RU2753288C1 - Denim from lyocell fibres - Google Patents

Abstract

FIELD: textiles.

SUBSTANCE: present invention relates to a denim fabric used for clothing (1). The fabric consists of weft threads (4) and warp threads (6). At least one of the warp and weft threads comprises at least 10% of lyocell fibres (8) or consists thereof. The resulting material combines high mechanical durability with excellent softness, smoothness and shine. The denim according to the present invention is also suitable for bleaching. The denim according to the present invention constitutes a new class of denim complementing the existing cotton denims and denims with a silk component.

EFFECT: creation of denim fabric, suitable for bleaching and combining high mechanical durability with excellent softness, smoothness and shine.

13 cl, 7 tbl, 3 dwg

Description

The present invention relates to a denim fabric.

Denim is a fabric that is usually woven from cotton as a warp textile material with a twill weave. The most common denim fabric is indigo-dyed denim in which only the base is dyed. The weft remains white. However, the core of the base remains unpainted, resulting in the fading properties that are typical of denim. Due to the warp weave, denim is dyed, usually indigo on the outside, and remains white (undyed) on the inside.

Although cotton is a fiber that has high strength and thus the ability to withstand very aggressive processing, its mechanical properties and its tactile qualities are not ideal and only allow a narrow range of denim usability.

For this reason, attempts have been made in the past to improve the properties of denim by at least partially replacing cotton with silk and / or man-made threads and fibers. One such example is the addition of elastane to increase elasticity. Typically, up to 3% elastane can be added; higher elastane content is detrimental to durability.

Man-made continuous filaments are widely used in the textile industry to produce fabrics that have distinctive characteristics over fabrics made from staple filaments. A continuous filament is a filament in which all filaments run continuously along the entire length of the filament. A continuous filament typically contains 20 to 200 or more individual filaments, all of which are parallel to each other and to the filament axis during production. The yarn is made by extrusion of a solution or melt of a polymer or a polymer derivative, and then the produced yarn is wound on a bobbin or bobbin, or a coil is obtained by centrifugal winding.

Filaments made of continuous synthetic polymer fibers are also common. For example, continuous nylon, polyester and polypropylene filaments are used in a wide variety of webs. They are made from a melt by spinning a molten polymer through a spinning mechanism having a number of holes corresponding to the required number of fibers in the yarn to be produced. After the molten polymer begins to solidify, the filament can be pulled to orient the polymer molecules and improve the properties of the filament.

Continuous filaments 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 spinning machine. The solvent quickly evaporates after extrusion, causing the polymer to precipitate in the form of a filament. The newly made thread can be stretched to orient the polymer molecules.

In addition, continuous filaments can be made from cellulose using the rayon process. Cellulose is converted to cellulose xanthate by reaction with sodium hydroxide and carbon disulfide and then dissolved in sodium hydroxide solution. The cellulose solution, commonly called rayon, is extruded through a spinning machine into an acid bath. Sodium hydroxide is neutralized causing cellulose to precipitate. In this case, cellulose xanthate is converted back to cellulose by reaction with an acid. The newly formed fiber is stretched to orient the cellulose molecules, washed to remove reagents from the fiber, and then dried and wound onto a bobbin. In early versions of this process, the wet yarn was collected into a skein using a spinning wheel-type Tofama system. The coil of yarn is then oven dried before being wound onto a bobbin.

Continuous cellulose filaments are also made using the copper-ammonia process. Cellulose is dissolved in a solution of copper ammonia complex hydroxide. The resulting solution is extruded into a water bath where the ammonia copper hydroxide is diluted and cellulose is precipitated. The resulting yarn is washed, dried and wound onto a bobbin.

Continuous cellulose filament yarn made by the viscose or copper-ammonia process can be made into webs by weaving. The fabrics produced are used for a variety of applications, including linings for women's dresses and men's clothing.

Webs containing continuous cellulosic filaments have good moisture control properties, which increases the comfort of the wearer. They do not generate static electricity as easily as canvases made from continuous synthetic filaments.

Webs made using currently available continuous cellulosic filaments generally have poor physical properties. Dry strength and tensile strength are unsatisfactory compared to webs made from synthetic polymers such as polyester. Wet strength is significantly less than dry strength due to the interaction between cellulose and water. The abrasion resistance is low. Interactions with water also soften the cellulose, resulting in webs made from such filament, which are unstable when wet. This is especially problematic when washing these materials in a household washing machine.

Due to these disadvantages, articles that were originally made using continuous cellulosic filaments are now mainly made using continuous synthetic polymer filaments such as polyester and nylon fibers.

However, there are problems in the case of synthetic yarns. Webs made with them do not have the same moisture control properties as webs made with cellulose filaments. Synthetic fabrics can generate static electricity. Some users find fabrics made from synthetic threads significantly less comfortable to wear than silk. In addition, fabrics made from synthetic filaments have poor wash resistance and require dry cleaning to prevent excessive shrinkage.

Thus, in view of the available denim fabrics, there is a need for a denim fabric that has high moisture absorption, can be treated with a wide variety of highly corrosive reagents, and is washable and soft.

This problem is solved by a denim fabric that is made from weft threads and warp threads, and at least one of the weft threads and warp threads contains or consists of lyocell fibers.

This lyocell denim withstands harsh processing agents. In addition, denim containing or consisting of lyocell threads is softer and smoother than denim containing a silk component. Thus, the lyocell denim of the present invention forms a new class of webs with a completely new range of properties. This turns out to be even more surprising than one would expect from the properties of cotton thread, if at all cotton denim is replaced by denim containing or composed of lyocell staple fibers.

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

A pulp suspension is prepared using an aqueous amine oxide solution. The water is then evaporated from the slurry in a thin film flash tank. When the water level falls below a certain level, cellulose forms a solution in amine oxide. The resulting viscous liquid solidifies at temperatures below about 70 ° C to form a glassy solid. If kept above this temperature, it can be pumped through a spinning mechanism to form fibers, which are then immediately immersed in water where dilution of the amine oxide causes the cellulose to precipitate.

The spinning mechanism used to extrude the cellulose amine oxide solution has a number of holes corresponding to the required number of fibers in the continuous filaments. After extrusion, the newly made filament is washed with water in a countercurrent mode to remove amine oxide. This rinsing can be carried out on movable spools, which are supplied with water to rinse the fibers. For further processing, a sizing agent can be applied, after which the thread is dried. The washed and dried thread 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 comes from permanently regenerated commercial forests. The fibers produced are 100% cellulose and are the only product in the manufacturing process. The amine oxide solvent is recovered from the wash water and reused to produce the following fibers. The degree of this regeneration can be very high, up to 99.7%. As a result, the environmental impact of the lyocell process is very low. There are virtually no emissions of gaseous or liquid substances in this process, and there is no solvent in the fiber produced.

On the other hand, the viscose process uses carbon disulfide, sodium hydroxide, sulfuric acid and zinc sulfate. If little effort is made, hydrogen sulphide and carbon disulfide can be liberated from this process. Sodium sulfate is obtained as a by-product of the process.

The present invention can be further improved by the following additional features, which can be combined independently of each other, all of which exhibit different technical effects

The continuous lyocell filaments used to manufacture the articles of the present invention can be directly manufactured filaments in an untwisted state, or can be twisted by rewinding. The thread can be a double thread. It can be combined with another continuous filament or staple filament by twisting the filaments together or by weaving using, for example, an air jet.

The lyocell denim according to the present invention preferably contains at least 10% lyocell fibers in at least one of the weft and warp threads. Preferably, the minimum total content of lyocell fibers in lyocell denim is greater than 10%. A content of more than 10% can significantly improve the feel of the web, which is imparted with a soft yarn structure, containing or composed of lyocell fibers. Therefore, a total lyocell content of at least 10% already imparts tactile properties, regardless of whether the lyocell fiber is used in the warp or weft. In addition, mixing at least 10% of lyocell fibers with other synthetic or cellulosic fibers, for example rayon or copper-ammonia fibers, or rayon or copper-ammonia staple fibers, or wool and cotton improves the strength of the yarn. Finally, mixing at least 10% lyocell fibers and synthetic fibers significantly improves the breathability and moisture control of the web.

Dyeing and finishing procedures in denim processing are very laborious, since they combine a strong chemical effect with intensive mechanical processing of the canvas. Therefore, viscose and silk fibers cannot be used in these processes, since they would not withstand this procedure. For this reason, rayon and / or copper-ammonia staple fibers and yarns can only be used in very small proportions in combination with lyocell fibers, or may even need to be replaced with lyocell fibers according to another embodiment.

In another preferred embodiment, the denim is bleached. Unlike, for example, denim containing silk, lyocell fibers are treatable with aggressive finishing agents such as chlorine bleach. In addition, it has surprisingly been found that such an aggressive sizing agent, in particular chlorine bleach, softens the yarn containing or composed of lyocell fibers, and thus significantly improves the softness and smoothness of the lyocell denim.

The lyocell denim according to the present invention has excellent softness. An indirect measure of softness is the TS7 value, which is determined by the Tissue Softness Analyzer (TSA). According to one embodiment of the present invention, the denim has a TS7 value of no more than 8 in the fixed state, i. E. before washing clothes. In addition, a TS7 e value of more than 6 can be obtained for the denim of the present invention after washing the clothes and even after bleaching.

The Tissue Softness Analyzer also detects another parameter, the TS750 value, which correlates with smoothness. Preferably, the denim according to the present invention in the fixed state has a TS750 value of not more than 120. A TS750 value of not more than 120 can also be retained after washing the garment and / or after bleaching.

At the above mentioned smoothness and / or softness values, the denim according to the present invention has a higher smoothness and / or softness than cotton denim, and even slightly surpasses the softness and / or smoothness of denim containing silk thread.

Preferably denim also has a high mechanical resistance. For example, denim can withstand at least 15,000 cycles of perforation in the Martindale Abrasion Test in the fixed state, i. E. before washing clothes. In another embodiment, the denim can withstand 8000 cycles before being perforated after washing the garment and / or after bleaching. This shows that the denim of the present invention can be used for textiles that are subject to heavy wear.

In another embodiment, the outer side of the denim, i. E. the side of the denim base can have a knot degree of at least 5 in the fixed state, i.e. before washing clothes, and / or no worse than 5 after washing clothes and no worse than 5 after bleaching.

The strength of the denim yarn in at least one of the warp and / or weft directions in which the lyocell yarn is used is preferably at least 20 cN / tex, more preferably at least 25 cN / tex in a fixed state at a temperature of 20 ° C. and a relative humidity of 65% (20/65) and / or at least 10 cN / tex, preferably at least 20 cN / tex when wet. After washing the garment, the yarn strength in at least one of the warp and / or weft directions in which the lyocell yarn is used is preferably at least 4.5 cN / tex, more preferably at least 5 cN / tex 20/65 state and preferably at least 3, preferably at least 7 cN / tex when wet. After bleaching, the strength of the yarn in at least one of the warp and / or weft directions in which the lyocell yarn is used is at least 2 cN / tex, preferably at least 3 cN / tex in the 20/65 condition and preferably at least 2 cN / tex, more preferably at least 5 cN / tex when wet.

The elongation of the thread in the case of a weft and / or warp thread that contains or consists of lyocell fibers can be at least 4% after fixation and / or at least 2% after washing the clothes and / or at least 1% after bleaching ...

The hairiness of the denim according to the present invention can have a degree of not worse than 4 after washing the clothes and not worse than 3 after bleaching on the base side, i.e. on the outside of the denim.

The weave of denim fibers according to the present invention can have a degree of not worse than 4 before and / or after fixation and / or not worse than 4.5 after washing the clothes and / or not worse than 4.5 after bleaching.

All of the above parameters qualify the denim of the present invention as a fabric suitable for an extremely wide range of denim applications. The combination of softness, smoothness and shine on the one hand, and mechanical properties such as durability and thread strength, on the other hand, is a unique combination for denim.

The bar, which is determined by the bar tester in the direction of the warp and / or weft yarns, which contain or consist of lyocell fibers, is at least 4 mN⋅m ² g ^-1 after washing the clothes and / or at least 3 mN⋅m ² ⋅g ^-1 after bleaching. These values show the high smoothness and flexibility of the denim according to the present invention.

The gloss of the warp and / or weft yarn, preferably containing or consisting of lyocell fibers, can be a reflection of at least 20%. This produces denim with a high sheen.

The present invention also relates to garments, in particular women's dresses and / or men's clothing, such as shirts, jackets, blouses, dresses and trousers, using the lyocell denim described above.

In addition, the present invention relates to the use of yarn containing or consisting of lyocell fibers in a denim fabric.

The residual moisture in the web, measured according to ASTMD 1909, is an indicator of the comfort level. The silkworm silk has a residual moisture content of 11% and provides one of the best comfort levels of all fabrics in terms of residual moisture. The lyocell and / or denim yarn of the present invention preferably has a residual moisture of at least 13%, resulting in similar or even better comfort than silkworm silk.

The lyocell denim of the present invention can have any style, weave, or finish that is suitable for continuous filament yarn, resulting in denim comparable to cotton. Lyocell denim is available in plain, twill, satin, satin, checkered, cord and intricate weaves. Woven fabrics can be made using any loom suitable for weaving with continuous filaments, including shuttle looms, rapier looms, micro-shuttle looms or ribbon looms.

Lyocell denim fabrics made with continuous lyocell filaments can be similar in aesthetics and appearance to fabrics made from filaments containing continuous rayon filaments, but have significantly improved physical properties. As a result of the higher tensile strength and modulus of elasticity of the yarn, a fabric is obtained having improved fracture toughness, tensile strength, abrasion resistance and stability. This web also has excellent wet properties.

FIG. 1 is a schematic representation of a garment 1 which is at least partially made from lyocell denim 2. Garment 1 is only schematically represented by trousers, but this is not limiting. A dress, overalls, suit, jacket, shirt or blouse, or parts and / or accessories of said clothing may also be present as clothing 1.

Lyocell denim 2 contains 4 weft threads and 6 warp threads, which can be twisted. At least one of the weft threads 4 and the warp threads 6 contains or consists of lyocell fibers.

FIG. 2 shows an example of warp and / or weft yarns 6, 4 containing at least one lyocell fiber 8. FIG. 3 shows a twisted warp and / or weft three-fiber yarn 4, 6 containing at least one lyocell fiber. At least one of the fibers 8 is a lyocell fiber. The twisted thread can contain any number of fibers and have any twisting direction. Preferably at least 50% of the yarns 4, 6 are composed of lyocell fibers 8.

To investigate the quality of denim from lyocell fibers according to the present invention in comparison with silk, samples were made and compared with comparative examples made from denim containing or consisting of cotton. For denim, the bottom is the standard that any man-made denim must compete against in the market. The lyocell denim samples of the present invention were compared with comparative examples using the following tests:

RESEARCH

* Martindale abrasion test according to DIN EN ISO 12947-2;

* test for rolling into knots according to Martindale according to DIN EN ISO 12945-2;

* shrinkage when washing according to DIN EN ISO 5077; from the absolute values of shrinkage in both directions of the samples, the sum is calculated, representing the combined shrinkage;

* resistance to friction according to ISO 105 X12;

* crease resistance index, determined by the Association of Chemists and Colourists of the United States of America (AATCC) according to DIN EN ISO 15487;

* breathability according to DIN EN ISO 9237;

* wear resistance according to DIN EN 20105-A02;

* strength of warp and weft thread according to DIN EN ISO 2062,

* residual moisture according to ASTMD 1909,

* thread gloss determined at an angle of 45 ° according to standard EN 14086-01 / 2003,

* gloss of the web, determined at an angle of 75 ° according to the Technical Association for the Pulp and Paper Industry (TAPPI) T480.

It is important for the end consumer how the appearance of the linen will change after washing. For appropriate evaluation, these surface aspects, including hairiness, knotting and fiber entanglement, were determined by performing the following tests:

The studies were carried out by three researchers in a dark room in which a Multilight Datacolor unit containing Variolux D65 fluorescent lamps was installed. The lamps were installed on the top of the unit.

To study hairiness, the test sample was placed in an inclined state in relation to the investigator, who determined the hairiness from the best (grade 5, no hairiness) to the worst (grade 1, long protruding fibers up to 2 mm).

The number of knots rolled up (rolls on the surface of the fabric) was determined using standard samples (knitted fabrics K3 or K2 or woven fabrics W3 or W2) according to the Swiss Federal Laboratory for Materials Science (EMPA) SN 198525, similar to DIN EN ISO 12 945-2. Standard samples were evaluated on a scale from 1 to 5 and compared with the test samples. Grade 5 corresponds to denim that does not roll into knots. The greater the degree of rolling into nodules on the surface, the less the test specimens receive. The worst degree is 1.

Fiber entanglement occurs when fibrillated fibers move across the surface under the action of cleaning. Fibrillated fibers are cyst-like ends with protrusions when viewed under a microscope. An SM microscope with an X10 eyepiece from UHL Technische Mikroskope was used to measure fiber plexus. A smooth surface with no fibrillated fibers is Grade 5. If there was dense fluff of long, curved fiber ends that were partially detached from the surface, Grade 1 was determined.

In all three studies, intermediate degrees are possible.

If the samples were washed, the washing was carried out according to DIN EN ISO 6330. The dry tests were carried out under 20/65 conditioned conditions. All standards mentioned in this application are incorporated in their entirety into this document by reference.

Samples were made as follows. Here the basis weight was determined according to DIN EN 12127. The number of fibers in the weft and warp threads was determined according to DIN 53820-3.

Table 1 provides an overview of the materials and properties of Samples 1, 2, 3, 5 and 6, which contain lyocell denim, and Comparative Samples 4 and 7, which contain the comparative cotton against which Samples 1, 2, 3 were tested. , 5 and 6.

Samples 1, 2, 3, 5 and 6 and Comparative Samples 4 and 7

Sample 1 was 1857-A denim in which the warp consisted of a shiny, untwisted yarn having a linear density of 500 dtex and composed of lyocell fibers. The weft thread was a cotton thread having a T400 Lycra core. As a result, a fabric was obtained containing 70% lyocell yarns, 20% cotton, 8% elastomultiester and 2% elastane. Denim had an areal density of 343 g⋅m ^-2 .

Sample 2 was 978-150-814 denim containing 33% lyocell fibers and 67% cotton. The surface density was 143 g⋅m ^-2 . The warp consisted of cotton yarn from a ring spinning machine with the right twist direction (Z). The weft consisted of a yarn having a linear density of 150 dtex and consisting of 90 fibers.

Sample 3 was denim 1857-8, in which the warp consisted of a shiny untwisted yarn containing 100% lyocell fibers, having a linear density of 500 dtex and composed of 300 fibers. The weft consisted of 100% polyester yarn with an elastane core containing T400 Lycra. The result was a denim having a basis weight of 356 g⋅m ^-2 and containing 70% lyocell, 28% polyester and 2% elastane.

Sample 6 was 1857-CNF denim containing 70% lyocell, 28% cotton and 2% elastane. The warp consisted of 556 dtex lyocell filaments. The weft consisted of matte cotton thread from a ring spinning machine with an elastane core

Sample 5 was denim 978-100-814 containing 45% lyocell and 55% cotton. The warp consisted of cotton yarn from a ring spinning machine with a right twist direction (Z), and the weft consisted of lyocell yarn having a linear density of 100 dtex and consisting of 60 fibers. The surface density of the material was 128 g⋅m ^-2 .

Comparative Sample 4 was denim 840-814 composed of 59% cotton and 41% silk, where the warp thread was cotton and the weft thread was silk. The result was a denim that had a high softness, smoothness and shine. The surface density was 171 g⋅m ^-2 .

Comparative Sample 7 was denim 435-4047 composed of 98% cotton and 2% elastane. The warp consisted of cotton yarn from a ring spinning machine, and the weft consisted of cotton yarn from a ring spinning machine with a matte elastane core.

Samples 1-3 and 6 were compared with Comparative Sample 7 for washing fastness, finishing agent fastness, smoothness, softness and gloss.

Samples 2 and 5 were compared with Comparative Sample 4 comparing lyocell-based denim and cotton-based denim that had the same weft material.

Samples and comparative samples were processed in the following steps. After each processing step, the samples and comparative samples were examined.

Fixation

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

Washing clothes

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

Fibrillation was carried out in solution at a ratio of 1:60 using 2.5 kg of cloth and 150 L of solution and stirring at 22 rpm for 20 minutes at 60 ° C with maximum heating rate; the solution contained 2 g / L Personal L, 2 g / L soda and 0.3 g / L Lava Sperse KDS cone.

Then the solution was cooled to 40 ° C and rinsing was carried out using 300 L of cold water, then rinsing was carried out using 150 L of warm water for 5 minutes at 50 ° C, and heating was carried out from the very beginning of rinsing, and then rinsing was repeated. using 300 liters of cold water.

After rinsing, an enzymatic wash was carried out in a solution at the same ratio of 1:60, using 2.5 kg of cloth and 150 liters of solution and stirring at a speed of 22 rpm. The solution contained 2 g / L Personal L, 3 g / L Peristal E and 0.3 g / L Lava Sperse KDS cone. The pH was adjusted to a range of 4.5 to 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 before the enzyme was added, and then the material was processed at 55 ° C for 55 minutes. The material was then heated to 85 ° C and processed at 85 ° C for 15 minutes.

Thereafter, the solution was discarded and the material was rinsed as follows. First, rinsing was carried out using 300 L of cold water, and then rinsing was carried out using 150 L of warm water, and heating was started from the moment water was added for the second rinse step. The warm water rinse was continued for 5 minutes at 50 ° C. Finally, a rinse was carried out using 300 L of cold water.

Reconstitution was carried out using, in the above ratio of 1:60, a solution containing 2% Tubingal RGH, 1% Tubingal RWM, 3 g / L Peristal E, for 15 minutes at 40 ° C after heating at maximum speed.

The solution was then decanted and the material was drum dried for 50 minutes at 80 ° C. and then allowed to cool for 20 minutes.

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

Strong whitening

For the final test run, Samples 1, 2, 3, 5, 6 and Comparative Samples 4 and 7 were bleached as follows.

The preliminary wash was carried out in a solution at a ratio of 1:60, using 2.5 kg of linen and 150 liters of solution. For prewash, 2 g / L Personal L, 0.5 g / L NaOH 100% (1 g / L NaOH 50%) and 0.2 g / L Lava Sperse KDS conc were used. The pre-wash was carried out for 20 minutes at 60 ° C (maximum heating rate).

Thereafter, cooling to 40 ° C. followed by rinsing using 300 l of cold water.

Bleaching was carried out in a solution at a ratio of 1:60 and a stirring speed of 15 rpm for 30 minutes, again using 2.5 kg of cloth and 150 L of a cold solution containing 2 g / L of soda and 0.4 g / L of Lava Sperse KDS cone. The pH value was checked and maintained at 10. A solution containing 3 g / L of active chlorine (20 ml / L of 150 g / L bleaching solution) was used as the bleach.

The solution was then decanted and the material was rinsed using 300 L of cold water and 150 L of warm water as described above.

Dechlorination was carried out using a 2 ml / L solution of 50% hydrogen peroxide for 30 minutes at 40 ° C.

Then rinsing was carried out using 300 L of cold water, rinsing using 150 L of warm water for 5 minutes at 50 ° C (heating was started at the same time as rinsing), and rinsing using 300 L of cold water.

Then, enzymatic washing was carried out, followed by rinsing, reconstitution and drying in a drum as follows:

After rinsing, an enzymatic wash was carried out in a solution at the same ratio of 1:60, using 2.5 kg of cloth and 150 liters of solution and stirring at a speed of 22 rpm. The solution contained 2 g / L Personal L, 3 g / L Peristal E and 0.3 g / L Lava Sperse KDS cone. The pH was adjusted to a range of 4.5 to 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 before the enzyme was added, and then the material was processed at 55 ° C for 55 minutes. The material was then heated to 85 ° C and processed at 85 ° C for 15 minutes.

Thereafter, the solution was discarded and the material was rinsed as follows. First, rinsing was carried out using 300 L of cold water, and then rinsing was carried out using 150 L of warm water, and heating was started from the moment water was added for the second rinse step. The warm water rinse was continued for 5 minutes at 50 ° C. Finally, a rinse was carried out using 300 L of cold water.

Reconstitution was carried out using, in the above ratio of 1:60, a solution containing 2% Tubingal RGH, 1% Tubingal RWM, 3 g / L Peristal E, for 15 minutes at 40 ° C. after heating at maximum speed.

Thereafter, the samples and comparative samples were examined as described above. The results are summarized in Table 4.

results

From tables 1-4, the following results become apparent. When comparing Samples 2 and 5 with Comparative Sample 4, the wet and dry tenacity of the lyocell fiber of the present invention was found to be significantly higher than the tenacity of silk denim in Comparative Sample 4. In addition, the yarn strength and yarn elongation in wet condition and dry condition is excellent for all Lyocell denim compared to comparative 4 and 7 non-Lyocell cotton denim.

In addition, lyocell denim, like cotton, has been shown to withstand highly aggressive finishing agents such as chlorine bleach, which degrades silk.

Lyocell denim is at least comparable, if not one point better, than cotton denim before and after washing and after bleaching in terms of knotiness, hairiness and weaving of fibers. In addition, lyocell fibers do not undergo the fibrillation that occurs with cotton after washing.

Although cotton has a higher yarn strength before and after washing clothes and after bleaching, the strength of the lyocell denim yarn of the present invention is still quite good. In particular, the durability of a lyocell denim yarn combines shine, softness and smoothness, all of which are superior to cotton denim and can only be achieved with denim containing silk. However, the latter cannot be whitened.

This is clear from the following studies, in which softness and smoothness were analyzed using a tissue softness analyzer (TSA), a fingerstock analyzer, with a team of researchers to determine the quality by touch.

TSA study

A TSA study was carried out to verify that the tactile qualities of the lyocell denim in Samples 1-5 are at least the same if not superior to the tactile qualities of the silk denim in Comparative Sample 4.

Two advantageous tactile qualities that are enhanced by the use of silk in denim are softness and smoothness. For an objective assessment of these characteristics, a TSA study was carried out.

et al., "Исследование грифа текстильных материалов с применением акустического анализа", Meilland Textilberichte, 1/2102, p. 43-45; в публикации ЕМТЕС,

, "Новая и объективная измерительная методика для анализа мягкости ткани" (2012); в инструкциях по эксплуатации прибора TSA; и в статье "Новая и объективная измерительная методика для анализа мягкости", Allgemeiner Vliesstoff Report (AVR), 5/2015, p. 99-101. Это исследование, первоначально разработанное для измерении мягкости и гладкости тонкой бумаги и нетканых материалов с применением акустических спектров, было также приспособлено для оценки мягкости и гладкости тканых полотен.The TSA study is described in the article

et al., "Investigating the Neck of Textile Materials Using Acoustic Analysis", Meilland Textilberichte, 1/2102, p. 43-45; in the EMTEC publication,

, "A New and Objective Measurement Technique for Tissue Softness Analysis"(2012); in the operating instructions for the TSA instrument; and in the article "A New and Objective Measurement Technique for Softness Analysis", Allgemeiner Vliesstoff Report (AVR), 5/2015, p. 99-101. This study, originally designed to measure the softness and smoothness of tissue paper and nonwovens using acoustic spectra, was also adapted to evaluate the softness and smoothness of woven fabrics.

The TSA study was carried out using a tissue softness analyzer (TSA) device from EMTEC Electronics GmbH (Leipzig, Germany) and the ESM software that is supplied with the TSA device. In the TSA study, the acoustic spectrum is measured, which is obtained by pressing and rotating a star-shaped body against a web sample with a predetermined force. For research, the web is clamped around its perimeter and left unsupported at other points, in particular, opposite the rotating body. Here, the TSA study did not use software and associated scoring algorithms. Instead, in the acoustic spectrum, the TS7 acoustic pressure measured by the TSA at 7 kHz was taken as an objective indirect measure of softness, and the TS750 acoustic pressure measured by the TSA at 750 Hz was taken as an objective indirect measure of smoothness. The acoustic pressure was automatically determined by the TSA as the rms dB⋅V ² , where V is the rotational speed of the rotating body. The direct application of these values avoided any problems that might arise from the Evaluation, Maximization, and Smoothing (EMS) algorithm designed for tissue paper rather than woven fabrics. The TSA study was performed on four samples for each sample.

For testing in the TSA device, a sample of the web with a diameter of 11 cm was clamped in the required manner, which was examined without stretching.

Smaller TS7 values show higher softness, and lower TS750 values show higher smoothness.

Neck Testing

дюйма, балку массой 1000 г и поверхность из нержавеющей стали. Исследования образцов проводили в условиях 20/65.Headstock studies were performed using an appropriate instrument from the Thwing-Albert Instrument Company (West Berlin, NJ, USA). The sample dimensions were 10 cm × 10 cm. A slit with a width of

inch, 1000 g beam and stainless steel surface. Samples were tested under 20/65 conditions.

In both studies using the TSA and the bar finder, only the front (outer) side of the denim was analyzed. The results are summarized in Table 5.

During examination, the bar finder makes two force measurements that correspond to two orthogonal directions, including the machine direction MD, which in the selected orientation is the main direction, and the transverse direction CD, which in the selected orientation is the weft direction. The stiffness and smoothness of the investigated surface are correlated with the indicated forces. The force is normalized in relation to the surface density of the test sample, and as a result, a bar is obtained, expressed in mN⋅m ² g ^-1 .

Table 5 shows that the cotton denim in comparative sample 7 is inferior in terms of smoothness to samples 1, 3 and 6. Although these denims made of lyocell fibers are stiffer than the cotton denim in comparative sample 7 before washing, they become more softer than comparative sample 7.

The silk denim in comparative sample 4 is less smooth than samples 2 and 5, which use endless lyocell fibers in the weft yarns instead of silk. In addition, the lyocell denim is softer than the silk denim in Comparative 4 before finishing. After finishing, the softness of samples 2 and 5 corresponds to that of comparative sample 4.

Thus, based on studies using TSA and a finger tester, it can be concluded that the lyocell denim of the present invention does indeed combine excellent softness and smoothness with bleachability. In addition, lyocell denim has a high tenacity. The result of this combination is a new class of denim.

Determination of quality by touch by a group of researchers

To validate the results of the TSA and Neck Tester tests, a team of researchers tested the quality by touch. The research team consisted of ten independent textile experts. The task of the research team was to objectively evaluate the feel of the lyocell denim according to the present invention in comparison with comparative samples.

To obtain reproducible results that were independent of the research team members, the tactile quality was determined by the research team as follows:

All samples to be examined for tactile quality by the research team were made in 17 cm x 17 cm format and glued to cardboard using double-sided tape at a distance of about 2 cm from the border at the top edge. The sample sheet was glued to cardboard in such a way that the front (base) side was facing up. The specimen was oriented such that the weft direction was horizontal and the main direction was vertical.

In order to assess the quality of touch, a semantic grid was defined by presenting pairs of opposite qualitative adjectives to describe touch quality. The term from pairs of opposing adjectives that corresponds to the desired quality is considered "best". Thus, a web whose smoothness is of the desired quality will score higher than the opposite quality, which is roughness. The scores were scored on a scale from 1 (worst) to 10 (best).

In addition, a method has been determined for determining the score, for example, by a predetermined movement of the hand over the canvas to evaluate the smoothness.

Samples of standard webs, which had the same type of structure (weave) and similar structure parameters as possible, and at the same time significant differences in terms of quality to the touch, were pre-defined for each pair of words. For example, to assess the feel quality, the research team received a canvas that was considered to have a standard roughness and a canvas that was considered to have a standard smoothness.

The corresponding standard webs received fixed scores of 2 and 8, respectively. Thus, by definition, the standard canvas for the worst quality of a pair of words had a rating of 2, and the standard canvas for the best quality of a pair of words had an 8 rating. better or worse quality than two standard materials. Thus, the standard material for roughness was determined to have a rating of 2, and the standard material for smoothness was determined as having a rating of 8 on the roughness-smoothness scale. All other materials, which were then examined, were judged by the tactile quality of the research team in comparison with the standard material.

For the study of denim samples, the following semantic was used

net:

- for the sense of touch: cotton-like (score 2) and silk-like (score 8);

- for density assessment: loose (grade 2) and dense (grade 8);

- for the assessment of the feeling when worn: hard (grade 2) and flexible (grade 8);

- for surface assessment: rough (grade 2); and smooth (score 8).

Comparative Sample 7 was used as the standard material for Grade 2. Comparative Sample 4 was used as the standard material for Grade 8 for all word pairs.

A research team was tasked with assessing the aforementioned characteristics as follows:

- To assess the sense of touch, the sample carton was lifted with one hand so that the canvas could be folded. Then, participants in the tactile study group were asked to grab the dangling canvas so that the hand could touch the front (warp) side of the denim.

- Density describes whether the fabric imparts a looser or tighter weave feel. The sample board was placed on a table in front of individual participants by a tactile research team. They took the canvas with both hands, crumpled and stretched the canvas.

- The feel of wearing was determined by picking up the sample carton again with one hand and allowing the canvas to fold. The sample carton was then shaken to assess the pattern of falling of the web. The web was then gripped with the free hand for further evaluation.

- Finally, to assess the surface feel, the sample carton was placed on the table. The warp surface was evaluated by moving the hand in the main direction and in the weft direction.

For each web sample and each word pair, the average of the individual participants' assessments of the tactile group of researchers was calculated, as well as the deviation from the average. The average was used to evaluate and qualify the samples. The results are summarized in Table 6.

Shine

The gloss of the individual threads used in the lyocell denim of the present invention was measured using a gloss meter. Table 7 shows the results expressed as percentage of incident light reflection. To measure the gloss of the threads, they were wound on wrapping cardboard and the gloss was measured according to EN 14086-01 / 2003 at an angle of 45 °. The gloss of the webs was determined according to the TAPPI T480 standard at an angle of 75 °. The viewing angle was measured relative to the direction of the filament to measure the gloss of the filament.

Samples 1, 3, 7, 8 were yarns composed of 100% shiny lyocell fibers having the linear densities shown in Table 7.

Samples 2, 4, 5, 6 were comparative samples.

Sample 3 was significantly brighter than all other samples and comparative samples. Samples 1 and 6 were comparable in gloss to comparative sample 7 of denim containing silk.

The luster of a yarn suitable for use in denim had a reflection of at least 20%.

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

Claims (14)

1. Lyocell denim (2), consisting of weft threads (4) and warp threads (6), in which at least one of the weft threads (4) and warp threads (6) contains at least 10% lyocell fibers (8 ) or consists of them. 2. Lyocell denim according to claim 1, wherein the denim is bleached. 3. Lyocell denim according to claim 1 or 2, wherein the denim has a TS7 value of not more than 6 when tested for TSA in the fixed state and / or after washing and / or after bleaching. 4. Lyocell denim according to any one of paragraphs. 1-3, denim having a TS750 value of not more than 100 in the fixed state and / or after washing and / or after bleaching. 5. Lyocell denim according to any one of paragraphs. 1-4, in which the yarn strength for yarns containing or consisting of lyocell is at least 25 cN / tex after fixation and / or at least 4.5 cN / tex after washing the clothes and / or at least 2 cN / tex after bleaching. 6. Lyocell denim according to any one of paragraphs. 1-5, wherein denim withstands at least 15000 cycles before the Martindale Abrasion Test in the fixed state and 8000 cycles before the formation of holes in the Martindale Abrasion Test after washing the garment and / or after bleaching. 7. Lyocell denim according to any one of paragraphs. 1-6, and the side of the denim base has a degree of rolling into knots not worse than 5 in a fixed state and / or not worse than 5 after washing the clothes and not worse than 5 after bleaching when tested for rolling into knots according to Martindale. 8. Lyocell denim according to any one of paragraphs. 1-7, in which the yarn elongation for at least one of the warp and weft yarns containing lyocell fibers is at least 4% after fixation and / or at least 2% after washing the clothes and / or at least 1% after bleaching. 9. Lyocell denim according to any one of paragraphs. 1-8, and the denim on the side of the base has a hairiness degree not worse than 4 after washing the clothes and not worse than 3 after bleaching. 10. Lyocell denim according to any one of paragraphs. 1-9, and the denim fiber weave has degree not worse than 4 before and / or after fixation and / or not worse than 4.5 after washing clothes and / or not worse than 4.5 after bleaching. 11. Lyocell denim according to any one of paragraphs. 1-10, in which the neck in the direction of warp and / or weft yarns, which contain or consist of lyocell fibers, is at least 4 mN⋅m ² g ^-1 after washing the clothes and / or at least 3 mN⋅ m ² ⋅g ^-1 after bleaching. 12. Clothes containing lyocell denim according to any one of paragraphs. 1-11 or consisting of it. 13. The use of a yarn containing at least 10% or consisting of lyocell fibers in a denim fabric.

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