Elastic fiber with draping feeling and cotton feeling and preparation method thereof

Abstract

The invention relates to an elastic fiber with a draping feeling and a cotton feeling and a preparation method thereof. The elastic fiber with the draping feeling and the cotton feeling is prepared from a pre-oriented polyester fiber through an elasticity enhancing process; the elasticizing process comprises the following steps: pre-orienting polyester fibers, pre-interlacing, passing through a first yarn feeding roller, passing through a deformation hot box, passing through a cooling plate, passing through a false twister, passing through a second yarn feeding roller, passing through an auxiliary roller, passing through a shaping hot box, passing through a shaping yarn feeding roller, passing through an oiling roller, and passing through DTY winding forming overfeeding to obtain elastic fibers; the temperature of the deformation hot box is 230-250 DEG C, and closing the shaping hot box; the ratio of the speed of the second yarn feeding roller to the speed of the first yarn feeding roller is 1.2-1.5; the elongation at break of the prepared elastic fiber with the draping feeling and the cotton feeling is 19-23%, the crimp shrinkage rate is 8-11%, and the draping resilience percentage of a fabric woven from the fiber is 15-26%. The method disclosed by the invention is simple and can meet large-scale development and use; the product has the characteristics of high drapability and cotton softness balance.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical fibers and relates to an elastic fiber with drape and cotton feel and a preparation method thereof. Background Art

[0002] With the continuous progress and innovation of the textile fabric market, the appearance, pattern and characteristics of traditional polyester fibers no longer meet the requirements of the fabric and textile market. Therefore, various differentiated fibers have been created for use in various fabrics and textiles.

[0003] Currently, there is a kind of stretch cotton and linen blended fabric on the market, which is made of stretch yarn blended with mulberry silk and flax twisted composite yarn. It has the softness and moisture absorption properties of cotton fiber and the breathability and glossiness of linen fiber, while also having the elasticity of stretch yarn.

[0004] Polyester fibers generally possess a range of excellent properties, including high breaking strength and elastic modulus, moderate resilience, excellent heat setting, good heat and light resistance, and resistance to acids, alkalis, and corrosion. Their fabrics are also wrinkle-resistant, iron-free, and crisp, making them widely used in clothing, home textiles, and other fields. By adjusting equipment and processes, differentiated fibers with unique appearances and varying handfeel can be produced while maintaining stable physical properties and weaving quality.

[0005] However, in fabric design, drape and a cottony feel are two properties that are difficult to achieve simultaneously. Currently, a common method for achieving drape is to combine multiple fibers with different elastic moduli and twists, creating a contraction torque through the difference in elasticity and twist, thereby achieving high drape. The cottony feel of the fabric can be achieved by applying an air pressure network after secondary stretching. However, since uniform stretching destroys the elasticity and twist of the fiber, causing the fiber to lose drape, the drape and cottony feel conflict with each other, making it difficult to achieve a balance.

[0006] To achieve both drape and a cottony feel, existing technologies typically use multiple fibers of varying composition. For example, patent CN202411023018.3 describes a stretch cotton fabric and its production process, which is woven from two membrane layers: a non-woven fabric layer and an elastic membrane layer.

[0007] Patent CN207904452U mentions a stretch cotton, linen and silk blended fabric, the warp yarn is stretch yarn (the inner layer of the stretch yarn is modal fiber, and the outer layer is bamboo cotton), and the weft yarn is a composite yarn twisted together with mulberry silk and flax.

[0008] The existing technology of using different component fibers for composite has the following main disadvantages: (1) high requirements on the physical properties of each raw material and high cost; (2) single component and cannot be flexibly adjusted.

[0009] Therefore, it is of great significance to study an elastic fiber with drape and cotton feel and a preparation method thereof to solve the problems existing in the prior art. Summary of the Invention

[0010] The purpose of the present invention is to solve the problems existing in the prior art and provide an elastic fiber with drape and cotton feel and a preparation method thereof.

[0011] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0012] A method for preparing elastic fibers with drape and cotton feel, wherein pre-oriented polyester fibers are subjected to a texturizing process to prepare elastic fibers with drape and cotton feel;

[0013] The texturing process is as follows: pre-oriented polyester fiber → pre-interlocking → first feed roller → texturing hot box → cooling plate → false twister → second feed roller (W2 roller) → auxiliary roller (W2X roller) → shaping hot box → shaping feed roller → oiling roller → DTY winding and overfeeding → elastic fiber. Compared with the prior art texturing process, the present invention does not include a mid-interlocking device, which would destroy the uneven thickness of the yarns caused by high temperature and incomplete stretching. Instead, the present invention applies pre-interlocking air pressure before stretching to enhance the bundledness of the yarns and enhance the cottony feel of the product.

[0014] The temperature of the deformation hot box is 230-250°C, which activates the movement of polyester fiber macromolecular chains, making the movement disordered. The higher the temperature, the more active the macromolecular chain movement, and the more likely it is to form molecular chains. When the setting hot box is closed, that is, the setting hot box temperature is at room temperature, the lack of the internal stress relief effect of the setting temperature will enable the fiber to maintain a high elastic modulus, ensuring the elastic properties of the product. The rotation speed (i.e., the speed of the second feeding roller) is 300-600m / min, and the ratio of the second feeding roller speed to the first feeding roller speed (i.e., the draft ratio) is 1.29-1.5. The draft ratio of conventional fibers is between 1.55-1.75. When stretched at a low draft ratio, the smaller orientation force prevents some active macromolecular segments from completing orientation, resulting in cross-linking, which appears as thin segments of monofilament adhesion.

[0015] The false twister is a friction-disc type. Both the upper inlet disc (for yarn introduction) and the lower outlet disc (for yarn outlet) are smooth discs, while the middle layer (for frictional false twisting) uses five polyurethane friction plates. Unlike conventional false twister installation methods, the lowermost layer, which is a ceramic trapezoidal blade disc, is replaced with a ceramic disc to reduce friction damage, preserve the thick and thin segment structure created by high temperature and low stretching, and create a three-dimensional effect. The false twister speed ratio (the ratio of the false twister speed to the speed of the second yarn feed roller) is 1.5 to 2.13. With the second yarn feed roller speed (i.e., the vehicle speed) determined, the false twister speed is controlled by controlling the false twister speed ratio.

[0016] The overfeed of the auxiliary roller (i.e., the speed difference ratio, calculated as (W2X roller speed - W2 roller speed) / W2 roller speed) is -24.5% to -16.0%. The auxiliary roller speed is controlled by a frequency converter, which has low and high frequencies. The low frequency range is 10-30 Hz, and the high frequency range is 50-90 Hz. The frequency of the frequency converter changes periodically. Within one cycle, the frequency converter first switches to a low frequency state and then switches to a high frequency state. The duration of one cycle is 10-30 seconds. Within one cycle, the time the frequency converter is in the low frequency state accounts for 20-40% of the cycle time. The switching time of the frequency converter from the low frequency state to the high frequency state is 0.5-0.8 seconds.

[0017] The change in speed is mainly caused by the change in the set frequency period. The basic formula is n=60f / p, where n is the speed, f is the frequency, and p is the number of pole pairs of the motor's rotating magnetic field.

[0018] As the preferred technical solution:

[0019] In the method for preparing elastic fibers having a drape and cotton feel, the pre-network pressure is 0.15-0.20 MPa, the cooling plate length is 1-1.5 m, the setting feeding roller overfeed is 8.0-10.0%, and the winding forming overfeed is 8.0-10.0%.

[0020] In the method for preparing elastic fibers having a drape and cotton feel as described above, the texturizing process adopts a TMT1500-FOUR automatic doffing single-strand machine, which has the following features: (1) the deformation hot box adopts trough-type biphenyl insulation, and the deformation temperature is stable; (2) auxiliary rollers are added to enhance the stability of the yarn bundle before entering the shaping hot box; (3) automatic doffing is adopted to reduce the cost of manual doffing.

[0021] In the method for preparing elastic fibers having a drapey and cottony feel as described above, the fineness of the pre-oriented polyester fibers is 135-600 dtex.

[0022] The present invention also provides an elastic fiber with drape and cotton feel obtained by the preparation method as described in any of the above items. The elastic fiber is a pre-oriented polyester fiber that has uniform thickness and thin segments and has both cotton softness and elasticity after the orderliness of the internal molecular chain is destroyed due to high temperature and then subjected to roller stretching and twisting processes. The elastic fiber with drape and cotton feel has thick segments that rebound and curl to appear like down, while thin segments are slender and have small twist. The combination of the two characteristics results in a drape of a spring-like structure; the elastic fiber with drape and cotton feel has a single yarn fineness of 1.3~2.5dtex, a breaking strength of 2.9~3.2cN / dtex, an elongation at break of 19~23%, a curl shrinkage of 8~11%, and a boiling water shrinkage of 3.9~5.0%; the cotton softness is characterized by the softness of the fabric, which is reflected in the curvature of the fabric The degree of deformation can be obtained from the elongation and curling indicators of elastic fibers with drape and cotton feel; among them, the elongation reflects the tensile strength of the fiber monomer and the degree of deformation resistance of the fabric. The greater the elongation, the greater the fiber elongation, the greater the extrusion and tensile force that the fiber in the woven fabric can bear, the faster the recovery and stability after being subjected to deformation force, and the stronger the overall cotton feel of the fabric; the curling shrinkage stability index reflects the uniformity of the shrinkage and bending deformation of each unit fiber. In terms of fabric, it reflects the uniformity of the compression deformation of each unit fabric. The better the stability, the better the overall softness and uniformity of the fabric; the drape is reflected in the regular percentage rebound of the fabric due to the drape characteristics when the fabric is hung. The strength of the fabric drape is reflected in the rebound percentage of the fabric. The drape rebound percentage of elastic fibers with drape and cotton feel woven into fabric is 15~26%.

[0023] Principle of the invention:

[0024] Drape and cottony softness are two opposing properties. To achieve both, existing fabrics typically use a composite of fibers with multiple different components. This invention innovatively proposes a method for preparing elastic fibers with both drape and cottony feel. The fibers are first subjected to unstable stretching to create a fiber structure with varying thicknesses. Subsequently, through equipment modification and process tuning, uniform stretching destroys a certain amount of thin segments. The thick segments, due to false twisting, acquire a high twist, which then retracts at low heat box temperatures to achieve a certain degree of cottony softness. This method achieves a polyester fiber that achieves a balance between the two.

[0025] At high deformation hot box temperature, the orderly movement of molecules in the fiber is destroyed, resulting in disordered development per unit distance. The low speed ensures that the fiber is fully heated in the high deformation hot box temperature, which more effectively destroys the orderly movement of the molecular chain. The low drafting effect insufficiently stretches the fiber. After the high deformation temperature and low speed are combined, the fiber surface is unevenly stretched to form an uneven thickness state. Combined with the modification of the false twister equipment and the false twist speed control, the uneven twist characteristic of the fiber can be obtained (the role of the lead-out disk of the false twister equipment in the prior art is to evenly reduce the twist of the fiber after continuous false twisting by each friction disk of the false twister. The present invention reduces the twist reduction effect by modifying the equipment and replacing the lead-out disk structure, and can obtain an uneven twist reduction effect; different speed ratios need to be adjusted for fibers of different specifications and varieties), and the fiber obtains high drapability. By adding a frequency converter to the auxiliary rollers, the fibers are regularly untwisted at a certain speed, and the untwisted fibers produce elasticity and a cottony feel (the setting value of the frequency converter is specified as "low-speed duration - high-speed duration". By adjusting the high-frequency and low-frequency times within a certain period, the magnitude and frequency of the stretching force on the fibers are controlled to achieve a certain regular stretching effect and obtain the required product characteristics. The faster the high-speed frequency ratio, the more complete the stretching and the stronger the cottony feel; conversely, the faster the low-speed frequency ratio, the weaker the cottony feel). The drape and cottony feel will be slightly different under different process settings and auxiliary roller frequency converter and false twister speeds. The product prepared by the method of the present invention has the characteristics of high drape and a balanced cottony feel.

[0026] Beneficial effects:

[0027] (1) The present invention provides a method for preparing elastic fibers with a drape and cotton feel, wherein the fibers are first subjected to unstable stretching to obtain fiber structures of different thicknesses, and then, through subsequent equipment modification and process debugging, a certain amount of thin segment structure is destroyed by uniform stretching. The thick segment structure fibers obtain high twist due to false twisting and shrink under low hot box temperature to form a certain cotton softness, thereby obtaining fibers with a high drape and a balanced cotton feel. The fibers can be widely used in the development and use of heterogeneous functional fabrics in the market. At the same time, the equipment modification and process properties of the present invention can meet the requirements of large-scale development and use.

[0028] (2) The present invention provides a method for preparing elastic fibers having a drapey and cottony feel. The physical properties of the fibers produced are stable, and the fiber fineness (mass per unit length) can be adjusted flexibly according to the raw materials. The product also has the physical properties required for fabrics and has no special requirements for weaving.

[0029] (3) The elastic fiber of the present invention has a drape and cotton feel, which is consistent with the linen feel and drape of the elastic cotton and linen prepared by twisting elastic fiber with mulberry silk and flax on the market. The strength, curl shrinkage and boiling water shrinkage physical properties of the produced fiber can meet the requirements of post-spinning for the cotton feel and drape of the fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of a process for texturizing elastic fibers according to the present invention;

[0031] Figure 2 This is a schematic diagram of the false twister disc assembly;

[0032] Figure 3 It is a structural feature of elastic fibers that have a drapey and cottony feel;

[0033] Among them, 1-pre-oriented polyester fiber, 2-pre-network, 3-first feeding roller, 4-first deformation hot box, 5-cooling plate, 6-false twister, 7-second feeding roller, 8-auxiliary roller, 9-second shaping hot box, 10-shaping feeding roller, 11-oiling roller, 12-DTY winding forming overfeed, 13-upper introduction disk, 14-lower output disk. DETAILED DESCRIPTION

[0034] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0035] The test methods involved in the performance indicators in the embodiments and comparative examples of the present invention are as follows:

[0036] Breaking strength and elongation at break: in accordance with GB / T14344-2022.

[0037] Curl shrinkage: in accordance with GBT / 6506-2017.

[0038] Boiling water shrinkage: in accordance with GBT / 6505-2017.

[0039] Drape rebound percentage: When testing, use a tensile testing machine (universal tensile testing machine) to stretch the fabric vertically for a certain length, then release the tension and record the rebound length; rebound percentage = (rebound length / stretched length) * 100%.

[0040] Example 1

[0041] A method for preparing elastic fiber with drape and cotton feel, the specific process is as follows:

[0042] Pre-oriented polyester fiber with a specification of 266dtex / 144f is made into elastic fiber with drape and cotton feel through a texturizing process;

[0043] The texturing process uses TMT1500-FOUR automatic doffing single strand machine, such as Figure 1 As shown in the figure, the texturing process is as follows: pre-oriented polyester fiber 1 → pre-network 2 → first feeding roller 3 → first texturing hot box 4 → cooling plate 5 → false twister 6 → second feeding roller 7 → auxiliary roller 8 → second setting hot box 9 → setting feeding roller 10 → oiling roller 11 → DTY winding and forming overfeed 12 → elastic fiber;

[0044] like Figure 2 As shown, the false twister is a friction disc type false twister; the upper inlet disc and the lower outlet disc are both smooth discs, and the middle layer uses 5 polyurethane friction plates;

[0045] The pre-interlacing pressure was 0.17 MPa, the cooling plate length was 1.5 m, the false twister speed ratio was 1.5, the texturing hot box temperature was 230°C, the setting hot box was closed, the second feeding roller speed was 350 m / min, the ratio of the second feeding roller speed to the first feeding roller speed was 1.3, the setting feeding roller overfeed was 9%, and the winding forming overfeed was 8%.

[0046] The overfeed of the auxiliary roller is -22.5%. The speed of the auxiliary roller is controlled by a frequency converter. The frequency of the frequency converter includes low frequency and high frequency. The low frequency is 15Hz and the high frequency is 55Hz. The frequency of the frequency converter changes periodically. Within one cycle, the frequency converter is first in a low frequency state and then switches to a high frequency state. The time of one cycle is 10s. Within one cycle, the time when the frequency converter is in a low frequency state accounts for 30% of the time of one cycle.

[0047] like Figure 3 As shown, the unit structure of the elastic fiber with drape and cotton feel finally obtained is composed of a thin segment and a thick segment of fiber that rebounds up and down.

[0048] The single-filament fineness of the elastic fiber with drape and cotton feel is 1.85 dtex, the breaking strength is 3.09 cN / dtex, the breaking elongation is 22.62%, the curl shrinkage is 9.52%, and the boiling water shrinkage is 4.63%; the drape rebound percentage of the elastic fiber with drape and cotton feel after being woven into a fabric is 23%.

[0049] Comparative Example 1

[0050] A method for preparing elastic fiber is basically the same as that of Example 1, except that the temperature of the deformation hot box is 225°C.

[0051] The final elastic fiber has a single-filament fineness of 1.91 dtex, a breaking strength of 3.11 cN / dtex, a breaking elongation of 23.50%, a curl shrinkage rate of 10.23%, and a boiling water shrinkage rate of 4.25%; the drape rebound percentage of the elastic fiber after being woven into a fabric is 13.5%.

[0052] Comparing Comparative Example 1 with Example 1, it can be found that the drape resilience of the fiber prepared in Comparative Example 1 is significantly reduced. This is because the deformation temperature decreases, resulting in a decrease in the high-temperature destruction effect of the molecular chains, and the molecular chains tend to move stably. Although the cottony softness is enhanced, the drape is severely weakened, and the balance between high drape and cottony softness cannot be achieved.

[0053] Comparative Example 2

[0054] A method for preparing elastic fiber is basically the same as that of Example 1, except that the ratio of the speed of the second feeding roller to the speed of the first feeding roller is 1.55.

[0055] The final elastic fiber has a single-filament fineness of 1.78 dtex, a breaking strength of 3.18 cN / dtex, a breaking elongation of 23.7%, a curl shrinkage rate of 9.89%, and a boiling water shrinkage rate of 4.32%; the drape rebound percentage of the elastic fiber after being woven into a fabric is 14.8%.

[0056] Comparing Comparative Example 2 with Example 1, it can be found that the drape resilience of the fiber prepared in Comparative Example 2 is significantly reduced. This is because the greater the ratio of the speed of the second feeding roller to the speed of the first feeding roller, the greater the tensile force on the fiber; the thin segments of the fiber are reduced and the thick segments are increased. Due to the reduction of the thin segments, the drape feeling is greatly weakened, and the balance between high drape and cotton softness cannot be achieved.

[0057] Comparative Example 3

[0058] A method for preparing elastic fiber is basically the same as that of Example 1, except that no frequency conversion device is installed at the auxiliary feeding roller.

[0059] The final elastic fiber has a single-filament fineness of 1.85 dtex, a breaking strength of 2.98 cN / dtex, an elongation at break of 18.74%, a curl shrinkage of 8.7%, and a boiling water shrinkage of 4.50%; the drape rebound percentage of the elastic fiber after being woven into a fabric is 13.27%.

[0060] Comparing Comparative Example 3 with Example 1, it can be found that the overall elongation and fabric drape percentage of Comparative Example 1 are both reduced. This is because the lack of regular stretching makes it impossible to produce a periodic thick and thin segment structure, and the overall drape and cotton softness are uneven, resulting in a simultaneous decrease in the physical properties of elongation and fabric drape percentage.

[0061] Example 2

[0062] A method for preparing elastic fiber with drape and cotton feel, the specific process is as follows:

[0063] Pre-oriented polyester fiber with a specification of 136dtex / 72f is made into elastic fiber with drape and cotton feel through a texturizing process;

[0064] The texturing process uses the TMT1500-FOUR automatic doffing single-strand machine. The texturing process flow is: pre-oriented polyester fiber → pre-netting → first feeding roller → texturing hot box → cooling plate → false twister → second feeding roller → auxiliary roller → shaping hot box → shaping feeding roller → oiling roller → DTY winding and overfeeding → elastic fiber;

[0065] The false twister is a friction disc type; the upper inlet disc and the lower outlet disc are both smooth discs, and the middle layer uses 5 polyurethane friction plates;

[0066] The pre-interlacing pressure was 0.15 MPa, the cooling plate length was 1.5 m, the false twister speed ratio was 1.72, the texturing hot box temperature was 245°C, the setting hot box was closed, the second feeding roller speed was 580 m / min, the ratio of the second feeding roller speed to the first feeding roller speed was 1.49, the setting feeding roller overfeed was 8%, and the winding forming overfeed was 8.5%.

[0067] The overfeed of the auxiliary roller is -16%. The speed of the auxiliary roller is controlled by a frequency converter. The frequency of the frequency converter includes low frequency and high frequency. The low frequency is 30 Hz and the high frequency is 80 Hz. The frequency of the frequency converter changes periodically. Within one cycle, the frequency converter is first in a low frequency state and then switches to a high frequency state. The time of one cycle is 30 seconds. Within one cycle, the time when the frequency converter is in a low frequency state accounts for 34% of the time of one cycle.

[0068] The final elastic fiber with drape and cotton feel has a single yarn fineness of 1.89 dtex, a breaking strength of 3.12 cN / dtex, an elongation at break of 22.36%, a curl shrinkage rate of 8.84%, and a boiling water shrinkage rate of 4.53%; the drape rebound percentage of the elastic fiber with drape and cotton feel after being woven into a fabric is 24%.

[0069] Example 3

[0070] A method for preparing elastic fiber with drape and cotton feel, the specific process is as follows:

[0071] Pre-oriented polyester fiber with a specification of 540dtex / 288f is made into elastic fiber with drape and cotton feel through a texturizing process;

[0072] The texturing process uses the TMT1500-FOUR automatic doffing single-strand machine. The texturing process flow is: pre-oriented polyester fiber → pre-netting → first feeding roller → texturing hot box → cooling plate → false twister → second feeding roller → auxiliary roller → shaping hot box → shaping feeding roller → oiling roller → DTY winding and overfeeding → elastic fiber;

[0073] The false twister is a friction disc type; the upper inlet disc and the lower outlet disc are both smooth discs, and the middle layer uses 5 polyurethane friction plates;

[0074] The pre-interlacing pressure was 0.20 MPa, the cooling plate length was 1.5 m, the false twister speed ratio was 1.7, the texturing hot box temperature was 247°C, the setting hot box was closed, the second feeding roller speed was 300 m / min, the ratio of the second feeding roller speed to the first feeding roller speed was 1.29, the setting feeding roller overfeed was 9.5%, and the winding forming overfeed was 10%;

[0075] The overfeed of the auxiliary roller is -18%. The speed of the auxiliary roller is controlled by a frequency converter. The frequency of the frequency converter includes low frequency and high frequency. The low frequency is 10 Hz and the high frequency is 70 Hz. The frequency of the frequency converter changes periodically. Within one cycle, the frequency converter is first in a low frequency state and then switches to a high frequency state. The time of one cycle is 20 seconds. Within one cycle, the time when the frequency converter is in a low frequency state accounts for 24% of the time of one cycle.

[0076] The final elastic fiber with drape and cotton feel has a single yarn fineness of 1.88 dtex, a breaking strength of 2.93 cN / dtex, an elongation at break of 20.22%, a curl shrinkage rate of 10.32%, and a boiling water shrinkage rate of 4.03%; the drape rebound percentage of the elastic fiber with drape and cotton feel after being woven into a fabric is 17%.

[0077] Example 4

[0078] A method for preparing elastic fiber with drape and cotton feel, the specific process is as follows:

[0079] Pre-oriented polyester fiber with a specification of 190dtex / 144f is made into elastic fiber with drape and cotton feel through a texturizing process;

[0080] The texturing process uses the TMT1500-FOUR automatic doffing single-strand machine. The texturing process flow is: pre-oriented polyester fiber → pre-netting → first feeding roller → texturing hot box → cooling plate → false twister → second feeding roller → auxiliary roller → shaping hot box → shaping feeding roller → oiling roller → DTY winding and overfeeding → elastic fiber;

[0081] The false twister is a friction disc type; the upper inlet disc and the lower outlet disc are both smooth discs, and the middle layer uses 5 polyurethane friction plates;

[0082] The pre-interlacing pressure was 0.16 MPa, the cooling plate length was 1.5 m, the false twister speed ratio was 1.63, the texturing hot box temperature was 235°C, the setting hot box was closed, the second feeding roller speed was 500 m / min, the ratio of the second feeding roller speed to the first feeding roller speed was 1.33, the setting feeding roller overfeed was 10%, and the winding forming overfeed was 10%;

[0083] The overfeed of the auxiliary roller is -24.5%. The speed of the auxiliary roller is controlled by a frequency converter. The frequency of the frequency converter includes low frequency and high frequency. The low frequency is 10 Hz and the high frequency is 60 Hz. The frequency of the frequency converter changes periodically. Within one cycle, the frequency converter is first in a low frequency state and then switches to a high frequency state. The time of one cycle is 10 seconds. Within one cycle, the time when the frequency converter is in a low frequency state accounts for 40% of the time of one cycle.

[0084] The final elastic fiber with drape and cotton feel has a single yarn fineness of 1.32 dtex, a breaking strength of 3.05 cN / dtex, an elongation at break of 22.15%, a curl shrinkage rate of 10.98%, and a boiling water shrinkage rate of 4.75%; the drape rebound percentage of the elastic fiber with drape and cotton feel after being woven into a fabric is 25%.

[0085] Example 5

[0086] A method for preparing elastic fiber with drape and cotton feel, the specific process is as follows:

[0087] Pre-oriented polyester fiber with a specification of 350dtex / 144f is made into elastic fiber with drape and cotton feel through a texturizing process;

[0088] The texturing process uses the TMT1500-FOUR automatic doffing single-strand machine. The texturing process flow is: pre-oriented polyester fiber → pre-netting → first feeding roller → texturing hot box → cooling plate → false twister → second feeding roller → auxiliary roller → shaping hot box → shaping feeding roller → oiling roller → DTY winding and overfeeding → elastic fiber;

[0089] The false twister is a friction disc type; the upper inlet disc and the lower outlet disc are both smooth discs, and the middle layer uses 5 polyurethane friction plates;

[0090] The pre-interlacing pressure was 0.19 MPa, the cooling plate length was 1.5 m, the false twister speed ratio was 2.13, the texturing hot box temperature was 242°C, the setting hot box was closed, the second feeding roller speed was 500 m / min, the ratio of the second feeding roller speed to the first feeding roller speed was 1.32, the setting feeding roller overfeed was 9.4%, and the winding forming overfeed was 10%;

[0091] The overfeed of the auxiliary roller is -18%. The speed of the auxiliary roller is controlled by a frequency converter. The frequency of the frequency converter includes low frequency and high frequency. The low frequency is 20 Hz and the high frequency is 80 Hz. The frequency of the frequency converter changes periodically. Within one cycle, the frequency converter is first in a low frequency state and then switches to a high frequency state. The time of one cycle is 30 seconds. Within one cycle, the time when the frequency converter is in a low frequency state accounts for 20% of the time of one cycle.

[0092] The final elastic fiber with drape and cotton feel has a single yarn fineness of 2.43 dtex, a breaking strength of 3.16 cN / dtex, an elongation at break of 19.78%, a curl shrinkage rate of 8.92%, and a boiling water shrinkage rate of 3.93%; the drape rebound percentage of the elastic fiber with drape and cotton feel after being woven into a fabric is 16%.

Claims

1. A method for preparing elastic fibers having a drapey and cottony feel, characterized in that: Pre-oriented polyester fibers are made into elastic fibers with drape and cotton feel through a texturing process; The texturing process is: pre-oriented polyester fiber → pre-network → first feeding roller → texturing hot box → cooling plate → false twister → second feeding roller → auxiliary roller → shaping hot box → shaping feeding roller → oiling roller → DTY winding forming overfeed → elastic fiber; The temperature of the deformation hot box is 230~250℃; the setting hot box is closed; the speed of the second wire feeding roller is 300~600m / min, and the ratio of the speed of the second wire feeding roller to the speed of the first wire feeding roller is 1.29~1.5; The false twister is a friction disc type false twister; the upper inlet disc and the lower outlet disc are both smooth discs, and the middle layer is made of 5 polyurethane friction plates; the speed ratio of the false twister is 1.5~2.13; The overfeed of the auxiliary roller is -24.5~-16.0%. The speed of the auxiliary roller is controlled by a frequency converter. The frequency of the frequency converter includes low frequency and high frequency. The low frequency is 10~30Hz, and the high frequency is 50~90Hz. The frequency of the frequency converter changes periodically. In one cycle, the frequency converter is first in a low frequency state and then switches to a high frequency state. The time of one cycle is 10~30s. In one cycle, the time when the frequency converter is in a low frequency state accounts for 20~40% of the time of one cycle.

2. The method for preparing elastic fiber with drape and cotton feel according to claim 1, characterized in that: The pre-network pressure is 0.15~0.20MPa, the cooling plate length is 1~1.5m, the shaping wire roller overfeed is 8.0~10.0%, and the winding forming overfeed is 8.0~10.0%.

3. The method for preparing elastic fiber with drape and cotton feel according to claim 1, characterized in that: The texturing process uses the TMT1500-FOUR automatic doffing single-strand machine.

4. The method for preparing elastic fiber with drape and cotton feel according to claim 1, characterized in that: The fineness of pre-oriented polyester fiber is 135~600dtex.

5. An elastic fiber with drape and cotton feel obtained by the preparation method according to any one of claims 1 to 4, characterized in that: The single-filament fineness of the elastic fiber with drape and cotton feel is 1.3~2.5dtex, the breaking strength is 2.9~3.2cN / dtex, the breaking elongation is 19~23%, the curl shrinkage is 8~11%, and the boiling water shrinkage is 3.9~5.0%; the drape rebound percentage of the elastic fiber with drape and cotton feel after being woven into a fabric is 15~26%.

Images