Low-twist soft light silk yarn based on strength compensation, fabric and preparation method of low-twist soft light silk yarn

Abstract

The invention relates to a low-twist soft light silk yarn based on strength compensation, a fabric and a preparation method of the low-twist soft light silk yarn, and the low-twist soft light silk yarn is prepared by the following steps: (1) taking mulberry silk short fibers as raw materials, carrying out carding, drawing and roving procedures to obtain fiber-oriented mulberry silk roving, and carrying out pre-humidifying and antistatic treatment on the fiber-oriented mulberry silk roving; and (2) feeding the mulberry silk roving in the step (1) into a spinning frame in two strands, conditioning to control the environment humidity, and preparing the low-twist soft-light silk yarn based on strength compensation by adopting a phase spinning technology. By introducing the phase spinning device, the twist coefficient of the yarn can be reduced by 10%-20% under the condition that the strength is kept, the spinning efficiency is improved, the diameter of the yarn is increased by 5%-7%, the color of the yarn is soft, and the yarn can obtain better hand feeling and luster when being used for high-grade fabric development.

Description

Technical Field

[0001] This invention belongs to the field of textile engineering technology, and specifically relates to a low-twist soft silk yarn and fabric based on strength compensation, and a method for preparing the same. Background Technology

[0002] Silk yarn, with its soft hand feel and elegant luster, occupies an important position in the high-end textile industry and is widely used in women's clothing, home textiles, scarves, and other products. In the production and application of silk yarn, twist is a key parameter affecting the performance of yarn and fabric: while higher twist yarn can ensure sufficient strength, it will result in a tighter yarn structure and a finer diameter, leading to a stiffer hand feel and a glaring luster in the woven fabric, making it difficult to meet the "soft and supple" requirements of high-end fabrics. At the same time, increasing twist will reduce production efficiency. On the other hand, reducing yarn twist is an effective way to improve the luster and hand feel of the fabric, but traditional low-twist silk yarn is often accompanied by a significant decrease in strength, making the yarn prone to breakage during weaving, reducing weaving efficiency, and seriously affecting the durability of the fabric.

[0003] To resolve the conflict between low twist and high strength, existing technologies often employ sizing or finishing processes. Patent CN109629235A uses ultrafine mulberry silk to prepare soft silk fabrics, and sizing is applied to ensure yarn strength during weaving. While this temporarily increases strength, it affects the softness of the yarn, and the subsequent desizing process increases production steps and environmental pressure. Patent CN201710451824.4 uses silicone finishing agents to treat silk fabrics, giving them softness, stain resistance, and antistatic properties. However, high-temperature drying after impregnation causes yellowing of the silk fabric and a loss of strength.

[0004] Sirospinning, as a spinning method, involves feeding two rovings in parallel and twisting them simultaneously, resulting in yarns with good strength and evenness. However, using Sirospinning alone makes it difficult to significantly reduce twist. Phase spinning, on the other hand, improves fiber cohesion and increases yarn strength by applying temporary twist to the yarn. Combining Sirospinning and phase spinning in silk yarn production can achieve low-twist production with strength compensation, solving the current problem of balancing strength, hand feel, and luster in silk fabrics. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a low-twist soft silk yarn, fabric and preparation method based on strength compensation, so as to overcome the defects of insufficient strength of existing low-twist silk yarn and difficulty in achieving the performance of high-grade fabric.

[0006] This invention provides a method for preparing low-twist soft silk yarn based on strength compensation, comprising the following steps:

[0007] (1) Using mulberry silk short fibers as raw materials, after combing, drawing and roving processes, fiber-oriented mulberry silk roving is obtained, and it is pre-humidified and subjected to antistatic treatment.

[0008] (2) The mulberry silk roving from step (1) is fed into the spinning machine in two strands, the ambient humidity is controlled by humidification, and low twist soft silk yarn based on strength compensation is prepared by phase spinning technology.

[0009] Preferably, in step (1), the length of the mulberry silk short fiber is 38~51 mm and the fineness is 1.3~1.8 dtex.

[0010] Preferably, in step (1), the roving quantity is 3~5 g / 10m and the twist is 3~4 twists / 10m.

[0011] Preferably, the pre-humidification in step (1) specifically involves spraying water vapor onto the roving to control the fiber moisture content at 15-16%, sealing and allowing it to stand for more than 24 hours, and then performing antistatic treatment.

[0012] Preferably, in step (2) phase spinning technology, the phase spinning device includes two belts arranged vertically, moving in opposite directions, and with independently controlled speeds; the yarn passes through them and contacts the belts. During the spinning process, the positions of the two belts remain constant, and the yarn to be twisted runs along an S-shaped trajectory between the belts; the drafted yarn converges through false twist and true twist to form a triangular area, and then partially releases the twist downstream of the phase spinning device until it reaches the set twist and is wound onto the yarn tube; the ratio of the rotational speed of the phase spinning device to the output speed of the front roller is 8~12; the contact angle between the yarn and the belt is controlled by adjusting the front and rear positions of the phase spinning device; the phase spinning device enables the fibers to obtain pre-orientation and cohesion before yarn formation, thereby compensating for the dynamic strength and final strength of the yarn formed under low twist.

[0013] Furthermore, the phase spinning device is positioned between the front drafting device and the yarn guiding structure, and mainly consists of a driving wheel, a driven wheel, and an annular belt. The annular belt wraps around the driving wheel and the driven wheel, with the side closer to the front drafting device being the upper belt and the side farther away being the lower belt. The rotation speed of the phase spinning device is controlled by the driving wheel, which is controlled by a motor. The motor is connected to a U-shaped groove pulley, with a rectangular pad between them. The rectangular pad is connected to a ring that fits around the outside of the guide rail. The yarn is subjected to false twisting between the front drafting device and the yarn guiding mechanism. Both the upper and lower belts are in sliding contact with the yarn, maintaining parallelism and allowing the yarn to run along an S-shaped trajectory. The driving wheel and the driven wheel are used to position the belts, controlled by the guide rail, maintaining a constant position during the spinning process, and acting on the yarn through tangential friction from the belt rotation.

[0014] Furthermore, the front drafting device includes a rear roller, a drafting roller, and a front roller; the yarn guiding mechanism includes a yarn guide hook and a yarn tube.

[0015] Preferably, the contact angle between the yarn and the belt is 10~90°.

[0016] Preferably, the fine yarn process parameters in step (2) include: spindle speed of 7000~15000 rpm, twist coefficient of 200~320 (20%~30% lower than traditional silk yarn of the same grade), roving spacing of 8~12 mm, and humidity control environment of 65% or higher.

[0017] Preferably, in step (2), the low-twist soft silk yarn is pure spun yarn with a yarn count of 21~32 s.

[0018] The present invention provides a low-twist soft silk yarn based on strength compensation prepared according to the above preparation method.

[0019] The present invention also provides a low-twist soft silk yarn fabric, which is spun into a high-density 1+1 rib fabric or a high-density plain weave fabric by the above-mentioned low-twist soft silk yarn based on strength compensation, thereby reducing the fabric density by 5.5~6% while keeping the total fabric tightness unchanged.

[0020] Preferably, the high-density 1+1 rib fabric has a warp density of 56~60 meshes / 5cm and a weft density of 76~80 meshes / 5cm; the high-density plain weave fabric has a warp density of 188~208 and a weft density of 170~190.

[0021] Beneficial effects

[0022] (1) Significant strength compensation effect: This invention uses phase spinning technology, where the false twisting process causes the fibers to temporarily cohede, and the two filaments intertwine during true twisting to form a "double-strand cohesion" structure. Compared with Siro-spun yarn, the yarn breaking strength is maintained even when the twist is reduced by 20%, thus solving the problem of insufficient strength of traditional low-twist yarn;

[0023] (2) Optimization of yarn and fabric performance: In this invention, the yarn twist is reduced and the "double strand cohesion" structure increases the yarn diameter by 5% to 7%, increases the internal gap of the yarn, and increases the fabric thickness; at the same time, the low twist reduces the torsional stress of the fiber, reduces the rigidity of the yarn and reduces specular reflection, making the fabric have a soft luster, a soft hand feel, and excellent drape.

[0024] (3) Good production economy: The yarn twist is reduced in this invention, which improves spinning efficiency at the same spindle speed; compared with traditional fabrics of the same style, the weaving density can be reduced by 5.5~6%, which improves production efficiency and is suitable for large-scale industrial production. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the apparatus for preparing low-twist soft silk yarn according to the present invention.

[0026] Figure 2 This is a schematic diagram of the drive wheel in the phase change spinning device of the present invention.

[0027] Figure 3 This is a comparison diagram of the breaking strength of the low-twist soft silk yarn and ordinary yarn prepared in Example 1.

[0028] Figure 4 Scanning electron microscope (SEM) images of the low-twist soft silk yarn (left) prepared in Example 1 and the ordinary yarn (right) prepared in Comparative Example 1.

[0029] Figure 5 The breaking strength of the phase yarn with a rotation speed ratio in the range of 4 to 12, a yarn count of 21s, and a twist coefficient of 320 in Example 2.

[0030] Figure 6 The unevenness (CVm%) of the yarn with a rotation speed ratio in the range of 4 to 12, a yarn count of 21s, and a twist coefficient of 320 in Example 2 is defined as follows.

[0031] Figure reference numerals: 1-Silk roving, 2-Back roller, 3-Drafting roller, 4-Front roller, 5-Upper belt, 6-Lower belt, 7-Yarn guide hook, 8-Yarn, 9-Yarn tube, 10-Drive wheel, 11-Driven wheel, 12-Guide rail, 101-Motor, 102-Rectangular pad, 103-U-groove pulley. Detailed Implementation

[0032] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0033] Example 1

[0034] This embodiment provides a low-twist soft silk yarn and its fabric based on strength compensation, the preparation method of which includes the following steps:

[0035] (1) Select mulberry silk short fiber raw material with a length of 38 mm and a fineness of 1.4 dtex. After combing, drawing and roving, mulberry silk roving with fiber orientation is obtained. The sliver weight is 15.3 g / 5m, the roving weight is controlled at 5 g / 10m, the roving twist is 4 twists / 10cm, and the spindle speed is 200 r / min. Then turn on the humidifier to spray water vapor on the roving to control the fiber moisture content at 15%, control the ambient temperature at 25 ℃, and pre-condition for more than 24 hours.

[0036] (2) Using two strands of mulberry silk roving of the same specification, feed them into a spinning machine and use phase spinning technology to prepare low-twist, soft-light silk yarn with strength compensation. The phase spinning device is as follows: Figure 1 As shown, located between the front drafting device and the yarn guiding structure, it mainly consists of a driving wheel 10, a driven wheel 11, and an annular circular belt. The annular circular belt wraps around the driving wheel 10 and the driven wheel 11. The side closer to the front drafting device is called the upper belt 5, and the side farther away from the front drafting device is called the lower belt 6. The rotation speed of the phase spinning device is controlled by the driving wheel 10, which is controlled by a motor 101. The yarn is subjected to false twisting between the front drafting device and the yarn guiding mechanism. Both the upper belt 5 and the lower belt 6 form a sliding fit with the yarn, and they remain parallel to each other, causing the yarn to be twisted to run along an S-shaped trajectory. The driving wheel 10 and the driven wheel 11 are used to position the belt, which is controlled by the guide rail 12. The belt maintains a constant position during the spinning process and acts on the yarn through tangential friction from the belt rotation. The belt material is a smooth polyurethane circular belt with a Shore hardness of 90 A and a coefficient of friction with the yarn of 0.2.

[0037] Figure 2 The drive wheel 10 shown comprises a motor 101, a rectangular washer 102, and a U-shaped groove pulley 103. The motor 101 is connected to the U-shaped groove pulley 103, with a rectangular washer 102 positioned between them. The rectangular washer 102 is connected to a ring that fits around the guide rail 12. Figure 1 As shown, the mulberry silk roving 1 passes through the back roller 2, drafting roller 3, and front roller 4 in sequence, and contacts the inner side of the upper belt 5 and the outer side of the lower belt 6. After drafting, the roving converges under the action of false twist and true twist to form a triangular area. Then, some of the twist is released downstream of the phase spinning device until the set twist is reached to form yarn 8, which is wound onto the yarn tube 9 by the yarn guide hook 7.

[0038] The specific process parameters for fine spinning are as follows: spindle speed 12000 rpm, twist coefficients set to 200, 240, 280, and 320 respectively, yarn count 21s, roving spacing 10 mm, ratio of phase spinning device speed (belt speed) to front roller output speed 8, and humidity control environment humidity above 65%.

[0039] Comparative Example 1

[0040] Ordinary yarn (control group) was prepared using Siro spinning technology. The same treatment of mulberry silk roving was obtained by referring to step (1) of Example 1. The two strands were fed into the spinning machine. The mulberry silk roving 1 passed through the back roller 2, the drafting roller 3, and the front roller 4 in sequence. It converged at the outlet of the front roller 4 to form a triangular area. It was formed into yarn 8 by true twisting and then wound onto the yarn tube 9 by the yarn guide hook 7.

[0041] The specific process parameters for fine spinning are: spindle speed 12000 rpm, twist coefficient set to 240, 280 and 320 respectively, roving spacing 10mm, and humidity control environment humidity above 65%.

[0042] The performance of ordinary yarn (control group) and phase yarn (experimental group) prepared by the phase spinning technology of the present invention was compared.

[0043] The yarn breaking strength was tested and analyzed in accordance with the GB / T 3916-2013 standard. A YG061F electronic single yarn tensile tester was used, with the spacing set at 500mm ± 2mm, the moving clamp speed at 500 mm / min ± 10mm / min, and the initial tension at 0.5 cN / tex. The breaking strength of the yarn when stretched to break was measured.

[0044] The yarn diameter was tested and analyzed in accordance with the GB / T 3292.2-2009 standard. A CT3000 yarn evenness tester was used, with the test speed set to 200 m / min and the test time to 1 min. The yarn diameter was measured using a photoelectric detection system.

[0045] For yarn cross-sectional structure analysis, 5-10 mm segments of phase yarn and ordinary yarn were cut and vertically fixed on the sample stage with conductive adhesive to ensure cross-section observation. After gold sputtering, the cross-sectional morphology and fiber distribution of the yarn were photographed using a desktop scanning electron microscope TM3000.

[0046] contrast Figure 3 Table 1 shows the test results. When the twist coefficient is too low (200), the triangular zone of ordinary Siro spinning is too large, making yarn formation difficult. The phase spinning device allows the fibers to obtain pre-orientation and cohesion before yarn formation, thereby compensating for the dynamic strength of the yarn under low twist and improving spinnability. In the experimental group of this invention, with a 20% reduction in twist, the breaking strength of the phase yarn with a twist coefficient of 240 was comparable to that of ordinary yarn with a twist coefficient of 280, while the yarn diameter increased by 6%. Scanning electron microscopy images of the phase yarn and ordinary yarn are shown below. Figure 4 As shown, the phase yarn (left) is looser, while the regular yarn (right) is relatively tighter, resulting in the phase yarn diameter being larger than the regular yarn diameter.

[0047] Table 1. Breaking strength and diameter of phase yarn and ordinary yarn

[0048] Yarn type Twist coefficient Fracture strength (cN / Tex) Diameter (mm) Phase yarn 240 24.49 0.272 ordinary yarn 280 24.40 0.258

[0049] The obtained ordinary yarn with a twist coefficient of 280 (control group) and phase yarn with a twist coefficient of 240 (experimental group) were respectively knitted into high-density 1+1 rib fabrics on a computerized flat knitting machine. The weave parameters of the ordinary yarn in the control group were 62 in the warp and 82 in the weft. The weave parameters of the phase yarn in the experimental group were 58 in the warp and 78 in the weft.

[0050] The performance of ordinary yarn fabric (control group) and the phase yarn fabric of the present invention (experimental group) was compared. According to the standard FZ / T 01054-2012, the surface friction properties of the fabric were tested and analyzed using a KES-FB-4 fabric style tester. The average coefficient of dynamic friction (MIU), average deviation of friction coefficient (MMD), and surface roughness (SMD) in the warp direction of the fabric were obtained by observing the fluctuations of the instrument probe and sensor in the fabric thickness direction. Each sample was tested three times.

[0051] The differences in surface properties between ordinary yarn fabric (control group) and the phase yarn fabric of the present invention (experimental group) are shown in Table 2.

[0052] Comparing the test results in Table 2, the surface roughness (SMD) of the phase yarn fabric is approximately 63% higher than that of the ordinary yarn fabric. This is because the increased yarn diameter exacerbates the undulations caused by yarn interlacing within the fabric, macroscopically manifesting as increased roughness. Increased surface roughness enhances diffuse reflection on the fabric surface, thus improving the aurora effect.

[0053] Table 2. Test results of surface friction properties of phase yarn fabric and ordinary yarn fabric.

[0054] Fabric type MIU MMD SMD (μm) Phase yarn fabric 0.230 0.0075 3.814 Ordinary yarn fabric 0.226 0.0063 2.341

[0055] Comparative test results show that, compared with ordinary yarn fabrics, the low-twist soft silk yarn fabric of the present invention has a better hand feel and a softer luster when the fabric density is reduced while maintaining the same tightness.

[0056] Example 2

[0057] The yarn count was set to 21s, the twist coefficient to 320, and the ratio of the rotation speed of the phase spinning device to the output speed of the front roller was 4~12. Phase yarn was prepared using the same method as in Example 1, and the breaking strength and evenness were tested.

[0058] The yarn breaking strength test method is the same as that in Comparative Example 1.

[0059] The yarn evenness rate was tested and analyzed according to the GB / T 3292.1-2008 standard. A CT3000 yarn evenness tester was used, with a test speed of 200 m / min and a test time of 1 min. As the sample passed through the capacitor plates, the change in sample weight caused a change in capacitance, from which the percentage (CVm%) of the ratio of the standard deviation of yarn linear density to the average linear density over the total test length was obtained.

[0060] The strength and evenness (CVm%) of the resulting phase-spun yarn are as follows: Figure 5-6 As shown, when the speed ratio is 8~12, the false twisting effect of the phase spinning belt on the yarn is strong enough and the yarn unevenness is relatively low.

Claims

1. A method for preparing a low-twist soft silk based on force compensation, comprising the following steps: (1) using mulberry silk floc with a fiber length of 38-51 mm and a fineness of 1.3-1.8 dtex as raw material, after the processes of carding, drawing and roving, a mulberry silk roving with fiber orientation is obtained, the roving is pre-humidified by spraying water vapor, the water content of the fiber is controlled at 15-16%, and the fiber is subjected to antistatic treatment by being closed and static for 24 hours or more; (2) feeding the mulberry silk roving in step (1) into a spinning frame in two strands, controlling the environmental humidity to be 65% or more, and using phase spinning technology to prepare a low-twist soft silk based on force compensation; In the phase spinning technology, the phase spinning device includes two belts arranged above and below, moving in opposite directions, and independently controlled in speed; the sliver passes through and contacts the belts, and the positions of the two belts are constant during the spinning process, and the twisted sliver runs along an S-shaped trajectory between the two belts; the sliver after drafting is gathered by false twisting and true twisting to form a triangular area, and then the partial twist is removed downstream of the phase spinning device until the set twist is wound on the bobbin; the ratio of the rotational speed of the phase spinning device to the output speed of the front roller is 8-12.

2. The production method according to claim 1, characterized by, In step (1), the roving weight is 3-5 g / 10 m, and the twist is 3-4 twists / 10 m.

3. The production method according to claim 1, characterized by, In step (2), the spinning process parameters include: spindle speed of 7000-15000 rpm, twist factor of 200-320, and roving gauge of 8-12 mm.

4. The method of claim 1, wherein, In step (2), the low-twist soft silk is pure silk yarn, and the yarn count is 21-32 s. 5.A low-twist soft silk based on force compensation prepared by the method according to any one of claims 1-4.

6. A low twist, soft lustre muslin fabric, characterized by, The low-twist soft silk based on force compensation is spun into a high-density 1+1 rib fabric or a high-density plain fabric, and under the condition that the total tightness of the fabric remains unchanged, the fabric density is reduced by 5.5-6%.

7. The low twist sheer fabric of claim 6, wherein, The high-density 1+1 rib fabric has a horizontal density of 56-60 ends / 5 cm and a vertical density of 76-80 ends / 5 cm; the high-density plain fabric has a warp density of 188-208 and a weft density of 170-190.

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