Method for improving unwinding performance of polyester FDY (fully drawn yarn) for warp knitting

Abstract

The invention belongs to the technical field of polyester fully drawn yarn (FDY), and relates to a method for improving the unwinding performance of polyester FDY for warp knitting, which comprises the following steps of: oiling and drafting undrafted polyester yarn, winding and forming the undrafted polyester yarn by using a 24-32-head FDY winding machine to obtain an FDY spinning cake, unwinding the FDY spinning cake, uniformly winding the unwound FDY spinning cake on a warp beam, and weaving, the weight of the FDY spinning cake obtained through winding forming is 0.5-1 kg larger than the package weight specified by a 24-32-head FDY winding machine, the maximum unwinding tension value of the FDY spinning cake is smaller than or equal to 2.5 cN, the unwinding tension standard deviation is smaller than or equal to 0.5 cN, the PPF value is smaller than or equal to 11, and delaminating and end breaking do not occur in the process that the FDY spinning cake is wound to a warp beam after unwinding. By means of the method, the spinning cake with the weight exceeding the specified weight of a 24-32-head FDY winding machine in the prior art can be produced, and it can be guaranteed that good unwinding performance is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester FDY yarns and relates to a method for improving the unwinding performance of polyester FDY yarns for warp knitting. Background Art

[0002] At present, the weight of the silk cake produced by the 24-32-head FDY winding machine is 6.0-7.5kg, which can better guarantee the molding quality of the silk cake. However, in pursuit of higher production efficiency and cost-effectiveness, enterprises want to increase the standard weight of the silk cake, but the increase in the weight of the silk cake directly leads to the expansion of its diameter, which is difficult to maintain within the ideal size range. In order to keep the silk cake within the ideal size range, it is necessary to increase the tension to squeeze the silk cake, but the tension is too large, and the internal stress is too large during the winding process, causing the outer layer of the silk to squeeze the inner layer of the silk due to the stress. The result of the squeezing is the collapse of the edge of the inner layer of the silk. The slight collapse is the appearance of brake marks on the side. When the silk cake is unwound to the collapsed layer during the unwinding process, it is easy to cause multiple turns of silk to be taken out at the same time (i.e., delamination), which in turn causes the problem of unwinding knots, seriously affecting subsequent processing.

[0003] In order to solve the above problems, the existing technology considers modifying the equipment. For example, in the literature (Feasibility Study on Increasing the Quality of Polyester FDY Packages [J]. Synthetic Fibers, 2023, 52(8): 44-46.), the shift fork is modified to change the lateral movement distance of the yarn cake during the winding process to increase the quality of the package. However, due to the increase in the lateral movement distance (when the winding angle is the same, the number of winding turns increases), when unwinding to the bottom layer, since the circumference of each turn of the yarn is getting smaller, it is easy for a single yarn bundle to rub against the surface of the yarn cake multiple times, resulting in poor unwinding performance.

[0004] For example, in the literature (Improvement of unwinding performance of ultra-fine denier porous polyester false twist yarn. Synthetic Fiber 02 (2007): 40-43.), the process parameters such as overfeeding and winding angle are optimized to reduce the unwinding problems caused by poor forming, protruding belly, overlapping yarns, etc. However, if the equipment increases the weight of the yarn cake on the original basis, the purpose of improving the unwinding performance cannot be achieved by optimizing these process parameters alone.

[0005] Therefore, it is of great significance to need a method for improving the unwinding performance of polyester FDY yarn for warp knitting to solve the above problems. Summary of the invention

[0006] The purpose of the invention is to solve the problems existing in the prior art and provide a method for improving the unwinding performance of polyester FDY yarn for warp knitting.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A method for improving the unwinding performance of polyester FDY yarn for warp knitting, wherein the undrawn polyester yarn (i.e., the fiber obtained by melt extrusion and cooling) is oiled and drawn, and then wound by a 24-32-head FDY winder to obtain an FDY yarn cake, and the FDY yarn cake is evenly wound on a warp beam (i.e., warping) after unwinding, and then woven, and the weight of the FDY yarn cake obtained by winding is 0.5-1 kg greater than the package weight specified by the 24-32-head FDY winder, and the weight of the yarn cake that can ensure good forming by the conventional 24-32-head FDY winder without equipment modification is 6.0-7.5 kg, and the present invention increases the yarn cake weight by 0.5-1 kg on this basis, the maximum unwinding tension of the FDY yarn cake is ≤2.5 cN, the standard deviation of the unwinding tension is ≤0.5 cN, and the PPF value (which is an important index for evaluating the unwinding performance, and the test method refers to the published enterprise standard Q / ZTKHT 02-2023) ≤ 11, no delamination or breakage occurs during the process of winding the FDY yarn cake onto the warp beam after unwinding, indicating that the polyester FDY yarn for warp knitting has excellent unwinding performance;

[0009] In the oil used for oiling, the sizing agent is one or more of water-based epoxy resin and water-based polyurethane, and the sizing agent content is 1~2wt%;

[0010] After oiling and stretching, the difference in tension between the unstretched polyester yarn and the wire guide porcelain above the winding machine is 1.5~1.8cN, and the angle between the yarn bundle and the vertical direction before entering the wire guide porcelain is 13°~15°, and the angle between the yarn bundle and the vertical direction after entering the wire guide porcelain is 33°~37°. In this way, when the same bundle of yarn passes through the same wire guide porcelain, the difference in tension before and after is the friction resistance between the yarn bundle and the wire guide porcelain. The better the smoothness of the yarn bundle, the smaller the difference in tension value before and after; if the smoothness is worse, the friction resistance of the yarn bundle is large, resulting in a greater difference in tension value before and after.

[0011] In the prior art, the weight of the silk cake that can ensure good forming is 6.0~7.5kg for the 24~32-head FDY winding machine without equipment modification. However, in order to reduce costs, the enterprise wants to increase each silk cake by 0.5~1kg, so it is necessary to increase the tension to squeeze the silk cake to ensure that the diameter of the silk cake is within a reasonable range. However, if the tension is too large, the internal stress will be too large during the winding process, causing the outer layer of silk to squeeze the inner layer of silk due to stress. The result of the squeezing is the collapse of the edge of the inner layer of silk. The slight collapse is the appearance of brake marks on the side. When the silk cake is unwound to the collapsed layer during the unwinding process, if the smoothness of the silk bundle is too good, the slightly collapsed part will be brought out, and two or more circles of silk will be brought out together, that is, delamination will occur, and unwinding knots will occur; if the silk bundle is not smooth enough, the bundle of the silk bundle is relatively poor, and when the silk cake is unwound to the collapsed layer during the unwinding process, it is easy to have the problem of unwinding and breaking due to loose silk. The invention improves the oil formulation in the oiling process, so that the smoothness of the yarn bundle during unwinding is controlled within a suitable range, and the unwinding performance of the polyester FDY yarn for warp knitting is effectively improved.

[0012] The sizing agent can improve the bundling performance of the fiber, so that the fiber is not fluffy or scattered during processing. The sizing agent content of conventional oils is basically 10~30%. When the sizing agent is less than 10%, the bundling is relatively poor, and it is easy to have problems such as scattered fibers; when the sizing agent is higher than 30%, it will increase the viscosity between the fibers and affect the subsequent unwinding performance. The present invention uses one or more of water-based epoxy resin and water-based polyurethane as a sizing agent. Epoxy resin is a polymer containing epoxy groups, which has the advantages of good chemical stability, strong adhesion, high mechanical strength, and high modulus; water-based polyurethane has the advantages of high film-forming strength, strong adhesion, good fullness, and good wear resistance. Both water-based epoxy resin and water-based polyurethane have the advantage of strong adhesion, which can improve the adhesion of each single fiber in the winding process of FDY fiber, thereby reducing the problem of knotting caused by the simultaneous slipping of several turns of silk during unwinding due to excessive slippage of the tow. At the same time, the use of the sizing agent is mainly to ensure the smoothness of the FDY fiber during the spinning and drawing process, reduce the hairy fibers, and improve the smoothness of the FDY fiber during the subsequent processing. Based on the above advantages, the sizing agent is controlled to 1-2wt% in the present invention to achieve the corresponding effect, so that the smoothness of the tow is controlled within a suitable range during unwinding, avoiding excessive use of the sizing agent to affect the unwinding performance of the FDY fiber in the subsequent process.

[0013] As the preferred technical solution:

[0014] The method for improving the unwinding performance of polyester FDY yarn for warp knitting as described above comprises, by weight percentage, the oil agent used for oiling includes: base oil 18-35%, smoothing agent 30-48%, sizing agent 1-2%, emulsifier 8-12%, antistatic agent 5-7%, wetting penetrant 5-10%, and water 8-10%.

[0015] A method for improving the unwinding performance of polyester FDY yarn for warp knitting as described above, wherein the base oil is one or more of isooctyl stearate, isooctyl oleate, diisooctyl sebacate, trimethylolpropane oleate, pentaerythritol oleate and industrial white oil;

[0016] The lubricant is one or more of lauric acid polyethylene glycol 400 diester and C12-C14 fatty alcohol block polyoxyethylene polyoxypropylene ether;

[0017] The emulsifier is sorbitan fatty acid ester;

[0018] The antistatic agent is an organic quaternary ammonium salt antistatic agent;

[0019] The wetting and penetrating agent is fatty alcohol polyoxyethylene ether.

[0020] In the method for improving the unwinding performance of polyester FDY yarn for warp knitting as described above, the yarn cake winding diameter ranges from 368 to 378 mm.

[0021] In the method for improving the unwinding performance of polyester FDY yarn for warp knitting as described above, the setting value of the winding tension during winding forming is the density value of the polyester FDY yarn for warp knitting × (0.15~0.18) cN.

[0022] In the method for improving the unwinding performance of polyester FDY yarn for warp knitting as described above, the package contact pressure (i.e., the pressure of the friction roller on the yarn cake during winding) is 245-255N, and the initial winding diameter is 134mm.

[0023] During the winding process;

[0024] When the coil diameter of the silk cake is 134~145mm, the winding angle is 5.29°~5.31°;

[0025] When the coil diameter of the silk cake is 145~160mm, the winding angle is 5.49°~5.51°;

[0026] When the diameter of the silk cake is 160~180mm, the winding angle is 5.69°~5.71°;

[0027] When the coil diameter of the silk cake is 180~210mm, the winding angle is 5.99°~6.01°;

[0028] When the diameter of the silk cake is 210~230mm, the winding angle is 6.19°~6.21°;

[0029] When the diameter of the silk cake is 230~260mm, the winding angle is 5.99°~6.01°;

[0030] When the coil diameter of the silk cake is 260~300mm, the winding angle is 5.69°~5.71°;

[0031] When the diameter of the silk cake is 300~340mm, the winding angle is 5.49°~5.51°.

[0032] When the diameter of the silk cake is more than 340mm, the winding angle is 5.29°~5.31°;

[0033] The present invention changes the 6-step forming method of the prior art into a 9-step forming method, improves the forming quality of the silk cake by optimizing the winding angle during forming and adjusting the contact pressure and other process parameters, and avoids the problems of wire overlap.

[0034] In the method for improving the unwinding performance of polyester FDY yarn for warp knitting as described above, the specification of the polyester yarn after drawing is 45~75dtex / 24f.

[0035] As described above, a method for improving the unwinding performance of polyester FDY yarn for warp knitting has a reduction rate of poor yarn cake forming of ≤0.3% (mainly the reduction rate of brake marks, convex shoulders and convex bellies); the reduction rate of loose loop yarns and hairy yarns after the yarn cake is wound and formed is ≤0.4%, and there is no overlapping yarn.

[0036] Beneficial Effects

[0037] (1) The present invention can produce yarn cakes with a weight exceeding that specified by the prior art 24-32-head FDY winding machine. By improving the oil formulation in the oiling process and controlling the content of the sizing agent in the oil to 1-2wt%, the smoothness of the yarn bundle during unwinding is controlled within an appropriate range, thereby improving the bonding force of each single filament fiber during the FDY fiber winding process, thereby reducing the problem of knotting caused by the simultaneous slipping of several turns of yarn during unwinding due to excessive slippage of the yarn bundle, and effectively improving the unwinding performance of the polyester FDY yarn for warp knitting.

[0038] (2) The present invention improves the forming quality of the silk cake by changing the 6-step forming method of the prior art into a 9-step forming method, optimizing the process parameters such as the winding angle and adjusting the contact pressure during forming. DETAILED DESCRIPTION

[0040] 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.

[0041] The testing methods of the relevant performance indicators in the following embodiments and comparative examples are as follows: Degrading rate due to poor forming: (number of downgrades due to brake marks + number of downgrades due to abnormal surface unevenness) × 100% / total number; brake marks refer to the appearance of a spiral texture formed after a slight collapse of part of the end face, and the spiral texture exceeds the end face of the silk cake by 1mm; surface unevenness includes convex shoulders and convex bellies, which refers to the unevenness of the end face of the silk cake.

[0042] The downgrade rate of loose loop wire and hairy wire is: (the number of downgraded loose loop wire + the number of downgraded hairy wire) × 100% / total number of wires; among which, loose loop wire refers to the single wire that is exposed from the end surface of the package in an arc or ring shape and is not broken; hairy wire refers to the single wire with more than 2 broken defects on the surface of each wire roll.

[0043] Maximum unwinding tension, standard deviation of unwinding tension, PPF: tested in accordance with enterprise standard Q / ZTKHT 02-2023.

[0044] Example 1

[0045] A method for improving the unwinding performance of polyester FDY yarn for warp knitting, comprising the following steps;

[0046] (1) Preparation of raw materials;

[0047] PTA (purified terephthalic acid);

[0048] EG (ethylene glycol);

[0049] Base oil: 2-ethylhexyl stearate;

[0050] Smoothing agent: a mixture of lauric acid polyethylene glycol (manufacturer: Aladdin Reagent (Shanghai) Co., Ltd., CAS No.: 9004-81-3) and C12-C14 fatty alcohol block polyoxyethylene polyoxypropylene ether (manufacturer: Aladdin Reagent (Shanghai) Co., Ltd., CAS No.: 68439-51-0) in a mass ratio of 1:1;

[0051] Bunching agent: water-based epoxy resin, manufactured by Yueyang Baling Jiayun Petrochemical Co., Ltd., CAS No. 38891-59-7;

[0052] Emulsifier: sorbitan fatty acid ester (manufacturer: Aladdin Reagent (Shanghai) Co., Ltd., CAS No. 1338-39-2);

[0053] Wetting penetrant: fatty alcohol polyoxyethylene ether, manufactured by Shanghai McLean Biochemical Technology Co., Ltd., CAS No. 68131-39-5, number average molecular weight 1199.55;

[0054] Antistatic agent: organic quaternary ammonium salt antistatic agent, the manufacturer is Shanghai McLean Biochemical Technology Co., Ltd., CAS No. 4292-25-5;

[0055] water;

[0056] (2) Preparation of oil;

[0057] By weight percentage, 25% of base oil, 48% of smoothing agent, 1% of sizing agent, 8% of emulsifier, 5% of antistatic agent, 5% of wetting penetrant and 8% of water are mixed evenly to obtain an oil agent;

[0058] (3) Preparing FDY yarn cake;

[0059] (3.1) PTA and EG are used as raw materials, and a polyester melt is generated through the first esterification, the second esterification, the pre-polycondensation, and the final polycondensation; wherein the percentage of PTA in the total content is 69%, the temperature of the first esterification is 260°C, the pressure of the first esterification is 90KPa, the temperature of the second esterification is 275°C, the pressure of the second esterification is 40KPa, the temperature of the upper chamber of the pre-polycondensation is 280°C, the pressure of the upper chamber is 10KPa, the temperature of the lower chamber is 278°C, the pressure of the lower chamber is 1.8KPa, the inlet temperature of the final polycondensation is 280°C, the middle temperature is 282°C, the outlet temperature is 288°C, and the vacuum degree is 180Pa;

[0060] (3.2) The polyester melt in step (3.1) is extruded at 287°C and then cooled to 21°C, and then the undrawn polyester filament is oiled with the oil obtained in step (2), and then drawn to obtain a polyester drawn filament with a specification of 45dtex / 24f, and finally wound on a 32-head FDY winding machine to obtain an FDY yarn cake; wherein the setting value of the winding tension is 7cN; the winding contact pressure is 245N, and the initial winding diameter is 134mm; during the winding process, when the yarn cake diameter is 134-145mm, the winding angle is 5.29°; when the yarn cake diameter is 145-160mm, the winding angle is 5.49°; when the yarn cake diameter is 160-180mm, the winding angle is 5.7 1°; when the diameter of the silk cake is 180~210mm, the winding angle is 6.01°; when the diameter of the silk cake is 210~230mm, the winding angle is 6.21°; when the diameter of the silk cake is 230~260mm, the winding angle is 5.99°; when the diameter of the silk cake is 260~300mm, the winding angle is 5.69°; when the diameter of the silk cake is 300~340mm, the winding angle is 5.49°; when the diameter of the silk cake is 340~368mm, the winding angle is 5.29°; after oiling and drawing, the tension difference before and after the undrawn polyester yarn passes through the guide wheel porcelain above the winding machine is 1.5cN, and the angle between the yarn bundle and the vertical direction before entering the guide wheel porcelain is 13°, and the angle between the yarn bundle and the vertical direction after entering the guide wheel porcelain is 33°;

[0061] The weight of the obtained FDY yarn cake was 6.5kg, the width of the yarn cake was 76mm, and the winding diameter was 368mm. The downgrade rate of the yarn cake due to poor forming was 0.3%, and the downgrade rate of the loose loop yarn and the hair yarn after the yarn cake was wound was 0.35%, and there was no overlapping yarn.

[0062] (4) After the FDY yarn cake is unwound, it is evenly wound onto the warp beam for weaving.

[0063] The maximum unwinding tension of the FDY yarn cake is 2.31cN, the standard deviation of the unwinding tension is 0.35cN, and the PPF value is 10.3. No delamination or breakage occurs during the process of unwinding the FDY yarn cake and winding it onto the warp beam.

[0064] Comparative Example 1

[0065] A method for improving the unwinding performance of polyester FDY yarn for warp knitting is basically the same as that of Example 1, except that: in step (2), the content of the sizing agent is 0.5% and the content of water is 8.5% by weight;

[0066] The poor molding degradation rate of the FDY yarn cake obtained in step (3) is 0.3%, the degradation rate of the loose loop yarn and the hair yarn after the yarn cake is wound and formed is 0.9%, and there is no overlapping yarn;

[0067] The silk cake used in the weaving step (4) is the silk cake wound in this comparative example.

[0068] The maximum unwinding tension of the FDY yarn cake is 4.69cN, the standard deviation of the unwinding tension is 0.79cN, and the PPF value is 19. No delamination or breakage occurs during the unwinding of the FDY yarn cake onto the warp beam, but 19 unwinding breakages occur.

[0069] By comparing Comparative Example 1 with Example 1, it can be seen that the reduction rate of loose loop yarns and hairy yarns after the yarn cake obtained in Comparative Example 1 is greatly increased after winding and forming, and the tension suddenly increases and the PPF increases during weaving. This is because the bundling agent content is low and the bundling of the yarn bundle is relatively poor, which will reduce its smoothness during use and easily cause appearance problems such as loose yarns and loose loop yarns, thereby affecting the unwinding tension and PPF value, and the phenomenon of unwinding breakage will also occur during unwinding.

[0070] Comparative Example 2

[0071] A method for improving the unwinding performance of polyester FDY yarn for warp knitting is basically the same as that of Example 1, except that: in step (2), the content of the sizing agent is 4% and the content of water is 8.5% by weight;

[0072] The poor molding degradation rate of the FDY yarn cake obtained in step (3) is 0.3%, and the degradation rate of the loose loop yarn and the hair yarn after the yarn cake is wound is 0.38%, and there is no overlapping yarn;

[0073] The silk cake used in the weaving step (4) is the silk cake wound in this comparative example.

[0074] The maximum unwinding tension of the FDY yarn cake is 2.18 cN, the standard deviation of the unwinding tension is 0.31 cN, the PPF value is 9, and the FDY yarn cake delamination and breakage occur 12 times during the process of being unwound and wound onto the warp beam.

[0075] By comparing Comparative Example 2 with Example 1, it can be seen that the silk cake obtained in Comparative Example 2 will also experience multiple delamination and breakage during weaving. This is because the content of the sizing agent is too high, which will increase the viscosity between the fibers, resulting in delamination and breakage due to multiple turns of silk bundles being taken out at the same time during reeling; in addition, using too much sizing agent will also cause excess sizing agent to easily adhere to the surface of the hot roller, thereby causing fiber bonding and affecting its smoothness.

[0076] Comparative Example 3

[0077] A method for improving the unwinding performance of polyester FDY yarn for warp knitting is basically the same as Example 1, except that: the sizing agent in steps (1) and (2) is replaced by triethanolamine oleate (manufacturer: Shanghai MacLean Biochemical Technology Co., Ltd., CAS No. 2717-15-9);

[0078] The poor forming rate of the FDY yarn cake obtained in step (3) is 0.4%, the loose loop yarn and the hair yarn are degraded by 1.3% after the yarn cake is wound and formed, and there is no overlapping yarn;

[0079] The silk cake used in the weaving step (4) is the silk cake wound in this comparative example.

[0080] The maximum unwinding tension of the FDY yarn cake is 6.14 cN, the standard deviation of the unwinding tension is 0.81 cN, and the PPF value is 24.1. No delamination or breakage occurs during the unwinding of the FDY yarn cake onto the warp beam, but 24 unwinding breakages occur.

[0081] By comparing Comparative Example 3 with Example 1, it can be seen that the reduction rate of loose loop yarns and wool yarns after the yarn cake obtained in Comparative Example 3 is greatly increased after winding and forming, and the tension suddenly increases and the PPF increases during weaving. This is because the bundling agent is triethanolamine oleate. When its content is low, the bundling of the yarn bundle is relatively poor, and appearance problems such as loose yarns and loose loop yarns are prone to occur, thereby affecting the unwinding tension and PPF value, and the phenomenon of unwinding breakage may also occur during unwinding.

[0082] Example 2

[0083] A method for improving the unwinding performance of polyester FDY yarn for warp knitting, comprising the following steps;

[0084] (1) Preparation of raw materials;

[0085] PTA;

[0086] EG;

[0087] Base oil: industrial white oil, manufactured by Shanghai MacLean Biochemical Technology Co., Ltd., CAS No. 8020-83-5);

[0088] Smoothing agent: C12-C14 fatty alcohol block polyoxyethylene polyoxypropylene ether, manufacturer: Aladdin Reagent (Shanghai) Co., Ltd., CAS No. 68439-51-0;

[0089] Clustering agent: water-based polyurethane, the manufacturer is Guangzhou Ruilin New Materials Co., Ltd., the brand is RL-8401;

[0090] Emulsifier: sorbitan fatty acid ester (manufacturer: Aladdin Reagent (Shanghai) Co., Ltd., CAS No. 1338-39-2);

[0091] Wetting penetrant: fatty alcohol polyoxyethylene ether, manufactured by Shanghai McLean Biochemical Technology Co., Ltd., CAS No. 68131-39-5, number average molecular weight 1199.55;

[0092] Antistatic agent: organic quaternary ammonium salt antistatic agent, the manufacturer is Shanghai McLean Biochemical Technology Co., Ltd., CAS No. 4292-25-5;

[0093] water;

[0094] (2) Preparation of oil;

[0095] By weight percentage, 35% of base oil, 30% of lubricant, 1.5% of sizing agent, 10% of emulsifier, 6% of antistatic agent, 7.5% of wetting penetrant and 10% of water are mixed evenly to obtain an oil agent;

[0096] (3) Preparing FDY yarn cake;

[0097] (3.1) PTA and EG are used as raw materials, and a polyester melt is generated through the first esterification, the second esterification, the pre-polycondensation, and the final polycondensation; wherein the percentage of PTA in the total content is 69.5%, the temperature of the first esterification is 262°C, the pressure of the first esterification is 80KPa, the temperature of the second esterification is 273°C, the pressure of the second esterification is 38KPa, the upper chamber temperature of the pre-polycondensation is 279°C, the upper chamber pressure is 11KPa, the lower chamber temperature is 279°C, the lower chamber pressure is 2KPa, the inlet temperature of the final polycondensation is 281°C, the middle temperature is 284°C, the outlet temperature is 287°C, and the vacuum degree is 200Pa;

[0098] (3.2) The polyester melt in step (3.1) is extruded at 288°C and then cooled to 22°C, and then the undrawn polyester filament is oiled with the oil obtained in step (2), and then drawn to obtain a polyester drawn filament with a specification of 50 dtex / 24f, and finally wound with a 32-head FDY winding machine to obtain an FDY yarn cake; wherein the setting value of the winding tension is 8cN; the winding contact pressure is 255N, and the initial winding diameter is 134mm; during the winding process, when the yarn cake diameter is 134-145mm, the winding angle is 5.31°; when the yarn cake diameter is 145-160mm, the winding angle is 5.51°; when the yarn cake diameter is 160-180mm, the winding angle is 5.6 9°; when the diameter of the silk cake is 180~210mm, the winding angle is 5.99°; when the diameter of the silk cake is 210~230mm, the winding angle is 6.19°; when the diameter of the silk cake is 230~260mm, the winding angle is 6.01°; when the diameter of the silk cake is 260~300mm, the winding angle is 5.71°; when the diameter of the silk cake is 300~340mm, the winding angle is 5.51°; when the diameter of the silk cake is 340~370mm, the winding angle is 5.31°; after oiling and drawing, the tension difference before and after the undrawn polyester yarn passes through the guide wheel porcelain above the winding machine is 1.6cN, and the angle between the yarn bundle and the vertical direction before entering the guide wheel porcelain is 13°, and the angle between the yarn bundle and the vertical direction after entering the guide wheel porcelain is 34°;

[0099] The weight of the obtained FDY yarn cake was 7.0kg, the width of the yarn cake was 77mm, and the winding diameter was 370mm. The downgrade rate of the yarn cake due to poor forming was 0.28%, and the downgrade rate of the loose loop yarn and the hair yarn after the yarn cake was wound was 0.37%, and there was no overlapping yarn.

[0100] (4) After the FDY yarn cake is unwound, it is evenly wound onto the warp beam for weaving.

[0101] The maximum unwinding tension of the FDY yarn cake is 2.14 cN, the standard deviation of the unwinding tension is 0.34 cN, and the PPF value is 10.1. No delamination or breakage occurs during the process of unwinding the FDY yarn cake and winding it onto the warp beam.

[0102] Example 3

[0103] A method for improving the unwinding performance of polyester FDY yarn for warp knitting, comprising the following steps;

[0104] (1) Preparation of raw materials;

[0105] PTA;

[0106] EG;

[0107] Base oil: dioctyl sebacate;

[0108] Smoothing agent: C12~C14 fatty alcohol block polyoxyethylene polyoxypropylene ether, manufacturer is Aladdin Reagent (Shanghai) Co., Ltd., brand number 68439-51-0;

[0109] Sizing agent: a mixture of water-based epoxy resin (manufacturer: Yueyang Baling Jiayun Petrochemical Co., Ltd., CAS No.: 38891-59-7) and water-based polyurethane (manufacturer: Guangzhou Ruilin New Materials Co., Ltd., brand: RL-8401) in a mass ratio of 1:1;

[0110] Emulsifier: sorbitan fatty acid ester (manufacturer: Aladdin Reagent (Shanghai) Co., Ltd., CAS No. 1338-39-2);

[0111] Wetting penetrant: fatty alcohol polyoxyethylene ether, manufactured by Shanghai McLean Biochemical Technology Co., Ltd., CAS No. 68131-39-5, number average molecular weight 1199.55;

[0112] Antistatic agent: organic quaternary ammonium salt antistatic agent, the manufacturer is Shanghai McLean Biochemical Technology Co., Ltd., CAS No. 4292-25-5;

[0113] water;

[0114] (2) Preparation of oil;

[0115] By weight percentage, 18% of base oil, 42% of lubricant, 2% of sizing agent, 12% of emulsifier, 7% of antistatic agent, 10% of wetting penetrant and 9% of water are mixed evenly to obtain an oil agent;

[0116] (3) Preparing FDY yarn cake;

[0117] (3.1) PTA and EG are used as raw materials, and a polyester melt is generated through the first esterification, the second esterification, the pre-polycondensation, and the final polycondensation; wherein the percentage of PTA in the total content is 70%, the temperature of the first esterification is 266°C, the pressure of the first esterification is 100KPa, the temperature of the second esterification is 270°C, the pressure of the second esterification is 35KPa, the temperature of the upper chamber of the pre-polycondensation is 278°C, the pressure of the upper chamber is 12KPa, the temperature of the lower chamber is 280°C, the pressure of the lower chamber is 1.9KPa, the inlet temperature of the final polycondensation is 282°C, the middle temperature is 285°C, the outlet temperature is 286°C, and the vacuum degree is 230Pa;

[0118] (3.2) The polyester melt in step (3.1) is extruded at 289°C and then cooled to 21.5°C, and then the undrawn polyester filament is oiled with the oil obtained in step (2), and then drawn to obtain a polyester drawn filament with a specification of 60dtex / 24f, and finally wound with a 32-head FDY winder to obtain an FDY yarn cake; wherein the setting value of the winding tension is 10cN; the winding contact pressure is 249N, and the initial winding diameter is 134mm; during the winding process, when the yarn cake diameter is 134-145mm, the winding angle is 5.3°; when the yarn cake diameter is 145-160mm, the winding angle is 5.5°; when the yarn cake diameter is 160-180mm, the winding angle is The winding angle is 5.7°; when the diameter of the silk cake is 180~210mm, the winding angle is 6°; when the diameter of the silk cake is 210~230mm, the winding angle is 6.2°; when the diameter of the silk cake is 230~260mm, the winding angle is 6°; when the diameter of the silk cake is 260~300mm, the winding angle is 5.7°; when the diameter of the silk cake is 300~340mm, the winding angle is 5.5°; when the diameter of the silk cake is 340~372mm, the winding angle is 5.3°; after oiling and drawing, the tension difference before and after the undrawn polyester yarn passes through the guide wheel porcelain above the winding machine is 1.5cN, and the angle between the yarn bundle and the vertical direction before entering the guide wheel porcelain is 13°, and the angle between the yarn bundle and the vertical direction after entering the guide wheel porcelain is 35°;

[0119] The weight of the obtained FDY yarn cake was 7.0kg, the width of the yarn cake was 77.5mm, and the winding diameter was 372mm. The downgrade rate of the yarn cake due to poor forming was 0.29%, and the downgrade rate of the loose loop yarn and the hair yarn after the yarn cake was wound was 0.25%, and there was no overlapping yarn.

[0120] (4) After the FDY yarn cake is unwound, it is evenly wound onto the warp beam for weaving.

[0121] The maximum unwinding tension of the FDY yarn cake is 2.08cN, the standard deviation of the unwinding tension is 0.31cN, and the PPF value is 9.8. No delamination or breakage occurs during the process of unwinding the FDY yarn cake and winding it onto the warp beam.

[0122] Example 4

[0123] A method for improving the unwinding performance of polyester FDY yarn for warp knitting, comprising the following steps;

[0124] (1) Preparation of raw materials;

[0125] PTA;

[0126] EG;

[0127] Base oil: trimethylolpropane oleate;

[0128] Smoothing agent: C12~C14 fatty alcohol block polyoxyethylene polyoxypropylene ether, manufacturer is Aladdin Reagent (Shanghai) Co., Ltd., brand number 68439-51-0;

[0129] Bunching agent: water-based epoxy resin, manufactured by Yueyang Baling Jiayun Petrochemical Co., Ltd., CAS No. 38891-59-7;

[0130] Emulsifier: sorbitan fatty acid ester (manufacturer: Aladdin Reagent (Shanghai) Co., Ltd., CAS No. 1338-39-2);

[0131] Wetting penetrant: fatty alcohol polyoxyethylene ether, manufactured by Shanghai McLean Biochemical Technology Co., Ltd., CAS No. 68131-39-5, number average molecular weight 1199.55;

[0132] Antistatic agent: organic quaternary ammonium salt antistatic agent, the manufacturer is Shanghai McLean Biochemical Technology Co., Ltd., CAS No. 4292-25-5;

[0133] water;

[0134] (2) Preparation of oil;

[0135] By weight percentage, 20% of base oil, 45% of lubricant, 2% of sizing agent, 11% of emulsifier, 6.5% of antistatic agent, 7% of wetting penetrant, and 8.5% of water are mixed evenly to obtain an oil agent;

[0136] (3) Preparing FDY yarn cake;

[0137] (3.1) PTA and EG are used as raw materials, and a polyester melt is generated through the first esterification, the second esterification, the pre-polycondensation, and the final polycondensation; wherein the percentage of PTA in the total content is 70.5%, the temperature of the first esterification is 268°C, the pressure of the first esterification is 105KPa, the temperature of the second esterification is 268°C, the pressure of the second esterification is 33KPa, the temperature of the upper chamber of the pre-polycondensation is 276°C, the pressure of the upper chamber is 13KPa, the temperature of the lower chamber is 282°C, the pressure of the lower chamber is 2.1KPa, the inlet temperature of the final polycondensation is 281°C, the middle temperature is 283°C, the outlet temperature is 287°C, and the vacuum degree is 270Pa;

[0138] (3.2) The polyester melt in step (3.1) is extruded at 288°C and then cooled to 21.5°C, and then the undrawn polyester filament is oiled with the oil obtained in step (2), and then drawn to obtain a polyester drawn filament with a specification of 65dtex / 24f, and finally wound with a 24-head FDY winder to obtain an FDY yarn cake; wherein the setting value of the winding tension is 11cN; the winding contact pressure is 252N, and the initial winding diameter is 134mm; during the winding process, when the yarn cake diameter is 134-145mm, the winding angle is 5.3°; when the yarn cake diameter is 145-160mm, the winding angle is 5.5°; when the yarn cake diameter is 160-180mm, the winding angle is 5.69°; when the diameter of the silk cake is 180~210mm, the winding angle is 6°; when the diameter of the silk cake is 210~230mm, the winding angle is 6.2°; when the diameter of the silk cake is 230~260mm, the winding angle is 5.01°; when the diameter of the silk cake is 260~300mm, the winding angle is 5.69°; when the diameter of the silk cake is 300~340mm, the winding angle is 5.5°; when the diameter of the silk cake is 340~375mm, the winding angle is 5.31°; after oiling and drawing, the tension difference before and after the undrawn polyester yarn passes through the guide wheel porcelain above the winding machine is 1.7cN, and the angle between the yarn bundle and the vertical direction before entering the guide wheel porcelain is 14°, and the angle between the yarn bundle and the vertical direction after entering the guide wheel porcelain is 36°;

[0139] The weight of the obtained FDY yarn cake was 7.5kg, the width of the yarn cake was 78mm, and the winding diameter was 375mm. The downgrade rate of the yarn cake due to poor forming was 0.27%, and the downgrade rate of the loose loop yarn and the hair yarn after the yarn cake was wound was 0.3%, and there was no overlapping yarn.

[0140] (4) After the FDY yarn cake is unwound, it is evenly wound onto the warp beam for weaving.

[0141] The maximum unwinding tension of the FDY yarn cake is 2.14cN, the standard deviation of the unwinding tension is 0.29cN, and the PPF value is 9.2. No delamination or breakage occurs during the process of winding the FDY yarn cake onto the warp beam after unwinding.

[0142] Embodiment 5;

[0143] A method for improving the unwinding performance of polyester FDY yarn for warp knitting, comprising the following steps;

[0144] (1) Preparation of raw materials;

[0145] PTA;

[0146] EG;

[0147] Base oil: a mixture of pentaerythritol oleate and isooctyl oleate in a mass ratio of 1:1;

[0148] Smoothing agent: polyethylene glycol laurate, manufacturer: Aladdin Reagent (Shanghai) Co., Ltd., CAS No. 9004-81-3;

[0149] Clustering agent: water-based polyurethane, the manufacturer is Guangzhou Ruilin New Materials Co., Ltd., the brand is RL-8401;

[0150] Emulsifier: sorbitan fatty acid ester (manufacturer: Aladdin Reagent (Shanghai) Co., Ltd., CAS No. 1338-39-2);

[0151] Antistatic agent: organic quaternary ammonium salt antistatic agent, the manufacturer is Shanghai McLean Biochemical Technology Co., Ltd., CAS No. 4292-25-5;

[0152] Wetting penetrant: fatty alcohol polyoxyethylene ether, manufactured by Shanghai McLean Biochemical Technology Co., Ltd., CAS No. 68131-39-5, number average molecular weight 1199.55;

[0153] water;

[0154] (2) Preparation of oil;

[0155] By weight percentage, 28% of base oil, 40% of lubricant, 2% of sizing agent, 9% of emulsifier, 5% of antistatic agent, 7% of wetting penetrant, and 9% of water are mixed evenly to obtain an oil agent;

[0156] (3) Preparing FDY yarn cake;

[0157] (3.1) PTA and EG are used as raw materials, and a polyester melt is generated through the first esterification, the second esterification, the pre-polycondensation, and the final polycondensation; wherein the percentage of PTA in the total content is 71%, the temperature of the first esterification is 270°C, the pressure of the first esterification is 110KPa, the temperature of the second esterification is 270°C, the pressure of the second esterification is 30KPa, the temperature of the upper chamber of the pre-polycondensation is 277°C, the pressure of the upper chamber is 15KPa, the temperature of the lower chamber is 281°C, the pressure of the lower chamber is 2.2KPa, the inlet temperature of the final polycondensation is 281°C, the middle temperature is 282°C, the outlet temperature is 288°C, and the vacuum degree is 3Pa;

[0158] (3.2) The polyester melt in step (3.1) is extruded at 289°C and then cooled to 21.5°C, and then the undrawn polyester filament is oiled with the oil obtained in step (2), and then drawn to obtain a polyester drawn filament with a specification of 75dtex / 24f, and finally wound with a 24-head FDY winder to obtain an FDY yarn cake; wherein the setting value of the winding tension is 12cN; the winding contact pressure is 251N, and the initial winding diameter is 134mm; during the winding process, when the yarn cake diameter is 134-145mm, the winding angle is 5.29°; when the yarn cake diameter is 145-160mm, the winding angle is 5.49°; when the yarn cake diameter is 160-180mm, the winding angle is The winding angle is 5.7°; when the diameter of the silk cake is 180-210mm, the winding angle is 5.99°; when the diameter of the silk cake is 210-230mm, the winding angle is 6.19°; when the diameter of the silk cake is 230-260mm, the winding angle is 6°; when the diameter of the silk cake is 260-300mm, the winding angle is 5.71°; when the diameter of the silk cake is 300-340mm, the winding angle is 5.51°; when the diameter of the silk cake is 340-378mm, the winding angle is 5.3°; after oiling and drawing, the tension difference before and after the undrawn polyester yarn passes through the guide wheel porcelain above the winding machine is 1.8cN, and the angle between the yarn bundle and the vertical direction before entering the guide wheel porcelain is 15°, and the angle between the yarn bundle and the vertical direction after entering the guide wheel porcelain is 37°;

[0159] The weight of the obtained FDY yarn cake is 8kg, the width of the yarn cake is 77mm, and the winding diameter is 378mm. The downgrade rate of the yarn cake due to poor forming is 0.24%, and the downgrade rate of the loose loop yarn and the hair yarn after the yarn cake is wound is 0.34%, and there is no overlapping yarn.

[0160] (4) After the FDY yarn cake is unwound, it is evenly wound onto the warp beam for weaving.

[0161] The maximum unwinding tension of the FDY yarn cake is 1.7 cN, the standard deviation of the unwinding tension is 0.37 cN, and the PPF value is 9.7. No delamination or breakage occurs during the process of winding the FDY yarn cake onto the warp beam after unwinding.

Claims

1. A method for improving the unwinding performance of polyester FDY yarn for warp knitting, wherein the undrawn polyester yarn is oiled and drawn and then wound by a 24-32-head FDY winder to obtain an FDY yarn cake, and the FDY yarn cake is evenly wound onto a warp beam after unwinding for weaving, characterized in that: The weight of the FDY yarn cake obtained by winding is 0.5~1kg greater than the package weight specified by the 24~32-head FDY winding machine. The maximum unwinding tension of the FDY yarn cake is ≤2.5cN, the standard deviation of the unwinding tension is ≤0.5cN, the PPF value is ≤11, and no delamination or breakage occurs during the process of winding the FDY yarn cake onto the warp beam after unwinding. In the oil used for oiling, the sizing agent is one or more of water-based epoxy resin and water-based polyurethane, and the sizing agent content is 1~2wt%; After oiling and stretching, the tension difference between the unstretched polyester yarn and the guide wheel porcelain above the winding machine is 1.5~1.8cN, and the angle between the yarn bundle and the vertical direction before entering the guide wheel porcelain is 13°~15°, and the angle between the yarn bundle and the vertical direction after entering the guide wheel porcelain is 33°~37°.

2. A method for improving the unwinding performance of polyester FDY yarn for warp knitting according to claim 1, characterized in that: Calculated by weight percentage, the oil used for oiling includes: base oil 18~35%, smoothing agent 30~48%, sizing agent 1~2%, emulsifier 8~12%, antistatic agent 5~7%, wetting penetrant 5~10%, and water 8~10%.

3. A method for improving the unwinding performance of polyester FDY yarn for warp knitting according to claim 2, characterized in that: The base oil is one or more of isooctyl stearate, isooctyl oleate, diisooctyl sebacate, trimethylolpropane oleate, pentaerythritol oleate and industrial white oil; The lubricant is one or more of lauric acid polyethylene glycol 400 diester and C12-C14 fatty alcohol block polyoxyethylene polyoxypropylene ether; The emulsifier is sorbitan fatty acid ester; The antistatic agent is an organic quaternary ammonium salt antistatic agent; The wetting and penetrating agent is fatty alcohol polyoxyethylene ether.

4. The method for improving the unwinding performance of polyester FDY yarn for warp knitting according to claim 1, characterized in that: The diameter of the silk cake roll ranges from 368 to 378 mm.

5. A method for improving the unwinding performance of polyester FDY yarn for warp knitting according to claim 4, characterized in that: The setting value of the winding tension during winding forming is the density value of the polyester FDY yarn for warp knitting × (0.15~0.18) cN.

6. A method for improving the unwinding performance of polyester FDY yarn for warp knitting according to claim 5, characterized in that: The package contact pressure is 245~255N, and the initial roll diameter is 134mm; During the winding process: When the coil diameter of the silk cake is 134~145mm, the winding angle is 5.29°~5.31°; When the coil diameter of the silk cake is 145~160mm, the winding angle is 5.49°~5.51°; When the coil diameter of the silk cake is 160~180mm, the winding angle is 5.69°~5.71°; When the coil diameter of the silk cake is 180~210mm, the winding angle is 5.99°~6.01°; When the coil diameter of the silk cake is 210~230mm, the winding angle is 6.19°~6.21°; When the diameter of the silk cake is 230~260mm, the winding angle is 5.99°~6.01°; When the coil diameter of the silk cake is 260~300mm, the winding angle is 5.69°~5.71°; When the diameter of the silk cake is 300~340mm, the winding angle is 5.49°~5.51°; When the diameter of the silk cake is above 340mm, the winding angle is 5.29°~5.31°.

7. A method for improving the unwinding performance of polyester FDY yarn for warp knitting according to claim 1, characterized in that: The specifications of the polyester yarn after drawing are 45~75dtex / 24f.

8. The method for improving the unwinding performance of polyester FDY yarn for warp knitting according to claim 1, characterized in that: The downgrade rate of poor silk cake forming is ≤0.3%; the downgrade rate of loose wire and hairy wire after silk cake winding is ≤0.4%, and there is no overlapping wire.