Acquisition method of texturing critical speed of polyester pre-oriented yarn

Abstract

The invention belongs to the technical field of polyester draw texturing yarn production processes, and discloses a method for acquiring the draw texturing critical speed of a polyester pre-oriented yarn, which comprises the following steps of: debugging the draw texturing speed on line to obtain the draw texturing critical speed of the polyester pre-oriented yarn with the fineness of 88-530 dtex; the calculation formula of the debugging starting point value is SS = K * (Vmachine * [0.47 * R-0.00032 * F]), in the formula, SS is the debugging starting point value, R is the deformation ratio of the polyester pre-oriented yarn in the elasticizing process, F is the number of multifilaments of the polyester pre-oriented yarn, and K is a correction coefficient. The method for obtaining the elasticizing critical speed is relatively simple to operate, the test efficiency is improved, and the test consumption is reduced.

Description

Technical Field

[0001] This invention belongs to the technical field of polyester texturing yarn production process, and relates to a method for obtaining the critical speed of texturing polyester pre-oriented yarn. Background Technology

[0002] In the production of polyester textured yarn (DTY), the texturing speed is a core process parameter that determines production efficiency, product cost, and quality.

[0003] Existing technologies generally rely on experience to determine texturing speeds. These empirically derived speeds are summaries of results from mass production. For example, the texturing speed used in the preparation of cationic polyester DTY in patent CN119571610B is an empirical value. However, this empirical value may not be the optimal solution, and further increases are needed to improve yield. But if the increase is too large, exceeding the limits of polyester pre-oriented yarn (POY) or the equipment, it can lead to quality problems such as fuzzy fibers, yarn breakage, and uneven dyeing, and may even damage critical components such as the texturing machine rollers and false twisters.

[0004] Therefore, those skilled in the art use the texturing critical speed to calculate the texturing rate. Specifically, based on the type of texturing machine, the type and specifications of the raw materials, and the performance requirements of subsequent processes, the actual texturing rate is determined using the formula "texturing critical speed × 0.8~0.9". The texturing critical speed refers to the highest operating speed at which the texturing machine can operate stably while ensuring product quality (no loose fibers, broken ends, or other abnormalities) and equipment safety. Different texturing machines have different achievable texturing critical speeds due to differences in their design logic.

[0005] There are two main methods for determining the critical velocity of the projectile in the existing technology:

[0006] (1) Determine the critical loading speed based on experience.

[0007] The texturing critical speed is determined by experience, but the experience judgment lacks a standardized process, is highly subjective, and is easily affected by the fluctuation of raw yarn batches and the difference in equipment status, resulting in poor repeatability of test results. It cannot provide a unified process reference for different specifications of products (such as POY of different denier and varieties), and may also lead to batch quality problems or waste of production capacity due to misjudgment of the texturing critical speed.

[0008] (2) Determine the critical loading speed through debugging.

[0009] The specific steps are as follows:

[0010] (a) Setting process parameters: Determine the values ​​of each process parameter set on the texturing machine used for the produced polyester texturing yarn based on historical data.

[0011] (b) Gradually increase the texturing speed and observe for abnormalities: Allow the polyester pre-oriented yarn to run stably on the texturing machine with the process parameters set, and then gradually increase the texturing speed at a rate of 30~50 m / min. Each increase requires a period of stable operation (e.g., 2~3 minutes) to check for any vibration in the yarn (specifically, check for vibration in the yarn groove or cooling plate of the first heating box), or to check if the tension fluctuation value exceeds the threshold. When the above abnormalities are found, it indicates that the texturing speed has exceeded the critical texturing speed, meaning that the equipment can no longer operate safely and stably at this speed and produce qualified products.

[0012] (c) Adjust the texturing speed to determine the critical texturing speed: Reduce the texturing speed at which the abnormality occurred in step (b) by 100 m / min. The reason for reducing it by 100 m / min is to quickly bring the equipment back to a safe operating range. If the reduction is too small, it will not be able to offset the unstable factors. Then increase the speed by 10~20 m / min. When the above abnormality occurs again, reduce it by 10~20 m / min again. The speed at which the filament stabilizes is the critical texturing speed for this type of polyester pre-oriented yarn.

[0013] This method is quite complex and takes a long time.

[0014] Therefore, it is of great significance to study a method for obtaining the critical speed of texturing polyester pre-oriented yarn in order to solve the above problems. Summary of the Invention

[0015] The purpose of this invention is to solve the problems existing in the prior art and to provide a method for obtaining the texturing critical speed of polyester pre-oriented yarn.

[0016] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0017] A method for obtaining the critical texturing speed of polyester pre-oriented yarn is disclosed. The critical texturing speed is obtained by online adjustment of the texturing speed. The fineness of the polyester pre-oriented yarn is 88~530 dtex. The starting value for adjustment is obtained through calculation, and the calculation formula is as follows:

[0018] SS=K×(V 机 ×[0.47×R-0.00032×F]);

[0019] In the formula, SS is the starting value for debugging, in m / min;

[0020] V 机The mechanical speed of the texturing machine (the speed inherent to the texturing machine, such as the Japanese TMTATF-1500FOURF / T and TMTATF-1500FOURF / V texturing machines, with a mechanical speed of 1350 m / min), in m / min;

[0021] R is the deformation ratio of the pre-oriented polyester yarn during the texturing process, R=d1 / d2, d1 is the fineness of the pre-oriented polyester yarn (dtex), and d2 is the fineness of the texturized polyester yarn produced from the pre-oriented polyester yarn (dtex).

[0022] F is the number of multifilaments in the pre-oriented polyester yarn, dimensionless;

[0023] K is a correction factor, dimensionless. When the polyester pre-oriented yarn is a semi-dull polyester pre-oriented yarn with a circular cross section, if the fineness is ≥88dtex and <355dtex, then K=1; if the fineness is 355~530dtex, then K=0.9. When the polyester pre-oriented yarn is a fully dull polyester pre-oriented yarn with a circular cross section and a fineness of 88~530dtex, then K=0.95. When the polyester pre-oriented yarn is a cationic polyester pre-oriented yarn with a circular cross section or a polyester pre-oriented yarn with an irregular cross section and a fineness of 88~530dtex, then K=0.9.

[0024] Through investigation, this invention has discovered that the main factors affecting the texturing critical speed are the type of texturing machine, the deformation ratio of the polyester pre-oriented yarn during texturing, the number of multifilaments in the polyester texturing yarn, the cross-sectional shape of the polyester pre-oriented yarn, and the type of raw material (e.g., semi-dull, fully dull, cationic). Therefore, this invention, following the methods and procedures of existing technologies, conducts extensive testing experiments on different varieties and / or specifications of polyester texturing yarn to obtain the corresponding texturing critical speed. Based on the aforementioned main factors and texturing critical speed, a fitting process is performed to obtain the formula of this invention. By substituting relevant parameters of different varieties and specifications of polyester texturing yarn into the fitting formula, the fitting results were obtained. The fitting results were compared with the measured actual texturing critical speed. The inventors found that when the fineness of the polyester pre-oriented yarn is 88~530 dtex, the fitting result is close to the actual texturing critical speed. When the fineness is too small (<88 dtex): the fiber strength is insufficient and it is easy to break during processing. Therefore, the actual texturing critical speed deviates greatly from the predicted value. When the fineness is too large (>530 dtex): the fiber rigidity is strong and it is easy to cause uneven stretching under force. The yarn will shake or the yarn tension will be abnormal. Therefore, the actual texturing critical speed also deviates greatly from the predicted value.

[0025] In summary, this invention selects polyester pre-oriented yarn with a fineness of 88-530 dtex as the application object of this formula to avoid a large deviation between the fitting result and the actual texturing critical speed. The formula of this invention can calculate the starting point value for adjusting to approximate the texturing critical speed, saving a significant number of testing steps and improving testing efficiency.

[0026] The test data are shown in Table 1:

[0027] Table 1

[0028] Serial Number DTY processing machine models POY specifications DTY Specifications Actual critical loading velocity (m / min) SS fitting results (m / min) Difference (m / min) 1 TMT "V" type 165dtex / 48F semi-optical 103 dtex / 48F 970 995.7 25.7 2 TMT "V" type 278dtex / 288F semi-optical 170dtex / 288F 940 913.2 -26.8 3 TMT "V" type 200dtex / 144F semi-optical 120dtex / 144F 1000 995.3 -4.7 4 TMT "V" type 267dtex / 96F semi-optical 167dtex / 96F 960 973.0 13.0 5 TMT "V" type 355dtex / 288F semi-optical 220dtex / 288F 830 809.5 -20.5 6 TMT "V" type 133dtex / 72F Fully Matte 80dtex / 72F 960 972.6 12.6 7 TMT "V" type 260dtex / 48F cation 165dtex / 48F 870 881.2 11.2 8 TMT "V" type 355dtex / 96F cation 220dtex / 96F 900 884.1 -15.9 9 TMT "V" type 135dtex / 36F semi-optical 83dtex / 36F 1010 1016.5 6.5 10 TMT "V" type 138dtex / 144F semi-optical 85dtex / 144F 980 967.9 -12.1 11 TMT "V" type 178dtex / 96F semi-optical 111dtex / 96F 980 976.0 -4.0 12 TMT "V" type 525dtex / 96F semi-optical 330dtex / 96F 850 871.2 21.2 13 TMT "V" type 530dtex / 288F semi-optical 330dtex / 288F 830 805.2 -24.8 14 TMT "V" type 172dtex / 48F semi-optical 108dtex / 48F 970 989.8 19.8 15 TMT "V" type 350dtex / 72F semi-optical 220dtex / 72F 860 880.5 20.5 16 TMT "V" type 430dtex / 96F semi-optical 268dtex / 96F 900 878.9 -21.1 17 TMT "V" type 140dtex / 144F semi-optical 87dtex / 144F 950 958.8 8.8 18 TMT "V" type 183dtex / 48F semi-optical 115dtex / 48F 970 988.9 18.9 19 TMT "V" type 218dtex / 192F Fully Matte Flat 136dtex / 192F 830 840.7 10.7 20 TMT "V" type 230dtex / 192F Fully Matte Flat 143dtex / 192F 820 843.8 23.8 21 TMT "V" type 267dtex / 48F semi-optical 165dtex / 48F 980 1006.0 26.0 22 TMT "V" type 230dtex / 144F semi-optical 143dtex / 144F 960 958.3 -1.7 23 TMT "V" type 288dtex / 288 fully matte flat 180dtex / 288F 830 801.7 -28.3 24 TMT "V" type 272dtex / 144F semi-optical 167dtex / 144F 1000 971.2 -28.8 25 TMT "V" type 355dtex / 96F semi-optical 220dtex / 96F 860 884.1 24.1 26 TMT "V" type 205dtex / 144F semi-optical 128dtex / 144F 940 954.0 14.0 27 TMT "V" type 280dtex / 288F with optical flatness 180dtex / 288F 830 776.3 -53.7 28 TMT "V" type Y170dtex / 48F has light. 106 dtex / 48F 870 897.2 27.2 29 TMT "V" type 240dtex / 48F semi-optical 150dtex / 48F 1000 994.5 -5.5 31 TMT "V" type 460dtex / 288F semi-optical 287dtex / 288F 780 803.3 23.3 32 TMT "V" type 525dtex / 72F semi-optical 330dtex / 72F 940 880.5 -59.5 33 TMT "V" type 81dtex / 72F Fully Extinct 50dtex / 72F 950 946.9 -3.1 34 TMT "T" type 138dtex / 144F semi-optical 85dtex / 144F 1000 967.9 -32.1 35 TMT "T" type 272dtex / 144F Fully Extinct 167dtex / 144F 920 922.7 2.7 36 TMT "T" type 175dtex / 48F anodic elimination 110dtex / 48F 900 889.8 -10.2 37 TMT "T" type 246dtex / 48F cation 160dtex / 48F 870 859.3 -10.7 38 TMT "T" type 171dtex / 144F semi-optical 108 dtex / 144F 1020 942.4 -77.6 39 TMT "T" type 165dtex / 96F semi-optical 105 dtex / 96F 1030 955.6 -74.4 40 TMT "T" type 122dtex / 72F Fully Extinct 75dtex / 72F 1000 951.0 -49.0 41 TMT "T" type 175dtex / 144F Fully Extinct 110dtex / 144F 950 899.9 -50.1 42 TMT "T" type 170dtex / 96F semi-optical 108dtex / 96F 970 957.3 -12.7 43 TMT "T" type 260dtex / 96F semi-optical 165dtex / 96F 1000 958.3 -41.7 44 TMT "T" type 265dtex / 144F semi-optical 165dtex / 144F 1000 956.8 -43.2 45 TMT "T" type 218dtex / 192F Fully Matte Flat 136dtex / 192F 910 840.7 -69.3 46 TMT "T" type 267dtex / 48F semi-optical 165dtex / 48F 1000 1006.0 6.0 47 TMT "T" type 272dtex / 144F semi-optical 167dtex / 144F 990 971.2 -18.8 48 TMT "T" type 270dtex / 144F large light 167dtex / 144F 920 867.3 -52.7 49 TMT "T" type 125dtex / 72F semi-optical 78dtex / 72F 1040 985.7 -54.3 50 TMT "T" type 230dtex / 144F semi-optical 140dtex / 144F 950 980.2 30.2 51 TMT "T" type 218dtex / 192F semi-optical 136dtex / 192F 900 934.1 34.1 52 TMT "T" type 118dtex / 72F semi-optical 74dtex / 72F 1030 980.7 -49.3 53 TMT "T" type 183dtex / 48F semi-optical 115dtex / 48F 1000 988.9 -11.1 54 TMT "T" type 200dtex / 144F semi-optical 120dtex / 144F 1000 995.3 -4.7 55 TMT "T" type 135dtex / 36F semi-optical 83dtex / 36F 1060 1016.5 -43.5 56 TMT "T" type 175dtex / 36F semi-optical 110dtex / 36F 1050 993.9 -56.1 57 TMT "T" type 272dtex / 48F semi-optical 165dtex / 48F 1030 1025.2 -4.8 58 TMT "T" type 88 dtex / 72F semi-optical 55 dtex / 72F 980 984.1 4.1

[0029] As a preferred technical solution:

[0030] As described above, the method for obtaining the critical speed of texturing polyester pre-oriented yarn involves adjusting the actual texturing speed to the starting point of the adjustment during the debugging process. Then, it is determined whether there is any yarn abnormality. If so, the speed is reduced; otherwise, the speed is increased first, and then the speed is reduced.

[0031] The speed-up operation involves gradually increasing the texturing speed by no more than 20 m / min until an abnormality in the yarn appears.

[0032] The speed reduction operation is to gradually reduce the texturing speed by no more than 20 m / min until the abnormality of the filament disappears. The texturing speed at which the abnormality of the filament disappears is the critical texturing speed.

[0033] Among them, abnormality refers to the filament shaking or abnormal filament tension.

[0034] Since the starting point value for debugging calculated by this invention is close to the critical speed of texturing, this invention does not need to find the unknown critical speed of texturing by significantly increasing the texturing speed as in the prior art. Because the increase in texturing speed is small, when a filament abnormality occurs, the texturing speed will only slightly exceed the critical speed of texturing, which is still within a controllable range. Therefore, this invention does not need to find the unknown critical speed of texturing by significantly decreasing the texturing speed as in the prior art. Furthermore, this invention does not need to repeat the operation of increasing and decreasing the texturing speed in the future.

[0035] The method for obtaining the critical speed of texturing in polyester pre-oriented yarn as described above requires that the increase or decrease in texturing speed be no less than 5 m / min, thus ensuring high overall debugging efficiency.

[0036] As described above, in a method for obtaining the critical speed of texturing polyester pre-oriented yarn, the time interval between two adjacent adjustments of the texturing speed is 2 to 3 minutes. This is because, from the perspective of actual production logic, after the texturing speed is adjusted, key parameters such as the tension and roller speed of the equipment will not stabilize immediately and require a buffer time of 2 to 3 minutes to reach a new equilibrium.

[0037] As described above, the method for obtaining the texturing critical speed of polyester pre-oriented yarn refers to the abnormal tension of the yarn, which means that the coefficient of variation of tension (CV), fluctuating tension (FL), or global tension (GL) of the yarn exceeds the threshold. How to set the online tension threshold is an existing technology, and those skilled in the art can set an empirical value based on experience.

[0038] Global tension (GL) reflects the average tension level of the yarn bundle during the overall operation of the equipment; fluctuating tension (FL) records the real-time change in yarn tension during operation, which is directly related to the yarn breakage rate and the uniformity of finished product quality; ③ Coefficient of variation (CV) is used to quantify the relative degree of tension fluctuation.

[0039] Compared to silk sliver vibration, the core advantage of judging by abnormal silk sliver tension is that it provides stronger early warning and more accurate judgment.

[0040] As described above, the method for obtaining the critical speed of texturing polyester pre-oriented yarn is described. Abnormal yarn tension refers to the real-time detected tension variation coefficient of the yarn being greater than 3 times the average tension variation coefficient. The average tension variation coefficient is the average value of the tension variation coefficients detected during the texturing production process. Due to continuous production, the measured tension variation coefficient data will increase, and the value of the average tension variation coefficient will also change.

[0041] The method for obtaining the texturing critical speed of polyester pre-oriented yarn as described above uses texturing machines such as TMT ATF-1500FOUR“T”, TMT ATF-1500FOUR“V”, Suba eFK (V), Suba FK6-1000 (M), Suba FK6-1000 (V), Hongyuan FK6-HY-1 (M), Hongyuan FK6-HY-1 (V), Hongyuan HY-9 (V), Hongyuan HY-7HM (M), Hongyuan FK6.HY-1B (V), Hongyuan HY-7Pro, Rongteng RT-II (V), and Jinyi JYT-V-1000 (V).

[0042] Beneficial effects:

[0043] (1) The method for obtaining the texturing critical speed of the present invention is applicable to polyester pre-oriented yarn with a fineness of 88~530dtex. Moreover, the texturing critical speed obtained by the method of the present invention not only has a small deviation from the actual texturing critical speed, but also has high efficiency in obtaining the texturing critical speed.

[0044] (2) The formula of this invention can calculate the starting point value of the adjustment of the critical speed of the loading, which can save a lot of test steps and improve test efficiency.

[0045] (3) Even when encountering a new type of texturing machine, the method of the present invention can still obtain the critical speed of texturing, which has a wider range of applications and higher efficiency. Detailed Implementation

[0046] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0047] A method for obtaining the texturing critical velocity of polyester pre-oriented yarn, wherein the fineness of the polyester pre-oriented yarn is 88~530 dtex, the specific process is as follows:

[0048] First, adjust the actual texturing speed to the starting value for debugging. Then, determine if any yarn abnormalities occur. If so, gradually decrease the texturing speed in increments of 10-20 m / min until the yarn abnormality disappears. The texturing speed at which the yarn abnormality disappears is the critical texturing speed. Conversely, if no abnormality occurs, first gradually increase the texturing speed in increments of 10-20 m / min until a yarn abnormality occurs, then gradually decrease the texturing speed in increments of 10-20 m / min until the yarn abnormality disappears. The texturing speed at which the yarn abnormality disappears is the critical texturing speed. Abnormality refers to yarn vibration or abnormal yarn tension. Abnormal yarn tension means that the real-time detected tension variation coefficient of the yarn is greater than three times the average tension variation coefficient. The time interval between two consecutive adjustments to the texturing speed is 2-3 minutes. The starting value for debugging is obtained through calculation, and the calculation formula is as follows:

[0049] SS=K×(V 机 ×[0.47×R-0.00032×F]);

[0050] In the formula, SS is the starting value for debugging, in m / min; V 机 R is the mechanical speed of the texturing machine, in m / min; R is the deformation ratio of the polyester pre-oriented yarn during the texturing process, R=d1 / d2, where d1 is the fineness of the polyester pre-oriented yarn (in dtex), and d2 is the fineness of the polyester texturing yarn corresponding to the polyester pre-oriented yarn in the historical production process (in dtex).

[0051] F is the number of multifilaments in the pre-oriented polyester yarn, dimensionless;

[0052] K is a correction factor, dimensionless. When the polyester pre-oriented yarn is a semi-dull polyester pre-oriented yarn with a circular cross section, if the fineness is ≥88dtex and <355dtex, then K=1; if the fineness is 355~530dtex, then K=0.9. When the polyester pre-oriented yarn is a fully dull polyester pre-oriented yarn with a circular cross section and a fineness of 88~530dtex, then K=0.95. When the polyester pre-oriented yarn is a cationic polyester pre-oriented yarn with a circular cross section or a polyester pre-oriented yarn with an irregular cross section and a fineness of 88~530dtex, then K=0.9.

[0053] To verify the feasibility of the method for obtaining the texturing critical speed of polyester pre-oriented yarn of the present invention, three production lines for texturing polyester pre-oriented yarn were selected for verification.

[0054] The texturing machine, polyester pre-oriented yarn, texturing process flow, and texturing process parameters for the first production line are as follows:

[0055] Texturing machine: Manufacturer is TMT Machinery Co., Ltd. of Japan, model ATF-1500FOURF / T, machine speed is 1350m / min;

[0056] Polyester pre-oriented yarn: semi-dull polyester pre-oriented yarn with a circular cross section, a fineness of 135 dtex, and a multifilament count of 36F;

[0057] Texturing process flow: Wire cutter → Feed roller (FR1) → Twist stopper → First heating box (high temperature short heating box) → SCP suction cooling plate → False twister → TCS tension sensor → Feed roller (FR2) → Feed roller (FR2A) → Second heating box → Feed roller (FR3) → Wire probe → Oiling device → Automatic doffing and winding device;

[0058] Texturing process parameters: false twist ratio is 1.71, draw ratio is 1.75, short zone temperature in the first hot box is 395℃, long zone temperature is 270℃, second hot box temperature is 175℃, second A overfeed rate is 3%, yarn output ratio is 2%, winding ratio is 1.8%, oil roller speed is 0.8rpm, SCP suction cooling plate negative pressure is 1.0bar, and actual texturing speed is 950m / min;

[0059] During verification on the first production line, the texturing speed was increased by 20 m / min and decreased by 10 m / min, with a 2-min time interval between two consecutive adjustments. R was 1.6265, K was 1, and the initial adjustment speed was 1016.5 m / min. The final critical texturing speed was 1060 m / min. (Specifically, during the preparation process, the actual texturing speed was first increased to the initial adjustment value. It was observed that no filament abnormalities occurred during processing at this speed. The texturing speed was then gradually increased in increments of 20 m / min until filament abnormalities appeared. Then, the speed was gradually decreased in increments of 10 m / min until the filament abnormalities disappeared. The texturing speed at which the filament abnormalities disappeared was the final critical texturing speed.) At this critical speed, no abnormalities such as filament slippage or breakage occurred in the produced texturing yarn. Obtaining the critical speed took 13-15 minutes.

[0060] To verify the accuracy of the texturing critical speed obtained by the above method, existing technology was used to adjust the above-mentioned process flow for preparing texturing yarn to obtain the texturing critical speed. Specifically, the starting point value for adjustment was not calculated using the method of this invention. Instead, the texturing speed was gradually increased from the actual speed at 50 m / min. Each increase required a stable 3-minute run to check for yarn vibration or tension fluctuation exceeding the threshold. When such anomalies were detected, the texturing speed was reduced by 100 m / min, then increased again by 20 m / min. When the anomalies reappeared, the speed was reduced by another 10 m / min. The speed at which the yarn stabilized was then the texturing critical speed for this type of polyester pre-oriented yarn, which was 1065 m / min. Obtaining the texturing critical speed took 20-25 minutes.

[0061] A comparison of the texturing critical speeds obtained by the two methods above shows that the texturing critical speed obtained by the method of the present invention for obtaining the texturing critical speed of polyester pre-oriented yarn is accurate and takes much less time than the prior art.

[0062] The texturing machine, polyester pre-oriented yarn, texturing process flow, and texturing process parameters for the second production line are as follows:

[0063] Texturing machine: Manufacturer is TMT Machinery Co., Ltd. of Japan, model ATF-1500FOURF / T, and the mechanical speed of the texturing machine is 1350m / min;

[0064] Polyester pre-oriented yarn: Circular cross-section fully dull polyester pre-oriented yarn with a fineness of 133 dtex and a multifilament count of 72F;

[0065] Texturing process flow: Wire cutter → Feed roller (FR1) → Twist stopper → First heating box (high temperature short heating box) → SCP suction cooling plate → False twister → TCS tension sensor → Feed roller (FR2) → Feed roller (FR2A) → Second heating box → Feed roller (FR3) → Wire probe → Oiling device → Automatic doffing and winding device;

[0066] The texturing process parameters are as follows: false twist ratio is 1.8, draw ratio is 1.75, short zone temperature in the first hot box is 406℃, long zone temperature is 284℃, second hot box temperature is 175℃, second A overfeed rate is 3.1%, yarn output ratio is 2.7%, winding ratio is 1.75%, oil roller speed is 0.52, SCP suction cooling plate negative pressure is 1.0 bar; the actual texturing speed is 880m / min.

[0067] During verification on the second production line, the texturing speed was increased by 20 m / min and decreased by 10 m / min, with a 2-min time interval between two consecutive adjustments. R was 1.6625, K was 0.95, and the initial adjustment value was 972.6 m / min. The final critical texturing speed was 960 m / min. (Specifically, during the preparation process, the actual texturing speed was first increased to the initial adjustment value. When processing at this speed, abnormal filaments were observed. The texturing speed was then gradually decreased in increments of 10 m / min until the abnormalities disappeared. The texturing speed at which the abnormalities disappeared was the final critical texturing speed.) At this critical speed, no abnormalities such as filament slippage or breakage occurred in the produced texturing yarn. Obtaining the critical speed took 8-10 minutes.

[0068] To verify the accuracy of the texturing critical speed obtained by the above method, existing technology was used to adjust the above-mentioned process flow for preparing texturing yarn to obtain the texturing critical speed. Specifically, the starting point value for adjustment was not calculated using the method of this invention. Instead, the texturing speed was gradually increased from the actual speed at 50 m / min. Each increase required a stable 3-minute run to check for yarn vibration or whether the tension fluctuation exceeded the threshold. When the above abnormalities were detected, the texturing speed was reduced by 100 m / min, and then increased again at 20 m / min. When the above abnormalities reappeared, the speed was reduced by another 10 m / min. The speed at which the yarn stabilized at this point is the texturing critical speed for this type of polyester pre-oriented yarn, which was found to be 960 m / min. Obtaining the texturing critical speed took 20-25 minutes.

[0069] A comparison of the texturing critical speeds obtained by the two methods above shows that the texturing critical speed obtained by the method of the present invention for obtaining the texturing critical speed of polyester pre-oriented yarn is accurate and takes much less time than the prior art.

[0070] The texturing machine, polyester pre-oriented yarn, texturing process flow, and texturing process parameters for the third production line are as follows:

[0071] Texturing machine: Manufacturer is TMT Machinery Co., Ltd. of Japan, model ATF-1500FOURF / V, and the mechanical speed of the texturing machine is 1350m / min;

[0072] Polyester pre-oriented yarn: Circular cross-section cationic polyester pre-oriented yarn with a fineness of 260 dtex and a multifilament count of 48F;

[0073] Texturing process flow: Wire cutter → Feed roller (FR1) → Twist stopper → First heating box → Cooling plate → False twister → TCS tension sensor → Feed roller (FR2) → Feed roller (FR2A) → Second heating box → Feed roller (FR3) → Wire probe → Oiling device → Automatic doffing and winding device;

[0074] The texturing process parameters are as follows: false twist ratio is 1.93, draw ratio is 1.738, first heating box temperature is 168℃, second heating box temperature is 171℃, second A overfeed rate is 4.8%, yarn output ratio is 3.5%, winding ratio is 1.0%, and oil roller speed is 1.36; the actual texturing speed is 750m / min.

[0075] During verification on the third production line, the texturing speed was increased by 20 m / min and decreased by 10 m / min, with a 2-min time interval between two consecutive adjustments. R was 1.5757, K was 0.9, and the initial adjustment value was 881.2 m / min. The final critical texturing speed was 870 m / min. (Specifically, during the preparation process, the actual texturing speed was first increased to the initial adjustment value. When processing at this speed, abnormal filaments were observed. The texturing speed was then gradually decreased by 10 m / min until the abnormalities disappeared. The texturing speed at which the abnormalities disappeared was the final critical texturing speed.) At this critical speed, no abnormalities such as filament slippage or breakage occurred in the produced texturing yarn. Obtaining the critical texturing speed took 8-10 minutes.

[0076] To verify the accuracy of the texturing critical speed obtained by the above method, existing technology was used to adjust the above-mentioned process flow for preparing texturing yarn to obtain the texturing critical speed. Specifically, the starting point value for adjustment was not calculated using the method of this invention. Instead, the texturing speed was gradually increased from the actual speed at 50 m / min. Each increase required a stable 3-minute run to check for yarn vibration or whether the tension fluctuation exceeded the threshold. When the above abnormalities were detected, the texturing speed was reduced by 100 m / min, and then increased again at 20 m / min. When the above abnormalities reappeared, the speed was reduced by another 10 m / min. The speed at which the yarn stabilized at this point is the texturing critical speed for this type of polyester pre-oriented yarn, which was found to be 865 m / min. Obtaining the texturing critical speed took 20-25 minutes.

[0077] A comparison of the texturing critical speeds obtained by the two methods above shows that the texturing critical speed obtained by the method of the present invention for obtaining the texturing critical speed of polyester pre-oriented yarn is accurate and takes much less time than the prior art.

Claims

1. A method for obtaining the critical speed of texturing polyester pre-oriented yarn, wherein the critical speed of texturing polyester pre-oriented yarn is obtained by online adjustment of the texturing speed, characterized in that, The fineness of the pre-oriented polyester yarn is 88~530 dtex; the starting value for adjustment is obtained through calculation, and the calculation formula is as follows: SS=K×(V 机 ×[0.47×R-0.00032×F]); In the formula, SS is the starting value for debugging, in m / min; V 机 The mechanical speed of the texturing machine is expressed in m / min. R is the deformation ratio of the pre-oriented polyester yarn during the texturing process; F is the number of multifilaments in the pre-oriented polyester yarn, dimensionless; K is a correction factor, dimensionless. When the polyester pre-oriented yarn is a semi-dull polyester pre-oriented yarn with a circular cross section, if the fineness is ≥88dtex and <355dtex, then K=1; if the fineness is 355~530dtex, then K=0.

9. When the polyester pre-oriented yarn is a fully dull polyester pre-oriented yarn with a circular cross section and a fineness of 88~530dtex, then K=0.

95. When the polyester pre-oriented yarn is a cationic polyester pre-oriented yarn with a circular cross section or a polyester pre-oriented yarn with an irregular cross section and a fineness of 88~530dtex, then K=0.

9.

2. The method for obtaining the critical texturing speed of polyester pre-oriented yarn according to claim 1, characterized in that, During the debugging process, first adjust the actual feeding speed to the starting value of the debugging, and then determine whether there is any abnormality in the yarn. If so, perform a speed reduction operation. Conversely, if the speed is increased, then the speed is decreased. The speed-up operation involves gradually increasing the texturing speed by no more than 20 m / min until an abnormality in the yarn appears. The speed reduction operation is to gradually reduce the texturing speed by no more than 20 m / min until the abnormality of the filament disappears. The texturing speed at which the abnormality of the filament disappears is the critical texturing speed. Among them, abnormality refers to the filament shaking or abnormal filament tension.

3. The method for obtaining the critical texturing speed of polyester pre-oriented yarn according to claim 2, characterized in that, The increase or decrease in loading speed shall not be less than 5 m / min.

4. The method for obtaining the critical texturing speed of polyester pre-oriented yarn according to claim 2, characterized in that, The time interval between two consecutive adjustments to the loading speed is 2 to 3 minutes.

5. The method for obtaining the texturing critical velocity of polyester pre-oriented yarn according to claim 2, characterized in that, Abnormal filament tension refers to the filament tension variation coefficient, fluctuating tension, or global tension exceeding a threshold.

6. The method for obtaining the critical texturing speed of polyester pre-oriented yarn according to claim 5, characterized in that, Abnormal yarn tension refers to a real-time detected tension variation coefficient of the yarn that is more than three times the average tension variation coefficient.