A production process for silk-like mercerized cotton polyester yarn

Abstract

The present invention belongs to the field of textile technology and relates to a production process of silk-like mercerized cotton polyester yarn. After the POY yarn and the FDY yarn are compounded, through specific drawing deformation and heat setting treatment, polyester yarn with excellent gloss, silkiness and drapability is prepared. Among them, the POY yarn is prepared by increasing the winding speed, with the breaking elongation rate reduced and the crystallinity and orientation degree increased; the drawing deformation multiple and the heat setting temperature are precisely controlled. The present invention does not need to rely on methods with high costs and poor environmental protection. By optimizing the preparation process of the POY yarn, increasing the winding speed to increase its crystallinity and orientation degree, and after compounding it with the FDY yarn, precisely controlling the drawing deformation multiple, the drawing deformation temperature and the heat setting temperature, silk-like mercerized cotton polyester yarn with strong gloss, good and lasting silkiness and excellent drapability is successfully prepared.

Description

Technical Field

[0001] The present invention belongs to the technical field of textiles and relates to a production process of silk-like mercerized cotton polyester yarn. Background Art

[0002] With the development of the textile market, the demand for polyester imitation cotton yarn products with properties similar to those of mercerized cotton has become increasingly prominent. Mercerized cotton fabrics are favored by consumers in the domestic market due to their good gloss, excellent smoothness, soft handfeel, and good drapability. Therefore, developing a silk-like mercerized cotton polyester yarn with excellent gloss, smoothness, and drapability is of great significance for meeting the market demand for high-quality yarns.

[0003] However, there is currently no polyester imitation cotton yarn product on the market that can fully meet the above requirements. The existing related technologies have many deficiencies in improving the various properties of the yarn and are difficult to achieve the goal of preparing high-quality silk-like mercerized cotton polyester yarn.

[0004] In terms of improving the gloss of the yarn, Patent Application CN102995198A improves the gloss by controlling the disc material, the number of false twister discs, and setting temperature conditions, but its application effect on ordinary semi-dull raw materials is very limited and cannot achieve the desired gloss improvement effect. Patent Application CN101177801A uses a method of adding chemicals to modify raw materials to prepare specific materials to improve the gloss. This approach is not only not environmentally friendly but also increases the production cost. Patent Applications CN106087098A and CN113529188A both improve the gloss by preparing profiled cross-section raw silk fibers, but this method is not applicable to the preparation of silk-like mercerized cotton polyester yarn. It can be seen that these existing technical means for improving the gloss of the yarn cannot effectively meet the requirements for preparing silk-like mercerized cotton polyester yarn with excellent gloss.

[0005] In terms of improving the smoothness of the yarn, the existing technologies mainly rely on methods such as adding surface oil agents, silicone finishing agents, or lubricants. However, these methods have many drawbacks. On the one hand, they increase the production cost. On the other hand, the effect of improving the smoothness by relying on the lubrication of external surface substances is difficult to last, and its smoothness will be significantly reduced after multiple washes. Therefore, it is also difficult to prepare silk-like mercerized cotton polyester yarn with excellent smoothness based on these existing technologies for improving the smoothness of the yarn.

[0006] In terms of improving the yarn drape, Patent Application CN110894633A increases the fabric drape by performing weight reduction processing after weaving, but its process is complex, which undoubtedly is not conducive to reducing production costs and cannot meet the requirements of efficiently producing imitation mercerized cotton polyester yarn with excellent performance. Patent Application CN107723861A attempts to improve the fiber drape by adding a pre-network process, but the actual effect is not obvious. In addition, Patent Applications CN101694031A, CN106978659A, CN116024713A and Patent CN216193061U also try to improve the drape by different methods, but they respectively have problems such as weak gloss, high production cost or insufficient environmental protection. It can be seen that the existing technologies for improving the yarn drape also have certain limitations and are difficult to meet the requirements for preparing high-quality imitation mercerized cotton polyester yarn.

[0007] In summary, in view of the deficiencies of the existing technologies in improving the yarn gloss, silkiness and drape, and accompanied by a series of problems such as high production cost and poor environmental protection, there is an urgent need to develop a new production process to prepare imitation mercerized cotton polyester yarn with excellent gloss, silkiness and drape, so as to meet the market demand for high-quality yarns. Summary of the Invention

[0008] The object of the present invention is to solve the problems existing in the prior art and provide a production process for imitation mercerized cotton polyester yarn.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] A production process for imitation mercerized cotton polyester yarn, in which POY yarn and FDY yarn are compounded and then subjected to draw texturing and heat setting in sequence;

[0011] The raw materials of POY yarn and FDY yarn are semi-dull PET, and the cross-section of the single filament is circular;

[0012] During the preparation of POY yarn, the winding speed is increased to improve the crystallinity and orientation degree of POY yarn, and then the elongation at break of POY yarn is reduced to 95-105%, which is 10-20% lower than that of conventional POY yarn;

[0013] The draw texturing multiple is 1.05-1.15;

[0014] The draw texturing temperature H1 < the heat setting temperature H2, H1 is 130-170 °C, and H2 is 170-190 °C.

[0015] The present invention has prepared a silk-like mercerized cotton polyester yarn with excellent gloss, silkiness, and drapability by controlling the breaking elongation rate of POY yarn, the draw ratio, H1 < H2, and the numerical values of H1 and H2. The specific principle is as follows:

[0016] The gloss of the yarn mainly comes from the light reflection performance of the fiber, and the light reflection performance of the fiber is closely related to its orientation degree and crystallinity. When the orientation degree and crystallinity of the fiber are relatively high, the macromolecules of the fiber are arranged more regularly, the voids in the fiber structure will decrease, the light reflection performance of the fiber will be enhanced, and the gloss of the yarn will also increase accordingly. The present invention starts from two aspects to improve the orientation degree and crystallinity of the fiber: one is to optimize the POY yarn, and the other is to improve the texturing process.

[0017] Regarding the optimization of the POY yarn, the present invention has prepared a POY yarn with higher orientation degree and crystallinity (specifically reflected in a lower breaking elongation rate) compared with the conventional variety by increasing the winding speed in the pre-spinning stage.

[0018] Regarding the improvement of the texturing process, the present invention reduces the value of H1 within a certain range, which can promote the further crystallization orientation of the POY yarn with high orientation degree and crystallinity, and further improve the orientation degree and crystallinity. It should be noted that the setting of the H1 value needs to be moderate. If the H1 value is too low, hairiness and breakage are likely to occur during drawing, resulting in fibers with a stiff texture; if the H1 value is too high, the activity of the fiber macromolecules will increase, which may cause the phenomenon of deorientation, and will also lead to an increase in the crimp shrinkage rate of the yarn, which is not conducive to obtaining a product with excellent drapability.

[0019] In addition, reducing the H1 value will cause an increase in the internal stress between the molecules of the POY yarn. Therefore, it is necessary to increase the H2 value to eliminate or reduce this internal stress and ensure the product stability. After reducing the H1 value, the two kinds of filaments that are compounded together after false twisting are likely to separate or form loose loops. Therefore, it is necessary to control the draw ratio within a lower range.

[0020] In order to obtain a product with a silk-like feeling, the key lies in ensuring that the friction coefficient of the yarn is maintained at a relatively low level, which means that the surface of the yarn needs to reach a mirror-like smoothness. This smoothness is not only crucial for improving the gloss of the product (because an excellent light reflection effect is the basis for excellent gloss), but also an important factor in enhancing the silkiness. In fact, the core problems faced in improving the gloss and enhancing the smoothness are the same: once the surface of the yarn reaches sufficient smoothness to improve the gloss, its smoothness will also naturally increase.

[0021] The drapability of the yarn is closely related to the density of the fiber. Yarns made of fibers with a high density usually have better drapability. As mentioned above, the fibers of the present invention have a relatively high orientation degree and crystallinity, the macromolecules of the fiber are arranged more regularly, and the voids in the fiber structure are relatively small, which results in a relatively high density of the fiber, and thus the drapability of the yarn is better.

[0022] As a preferred technical solution:

[0023] In the production process of the imitation mercerized cotton polyester yarn as described above, during the preparation of the POY yarn, the winding speed is increased to 2400 - 3700 m / min, which is 300 - 700 m / min higher than that in the ordinary production of POY yarn of the same specification. Increasing the winding speed not only improves the crystallinity and orientation degree of the POY yarn, but also improves the production efficiency of the POY yarn.

[0024] In the production process of the imitation mercerized cotton polyester yarn as described above, the POY yarn is obtained by the melt direct spinning process, and the production process flow is: semi-dull PET melt → booster pump → heat exchanger → spinning box → metering pump → component → cooling air → oiling → godet 1 → air interlacer → godet 2 → winding and forming.

[0025] In the production process of the imitation mercerized cotton polyester yarn as described above, the mass ratio of the FDY yarn to the POY yarn is 51 - 55:45 - 49.

[0026] In the production process of the imitation mercerized cotton polyester yarn as described above, the specific process is as follows: the POY yarn and the FDY yarn are led out from the creel through the guide tube, pass through the cutter, and then enter the air interlacer through the zero roller for compounding. The compounded yarn bundle passes through the first roller, the first hot box, the cooling plate, the false twister, and the second roller in sequence for drawing and deforming. The drawn and deformed yarn bundle enters the second hot box for heat setting, and then passes through the third roller and the oiling roller in sequence and is wound and formed to obtain the imitation mercerized cotton polyester yarn. Among them, the temperature of the first hot box is H1, the temperature of the second hot box is H2, and the ratio of the rotational speed of the second roller to the rotational speed of the first roller is the drawing and deformation multiple.

[0027] In the production process of the imitation mercerized cotton polyester yarn as described above, the network pressure of the air interlacer is 3.5 - 5.0 bar. Using a larger network pressure for compounding can make the yarn fully wind and knot to form network points before drawing and deforming, and it is not easy to loosen the loops.

[0028] In the production process of the imitation mercerized cotton polyester yarn as described above, the overfeed rate of the third roller relative to the second roller is -4.0% to -8%. The purpose is to control the relaxation heat setting of the yarn in the second hot box, reduce the curl shrinkage rate of the yarn, and can further increase the drapability of the yarn.

[0029] In the production process of the imitation mercerized cotton polyester yarn as described above, the false twister is a friction disc stacked type false twisting device, and the ratio K of the untwisting tension to the twisting tension is 0.6 - 1.0.

[0030] In the production process of the mercerized cotton polyester yarn described above, the false twister is configured as 1-4-1, and is composed of 1 introduction disk, 4 friction disks, and 1 knife-edge disk. After the number of introduction disks and knife-edge disks is determined, the more friction disks there are in the middle, the greater the curl shrinkage rate is. When the curl shrinkage rate is large, the drape effect is weakened. Therefore, the number of friction disks should be reduced. However, if the number of disks is too small, the false twist system is unstable and breakage is easy to occur. Taking comprehensive consideration of the number of friction disks, 4 are selected, which is beneficial to further increase the drape of the yarn.

[0031] According to the production process of the imitation mercerized cotton polyester yarn as described above, the maximum static friction of the imitation mercerized cotton polyester yarn is 20-22gf (gram force), and the maximum static friction of the imitation mercerized cotton polyester yarn after 20 times of water washing is 20.5-23gf. The glossiness of the imitation mercerized cotton polyester yarn appears brighter than that of ordinary imitation cotton yarn by naked eye observation, and the glossiness will be more obvious when placed under light. The fabric made of the imitation mercerized cotton polyester yarn will feel very obvious silky and cool when touched directly by hand. The glossiness, silky and cool feeling are all directly related to the smoothness of the yarn surface. The smoother the yarn surface, the better the reflective effect, thereby showing a higher glossiness; at the same time, this smoothness reduces friction and gives the yarn a silky touch; the smoother the yarn, the cooler it feels (when the surface is rougher, the contact area with the skin becomes smaller, and the still air between the fabric and the skin reduces the heat exchange between the fabric and the skin, and the touch feels warm). Therefore, the maximum static friction of the yarn can be used to evaluate its glossiness, silkiness, and coolness. The smaller the maximum static friction, the more significant these characteristics are.

[0032] The curl shrinkage rate of mercerized cotton-like polyester yarn is 1.5-2.0%. The study found that there is a correlation between drape and curl shrinkage. Specifically, among yarns of the same variety and specification, yarns with lower curl shrinkage rates show better drape effects. This conclusion is verified by experiments: in the experiment, two yarns of the same variety and specification were drawn to the same length and placed on the same plane, and the tension was released at the same time. It was observed that the yarn with a smaller curl shrinkage rate would sag before the other yarn. Therefore, the present invention uses the curl shrinkage rate to characterize the drape of the yarn. The curl shrinkage rate of ordinary polyester high-gloss yarn is greater than 15%, the curl shrinkage rate of ordinary imitation cotton yarn is greater than 10%, and the curl shrinkage rate of the yarn of patent CN102995198A is 2.5-3.5%. By comparison, it can be seen that the curl shrinkage rate of the yarn of the present invention is significantly lower than that of the prior art.

[0033] Beneficial effects:

[0034] The present invention does not rely on methods that are costly and have poor environmental friendliness. By optimizing the preparation process of POY yarn, the winding speed is increased to enhance its crystallinity and orientation degree. After compounding it with FDY yarn, the draw ratio, draw temperature, and heat setting temperature are precisely controlled, successfully preparing a silk-like cotton polyester yarn with strong gloss, good and lasting silkiness (remaining good after multiple washes), and excellent drapability. Detailed Embodiments

[0035] The present invention will be further elaborated below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it 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 also fall within the scope defined by the appended claims of this application.

[0036] The following are the test methods for relevant performance indicators in each embodiment and comparative example:

[0037] Elongation at break: After equilibrating the sample to be tested for 4 hours under the conditions of temperature 20°C ± 2°C and humidity 65% ± 5%, use the YG023B-Ⅲ type full-automatic single yarn strength tester produced by Changzhou Bafang Lishi Textile Instrument Co., Ltd. and test it with reference to GB / T 14344-2022; among them, the tensile speed is 500 mm / min.

[0038] Crimp shrinkage rate: After equilibrating the sample to be tested for 4 hours under the conditions of temperature 20°C ± 2°C and humidity 65% ± 5%, test it according to GB / T 6506-2017.

[0039] Washing: Execute according to the C-type washing machine 4N washing program in GB / T 8629-2017, and the detergent is Liby natural bright white low-foam phosphorus-free washing powder; after washing and before measuring the maximum static friction force, hang the sample to be tested to dry under the conditions of temperature 50°C and humidity 45%.

[0040] Maximum static friction force: First, use the KU483B type dyeing test warp knitting machine to knit the sample to be tested into a sock band, cut a 4 cm × 4 cm test specimen from the sock band, then lay the sock band flat and fix it on a horizontal table, place the test specimen flat on the sock band, place a cube with a side length of 3 cm and a weight of 53.21 g at the center position of the test specimen, and finally, use a force measuring instrument to slowly pull the test specimen horizontally and record the maximum pulling force value that appears during the process of the test specimen generating displacement relative to the sock band, which is the maximum static friction force; the test process is carried out in parallel 5 times, and the average value is taken as the test result; among them, the corresponding relationship between the number of knitting needles of the dyeing test warp knitting machine and the yarn count is shown in Table 1:

[0041] Table 1

[0042]

[0043] Example 1

[0044] A production process for silk-like cotton polyester yarn is as follows:

[0045] (1) Prepare semi-dull PET;

[0046] The production process flow of semi-dull PET is: slurry preparation (molar ratio of PTA to EG is 1:1.25) → esterification 1 → esterification 2 → pre-polycondensation 1 → pre-polycondensation 2 → final polycondensation → semi-dull PET;

[0047] Among them, the temperature of esterification 1 is 259 °C and the time is 4 h; the temperature of esterification 2 is 260 °C and the time is 2 h; the temperature of pre-polycondensation 1 is 265 °C and the time is 30 min; the temperature of pre-polycondensation 2 is 272 °C and the time is 50 min; the temperature of final polycondensation is 280 °C and the time is 2.5 h;

[0048] (2) Prepare POY yarn and FDY yarn respectively;

[0049] The production process flow of POY yarn is: semi-dull PET melt → booster pump → heat exchanger → spinning box → metering pump → filter pack → cooling air → oiling → godet 1 → texturing device → godet 2 → winding and forming; Related process parameters: melt conveying temperature is 282 - 285 °C, spinning box temperature is 287 - 290 °C, cooling air temperature is 21 - 23 °C, cooling air pressure is 23 - 25 Pa, texturing pressure is 0.03 MPa, winding speed is 3700 m / min;

[0050] The specification of the obtained POY yarn is 85 dtex / 72 f, and the breaking elongation is 105%;

[0051] The production process flow of FDY yarn is: semi-dull PET melt → melt pipe → heat exchanger → booster pump → static mixer → spinning box → cooling air → oiling → nozzle exit → pre-texturing device → first hot roll → second hot roll → main texturing device → winding and forming; Related process parameters: melt conveying temperature is 280 - 283 °C, spinning box temperature is 289 - 292 °C, cooling air temperature is 21 - 23 °C, cooling air velocity is 0.35 - 0.38 m / s, pre-texturing pressure is 0.05 MPa, temperature of the first hot roll is 78 - 80 °C, temperature of the second hot roll is 121 - 123 °C, main texturing pressure is 0.33 - 0.35 MPa, winding speed is 5000 m / min;

[0052] The specification of the obtained FDY yarn is 98 dtex / 72 f;

[0053] The cross section of the single filament of POY and FDY yarns is circular;

[0054] (3) Preparation of mercerized cotton polyester yarn;

[0055] The POY yarn and the FDY yarn with a mass ratio of 46:54 are led out from the raw yarn rack through the wire guide tube, passed through the wire cutter, and then entered into the network device through the zero roller for compounding. The compounded yarn bundle passes through the first roller, the first hot box, the cooling plate, the friction plate stacked disc type false twist device (1-4-1 configuration, the false twist device consists of 1 introduction disc, 4 friction discs, and 1 knife disc), and the second roller for drafting deformation. The drafted yarn bundle enters the second hot box for heat setting, and then passes through the third roller and the oiling wheel in sequence for winding and forming, so as to obtain the mercerized cotton polyester yarn;

[0056] Relevant process parameters: the network pressure of the network device is 5 bar, the ratio of the speed of the second roller to the speed of the first roller is 1.15, the temperature of the first hot box is 170°C, the ratio of the untwisting tension to the twisting tension K is 1, the overfeed rate of the third roller relative to the second roller is -8%, and the temperature of the second hot box is 190°C.

[0057] The final mercerized cotton-like polyester yarn has a count of 32S, a maximum static friction of 22gf, and a crimp shrinkage of 2%. After 20 washes, the maximum static friction of the mercerized cotton-like polyester yarn is 23gf.

[0058] Comparative Example 1

[0059] A polyester yarn production process is basically the same as that of Example 1, except that in the process of preparing POY yarn in step (2), the winding speed is 3000 m / min, and the elongation at break of the prepared POY yarn is 130%.

[0060] The maximum static friction of the polyester yarn finally obtained was 35 gf, and the crimp shrinkage was 5%.

[0061] Compared with Example 1, the maximum static friction and curl shrinkage rate of the polyester yarn in Comparative Example 1 are significantly increased. This is because in the process of preparing POY yarn in Comparative Example 1, the winding speed is set to a normal value, which is too low, and the fiber orientation and crystallinity are low. The arrangement of fiber macromolecules is not regular enough, the gaps in the fiber structure are large, the reflective properties of the fiber are weakened, and the glossiness of the yarn is also reduced. At the same time, the fiber density is low, which makes the drape of the yarn poor.

[0062] Comparative Example 2

[0063] A polyester yarn production process is basically the same as that of Example 1, except that in step (3), the ratio of the rotation speed of the second roller to the rotation speed of the first roller (i.e., the drafting deformation multiple) is 1.0.

[0064] The maximum static friction of the finally obtained polyester yarn is 42 gf, and the crimp shrinkage rate is 6%.

[0065] Compared with Example 1, the maximum static friction and crimp shrinkage rate of the polyester yarn in Comparative Example 2 are significantly increased. This is because in the preparation of the polyester yarn in Comparative Example 2, the drafting is insufficient, and it is difficult for the fiber macromolecules to achieve effective orientation crystallization. The fiber orientation degree and crystallinity are relatively low, the arrangement of the fiber macromolecules is not regular enough, the voids in the fiber structure are relatively large, the light reflection performance of the fiber is weakened, and the glossiness of the yarn also decreases accordingly. At the same time, the density of the fiber is relatively low, which further results in poor drapability of the yarn.

[0066] Comparative Example 3

[0067] A production process of polyester yarn is basically the same as that of Example 1, except that: in step (3), the ratio of the rotational speed of the second roller to the rotational speed of the first roller (i.e., the drafting and deformation multiple) is 1.5.

[0068] The maximum static friction of the finally obtained polyester yarn is 32 gf.

[0069] Compared with Example 1, the maximum static friction of the polyester yarn in Comparative Example 3 is significantly increased. This is because in the preparation of the polyester yarn in Comparative Example 3, the drafting is excessive, resulting in the phenomenon of single filament breakage. These broken single filaments will form burrs on the surface of the yarn, increasing the surface roughness of the yarn, and finally showing an increase in the maximum static friction of the polyester yarn.

[0070] Comparative Example 4

[0071] A production process of polyester yarn is basically the same as that of Example 1, except that: in step (3), the first hot box temperature (i.e., the drafting and deformation temperature H1) is 120 °C.

[0072] The maximum static friction of the finally obtained polyester yarn is 29 gf.

[0073] Compared with Example 1, the maximum static friction of the polyester yarn in Comparative Example 4 is significantly increased. This is because the first hot box temperature is too low, and the activity ability between fiber molecules is limited, resulting in uneven distribution of fibers during the stretching process, easy generation of fuzz and broken ends, and thus formation of rigid fibers. These fuzz and rigid parts make the surface of the yarn rough and uneven, increasing the frictional resistance between the yarn and the surface of other objects, and showing an increase in the maximum static friction of the polyester yarn.

[0074] Comparative Example 5

[0075] A production process of polyester yarn is basically the same as that of Example 1, except that: in step (3), the first hot box temperature (i.e., the drafting and deformation temperature H1) is 190 °C.

[0076] The maximum static friction of the finally obtained polyester yarn is 54 gf, and the crimp shrinkage rate is 8%.

[0077] Compared with Example 1, in Comparative Example 5, the maximum static friction and crimp shrinkage rate of the polyester yarn are significantly increased. This is because when the temperature of the first hot box is too high, the activity of fiber macromolecules will intensify, resulting in the phenomenon of deorientation. The original orientation degree of the fiber decreases, the regularity of the arrangement of fiber macromolecules is destroyed, the internal structure of the fiber becomes loose, the voids increase, the smoothness of the fiber surface decreases, and the friction coefficient of the yarn increases, thus significantly increasing the maximum static friction. A higher temperature will cause greater internal stress in the fiber after stretching. This internal stress still exists after the fiber cools and will lead to an increase in the crimp shrinkage rate of the yarn. Due to the influence of the higher temperature in the hot box, the movement of molecular chains is more active, and the morphology of the fiber changes greatly during the stretching process. When leaving the hot box environment, the fiber tries to return to its original state, resulting in obvious crimp shrinkage, so the crimp shrinkage rate increases significantly.

[0078] Example 2

[0079] A production process of silk-like cotton polyester yarn is as follows:

[0080] (1) Prepare semi-dull PET;

[0081] The production process flow of semi-dull PET is: slurry preparation (molar ratio of PTA to EG is 1:1.25) → esterification 1 → esterification 2 → pre-polycondensation 1 → pre-polycondensation 2 → final polycondensation → semi-dull PET;

[0082] Among them, the temperature of esterification 1 is 259 °C and the time is 4 h; the temperature of esterification 2 is 260 °C and the time is 2 h; the temperature of pre-polycondensation 1 is 265 °C and the time is 30 min; the temperature of pre-polycondensation 2 is 272 °C and the time is 50 min; the temperature of final polycondensation is 280 °C and the time is 2.5 h;

[0083] (2) Prepare POY yarn and FDY yarn respectively;

[0084] The production process flow of POY yarn is: semi-dull PET melt → booster pump → heat exchanger → spinning box → metering pump → spinneret pack → cooling air → oiling → godet 1 → texturing device → godet 2 → winding and forming; relevant process parameters: melt conveying temperature is 282 - 285 °C, spinning box temperature is 287.5 - 290.5 °C, cooling air temperature is 21 - 23 °C, cooling air pressure is 21 - 23 Pa, texturing pressure is 0.03 MPa, winding speed is 3400 m / min;

[0085] The specification of the obtained POY yarn is 75 dtex / 72 f, and the breaking elongation is 103%;

[0086] The production process flow of FDY yarn is as follows: semi-dull PET melt → melt pipeline → heat exchanger → booster pump → static mixer → spinning box → cooling air → oiling → nozzle opening → pre-networker → first hot roller → second hot roller → main networker → winding and forming; relevant process parameters: melt conveying temperature is 280 - 283 °C, spinning box temperature is 289 - 292 °C, cooling air temperature is 21 - 23 °C, cooling air velocity is 0.33 - 0.36 m / s, pre-network pressure is 0.05 MPa, first hot roller temperature is 76 - 78 °C, second hot roller temperature is 120 - 122 °C, main network pressure is 0.33 - 0.35 MPa, winding speed is 5000 m / min;

[0087] The specification of the obtained FDY yarn is 75 dtex / 72 f;

[0088] The single-filament cross-sections of both POY yarn and FDY yarn are circular;

[0089] (3)Prepare silk-like mercerized cotton polyester yarn;

[0090] POY yarn and FDY yarn with a mass ratio of 48:52 are led out from the raw yarn frame through a wire guide tube, pass through a cutter, and then enter the networker for compounding through a zero roller. The compounded filament bundle sequentially passes through a first roller, a first hot box, a cooling plate, a friction disc stacked false-twist device (1 - 4 - 1 configuration, the false-twister consists of 1 inlet disc, 4 friction discs, and 1 knife-edge disc), and a second roller for drafting and deformation. The drafted and deformed filament bundle enters the second hot box for heat setting, and then sequentially passes through a third roller and an oiling wheel and is wound and formed to obtain the silk-like mercerized cotton polyester yarn;

[0091] Relevant process parameters: the network pressure of the networker is 4.7 bar, the ratio of the rotational speed of the second roller to the rotational speed of the first roller is 1.12, the temperature of the first hot box is 165 °C, the ratio K of the untwisting tension to the twisting tension is 0.8, the overfeed rate of the third roller relative to the second roller is -7%, and the temperature of the second hot box is 187 °C.

[0092] The final obtained silk-like mercerized cotton polyester yarn has a count of 40S, a maximum static friction force of 21.5 gf, and a crimp shrinkage rate of 1.9%; after 20 times of washing, the maximum static friction force of the silk-like mercerized cotton polyester yarn is 22 gf.

[0093] Example 3

[0094] A production process of silk-like mercerized cotton polyester yarn, the specific steps are as follows:

[0095] (1)Prepare semi-dull PET;

[0096] The production process flow of semi-dull PET is as follows: slurry preparation (molar ratio of PTA to EG is 1:1.25) → esterification 1 → esterification 2 → pre-polycondensation 1 → pre-polycondensation 2 → final polycondensation → semi-dull PET;

[0097] Among them, the temperature of esterification 1 is 259 °C and the time is 4 h; the temperature of esterification 2 is 260 °C and the time is 2 h; the temperature of pre-polycondensation 1 is 265 °C and the time is 30 min; the temperature of pre-polycondensation 2 is 272 °C and the time is 50 min; the temperature of final polycondensation is 280 °C and the time is 2.5 h;

[0098] (2)Prepare POY yarn and FDY yarn respectively;

[0099] The production process flow of POY yarn is as follows: semi-dull PET melt → booster pump → heat exchanger → spinning box → metering pump → spinneret pack → cooling air → oiling → godet 1 → texturing device → godet 2 → winding and forming; Related process parameters: melt conveying temperature is 281 - 284 °C, spinning box temperature is 288 - 291 °C, cooling air temperature is 21 - 23 °C, cooling air pressure is 19 - 21 Pa, texturing pressure is 0.03 MPa, winding speed is 3000 m / min;

[0100] The specification of the obtained POY yarn is 58 dtex / 72 f, and the elongation at break is 100%;

[0101] The production process flow of FDY yarn is as follows: semi-dull PET melt → melt pipe → heat exchanger → booster pump → static mixer → spinning box → cooling air → oiling → nozzle exit → pre-texturing device → first hot roll → second hot roll → main texturing device → winding and forming; Related process parameters: melt conveying temperature is 280 - 283 °C, spinning box temperature is 289 - 292 °C, cooling air temperature is 21 - 23 °C, cooling air velocity is 0.35 - 0.38 m / s, pre-texturing pressure is 0.05 MPa, the temperature of the first hot roll is 78 - 80 °C, the temperature of the second hot roll is 122 - 124 °C, main texturing pressure is 0.36 - 0.39 MPa, winding speed is 5200 m / min;

[0102] The specification of the obtained FDY yarn is 60 dtex / 36 f;

[0103] The cross-section of the single filament of both POY yarn and FDY yarn is circular;

[0104] (3)Prepare silk-like cotton polyester yarn;

[0105] POY yarn and FDY yarn with a mass ratio of 49:51 are led out from the raw yarn stand through a wire guide tube, pass through a cutter, and then enter the networker through a zero roller for compounding. The compounded filament bundle passes through the first roller, the first hot box, a cooling plate, a friction disc stack type false twist device (configured as 1-4-1, the false twister consists of 1 inlet disc, 4 friction discs, and 1 knife-edge disc) in sequence, and is drawn and deformed by the second roller. The drawn and deformed filament bundle enters the second hot box for heat setting, and then passes through the third roller and an oiling roller in sequence and is wound into shape, thus obtaining the silk-like mercerized cotton polyester yarn;

[0106] Relevant process parameters: The network pressure of the networker is 4.3 bar, the ratio of the rotational speed of the second roller to that of the first roller is 1.1, the temperature of the first hot box is 150 °C, the ratio K of the untwisting tension to the twisting tension is 0.7, the overfeed rate of the third roller relative to the second roller is 6%, and the temperature of the second hot box is 184 °C.

[0107] The fineness of the finally obtained silk-like mercerized cotton polyester yarn is 50S, the maximum static friction force is 21 gf, and the crimp shrinkage rate is 1.8%; after 20 times of water washing, the maximum static friction force of the silk-like mercerized cotton polyester yarn is 21.5 gf.

[0108] Example 4

[0109] A production process of silk-like mercerized cotton polyester yarn, the specific steps are as follows:

[0110] (1) Prepare semi-dull PET;

[0111] The production process flow of semi-dull PET is: slurry preparation (molar ratio of PTA to EG is 1:1.25) → esterification 1 → esterification 2 → pre-polycondensation 1 → pre-polycondensation 2 → final polycondensation → semi-dull PET;

[0112] Among them, the temperature of esterification 1 is 259 °C and the time is 4 h; the temperature of esterification 2 is 260 °C and the time is 2 h; the temperature of pre-polycondensation 1 is 265 °C and the time is 30 min; the temperature of pre-polycondensation 2 is 272 °C and the time is 50 min; the temperature of final polycondensation is 280 °C and the time is 2.5 h;

[0113] (2) Prepare POY yarn and FDY yarn respectively;

[0114] The production process flow of POY yarn is: semi-dull PET melt → booster pump → heat exchanger → spinning box → metering pump → assembly → cooling air → oiling → guide disc 1 → networker → guide disc 2 → winding into shape; relevant process parameters: the melt conveying temperature is 280.5 - 283.5 °C, the spinning box temperature is 288.5 - 291.5 °C, the cooling air temperature is 21 - 23 °C, the cooling air pressure is 15 - 17 Pa, the network pressure is 0.03 MPa, and the winding speed is 2700 m / min;

[0115] The prepared POY yarn has a specification of 45 dtex / 72 f and an elongation at break of 98%;

[0116] The production process flow of FDY yarn is as follows: semi-dull PET melt → melt pipeline → heat exchanger → booster pump → static mixer → spinning box → cooling air → oiling → nozzle → pre-networker → first hot roller → second hot roller → main networker → winding and forming; relevant process parameters: melt conveying temperature is 280 - 283 °C, spinning box temperature is 289 - 292 °C, cooling air temperature is 21 - 23 °C, cooling air velocity is 0.35 - 0.38 m / s, pre-network pressure is 0.05 MPa, first hot roller temperature is 78 - 80 °C, second hot roller temperature is 122 - 124 °C, main network pressure is 0.36 - 0.39 MPa, winding speed is 5200 m / min;

[0117] The prepared FDY yarn has a specification of 55 dtex / 24 f;

[0118] The single-filament cross-sections of both POY yarn and FDY yarn are circular;

[0119] (3) Prepare imitation mercerized cotton polyester yarn;

[0120] The POY yarn and FDY yarn with a mass ratio of 45:55 are led out from the creel through the guide tube, pass through the cutter, and then enter the networker for compounding through the zero roller. The compounded filament bundle successively passes through the first roller, the first hot box, the cooling plate, the friction disc stacked disc false-twist device (1 - 4 - 1 configuration, the false-twister consists of 1 inlet disc, 4 friction discs, and 1 knife-edge disc), and the second roller for drafting and deformation. The drafted and deformed filament bundle enters the second hot box for heat setting, and then successively passes through the third roller and the oiling wheel and is wound and formed to obtain the imitation mercerized cotton polyester yarn;

[0121] Relevant process parameters: the network pressure of the networker is 4 bar, the ratio of the rotational speed of the second roller to the rotational speed of the first roller is 1.08, the temperature of the first hot box is 145 °C, the ratio K of the untwisting tension to the twisting tension is 0.65, the overfeed rate of the third roller relative to the second roller is 5%, and the temperature of the second hot box is 180 °C.

[0122] The finally prepared imitation mercerized cotton polyester yarn has a count of 60 S, a maximum static friction force of 20.5 gf, and a crimp shrinkage rate of 1.7%; after 20 times of washing, the maximum static friction force of the imitation mercerized cotton polyester yarn is 21 gf.

[0123] Example 5

[0124] A production process of imitation mercerized cotton polyester yarn, the specific steps are as follows:

[0125] (1)Prepare semi-dull PET;

[0126] The production process flow of semi-dull PET is: slurry preparation (molar ratio of PTA to EG is 1:1.25) → esterification 1 → esterification 2 → pre-polycondensation 1 → pre-polycondensation 2 → final polycondensation → semi-dull PET;

[0127] Among them, the temperature of esterification 1 is 259 °C and the time is 4 h; the temperature of esterification 2 is 260 °C and the time is 2 h; the temperature of pre-polycondensation 1 is 265 °C and the time is 30 min; the temperature of pre-polycondensation 2 is 272 °C and the time is 50 min; the temperature of final polycondensation is 280 °C and the time is 2.5 h;

[0128] (2)Prepare POY yarn and FDY yarn respectively;

[0129] The production process flow of POY yarn is: semi-dull PET melt → booster pump → heat exchanger → spinning box → metering pump → spinneret pack → cooling air → oiling → godet 1 → texturing device → godet 2 → winding and forming; Related process parameters: melt conveying temperature is 280 - 283 °C, spinning box temperature is 289 - 292 °C, cooling air temperature is 21 - 23 °C, cooling air pressure is 14 - 16 Pa, texturing pressure is 0.02 MPa, winding speed is 2400 m / min;

[0130] The specification of the obtained POY yarn is 35 dtex / 72 f, and the elongation at break is 95%;

[0131] The production process flow of FDY yarn is: semi-dull PET melt → melt pipe → heat exchanger → booster pump → static mixer → spinning box → cooling air → oiling → spinneret orifice → pre-texturing device → first hot roll → second hot roll → main texturing device → winding and forming; Related process parameters: melt conveying temperature is 280 - 283 °C, spinning box temperature is 289 - 292 °C, cooling air temperature is 21 - 23 °C, cooling air velocity is 0.33 - 0.36 m / s, pre-texturing pressure is 0.05 MPa, the temperature of the first hot roll is 78 - 80 °C, the temperature of the second hot roll is 122 - 124 °C, the main texturing pressure is 0.33 - 0.39 MPa, winding speed is 5100 m / min;

[0132] The specification of the obtained FDY yarn is 40 dtex / 24 f;

[0133] The cross-section of the single filament of POY yarn and FDY yarn is circular;

[0134] (3)Prepare silk-like mercerized cotton polyester yarn;

[0135] POY yarn and FDY yarn with a mass ratio of 47:53 are led out from the creel through a yarn guide tube, pass through a cutter, enter the networker through a zero roller for compounding. The compounded yarn bundle passes through the first roller, the first hot box, a cooling plate, a friction disc stacked false twist device (configured as 1-4-1, the false twister consists of 1 inlet disc, 4 friction discs, and 1 knife-edge disc) and the second roller for drafting and deforming. The drafted and deformed yarn bundle enters the second hot box for heat setting, then passes through the third roller and an oiling roller in sequence and is wound into shape, thus obtaining the mercerized cotton-like polyester yarn;

[0136] Relevant process parameters: the network pressure of the networker is 3.5 bar, the ratio of the rotational speed of the second roller to that of the first roller is 1.05, the temperature of the first hot box is 130 °C, the ratio K of the untwisting tension to the twisting tension is 0.6, the overfeed rate of the third roller relative to the second roller is 4%, and the temperature of the second hot box is 170 °C.

[0137] The fineness of the finally obtained mercerized cotton-like polyester yarn is 80S, the maximum static friction force is 20 gf, and the crimp shrinkage rate is 1.5%; after 20 times of washing, the maximum static friction force of the mercerized cotton-like polyester yarn is 20.5 gf.

Claims

1. A production process of imitation mercerized cotton polyester yarn, characterized in that: After the POY yarn and the FDY yarn are compounded, they are subjected to drawing deformation and heat setting in sequence; The raw materials of POY and FDY yarns are semi-dull PET, and the cross section of the single yarn is round; POY yarn is obtained by melt direct spinning process, and the production process is: semi-matt PET melt → booster pump → heat exchanger → spinning box → metering pump → assembly → cooling air → oiling → godet 1 → network device → godet 2 → winding and forming; in the process of preparing POY yarn, the winding speed is increased to 2400-3700m / min to improve the crystallinity and orientation of POY yarn, thereby reducing the elongation at break of POY yarn to 95-105%; The draft deformation multiple is 1.05-1.15; The drawing deformation temperature H1 is less than the heat setting temperature H2, H1 is 130-170℃, H2 is 170-190℃; The curl shrinkage rate of mercerized cotton polyester yarn is 1.5-2.0%.

2. The production process of a mercerized cotton polyester yarn according to claim 1, characterized in that: The mass ratio of FDY yarn to POY yarn is 51-55:45-49.

3. The production process of a mercerized cotton polyester yarn according to claim 1, characterized in that: The specific process is: POY yarn and FDY yarn are led out from the raw yarn rack through the wire guide tube, passed through the wire cutter, and then entered into the network device through the zero roller for compounding. The compounded yarn bundles are sequentially passed through the first roller, the first hot box, the cooling plate, the false twister, and the second roller for stretching and deformation. The stretched and deformed yarn bundles enter the second hot box for heat setting, and then sequentially pass through the third roller and the oil wheel for winding and forming, so as to obtain the imitation mercerized cotton polyester yarn.

4. The production process of the imitation mercerized cotton polyester yarn according to claim 3, characterized in that: The network pressure of the network device is 3.5-5.0bar.

5. The production process of the imitation mercerized cotton polyester yarn according to claim 3, characterized in that: The overfeed rate of the third roller relative to the second roller is -4.0% to -8%.

6. The production process of the imitation mercerized cotton polyester yarn according to claim 3, characterized in that: The false twister is a friction plate stacked disc type false twister, and the ratio K of the untwisting tension to the twisting tension is 0.6-1.

0.

7. The production process of the imitation mercerized cotton polyester yarn according to claim 6, characterized in that: The false twister consists of 1 introduction disc, 4 friction discs and 1 knife-edge disc.

8. The production process of the imitation mercerized cotton polyester yarn according to any one of claims 1 to 7, characterized in that: The maximum static friction of mercerized cotton polyester yarn is 20-22gf, and the maximum static friction of imitation mercerized cotton polyester yarn after 20 washes is 20.5-23gf.

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