Lyocell natural weft elastic woven fabric and preparation method thereof

Abstract

The invention provides a lyocell natural weft elastic woven fabric, which is prepared from the following raw materials: weft yarns are lyocell fibers, and warp yarns are selected from one or more of lyocell, cotton and hemp; the weft shrinkage rate is-3.0%-0%, the elastic elongation is 12%-18%, and the elastic residual elongation is less than or equal to 8%; the invention also provides a preparation method of the lyocell natural weft elastic woven fabric, which comprises the following steps: carrying out liquid ammonia finishing, loose washing, loose drying, sizing and preshrinking on lyocell woven grey cloth to obtain the lyocell natural weft elastic woven fabric. According to the preparation method, elastic fibers, resin finishing and yarn twisting are not needed, and comfort and elasticity of the lyocell fabric are achieved; the production process is short, the operation is simple, the control is easy, and the lyocell fiber strength is not damaged; the prepared lyocell natural weft elastic woven fabric has comfortable elasticity, good dimensional stability, high elastic recovery rate, silk luster and soft hand feeling.

Description

Technical Field

[0001] The invention relates to a natural elastic lyocell fiber woven fabric and a preparation method thereof, belonging to the technical field of textiles. Background Art

[0002] Stretch fabric clothing is popular among consumers because of its superior elasticity, the ability to stretch freely when worn, the ability to move with the body, and the fit and comfort.

[0003] Elastic fabrics are divided into fabrics containing elastic fibers and fabrics without elastic fibers. Common elastic fiber fabrics include spandex, PBT, PTT, two-component composite elastic fibers (PET / PTT two-component composite T400 and Sorona, PET / PBT two-component, Shu-Strand, etc.), polyolefin XLANCE, high-elastic polyester yarn, high-elastic nylon yarn, etc. Elastic fabrics are formed by core-spun yarn, covered yarn, blended yarn spun from elastic fibers, or directly interwoven.

[0004] The representative natural elastic fabric without elastic fiber fabric is pure cotton natural elastic fabric. With loose mercerization, cotton swells and shrinks when it encounters alkali, causing the buckling shape of the yarn in the fabric to change, giving the fabric elasticity. In order to solve the problem of poor elastic recovery, pure cotton natural elastic fabric usually needs to add resin finishing or increase the yarn twist. Adding resin finishing to increase the elastic recovery rate of the fabric increases the production process, increases production costs, damages the strength of the fabric, and affects the feel of the fabric; increasing the yarn twist increases the yarn cost and affects the feel of the fabric. Since pure lyocell fiber fabric is not resistant to concentrated caustic soda, it swells very violently in caustic soda, and the mercerized width shrinks greatly, it is difficult to produce pure lyocell fiber natural elastic fabric, which is prone to problems such as poor dimensional stability, poor elastic recovery, and difficult to control the width of the finished product. Summary of the invention

[0005]

Technical issues

[0006] The purpose of the present invention is to provide a lyocell natural weft elastic woven fabric and a preparation method thereof, so as to solve the technical problems of poor dimensional stability, poor elastic recovery and difficult control of finished product width in lyocell fiber natural elastic fabric produced by loose mercerization.

[0007]

Technical solution

[0008] The present invention adopts a suitable grey cloth width design so that the Lyocell natural weft elastic woven fabric has a reasonable shrinkage space in the subsequent processing. If the grey cloth width is too small, the elasticity of the fabric will be insufficient; if the grey cloth width is too large, the elastic elongation of the fabric will be too large and the elastic recovery will be poor. The appropriate grey cloth width is conducive to ensuring that the fabric has a comfortable elastic elongation, and avoids the problem of poor elastic recovery of the fabric due to excessive elasticity. Liquid ammonia finishing, which has a mild swelling effect on Lyocell fibers, is used to shrink the fabric width so that the fabric obtains weft elasticity. Liquid ammonia finishing can avoid the severe swelling and shrinkage caused by caustic soda loose mercerizing, which makes the fabric width too large, resulting in a large shrinkage rate or poor elastic recovery of the finished fabric, and liquid ammonia finishing does not damage the fiber strength. Through loose washing + loose drying + pre-shrinkage, the width is further shrunk, the dimensional stability of the fabric is improved, and the fabric feel is soft.

[0009] The first object of the present invention is to provide a lyocell natural weft elastic woven fabric, the raw materials of which are: the weft yarn is lyocell fiber, the warp yarn is selected from one or more of lyocell, cotton and linen; the weft shrinkage is -3.0% to 0%, the elastic elongation is 12% to 18%, and the elastic residual elongation is ≤8%.

[0010] The second object of the present invention is to provide a method for preparing the above-mentioned Lyocell natural weft stretch woven fabric, comprising the steps of: subjecting the Lyocell woven fabric to liquid ammonia finishing, loose water washing, loose drying, shaping, and pre-shrinking to obtain the Lyocell natural weft stretch woven fabric.

[0011] The liquid ammonia finishing is to make the lyocell fiber swell by liquid ammonia to shrink the width of the fabric, so that the fabric has weft elasticity.

[0012] In one embodiment of the present invention, the weaving structure of the Lyocell woven fabric is one or more of satin weave, twill weave and plain weave.

[0013] In one embodiment of the present invention, the warp density of the Lyocell woven fabric is 56 to 210 strands / inch, and the weft density is 42 to 130 strands / inch.

[0014] In one embodiment of the present invention, the Lyocell woven fabric is woven with 12S-80S yarns; the weft yarn of the Lyocell woven fabric is Lyocell fiber, and the warp yarn is selected from one or more of Lyocell, cotton and linen.

[0015] In one embodiment of the present invention, the warp yarn specifications of the Lyocell woven fabric are 21S-80S; the weft yarn specifications are 12S-80S, 1-2 strands.

[0016] In one embodiment of the present invention, the width of the Lyocell woven grey fabric is 1.15 to 1.20 times the width of the Lyocell natural weft stretch woven fabric.

[0017] In one embodiment of the present invention, the lyocell natural weft stretch woven fabric is one of bleached, grey-dyed or yarn-dyed.

[0018] In one embodiment of the present invention, the preparation method of bleached lyocell natural weft elastic woven fabric comprises the steps of: weaving lyocell woven grey fabric → singeing → desizing, scouring, bleaching → liquid ammonia finishing → loose water washing → loose drying → shaping → pre-shrinking.

[0019] In one embodiment of the present invention, the preparation method of grey-dyed Lyocell natural weft-stretch woven fabric comprises the steps of: Lyocell woven grey fabric weaving → singeing → desizing, scouring, bleaching → liquid ammonia finishing → dyeing → loose washing → loose drying → shaping → pre-shrinking.

[0020] In one embodiment of the present invention, the preparation method of the color-dyed lyocell natural weft elastic woven fabric comprises the steps of: yarn dyeing → warping → sizing → weaving of color-dyed lyocell woven grey fabric → singeing → desizing → liquid ammonia finishing → loose water washing → loose drying → shaping → pre-shrinking.

[0021] In one embodiment of the present invention, the conditions for liquid ammonia finishing are: vehicle speed is 35-60 m / min; liquid ammonia padding pressure is 0.10-0.16 MPa; and ammonia padding tension is 3-4 N / cm 2 ; The liquid ammonia washing temperature is 90-98°C; The pH value of the washing box is 5.0-5.5; The pH value of the falling cloth is controlled at 6.0-8.0.

[0022] In one embodiment of the present invention, the loose water washing is overflow water washing.

[0023] In one embodiment of the present invention, the steps of loose water washing are: two water washings; the first water washing temperature is 80-90°C, the vehicle speed is 30-40m / min and the water washing is 20-30min; the second water washing temperature is 35-40°C, the vehicle speed is 30-40m / min and the water washing is 10-15min.

[0024] In one embodiment of the present invention, the loose drying is flat net loose drying.

[0025] In one embodiment of the present invention, the conditions for loose drying are: vehicle speed 20-30 m / min; overfeed rate 1-7%; temperature 110-135° C.; working fluid is water; and padding pressure 0.08-0.12 MPa.

[0026] In one embodiment of the present invention, the shaping conditions are: vehicle speed 35-70 m / min; temperature 120-145° C.; working fluid is clean water or finishing fluid; and rolling rate 45-65%.

[0027] In one embodiment of the present invention, the finishing liquid is an aqueous solution of a softener or a functional finishing agent.

[0028] In one embodiment of the present invention, the finishing liquid is a softener aqueous solution with a concentration of 5 to 20 g / L.

[0029] In one embodiment of the present invention, the pre-shrinkage condition is: a vehicle speed of 50 to 80 m / min.

[0030] The third object of the present invention is to provide the application of the above-mentioned Lyocell natural weft stretch woven fabric in the field of textiles.

[0031] Beneficial effects:

[0032] (1) The preparation method of the present invention does not require the addition of elastic fibers, does not require the addition of resin finishing, and does not require yarn twisting. The comfortable elasticity of the lyocell fabric can be achieved by only relying on the reasonable design of the width of the grey fabric, liquid ammonia finishing, loose water washing, loose drying, and pre-shrinking.

[0033] (2) The Lyocell natural weft elastic woven fabric prepared by the present invention has the advantages of comfortable elasticity, good dimensional stability, high elastic recovery rate, silky luster, soft hand feel, etc. The weft shrinkage of the Lyocell natural weft elastic woven fabric prepared by the present invention is -3.0% to 0%, the weft elastic elongation is 12% to 18%, and the elastic residual elongation is ≤8%.

[0034] (3) The preparation method of the present invention has a short production process, is simple to operate, is easy to control, and does not damage the strength of lyocell fibers. DETAILED DESCRIPTION

[0035] Unless otherwise specified, the process methods used in the following examples are conventional methods.

[0036] 1. Determination method of shrinkage

[0037] The test was carried out in accordance with GBT8629-2017 “Household Washing and Drying Procedure for Textile Testing”, Procedure F-Spin Drying.

[0038] 2. Elasticity determination method

[0039] The test method is in accordance with ASTM D 3107-07 (2019) "Standard Method for Testing Tensile Stretching and Elastic Recovery of Elastic Woven Fabrics", testing 30-minute elastic elongation and 30-minute residual elongation.

[0040] Example 1

[0041] A lyocell natural weft stretch woven yarn-dyed fabric, finished product specifications: 50S cotton*40S lyocell*145 strands / inch*80 strands / inch, 2 / 2 twill, finished product width 146cm. The preparation method comprises the following steps:

[0042] Yarn dyeing → warping → sizing → weaving → singeing → desizing → liquid ammonia finishing → loose water washing → loose drying → shaping → pre-shrinking.

[0043] Weaving: The width of the woven grey fabric is 169cm. The specifications of the grey fabric are: 50S cotton*40S lyocell*125 threads / inch*78 threads / inch, 2 / 2 twill.

[0044] Liquid ammonia finishing: vehicle speed: 50m / min; liquid ammonia padding pressure: 0.12MPa; ammonia padding tension: 3N / cm 2 ; Liquid ammonia washing temperature: 95-98℃, pH value of washing box: 5-5.5, pH value of falling cloth controlled at 6-7. Cloth width: 141-143cm.

[0045] Loose water washing: The washing temperature of the first overflow water washing is 80-90℃, the washing time is 30min, and the vehicle speed is 30m / min; the washing temperature of the second overflow water washing is 40℃, the washing time is 10min, and the vehicle speed is 30m / min.

[0046] Loose drying: The LSMA341(VI)-200 type liquid-pressing loose drying machine produced by Yangzhou Jiangdu Printing and Dyeing Machinery Co., Ltd. was used for flat-net loose drying. The speed was 30 m / min, the overfeed rate was 7%, the temperature was 130°C, the working fluid was clean water, and the padding pressure was 0.08 MPa.

[0047] Setting: The machine speed is 70m / min, the temperature is 135℃, the working fluid is 10g / L softener aqueous solution, the rolling rate is 45%-50%. The weft density of the dropped cloth is 77-78 strands / inch, and the width of the dropped cloth is 148-149cm.

[0048] Pre-shrinkage: The machine speed is 70m / min, the shrinkage rate is 2%, the weft density of the dropped cloth is 79-80 strands / inch, and the pre-shrinkage width is 145-147cm.

[0049] Example 2

[0050] A pure lyocell natural weft stretch woven grey dyed fabric, finished product specifications: 60S cotton*60S lyocell*150 strands / inch*110 strands / inch, plain weave, finished product width 146cm. The preparation method comprises the following steps:

[0051] Grey cloth weaving → singeing → grey cloth pretreatment (de-sizing, scouring, bleaching) → liquid ammonia finishing → dyeing → loose washing → loose drying → shaping → pre-shrinking.

[0052] Weaving: The width of the woven grey fabric is 168cm. The specifications of the grey fabric are: 60S cotton*60S lyocell*130 threads / inch*110 threads / inch, plain weave.

[0053] Liquid ammonia finishing: vehicle speed: 50m / min; liquid ammonia padding pressure: 0.14MPa; ammonia padding tension: 3.6N / cm 2 ; Liquid ammonia washing temperature: 95-98℃, pH value of washing box: 5-5.5, pH value of falling cloth controlled at 6-7. Cloth width: 141-144cm.

[0054] Loose water washing: The washing temperature of the first overflow water washing is 80-90℃, the washing time is 30min, and the vehicle speed is 30m / min; the washing temperature of the second overflow water washing is 40℃, the washing time is 10min, and the vehicle speed is 30m / min.

[0055] Loose drying: The LSMA341(VI)-200 type liquid-pressing loose drying machine produced by Yangzhou Jiangdu Printing and Dyeing Machinery Co., Ltd. was used for flat-net loose drying. The speed was 30 m / min, the overfeed rate was 6%, the temperature was 130°C, the working liquid was clean water, and the padding pressure was 0.08 MPa.

[0056] Forming: The machine speed is 60m / min, the temperature is 135℃, the working fluid is water, the rolling rate is 45% to 50%, the weft density of the dropped cloth is 66 to 67 strands / inch, and the width of the dropped cloth is 147 to 149cm.

[0057] Pre-shrinkage: The machine speed is 35m / min, the shrinkage rate is 6%, the weft density of the dropped cloth is 69-70 strands / inch, and the pre-shrinkage width is 145-147cm.

[0058] Comparative Example 1

[0059] A lyocell woven yarn-dyed fabric, finished product specifications: 50S cotton*40S lyocell*145 threads / inch*80 threads / inch, 2 / 2 twill.

[0060] The difference from Example 1 is that the steps of liquid ammonia finishing → loose water washing → loose drying in the preparation method are replaced by mercerizing → high temperature water washing.

[0061] Mercerizing: Mercerizing uses a cloth clip mercerizing machine with a speed of 40±5m / min, a mercerizing alkali concentration of (NaOH) 100g / L, a door width of 158cm during mercerizing, a water washing box temperature before the alkali tank of 95°C, a liquid rate of the fabric after rolling in 1# and 2# alkali tanks of 78%, rolling pressure in 3# alkali tank: 4kg, and a flushing alkali water temperature of 85°C.

[0062] High temperature water washing: water washing temperature is 80℃, vehicle speed is 80m / min.

[0063] Comparative Example 2

[0064] A pure lyocell woven grey-dyed fabric, finished product specifications: 60S cotton*60S lyocell*150 strands / inch*110 strands / inch, plain weave.

[0065] The difference from Example 2 is that the steps of liquid ammonia finishing → dyeing → loose washing → loose drying in the preparation method are replaced by mercerizing → dyeing.

[0066] Mercerizing: Mercerizing uses a cloth clip mercerizing machine with a speed of 40±5m / min, a mercerizing alkali concentration of (NaOH) 90g / L, a door width of 158cm during mercerizing, a water washing box temperature before the alkali tank of 95°C, a liquid rate of the fabric after rolling in 1# and 2# alkali tanks of 78%, rolling pressure in 3# alkali tank: 4kg, and a flushing alkali water temperature of 85°C.

[0067] Table 1 Test results of physical indexes of Lyocell natural weft stretch woven fabrics

[0068]

[0069] Since pure lyocell fiber fabric swells violently in caustic soda, the effective width of the finished product of Comparative Examples 1 and 2 shrinks greatly after alkali mercerization. Compared with the lyocell natural weft elastic woven fabrics prepared in Examples 1 and 2, the pure lyocell woven fabrics prepared in Comparative Examples 1 and 2 have a larger elastic elongation, but a higher weft shrinkage rate and a larger residual elongation (poor elastic recovery rate), which affects the wearing performance of the fabric, and there are problems of narrow effective width, high warp density, and heavy gram weight.

[0070] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A lyocell natural weft stretch woven fabric, characterized in that: The raw materials are: the weft yarn is lyocell fiber, and the warp yarn is selected from one or more of lyocell, cotton and linen; its weft shrinkage is -3.0% to 0%, its elastic elongation is 12% to 18%, and its elastic residual elongation is ≤8%.

2. The method for preparing the lyocell natural weft stretch woven fabric according to claim 1, characterized in that: The method comprises the following steps: subjecting the lyocell woven grey fabric to liquid ammonia finishing, loose water washing, loose drying, shaping and pre-shrinking to obtain the lyocell natural weft stretch woven fabric.

3. The preparation method according to claim 2, characterized in that: The weaving structure of the Lyocell woven fabric is one or more of satin weave, twill weave and plain weave; the warp density of the Lyocell woven fabric is 56-210 strands / inch, and the weft density is 42-130 strands / inch; the Lyocell woven fabric is woven with 12S-80S yarn; the weft yarn of the Lyocell woven fabric is Lyocell fiber, and the warp yarn is selected from one or more of Lyocell, cotton and linen.

4. The preparation method according to claim 2, characterized in that: The warp yarn specifications of Lyocell woven fabric are 21S~80S; the weft yarn specifications are 12S~80S, 1~2 strands.

5. The preparation method according to claim 2, characterized in that: The width of Lyocell woven grey fabric is 1.15 to 1.20 times the width of Lyocell natural weft stretch woven fabric.

6. The preparation method according to claim 2, characterized in that: Lyocell natural weft stretch woven fabric is available in bleached, grey dyed or yarn-dyed varieties.

7. The preparation method according to claim 2, characterized in that: The conditions for liquid ammonia finishing are: vehicle speed is 35-60m / min; liquid ammonia padding pressure is 0.10-0.16MPa; ammonia padding tension is 3-4N / cm 2 ; The liquid ammonia washing temperature is 90-98℃; The pH value of the washing box is 5.0-5.5; The pH value of the falling cloth is controlled at 6.0-8.

0.

8. The preparation method according to claim 2, characterized in that: Loose washing is overflow washing; the steps of loose washing are: two washes; the first wash is at 80-90°C, at a speed of 30-40 m / min, for 20-30 min; the second wash is at 35-40°C, at a speed of 30-40 m / min, for 10-15 min; Loose drying is flat net loose drying; the conditions for loose drying are: vehicle speed 20-30m / min; overfeed rate 1-7%; temperature 110-135°C; working fluid is water; padding pressure 0.08-0.12MPa.

9. The preparation method according to claim 2, characterized in that: The conditions for setting are: speed 35-70m / min; temperature 120-145℃; working fluid is clean water or finishing fluid; rolling rate 45-65%; finishing fluid is an aqueous solution of softener or functional finishing agent; The pre-shrinkage conditions are: vehicle speed 50-80m / min.

10. Use of the lyocell natural weft stretch woven fabric according to claim 1 in the field of textiles.

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