocell yarns can have aesthetics and appearance similar to fabrics produced from continuous filament viscose yarns, but can have significantly better physical properties. The higher the yarn strength and modulus, the better the fabric breaking strength, tear strength, abrasion resistance and stability. Wet fabric properties are also excellent.

1 schematically shows a garment 1 made at least in part from a lyocell denim 2. The garment 1 is only schematically shown as being a trousers, but is not limited to this. The garment 1 can also be a dress, suit, garment, jacket, shirt or blouse or part of and / or part of such garments.

The lyocell denim 2 includes weft yarn 4 and warp yarn 6, which can be twisted. At least one of the weft yarn 4 and the warp yarn 6 contains or consists of lyocell filaments.

An example of warp yarn 6 and / or weft yarn 4 with at least one lyocell filament 8 is shown in FIG. 2. Figure 3 shows twisted warp and / or weft three-ply yarns 4 and 6 with at least one lyocell filament. At least one of the filaments 8 is a lyocell filament. Twisted filaments can have any number of filaments and any twist direction. Preferably, at least 50% of the yarns 4 and 6 consist of lyocell filaments 8.

In order to investigate the quality of the lyocell filament denim according to the present invention compared to silk, samples were prepared and compared with comparative examples made from cotton or made from cotton-containing denim. In the case of denim, the bottom is a benchmark, in which any denim using yarns from artificial fibers or filaments must compete in the market. Samples of lyocell filament denim of the present invention are compared to comparative examples using the following test:

exam

-Martindale wear test according to DIN EN ISO 12947-2;

-Martindale peeling test according to DIN EN ISO 12945-2;

-Washing shrinkage according to DIN EN ISO 5077; From the absolute value of the shrinkage in both sample directions, the sum is obtained as the combined shrinkage;

-Fastness to rubbing according to ISO 105 X12;

-AATCC durable press grade according to DIN EN ISO 15487;

-Breathability according to DIN EN ISO 9237;

-Fastness according to DIN EN 20105-A02;

-Yarn strength in warp and weft according to DIN EN ISO 2062,

-Moisture content according to ASTMD 1909,

-Yarn gloss measured at an angle of 45 ° according to EN 14086-01/2003,

-Glossiness of the fabric measured at an angle of 75 ° according to TAPPI T480.

For the end consumer, it is important how the appearance of the fabric changes after washing. To evaluate this, the surface modality, peeling and fiber splice were measured according to the following tests:

The test was conducted by 3 persons in a dark room provided with Variolux's color evaluation cabinet "Multilight Datacolor" with daylight lamp D65. The lamp was mounted on the top side of the cabinet.

In order to test the douche, the test sample was held obliquely by the investigator, and the douche was recorded between the highest (grade 5, no douche) and the lowest (grade 1, long protruding fibers up to 2 mm).

The peeling number (hairy knot on the fabric surface) was evaluated using a reference sample of EMPA Standard SN 198525 (knit K3 or K2, or woven W3 or W2) similar to DIN EN ISO 12 945-2. Reference samples are graded from 1 to 5 and compared to test samples. Grade 5 corresponds to denim without peeling. If more filling is present on the surface of the test sample, a lower rating is obtained. The lowest grade is 1.

Fiber splices are produced when fibrillic fibers are moved to the surface by scouring. Fibril fibers are protruding brush-like ends when the refined sample is analyzed under a microscope. To measure the fiber splice, a microscope SM with an X10 eyepiece from UHL Technische Mikroskope was used. For smooth surfaces that do not exhibit fibrils, a grade 5 was provided. Grade 1 was provided in the presence of dense fur at the end of the long, curved fiber partially detached from the surface.

In all three trials, intermediate grades were possible.

When the sample was washed, washing was performed according to DIN EN ISO 6330. The test for evaluating the parameters in the dry state is performed in the conditioned state 65/20. All standards mentioned in these applications are incorporated by reference in their entirety.

Samples were prepared as follows. Thereby, the weight was measured according to DIN EN 12127. Yarn counts on weft and warp were performed according to DIN 53820-3.

An overview of the materials and properties of Comparative Samples 4 and 7 in relation to the benchmark unknowns tested for Samples 1, 2, 3, 5 and 6, and Samples 1, 2, 3, 5 and 65 related to lyocell filament denim Is provided in 1.

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

Sample 1 is denim 1857-A, where the slope consists of bright unwrapped yarn with dtex 500f300 made of lyocell filaments. The weft yarn consisted of cotton yarn with a core of Lycra T400. This formed a fabric with 70% lyocell yarn, 20% cotton, 8% elastomer multiester and 2% elastane. Denim has a weight of 343 gm ^-2 .

Sample 2 is denim 978-150-814 containing 33% lyocell filament and 67% cotton. The basis weight was 143 gm ^-2 . The warp was made of cotton Lingyan Z. Wefts were made from yarn dtex 150f90.

Sample 3 consisted of bright loose yarns of 100% lyocell filaments, which were denim 1857-8 with a linear mass density of dtex 500f300. Weft yarn is 100% polyester yarn with ELAS core of Lycra T400. This formed denim with 356 gm ^-2 , and 70% lyocell, 28% polyester and 2% elastane.

Sample 6 is denim 1857-CNF with 70% lyocell, 28% cotton and 2% elastane. The slope consisted of lyocell filament yarn with 556 dtex. The weft yarn was made from a matte cotton ring yarn with an elastane core.

Sample 5 was 45% lyocell and 55% cotton denim 978-100-814. The warp was made of cotton ring yarn Z, and the weft yarn was made of lyocell yarn dtex 100f60. The material basis weight was 128 gm ^-2 .

Comparative sample 4 is denim 840-814 made from 59% cotton and 41% silk, where the warp yarn was made from cotton and the weft yarn was made from silk. This formed a denim with high flexibility and smoothness, and gloss. The basis weight was 171 gm ^-2 .

Comparative sample 7 is denim 435-4047 made of 98% cotton and 2% elastane. The warp yarns were made from cotton ring yarns, and the weft yarns were made from cotton ring yarns with a shiny elastane core.

Samples 1 to 3 and 6 were benchmarked against comparative sample 7 for washability, resistance to finish formulations, smoothness, flexibility and gloss.

Samples 2 and 5 were characterized by the same weft material and were benchmarked against comparative sample 4 to compare lyocell warp denim against cotton warp denim.

Samples and comparative samples were subjected to the following finishing steps. After each finishing step, samples and comparative examples were tested.

fixing

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.

Laundry washing

Samples 1, 2, 3, 5, 6 and comparative samples 4 and 7 were garment-washed as follows.

Fibrillation was performed in 2 g / L Persoftal L, 2 g / L soda and 0.3 g / L Lavasperse KDS concentrate at 2.5 ° C. for 20 minutes at 60 ° C. with maximum heating rate of 2.5 kg fabric and 150 L solution liquor) with a solution ratio of 1:60.

Thereafter, the liquid was cooled to 40 ° C., washed at a low temperature of 300 L, and then washed at 150 ° C. for 5 minutes at 50 ° C., where heating started immediately after the start of the cleaning, and then again 300 It was washed at low temperature with ℓ.

After washing, enzyme washing was carried out again at a solution ratio of 1:60 with 2.5 kg fabric and 150 L liquid at 22 rpm. The solution contained 2 g / L Persoftal L, 3 g / L Peristal E and 0.3 g / L Lavasperse KDS concentrate. The pH value was adjusted to be between pH 4.5 and 5. After heating to 55 ° C. at maximum heating rate, the pH value was checked. At pH 5.5, 2 g / L Perizym 2000 was added followed by enzyme addition, and then the material was treated at 55 ° C. for 55 minutes. Subsequently, the material was heated to 85 ° C and treated at 85 ° C for 15 minutes.

The solution was then taken out and the material was washed as follows: first, low temperature washing with 300 liters, followed by hot water washing with 150 liters, where heating commenced with filling of the second washing step. The hot water washing was continued at 50 ° C for 5 minutes. Finally, low temperature washing was performed at 300 liters.

The heating was performed at a solution ratio of 1:60 as above using 2% Tubingal RGH, 1% Tubingal RWM, 3 g / L Peristal E at 15 minutes and 40 ° C. after heating at maximum speed.

The solution was then withdrawn, and the material was tumble-dried at 80 ° C. for 50 minutes, then cooled for 20 minutes.

Thereafter, samples and comparative examples were tested as described above. The results are summarized in Table 3.

Strong Bleach

For the final test series, samples 1, 2, 3, 5, 6 and comparative samples 4 and 7 were bleached as follows:

Pre-refining was performed at a solution ratio of 1:60 with 2.5 kg of fabric and 150 L of solution. For pre-washing, 2 g / L Persoftal L, 0.5 g / L NaOH 100% (1 g / L NaOH 50%) and 0.2 g / L Lava Sperse KDS concentrate were used. Pre-refining was performed at 60 ° C. (maximum heating rate) for 20 minutes.

Thereafter, cooling to 40 ° C. and then low temperature washing to 300 L was performed.

Bleaching was again carried out with a 150 L solution containing 2.5 kg fabric, and 2 g / L soda and 0.4 g / L Lava Sperse KDS concentrate, at a solution ratio of 1:60 and 15 rpm at low temperature for 30 minutes. The pH value was checked and maintained at pH 10. As the bleaching agent, 3 g / L active chlorine (20 ml / L bleaching caustic soda solution 150 g / L) was used.

The solution was then withdrawn, the material was cold-washed to 300 L and washed with hot water at 150 L as above.

Dechlorination was performed at 40 ° C. for 30 minutes at 2 ml / L hydrogen peroxide 50%.

Subsequently, low temperature washing at 300 liters, hot water washing at 150 liters at 50 ° C for 5 minutes (heating starts with washing), and low temperature washing to 300 liters were performed.

Thereafter, after enzyme washing, washing and recovery and tumble drying were performed as follows:

After washing, the enzyme wash was carried out again at 22 rpm with a 2.5 kg fabric and 150 L solution at a solution ratio of 1:60. The solution contained 2 g / L Persoftal L, 3 g / L Peristal E and 0.3 g / L Lavasperse KDS concentrate. The pH value was maintained at pH 4.5-5. After heating to 55 ° C. at maximum heating rate, the pH value was checked, after which enzyme was added, and then the material was treated at 55 ° C. for 55 minutes. Subsequently, the material was heated to 85 ° C and treated at 85 ° C for 15 minutes.

Thereafter, the solution was withdrawn and the material was washed as follows: first, low temperature washing with 300 liters, then hot water washing with 150 liters, where heating started with filling of the second washing step. The hot water washing was continued at 50 ° C for 5 minutes. Finally, low temperature washing was performed at 300 liters.

Recovery was performed at a solution ratio of 1:60 as above using 2% Tubingal RGH, 1% Tubingal RWM, 3 g / L Peristal E at 15 min and 40 ° C. after heating at maximum rate.

Subsequently, samples and comparative examples were tested as above. The results of these tests are summarized in Table 4.

result

From Tables 1 to 4, the following is clear: Compared to Samples 2 and 5 with Comparative Sample 4, the tenacity of both wetting and drying of the lyocell filament according to the present invention is the strength of silk denim of Comparative Sample 4 Significantly higher than that. In addition, the yarn strength and yarn elongation of both dry and wet are superior in all lyocell filament denim compared to non-lyocell filament cotton denim as illustrated in comparative samples 4 and 7.

In addition, it has been demonstrated that lyocell filament denim withstands even aggressive finishing agents such as chlorine bleach that breaks silk.

With regard to peeling, wool, and fiber splices, lyocell filament denim is at least similar to cotton denim before and after garment washing and after bleaching, or at least a grade better than that. In addition, the lyocell filament is not fibrillated from cotton after washing.

Although the cotton still has higher 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 all superior to cotton denim and is paired with gloss, suppleness and smoothness, which can only be achieved with silk-containing denim. However, the latter cannot be bleached.

This becomes evident from the following tests, where flexibility and smoothness are analyzed using a TSA Tissue Software Analyzer (TSA test), a handle-O-meter, and a handfeel panel.

TSA  exam

TSA tests were performed to demonstrate that the tactile properties of the lyocell filament denim of Samples 1-5 were at least the same or better than the tactile properties of the silk denim of Comparative Sample 4.

The two main tactile properties improved by using silk in denim are flexibility and smoothness. To objectively evaluate these characteristics, a TSA test was performed.

The TSA test is described in Schloßer et al., "Griffbeurteilung von Textilien mittels Schallanalyse", Meilland Textilberichte, 1/2102, p. 43-45], emtec publication [Gruener, "A new and objective measuring technique to analyze the softness of tissue" (2012)], TSA Operating Instructions, and [Neue und Objektive Messtechnik fuer Softness-Analyse] "in avr-Allgemeiner Vliesstoff Report 5/2015, p. 99-101. Products originally developed to measure the softness and smoothness of tissues and nonwovens using sound spectra were also modified to evaluate the softness and smoothness of woven fabrics.

TSA testing was performed using a TSA tissue flexibility analyzer device from emtec electronics GmbH (Leipzig, Germany) and the software ESM provided with the TSA. TSA measures the sound spectrum formed by pressing and rotating the star-shaped body against the sample fabric with a defined force. For testing, the fabric was clamped around its circumference and, in particular, was not otherwise supported on the opposite side of the rotor. In the TSA tests performed herein, the software and its evaluation algorithm were not used. Instead, the sound pressure (TS7) as measured by TSA at 7 kHz was taken as an objective indirect measure of flexibility, and the sound pressure (TS750) at 750 Hz in the sound spectrum measured by TSA was smoothed. As an objective indirect measure of. The sound pressure is automatically provided by the TSA in dB V ² rms, where V is the rotational speed of the rotor. Using these values, any problems that may arise due to EMS algorithms developed for tissues other than woven fabrics can be avoided. A total of 4 probes were tested for TSA for each sample.

For testing, a 11 cm diameter fabric sample was clamped as required by a TSA device and tested without stretching.

A low TS7 value indicates high flexibility, and a low TS750 value indicates high smoothness value.

Handle-O-meter test

The handle-O-meter test was performed using a handle-O-meter test device from Thwing-Albert Instrument Company (West Berlin, NJ, USA). The sample size was 10 cm x 10 cm. A ¼ inch slot was used with a 1,000 g beam and stainless steel surface. Sample cond to test. 65/20.

In both the TSA and handle-O-meter tests, only the right outer side of denim was considered. The results are summarized in Table 5.

As a result, the handle-O-meter yields two force measurements assigned to two orthogonal directions, the machine direction MD where the selected setup corresponds to the warp direction, and the cross direction CD where the selected setup corresponds to the weft direction. This force is related to the stiffness and smoothness of the tested surface. The force is normalized to the bulk weight of the test sample, resulting in a specific hand of mN m ² g ^-1 .

From Table 5, it follows that the cotton denim of Comparative Sample 7 is lower in terms of smoothness compared to Samples 1, 3 and 6. This lyocell filament denim is stiffer than the cotton denim according to Comparative Sample 7 before washing the garment, but this is more flexible than Comparative Sample 7 after washing the garment.

The silk denim of Comparative Sample 4 is less smooth than Samples 2 and 5, where lyocell endless filaments are used in the weft yarns instead of silk. In addition, the lyocell filament denim is more flexible than the silk denim of Comparative Sample 4 before finishing. After finishing, the flexibility of Samples 2 and 5 corresponds to that of Comparative Sample 4.

Thus, from the TSA and handle-O-meter tests, it can be concluded that the lyocell filament denim according to the invention actually combines the ability to bleach with good flexibility and smoothness. In addition, lyocell filament denim has high strength. This combination creates a new class of denim fabric.

Tactile panel

To confirm the results from the TSA and handle-O-meter tests, a tactile panel was used. A panel of 10 independent textile experts came together. The task of the panel is to objectively evaluate the touch of the lyocell filament denim according to the present invention in comparison with a comparative example.

To obtain reproducible results independent of panel members, the tactile panels were operated as follows:

All samples tested by the tactile panel were provided in format 17 cm × 17 cm and adhered to the carbon using double-sided adhesive tape approximately 2 cm from the border on the top edge. The fabric samples were glued onto the cardboard, with the right and neck sides facing the front. It was oriented such that the weft direction was horizontal and the warp direction was vertical.

For evaluation of tactile sensation, a semantic grid was defined by providing a pair of adjectives of contrast description to describe tactile sensation. The term "best" is considered the term of the control pair corresponding to the desired property. Accordingly, for fabrics where the smoothness is a desired property, a higher rating will be provided than for the opposite quantity, roughness. Ratings range from 1 (lowest) to 10 (best).

It also stipulated how evaluation should be done, for example, by defining the movement of the hand over the fabric to evaluate smoothness.

Reference sample fabrics of the same structure type (woven) with structural parameters as close as possible while having significant tactile differences were pre-defined for each word pair. For example, fabrics considered to have a reference roughness and fabrics considered to have a reference smoothness were provided to the tactile panel.

The grades for the individual reference fabrics were fixed at 2 and 8 respectively. Accordingly, the reference fabric for the word pair of the lowest characteristic, by definition, had a grade 2, and the reference fabric for the word pair of the better characteristic had a grade 8. Each assignment of Grade 2 and Grade 8 can expand the scale during the test if a substance with better or worse properties than the two reference substances is met. Accordingly, the reference material for roughness was defined as having grade 2, and the reference material for smoothness was defined as having grade 8 on the roughness-smoothness scale. All other materials tested afterwards were graded against a reference material by a tactile panel.

To test denim samples, the following semantic grid was used:

-To evaluate the tactile feel: cotton-like (grade 2) and silk-like (grade 8);

-To evaluate the consistency: looseness (grade 2) and compactness (grade 8);

-To evaluate the fit: stiffness (grade 2) and flexibility (grade 8);

-To evaluate the surface: rough (grade 2); And smoothness (grade 8).

As reference material for grade 2, comparative sample 7 was used. As a reference material for grade 8, comparative sample 4 was used for all word pairs.

Panels were instructed to evaluate the characteristics as follows:

-To evaluate the feel, the sample card was held with one hand and the fabric was foldable. Subsequently, the tactile panel member asked to hold the pending fabric in such a way that the right side (neck) of the denim touched the palm:

-Hardness describes whether the fabric provides a more open or denser woven feel. Sample cards were placed on a table in front of the individual tactile panel members. The fabric was held with both hands, kneading the fabric and stretching.

-The fit is determined by lifting the sample card back with one hand and folding the fibers. The sample card is then shaken to evaluate the falling pattern of the fabric. Afterwards, the fabric is held freely for further evaluation.

-Finally, a cardboard placed on the table to judge the surface feel. The cervical surface was evaluated by moving the palm in the oblique and weft directions.

For each sample fabric and each word pair, the mean and deviation from the mean for evaluation by individual tactile panel members were calculated. The average was used to evaluate and rank the samples. A summary of the results is provided in Table 6.

Luster

The gloss of the individual yarns usable in the lyocell denim according to the present invention was measured using a gloss meter. The results of% reflectance of incident light are given in Table 7. To measure the gloss of the yarn, this was wound on a wrap-over cardboard, and the gloss was measured at 45 ° according to EN 14086-01 / 2003. The gloss of the fabric was measured at 75 ° according to TAPPI T480. The viewing angle was directed along the yarn direction to measure yarn gloss.

Samples 1, 3, 7, 8 were yarns made from 100% bright lyocell filaments with the linear mass density specified in Table 7.

Samples 2, 4, 5 and 6 are comparative samples.

Sample 3 has a much better gloss than all other samples and comparative examples. The gloss of Samples 1 and 6 was similar to that of Comparative Sample 7 containing silk.

The gloss of the yarn usable for denim was at least 20% reflectance.

Accordingly, it can be concluded that the lyocell filament denim of the present invention also combines good gloss with resistance to aggressive finishing agents.

Table 1-Untreated samples and comparative examples

Table 2-Samples and comparative examples after fixation

Table 3-Samples and comparative examples after washing clothes

Table 4-Samples and comparative examples after strong chlorine bleaching

Table 5-TSA and handle-O-meter test results

Table 6-Tactile Panel Test

Table 7-Gloss

Claims (14)

Lyocell denim (2) made from weft yarn (4) and warp yarn (6), at least one of the weft yarn (4) and the warp yarn (6) Is a lyocell denim containing or consisting of lyocell filaments (8). The lyocell denim of claim 1 wherein the denim is bleached. The lyocell denim according to claim 1 or 2, wherein the denim has a TS7 value of 6 or less in the TSA test in a fixed state and / or after washing and / or after bleaching the garment. The lyocell denim according to any one of claims 1 to 3, wherein the denim has a TS750 value of 100 or less after being fixed and / or after washing and / or bleaching the garment. The yarn strength of any one of claims 1 to 4, wherein the yarn strength of the yarn containing or consisting of lyocell is at least 25 cN / tex after fixing and / or at least 4.5 cN / tex after washing the garment and / or at least after bleaching. Lyocell denim with 2 cN / tex. The Martindale abrasion test according to any one of claims 1 to 5, wherein at least 15,000 cycles from the Martindale abrasion test to hole formation in the state where the denim is fixed and after washing and / or after bleaching the garment. Lyocell denim scoring at least one of 8,000 cycles from to hole formation. The filling grade and / or no worse than 5 according to any one of claims 1 to 6, wherein the warp face of the denim is fixed in the Martindale pilling test. A lyocell denim having a peeling grade no worse than 5 after washing clothes and a peeling grade no worse than 5 after bleaching. The elongation of at least one of the warp yarns and weft yarns containing lyocell filaments is at least 4% after fixing and / or at least 2% and / or bleaching after washing of the garment according to claim 1. A lyocell denim that is at least 1% later. 9. The lyocell denim of any one of claims 1 to 8, wherein the denim on the inclined surface has a hairiness no worse than 4 after washing the garment and no worse than 3 after bleaching. The grade according to claim 1, wherein the fiber splice of the denim is no worse than 4 before and / or after fixation and / or no worse than 4.5 after washing the garment. Or a lyocell denim with a grade no worse than 4.5 after bleaching. 11. The method according to any one of claims 1 to 10, wherein the specific hand in the direction of warp yarn and / or weft yarn in combination with or consisting of lyocell filaments is at least 4 mN m ² g ^-1 after washing the garment. And lyocell denim, at least 3 mN m ² g ^-1 after bleaching. 12. A lyocell denim according to any one of the preceding claims, wherein the yarn made of or containing lyocell filaments (8) has a luster of at least 20% reflectivity. A garment containing or consisting of the lyocell denim according to claim 1. Use of yarns containing or consisting of lyocell filaments in denim fabrics.

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