Production process of mercerized cotton-imitated polyester yarn

Abstract

The invention belongs to the technical field of textile, and relates to a production process of mercerized cotton-imitated polyester yarn. According to the process, after POY and FDY are compounded, the polyester yarn with excellent glossiness, silky feeling and drapability is prepared through specific drafting deformation and heat setting treatment. Wherein the POY is prepared by adopting a mode of increasing the winding speed, the elongation at break is reduced, and the crystallinity and the orientation degree are improved; the drafting deformation multiple and the heat setting temperature are accurately controlled. The method does not need to depend on a method which is high in cost and poor in environmental protection property, the crystallinity and orientation degree of the POY are increased by optimizing the preparation process of the POY and increasing the winding speed, and after the POY is compounded with the FDY, the drafting deformation multiple, the drafting deformation temperature and the heat setting temperature are accurately controlled, so that the production efficiency of the POY is improved. The mercerized cotton-imitated polyester yarn which is high in glossiness, good and durable in silky feeling and excellent in drapability is successfully prepared.

Description

Technical Field

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

[0002] With the development of the textile market, the demand for polyester imitation cotton yarn products with similar properties to mercerized cotton has become increasingly prominent. Mercerized cotton fabrics are favored by consumers in the domestic market for their good gloss, excellent smoothness, soft hand feel and good drape. Therefore, the development of a mercerized cotton imitation polyester yarn with excellent gloss, silky feel and drape is of great significance to meet the market demand for high-quality yarns.

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

[0004] In terms of improving the glossiness of yarn, patent application CN102995198A improves the glossiness by controlling the disc material, the number of false twister discs and setting temperature conditions, but the application effect on ordinary semi-dull raw materials is very limited and the ideal glossiness improvement effect cannot be achieved. Patent application CN101177801A adopts a method of adding chemical modified raw materials to prepare specific materials to improve glossiness. This approach is not only unfriendly to the environment, but also increases production costs. Patent application CN106087098A and patent application CN113529188A both improve the glossiness by preparing raw silk fibers with special cross-sections, but this method is not suitable for preparing imitation mercerized cotton polyester yarn. It can be seen that the existing technical means for improving the glossiness of yarn cannot effectively meet the demand for preparing imitation mercerized cotton polyester yarn with excellent glossiness.

[0005] In terms of improving the silkiness of yarn, the existing technologies mainly rely on methods such as adding surface oil, silicone finishing agent or lubricant to achieve this. However, these methods have many disadvantages. On the one hand, they increase the production cost. On the other hand, the effect of improving the silkiness by lubricating external surface substances is difficult to last. After multiple washings, the silkiness will be significantly weakened. Therefore, it is difficult to prepare mercerized cotton polyester yarn with excellent silkiness based on these existing technologies for improving the silkiness of yarn.

[0006] In terms of improving the drape of yarn, patent application CN110894633A increases the drape of fabric by reducing the amount of fabric after weaving, but its process is complicated, which is undoubtedly not conducive to reducing production costs and cannot meet the requirements of efficient production and excellent performance of imitation mercerized cotton polyester yarn. Patent application CN107723861A relies on adding a pre-network process to improve the drape of fiber, but the actual effect is not obvious. In addition, patent application CN101694031A, patent application CN106978659A, patent application CN116024713A and patent CN216193061U also try to improve drape by different methods, but they have problems such as weak gloss, high production cost or insufficient environmental protection. It can be seen that the existing technology for improving the drape of yarn also has certain limitations, and it is difficult to meet the requirements of preparing high-quality imitation mercerized cotton polyester yarn.

[0007] In summary, in view of the shortcomings of the existing technology in improving the gloss, silkiness and drape of yarn, and the high production cost, poor environmental protection and other problems, it is urgent to develop a new production process to prepare mercerized cotton polyester yarn with excellent gloss, silkiness and drape, so as to meet the market demand for high-quality yarn. Summary of the invention

[0008] The purpose of the invention is to solve the problems existing in the prior art and provide a production process of 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 mercerized cotton polyester yarn, comprising compounding POY yarn and FDY yarn, and then sequentially performing drafting and heat setting;

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

[0012] In the process of preparing POY yarn, the winding speed is increased to improve the crystallinity and orientation of POY yarn, which leads to the elongation at break of POY yarn being reduced to 95-105%, which is 10-20% lower than the elongation at break of conventional POY yarn;

[0013] The draft deformation multiple is 1.05-1.15;

[0014] The stretching deformation temperature H1 is less than 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 of the 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) 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 lowers 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 drafting, resulting in fibers with a rigid texture; if the H1 value is too high, the activity of the fiber macromolecules will increase, which may cause disorientation, and the crimp shrinkage rate of the yarn will increase, 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 silky 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 for 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 silkiness 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 yarn has better drapability.

[0022] As the preferred technical solution:

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

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

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

[0026] The production process of the imitation mercerized cotton polyester yarn as described above specifically comprises the following steps: 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 drafting and deformation; the drafted and deformed yarn bundles enter the second hot box for heat setting, and then sequentially passed through the third roller and the oiling wheel for winding and forming, thereby obtaining the imitation mercerized cotton polyester yarn, wherein the temperature of the first hot box is H1, the temperature of the second hot box is H2, and the ratio of the rotation speed of the second roller to the rotation speed of the first roller is the drafting and deformation multiple.

[0027] In the production process of the mercerized cotton polyester yarn described above, the network pressure of the network device is 3.5-5.0 bar. The use of a larger network pressure for compounding can make the yarn fully entangled and intertwined to form network points before stretching and deformation, and it is not easy to loosen the loop.

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

[0029] In the production process of the mercerized cotton polyester yarn described above, the false twister is a friction plate stacked disc false twister, 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 need to rely on costly and environmentally unfriendly methods. By optimizing the preparation process of POY yarn, increasing the winding speed to increase its crystallinity and orientation, and after compounding it with FDY yarn, accurately controlling the stretching deformation multiple, stretching deformation temperature and heat setting temperature, the mercerized cotton polyester yarn with strong gloss, good and long-lasting silky feeling (still good after multiple washings) and excellent drape is successfully prepared. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended 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 fall within the scope limited by the appended claims of the application equally.

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

[0037] Elongation at break: After the sample to be tested is balanced for 4 hours at a temperature of 20℃±2℃ and a humidity of 65%±5%, it is tested using a YG023B-Ⅲ fully automatic single yarn strength tester produced by Changzhou Bafang Lishi Textile Instrument Co., Ltd. in accordance with GB / T 14344-2022; the tensile speed is 500mm / min.

[0038] Curl shrinkage: After the sample is balanced at a temperature of 20℃±2℃ and a humidity of 65%±5% for 4 hours, the test is carried out according to GB / T 6506-2017.

[0039] Washing: According to the 4N washing program of type C washing machine in GB / T 8629-2017, the detergent is Liby Natural Bright Whitening Low Foaming Phosphorus-free Washing Powder; after washing and before measuring the maximum static friction, the samples to be tested are hung to dry at a temperature of 50°C and a humidity of 45%.

[0040] Maximum static friction: First, use the KU483B dyeing test warp knitting machine to knit the sample to be tested into a garter, cut a 4cm×4cm sample from the garter, then lay the garter flat on a horizontal table, place the sample flat on the garter, and place a cube with a side length of 3cm and a weight of 53.21g at the exact center of the sample. Finally, use a force gauge to slowly pull the sample horizontally, and record the maximum pulling force value that occurs during the displacement of the sample relative to the garter, which is the maximum static friction. 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 selected by 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 of mercerized cotton polyester yarn, the specific steps are as follows:

[0045] (1) Preparation of semi-matt PET;

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

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

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

[0049] The production process of POY yarn is: semi-matte PET melt → booster pump → heat exchanger → spinning box → metering pump → assembly → cooling air → oiling → godet 1 → network device → godet 2 → winding; 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 23-25Pa, network pressure is 0.03MPa, winding speed is 3700m / min;

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

[0051] The production process of FDY yarn is: semi-matte PET melt → melt pipeline → heat exchanger → booster pump → static mixer → spinning box → cooling air → oiling → tunnel mouth → pre-network → first hot roller → second hot roller → main network → winding; 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 speed is 0.35-0.38m / s, pre-network pressure is 0.05MPa, first hot roller temperature is 78-80°C, second hot roller temperature is 121-123°C, main network pressure is 0.33-0.35MPa, winding speed is 5000m / min;

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

[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 polyester yarn finally obtained was 42 gf, and the crimp shrinkage was 6%.

[0065] Compared with Example 1, the maximum static friction and curl shrinkage rate of the polyester yarn in Comparative Example 2 are significantly increased. This is because the polyester yarn in Comparative Example 2 is not sufficiently drafted when it is prepared, and it is difficult for the fiber macromolecules to achieve effective orientation and crystallization. The fiber orientation and crystallinity are low, the fiber macromolecules are not arranged regularly, 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.

[0066] Comparative Example 3

[0067] 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 1.5.

[0068] The maximum static friction of the finally produced polyester yarn was 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 the polyester yarn in Comparative Example 3 is over-stretched when prepared, resulting in single filament breakage. These broken single filaments will form burrs on the surface of the yarn, increasing the surface roughness of the yarn, which ultimately manifests as an increase in the maximum static friction of the polyester yarn.

[0070] Comparative Example 4

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

[0072] The maximum static friction of the finally produced polyester yarn was 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 temperature of the first hot box is too low and the mobility between the fiber molecules is limited, resulting in uneven distribution of the fibers during the stretching process, which is prone to produce fuzz and breakage, and then forming stiff fibers. These fuzz and stiff parts make the yarn surface rough and uneven, increasing the frictional resistance between the yarn and other object surfaces, which is manifested as an increase in the maximum static friction of the polyester yarn.

[0074] Comparative Example 5

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

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

[0077] Compared with Example 1, the maximum static friction and curl shrinkage rate of the polyester yarn in Comparative Example 5 are significantly increased. This is because the temperature of the first hot box is too high, the activity of the fiber macromolecules will be intensified, causing the deorientation phenomenon, which reduces the original orientation degree of the fiber, destroys the regularity of the arrangement of the fiber macromolecules, and makes the internal structure of the fiber loose. The gap increases, resulting in a decrease in the smoothness of the fiber surface and an increase in the friction coefficient of the yarn, thereby significantly increasing the maximum static friction; higher temperatures will cause the fiber to produce greater internal stress after stretching, and this internal stress still exists after the fiber is cooled, and will cause the curl shrinkage rate of the yarn to increase. Since the fiber is affected by the higher temperature in the hot box, the movement of the molecular chain is more active, and the fiber morphology changes significantly during the stretching process. When leaving the hot box environment, the fiber tries to return to its original state, and then there is obvious curl shrinkage, so the curl shrinkage rate is significantly increased.

[0078] Example 2

[0079] A production process of mercerized cotton polyester yarn, the specific steps are as follows:

[0080] (1) Preparation of semi-matt PET;

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

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

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

[0084] The production process of POY yarn is: semi-matte PET melt → booster pump → heat exchanger → spinning box → metering pump → assembly → cooling air → oiling → godet 1 → network device → godet 2 → winding; related 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 21-23Pa, network pressure is 0.03MPa, winding speed is 3400m / min;

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

[0086] The production process of FDY yarn is: semi-matte PET melt → melt pipeline → heat exchanger → booster pump → static mixer → spinning box → cooling air → oiling → tunnel mouth → pre-network → first hot roller → second hot roller → main network → winding; 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 speed is 0.33-0.36m / s, pre-network pressure is 0.05MPa, first hot roller temperature is 76-78°C, second hot roller temperature is 120-122°C, main network pressure is 0.33-0.35MPa, winding speed is 5000m / min;

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

[0088] The cross section of the single filament of POY and FDY yarns is circular;

[0089] (3) Preparation of mercerized cotton polyester yarn;

[0090] The POY yarn and the FDY yarn with a mass ratio of 48:52 are led out from the raw yarn rack through the wire guide tube, passed through the wire cutter, and then entered 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 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;

[0091] Relevant process parameters: the network pressure of the network device is 4.7 bar, the ratio of the speed of the second roller to the speed of the first roller is 1.12, the temperature of the first hot box is 165°C, the ratio of the untwisting tension to the twisting tension K 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 mercerized cotton-like polyester yarn has a count of 40S, a maximum static friction of 21.5 gf, and a curl shrinkage of 1.9%; after 20 washes, the maximum static friction of the mercerized cotton-like polyester yarn is 22 gf.

[0093] Example 3

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

[0095] (1) Preparation of semi-matt PET;

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

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

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

[0099] The production process of POY yarn is: semi-matte PET melt → booster pump → heat exchanger → spinning box → metering pump → assembly → cooling air → oiling → godet 1 → network device → godet 2 → winding; 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 19-21Pa, network pressure is 0.03MPa, winding speed is 3000m / min;

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

[0101] The production process of FDY yarn is: semi-matte PET melt → melt pipeline → heat exchanger → booster pump → static mixer → spinning box → cooling air → oiling → tunnel mouth → pre-network → first hot roller → second hot roller → main network → winding; 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 speed is 0.35-0.38m / s, pre-network pressure is 0.05MPa, first hot roller temperature is 78-80°C, second hot roller temperature is 122-124°C, main network pressure is 0.36-0.39MPa, winding speed is 5200m / min;

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

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

[0104] (3) Preparation of mercerized cotton polyester yarn;

[0105] The POY yarn and the FDY yarn with a mass ratio of 49:51 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 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;

[0106] Relevant process parameters: the network pressure of the network device is 4.3 bar, the ratio of the speed of the second roller to the speed of the first roller is 1.1, the temperature of the first hot box is 150°C, the ratio of the untwisting tension to the twisting tension K 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 final mercerized cotton-like polyester yarn has a count of 50S, a maximum static friction of 21gf, and a crimp shrinkage of 1.8%; after 20 washes, the maximum static friction of the mercerized cotton-like polyester yarn is 21.5gf.

[0108] Example 4

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

[0110] (1) Preparation of semi-matt PET;

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

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

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

[0114] The production process of POY yarn is: semi-matte PET melt → booster pump → heat exchanger → spinning box → metering pump → assembly → cooling air → oiling → godet 1 → network device → godet 2 → winding; related process parameters: melt conveying temperature is 280.5-283.5°C, spinning box temperature is 288.5-291.5°C, cooling air temperature is 21-23°C, cooling air pressure is 15-17Pa, network pressure is 0.03MPa, winding speed is 2700m / min;

[0115] The specification of the POY yarn produced is 45dtex / 72f, and the elongation at break is 98%;

[0116] The production process of FDY yarn is: semi-matte PET melt → melt pipeline → heat exchanger → booster pump → static mixer → spinning box → cooling air → oiling → tunnel mouth → pre-network → first hot roller → second hot roller → main network → winding; 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 speed is 0.35-0.38m / s, pre-network pressure is 0.05MPa, first hot roller temperature is 78-80°C, second hot roller temperature is 122-124°C, main network pressure is 0.36-0.39MPa, winding speed is 5200m / min;

[0117] The specification of the FDY yarn obtained is 55dtex / 24f;

[0118] The cross section of the single filament of POY and FDY yarns is circular;

[0119] (3) Preparation of mercerized cotton polyester yarn;

[0120] The POY yarn and the FDY yarn with a mass ratio of 45:55 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 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;

[0121] Relevant process parameters: the network pressure of the network device is 4 bar, the ratio of the speed of the second roller to the speed of the first roller is 1.08, the temperature of the first hot box is 145°C, the ratio of the untwisting tension to the twisting tension K 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 final mercerized cotton-like polyester yarn has a count of 60S, a maximum static friction of 20.5 gf, and a crimp shrinkage of 1.7%; after 20 washes, the maximum static friction of the mercerized cotton-like polyester yarn is 21 gf.

[0123] Example 5

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

[0125] (1) Preparation of semi-matt PET;

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

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

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

[0129] The production process of POY yarn is: semi-matte PET melt → booster pump → heat exchanger → spinning box → metering pump → assembly → cooling air → oiling → godet 1 → network device → godet 2 → winding; 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 14-16Pa, network pressure is 0.02MPa, winding speed is 2400m / min;

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

[0131] The production process of FDY yarn is: semi-matte PET melt → melt pipeline → heat exchanger → booster pump → static mixer → spinning box → cooling air → oiling → tunnel mouth → pre-network → first hot roller → second hot roller → main network → winding; 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 speed is 0.33-0.36m / s, pre-network pressure is 0.05MPa, first hot roller temperature is 78-80°C, second hot roller temperature is 122-124°C, main network pressure is 0.33-0.39MPa, winding speed is 5100m / min;

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

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

[0134] (3) Preparation of mercerized cotton polyester yarn;

[0135] The POY yarn and the FDY yarn with a mass ratio of 47:53 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 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;

[0136] Relevant process parameters: the network pressure of the network device is 3.5 bar, the ratio of the speed of the second roller to the speed of the first roller is 1.05, the temperature of the first hot box is 130°C, the ratio of the untwisting tension to the twisting tension K 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 final mercerized cotton-like polyester yarn has a count of 80S, a maximum static friction of 20gf, and a curl shrinkage rate of 1.5%; after 20 times of washing, the maximum static friction of the mercerized cotton-like polyester yarn is 20.5gf.

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; In the process of preparing POY yarn, the winding speed is increased to improve the crystallinity and orientation of POY yarn, which leads to a decrease in the elongation at break of POY yarn to 95-105%; The draft deformation multiple is 1.05-1.15; The stretching deformation temperature H1 is less than the heat setting temperature H2, H1 is 130-170°C, and H2 is 170-190°C.

2. The production process of a mercerized cotton polyester yarn according to claim 1, characterized in that: During the preparation of POY yarn, the winding speed is increased to 2400-3700 m / min.

3. The production process of a mercerized cotton polyester yarn according to claim 2, characterized in that: POY yarn is obtained by melt direct spinning process, and the production process flow is: semi-dull PET melt → booster pump → heat exchanger → spinning box → metering pump → assembly → cooling air → oiling → godet 1 → network device → godet 2 → winding and forming.

4. 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.

5. 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.

6. The production process of the imitation mercerized cotton polyester yarn according to claim 5, characterized in that: The network pressure of the network device is 3.5-5.0bar.

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

8. The production process of the imitation mercerized cotton polyester yarn according to claim 5, 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.

9. The production process of the imitation mercerized cotton polyester yarn according to claim 8, characterized in that: The false twister consists of 1 introduction disc, 4 friction discs and 1 knife-edge disc.

10. The production process of the imitation mercerized cotton polyester yarn according to any one of claims 1 to 9, 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 washings is 20.5-23gf; the curl shrinkage rate of imitation mercerized cotton polyester yarn is 1.5-2.0%.

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