A method for improving the forming quality of polyester drawn yarn

Abstract

The present invention relates to a method for improving the forming quality of polyester drawn yarn. During the winding forming process of polyester drawn yarn for warp knitting, the surface roughness of a friction roller and the relative position between the friction roller and the spindle are controlled, thereby improving the forming quality of the polyester drawn yarn. Along the axial direction, the friction roller corresponding to each yarn cake is sequentially divided into three regions: left, center, and right. The center region accounts for 55-60%, and the left and right regions each account for 20-22.5%. The surface roughness Ra of the friction roller in the center region is 0.8±0.2 μm, and gradually decreases from the center region to the left and right regions to 0.1±0.02 μm, respectively. The present invention ensures uniform stress at every point of the yarn cake, resulting in a more even stress distribution. Braking marks are prevented from forming due to excessive local stress causing partial layer collapse.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester drawn yarns and relates to a method for improving the molding quality of polyester drawn yarns. Background Art

[0002] Warping is a post-process of polyester drawn yarn, which is mainly used in conjunction with warp knitting machines. When weaving on warp knitting machines, it first needs to go through the warping stage. In this stage, hundreds of FDY fibers are drawn out from the bobbins on the creel through the warping machine, and then unwound in parallel and evenly according to the specified length, and wound on the warp beam or weaving beam for subsequent sizing or weaving.

[0003] During the warping process, FDY fibers need to be unwound onto a warp or weaving beam. However, residual stress is generated during the winding of polyester drawn yarn, which can lead to problems such as brake marks. When the yarn cake is unwound to the collapsed layer of the brake mark during the unwinding process, it is easy to carry out the slightly collapsed part, causing two or more turns of yarn to be carried out together, which is a delamination problem. This will cause knotting during unwinding, which in turn affects the quality and efficiency of subsequent weaving.

[0004] Reference 1 (Technical Analysis of Winding Forming [J]. Synthetic Fibers, 2005(1):29-30) and Reference 2 (Analysis of Winding Forming Problems in Stretch Texturing Machines [J]. 2006(5):30-32) both describe the use of shaping rollers for high-speed spinning of FDY. The solution to the forming problem mainly relies on optimizing the winding tension. However, since the number of spinning winders has increased from 8 to 16, simply optimizing process parameters such as winding tension cannot completely solve abnormal forming problems such as brake marks.

[0005] Therefore, it is of great significance to study a method for improving the forming quality of polyester drawn yarn to solve the problems existing in the prior art. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems existing in the prior art and provide a method for improving the forming quality of polyester drawn yarn.

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

[0008] A method for improving the forming quality of polyester drawn yarns, wherein the surface roughness of a friction roller and the relative position between the friction roller and a spindle are controlled during the winding forming process of the polyester drawn yarns for warp knitting, thereby improving the forming quality of the polyester drawn yarns;

[0009] Along the axial direction, the friction roller corresponding to each silk cake is divided into three regions: left, middle, and right. The middle region accounts for 55-60%, and the left and right regions each account for 20-22.5%. The surface roughness Ra of the friction roller in the middle region is 0.8±0.2μm. From the middle region to the left and right regions, the surface roughness Ra of the friction roller surface gradually decreases to 0.1±0.02μm.

[0010] Let the end of the spindle used to load the paper tube be end face a, and the other end be end face b. Establish a spatial rectangular coordinate system with the straight line passing through end face a and parallel to the horizontal plane as the X axis, the straight line passing through end face a and perpendicular to the horizontal plane as the Y axis, and the straight line parallel to the center axis of the spindle as the Z axis. Let the center of the spindle end face a be the origin, and the coordinates be (0, 0, 0). The end of the friction roller close to end face a is offset upward along the Y axis by 0.07~0.1mm. If the offset value is greater than 0.1mm or less than 0.07mm, it will be on the wire. During the initial winding stage and after the cake grows to a certain extent, one end of the friction roller will be out of contact with the cake. When the offset value is greater than 0.1mm, the contact pressure of the end face b will be less than the set value during the initial winding stage, resulting in excessive local stress in the cake. When the offset value is less than 0.07mm, the contact pressure of the friction roller at one end of the cake will decrease or even be out of contact with the friction roller in the middle and late stages of winding, resulting in an increase in the intrinsic stress of the cake, and the offset along the X-axis direction will be less than or equal to 0.09mm.

[0011] Y axis offset = Y a -Y b ; X-axis offset = X a , where X a is the X-axis coordinate value of the center of the circle on the friction roller close to the end surface a, Y a Y is the Y-axis coordinate value of the center of the friction roller near the end surface a. b is the Y-axis coordinate value of the center of the circle on the friction roller close to the end surface b.

[0012] As the preferred technical solution:

[0013] As described above, a method for improving the forming quality of polyester drawn yarn is provided, wherein the left and right areas on the friction roller corresponding to each yarn cake are equally divided into four small areas, the roughness Ra of the four small areas in the left area from right to left are 0.6±0.2μm, 0.4±0.1μm, 0.2±0.05μm, and 0.1±0.02μm, respectively, and the roughness Ra of the four small areas in the right area from left to right are 0.6±0.2μm, 0.4±0.1μm, 0.2±0.05μm, and 0.1±0.02μm, respectively.

[0014] In the above-mentioned method for improving the forming quality of polyester drawn yarn, the spindle shaft length is 1150~1800mm.

[0015] In the above-mentioned method for improving the forming quality of polyester drawn yarn, the number of yarn cakes arranged on the spindle shaft is 8 to 16.

[0016] In the above-mentioned method for improving the forming quality of polyester drawn yarn, the yarn cake winding diameter ranges from 360 to 380 mm.

[0017] In the above-mentioned method for improving the forming quality of polyester drawn yarn, the length of the friction roller is equal to that of the spindle shaft, and the diameter of the friction roller is 84.5-85.5 mm.

[0018] According to the method for improving the forming quality of polyester drawn yarn, the downgrade rate of the brake marks on the wound yarn cake is ≤0.1%.

[0019] Principle of the invention:

[0020] During the winding process of polyester drawn yarn, the factors that affect the winding process mainly include friction roller, shift fork, etc.

[0021] The friction roller rotates at a constant speed, while the motor drives the spindle to wind the yarn. The surface velocity of the friction roller matches that of the yarn cake wound on the spindle, and the friction roller contacts the surface of the yarn cake with a certain pressure, ensuring the yarn cake has a certain hardness and strength to meet post-processing requirements. The friction roller and the spindle shaft should ideally be parallel. However, since 8 to 16 yarn cakes are arranged on the spindle shaft, the increased weight of the yarn cake causes the unsupported end of the spindle shaft (i.e., the end loaded with the paper roll) to sink slightly during winding. This sinking, resulting in a deviation in parallelism between the friction roller and the spindle shaft, increases with the winding diameter. During the winding process, the drawn polyester yarn is subjected to both the contact pressure exerted by the friction roller and the centripetal pressure exerted from the outer layers of the yarn cake inward. When the spindle shaft vibrates as it sinks, the uneven contact pressure and centripetal pressure exerted from the outer layers of the yarn cake inward create residual stress inconsistencies, resulting in brake marks.

[0022] In order to reduce the vibration caused by the sinking of the a-end of the spindle during the increase of the weight of the yarn cake and ensure that each yarn cake is well formed, it is necessary to overcome the problem of increased flexibility as the weight of the spindle increases. Therefore, the present invention optimizes the parallelism (the angle between the friction roller and the spindle) so that one end of the friction roller (the same end of the spindle shaft without physical support) is offset upward by 0.07~0.1mm along the Y-axis direction, with a slightly upward angle. In this way, there will be a certain parallelism deviation in the initial stage of winding. Because this deviation has almost no effect on the initial winding formation, as the package grows, the parallelism deviation gradually returns to parallel due to the influence of the yarn cake weight; and the X-axis offset value is designed to be ≤0.09mm. The X-axis offset will cause the contact surface between the yarn bundle and the friction roller to change, resulting in a change in contact pressure, and then the residual stress caused by uneven pressure is inconsistent. If the offset is ≤0.09mm, the contact pressure between the yarn bundles can be guaranteed to be the same.

[0023] During the winding process, two stacked shift forks rotate clockwise and counterclockwise, respectively, driving the filament bundle in a reciprocating motion, causing the filament to be tightly wound in a spiral pattern, layer by layer, around the paper tube. However, if the friction coefficients of the friction rollers are the same, the filament will coil more in the center of the bobbin than at the edges during winding. This is because the filament first passes through the wire guides on the winding head, then reaches the two stacked shift forks, and then passes through the friction rollers before being wound onto the paper tube. The wire guides are located perpendicular to the center of the paper tube. Without the shift forks' left-right movement, the filament would remain wound in the center of the paper tube due to a certain tension. It is precisely because of the shift forks that the filament is dispersed around the paper tube. However, due to the certain tension of the filament, if the friction coefficients of the friction rollers are the same, the filament will experience the greatest lateral force toward the center due to tension when the shift forks are pushed to the extreme edges, and the least force when the filament is in the center. As a result, the filament will spend the least time at the edges and the most time near the center, resulting in more coils in the center of the bobbin than at the edges during winding. As winding continues, the diameter of the yarn cake increases, becoming higher in the middle than at the edges. This results in uneven contact force between the friction roller and the yarn cake, with the center being higher and the edges being lower, or even zero contact pressure at the edges. Due to the low pressure from the friction roller, internal stress increases at the edges, leading to severe edge collapse. Minor collapse is visible as brake marks on the sides. The present invention modifies the gripping force by changing the surface finish of the friction roller, ensuring that the centripetal force in the lateral direction of the yarn is as uniform as possible during the plucking process.

[0024] The present invention redesigns the friction roller. To improve the wire-grabbing force of the friction roller, the 55-60% area in the middle of the friction roller corresponding to each silk cake is designed as a friction surface with a roughness Ra of 0.8±0.2μm. The remaining 20-22.5% areas on the left and right sides gradually change from friction surfaces to smooth surfaces with roughness Ra of 0.6±0.2μm, 0.4±0.1μm, 0.2±0.05μm, and 0.1±0.02μm, respectively. The friction roller designed in this way can allow the silk to be evenly distributed at any point of the silk cake during the winding process. In this way, the contact between the friction roller and the silk cake is very uniform and close during the growth of the winding diameter. The force at each point of the silk cake is uniform, and the stress distribution is more uniform. Braking marks will not be formed due to the collapse of some layers due to excessive local (edge) stress.

[0025] Beneficial effects:

[0026] (1) A method for improving the forming quality of polyester drawn yarn of the present invention controls the surface roughness of the friction roller and the relative position between the friction roller and the spindle shaft, so that the force on each point of the yarn cake is uniform, the stress distribution is more uniform, and the formation of brake marks due to the collapse of some layers caused by excessive local (edge) stress will not occur;

[0027] (2) The present invention provides a method for improving the forming quality of polyester drawn yarn, which optimizes the parallelism (the angle and position between the friction roller and the spindle shaft), allows one end of the friction roller to be offset upward by 0.07 to 0.1 mm along the Y-axis direction, and designs the offset value in the X-axis direction to be ≤0.09 mm, thereby avoiding the influence of parallelism deviation on the forming of the yarn cake. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a side view of the friction roller and the spindle shaft;

[0029] Figure 2 This is the front view of the friction roller and the spindle shaft;

[0030] Among them, 1-friction roller, 2-spindle shaft;

[0031] Figure 1 In the figure, X1 and X2 represent the X-axis direction, and Y1 and Y2 represent the Y-axis direction;

[0032] Figure 2 Middle, Y 1A 、Y 2A 、Y 1B 、Y 2B Indicates the Y-axis direction, Z 1A 、Z 2A 、Z 1B 、Z 2B Indicates the Z-axis direction, where A corresponds to end surface a and B corresponds to end surface b. DETAILED DESCRIPTION

[0033] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0034] Braking Mark Downgrade Ratio: Braking mark occurs when uneven internal stress in the bobbin due to vibration causes slight collapse of the end surface, forming a spiral pattern. If the spiral pattern extends 1mm beyond the end surface, downgrade is indicated. Braking Mark Downgrade Ratio = Number of downgraded bobbin pieces × 100% / Total bobbin pieces.

[0035] Example 1

[0036] A method for improving the forming quality of polyester drawn yarn, the specific process is as follows:

[0037] In the winding process of polyester drawn yarn for warp knitting, the surface roughness of the friction roller and the relative position between the friction roller and the spindle are controlled to improve the forming quality of the polyester drawn yarn;

[0038] The spindle length is 1150mm, the number of silk cakes arranged on the spindle is 8; the silk cake winding diameter is 360mm;

[0039] The friction rollers correspond to the spindles one by one and are located directly above them, with the same length as the spindles. The diameter of the friction rollers is 84.5 mm. Along the axial direction, the friction rollers corresponding to each silk cake are divided into three regions: left, center, and right. The center region accounts for 60%, while the left and right regions each account for 20%. The surface roughness Ra of the friction roller in the center region is 0.8 μm.

[0040] The left and right areas of the friction roller corresponding to each silk cake are equally divided into four small areas. The roughness Ra of the four small areas from right to left in the left area are 0.6μm, 0.4μm, 0.2μm, and 0.1μm respectively. The roughness Ra of the four small areas from left to right in the right area are 0.6μm, 0.4μm, 0.2μm, and 0.1μm respectively.

[0041] like Figures 1 and 2 As shown, one end of the spindle shaft 2 for loading the paper tube is denoted as end face a, and the other end is denoted as end face b. A spatial rectangular coordinate system is established with the straight line passing through the end face a and parallel to the horizontal plane as the X-axis, the straight line passing through the end face a and perpendicular to the horizontal plane as the Y-axis, and the straight line parallel to the center axis of the spindle shaft as the Z-axis. The end of the friction roller 1 close to the end face a is offset upward by 0.07 mm along the Y-axis direction and by 0.05 mm along the X-axis direction.

[0042] The downgrade rate of brake marks on wound silk cakes is 0.05%.

[0043] Comparative Example 1

[0044] A method for improving the forming quality of polyester drawn yarn is basically the same as that of Example 1, except that the surface roughness of the friction roller is consistent, both of which are 0.8 μm;

[0045] The downgrade rate of brake marks on wound silk cakes is 1.35%.

[0046] Compared with Example 1, the braking mark degradation ratio of the wound silk cake increases significantly in Comparative Example 1. This is because the roughness of the friction roller surface is consistent in Comparative Example 1. As the diameter of the silk cake increases, the surface of the silk cake becomes higher in the middle than on both sides, resulting in uneven contact force between the friction roller and the silk cake. Since the pressure of the friction roller on both ends is too small, the internal stress on the two edges will increase, and the brake marks on the two edges will collapse, thereby significantly increasing the braking mark degradation ratio of the wound silk cake.

[0047] Comparative Example 2

[0048] A method for improving the forming quality of polyester drawn yarn is basically the same as that of Example 1, except that: the end of the friction roller close to the end surface a is offset upward by 0.12 mm along the Y-axis direction and by 0.10 mm along the X-axis direction;

[0049] The downgrade rate of brake marks on wound silk cakes is 1.01%.

[0050] Compared with Example 1, the proportion of brake marks on the wound silk cakes in Comparative Example 2 increases significantly. This is because in Comparative Example 2: the end of the friction roller close to the end face a is offset upward by 0.12 mm along the Y-axis direction and by 0.10 mm along the X-axis direction, resulting in a decrease in the contact pressure between the silk cake and the friction roller during winding or even a loss of contact with the friction roller, causing excessive local stress in the silk cake and the appearance of brake marks.

[0051] Example 2

[0052] A method for improving the forming quality of polyester drawn yarn, the specific process is as follows:

[0053] In the winding process of polyester drawn yarn for warp knitting, the surface roughness of the friction roller and the relative position between the friction roller and the spindle are controlled to improve the forming quality of the polyester drawn yarn;

[0054] The spindle length is 1380mm, the number of silk cakes arranged on the spindle is 10; the silk cake winding diameter is 370mm;

[0055] The friction rollers correspond to the spindles one by one and are located directly above them, with the same length as the spindles. The diameter of the friction rollers is 84.5 mm. Along the axial direction, the friction rollers corresponding to each yarn cake are divided into three regions: left, center, and right. The center region accounts for 58%, while the left and right regions each account for 21%. The surface roughness Ra of the friction roller in the center region is 0.9 μm.

[0056] The left and right areas of the friction roller corresponding to each silk cake are equally divided into four small areas. The roughness Ra of the four small areas from right to left in the left area are 0.7μm, 0.5μm, 0.25μm, and 0.12μm respectively. The roughness Ra of the four small areas from left to right in the right area are 0.7μm, 0.5μm, 0.25μm, and 0.12μm respectively.

[0057] Let one end of the spindle shaft for loading the paper tube be end face a, and the other end be end face b. Establish a spatial rectangular coordinate system with the straight line passing through end face a and parallel to the horizontal plane as the X-axis, the straight line passing through end face a and perpendicular to the horizontal plane as the Y-axis, and the straight line parallel to the center axis of the spindle shaft as the Z-axis. The end of the friction roller close to end face a is offset upward by 0.08 mm along the Y-axis direction and by 0.06 mm along the X-axis direction.

[0058] The downgrade rate of brake marks on wound silk cakes is 0.06%.

[0059] Example 3

[0060] A method for improving the forming quality of polyester drawn yarn, the specific process is as follows:

[0061] In the winding process of polyester drawn yarn for warp knitting, the surface roughness of the friction roller and the relative position between the friction roller and the spindle are controlled to improve the forming quality of the polyester drawn yarn;

[0062] The spindle shaft length is 1520mm, the number of silk cakes arranged on the spindle shaft is 12; the silk cake winding diameter is 372mm;

[0063] The friction rollers correspond to the spindles one by one and are located directly above them, with the same length as the spindles. The diameter of the friction rollers is 85 mm. Along the axial direction, the friction rollers corresponding to each silk cake are divided into three regions: left, center, and right. The center region accounts for 57%, while the left and right regions each account for 21.5%. The surface roughness Ra of the friction roller in the center region is 1 μm.

[0064] The left and right areas of the friction roller corresponding to each silk cake are equally divided into four small areas. The roughness Ra of the four small areas from right to left in the left area are 0.8μm, 0.5μm, 0.25μm, and 0.10μm respectively. The roughness Ra of the four small areas from left to right in the right area are 0.8μm, 0.5μm, 0.25μm, and 0.10μm respectively.

[0065] Let one end of the spindle shaft for loading the paper tube be end face a, and the other end be end face b. Establish a spatial rectangular coordinate system with the straight line passing through end face a and parallel to the horizontal plane as the X-axis, the straight line passing through end face a and perpendicular to the horizontal plane as the Y-axis, and the straight line parallel to the center axis of the spindle shaft as the Z-axis. The end of the friction roller close to end face a is offset upward by 0.08 mm along the Y-axis direction and by 0.07 mm along the X-axis direction.

[0066] The downgrade rate of brake marks on wound silk cakes is 0.06%.

[0067] Example 4

[0068] A method for improving the forming quality of polyester drawn yarn, the specific process is as follows:

[0069] In the winding process of polyester drawn yarn for warp knitting, the surface roughness of the friction roller and the relative position between the friction roller and the spindle are controlled to improve the forming quality of the polyester drawn yarn;

[0070] The spindle length is 1600mm, the number of silk cakes arranged on the spindle is 12; the silk cake winding diameter is 378mm;

[0071] The friction rollers correspond to the spindles one by one and are located directly above them, with the same length as the spindles. The diameter of the friction rollers is 85 mm. Along the axial direction, the friction rollers corresponding to each silk cake are divided into three regions: left, center, and right. The center region accounts for 56%, while the left and right regions each account for 22%. The surface roughness Ra of the friction roller in the center region is 0.7 μm.

[0072] The left and right areas of the friction roller corresponding to each silk cake are equally divided into four small areas. The roughness Ra of the four small areas from right to left in the left area are 0.5μm, 0.3μm, 0.15μm, and 0.08μm respectively. The roughness Ra of the four small areas from left to right in the right area are 0.5μm, 0.3μm, 0.15μm, and 0.08μm respectively.

[0073] Let one end of the spindle shaft for loading the paper tube be end face a, and the other end be end face b. Establish a spatial rectangular coordinate system with the straight line passing through end face a and parallel to the horizontal plane as the X-axis, the straight line passing through end face a and perpendicular to the horizontal plane as the Y-axis, and the straight line parallel to the center axis of the spindle shaft as the Z-axis. The end of the friction roller close to end face a is offset upward by 0.09 mm along the Y-axis direction and by 0.08 mm along the X-axis direction.

[0074] The downgrade rate of brake marks on wound silk cakes is 0.07%.

[0075] Example 5

[0076] A method for improving the forming quality of polyester drawn yarn, the specific process is as follows:

[0077] In the winding process of polyester drawn yarn for warp knitting, the surface roughness of the friction roller and the relative position between the friction roller and the spindle are controlled to improve the forming quality of the polyester drawn yarn;

[0078] The spindle length is 1800mm, the number of silk cakes arranged on the spindle is 16; the silk cake winding diameter is 380mm;

[0079] The friction rollers correspond to the spindles one by one and are located directly above them, with the same length as the spindles. The diameter of the friction rollers is 85.5 mm. Along the axial direction, the friction rollers corresponding to each bobbin are divided into three regions: left, center, and right. The center region accounts for 55%, while the left and right regions each account for 22.5%. The surface roughness Ra of the friction roller in the center region is 0.6 μm.

[0080] The left and right areas of the friction roller corresponding to each silk cake are divided into four small areas. The roughness Ra of the four small areas from right to left in the left area are 0.4μm, 0.3μm, 0.2μm, and 0.1μm respectively. The roughness Ra of the four small areas from left to right in the right area are 0.4μm, 0.3μm, 0.2μm, and 0.1μm respectively.

[0081] Let one end of the spindle shaft for loading the paper tube be end face a, and the other end be end face b. Establish a spatial rectangular coordinate system with the straight line passing through end face a and parallel to the horizontal plane as the X-axis, the straight line passing through end face a and perpendicular to the horizontal plane as the Y-axis, and the straight line parallel to the center axis of the spindle shaft as the Z-axis. The end of the friction roller close to end face a is offset upward by 0.1 mm along the Y-axis direction and by 0.09 mm along the X-axis direction.

[0082] The downgrade rate of brake marks on wound silk cakes is 0.09%.

Claims

1. A method for improving the forming quality of polyester drawn yarn, characterized by: In the winding process of polyester drawn yarn for warp knitting, the surface roughness of the friction roller and the relative position between the friction roller and the spindle are controlled to improve the forming quality of the polyester drawn yarn; Along the axial direction, the friction roller corresponding to each silk cake is divided into three regions: left, middle, and right. The middle region accounts for 55-60%, and the left and right regions each account for 20-22.5%. The surface roughness Ra of the friction roller in the middle region is 0.8±0.2μm. From the middle region to the left and right regions, the surface roughness Ra of the friction roller surface gradually decreases to 0.1±0.02μm. The end of the spindle shaft for loading the paper tube is denoted as end face a. A spatial rectangular coordinate system is established with the straight line passing through end face a and parallel to the horizontal plane as the X-axis, the straight line passing through end face a and perpendicular to the horizontal plane as the Y-axis, and the straight line parallel to the center axis of the spindle shaft as the Z-axis. The end of the friction roller close to end face a is offset upward by 0.07 to 0.1 mm along the Y-axis direction and is offset by less than or equal to 0.09 mm along the X-axis direction. The downgrade rate of brake marks on wound silk cakes is ≤0.1%.

2. A method for improving the forming quality of polyester drawn yarn according to claim 1, characterized in that: The left and right areas of the friction roller corresponding to each silk cake are divided into four small areas respectively. The roughness Ra of the four small areas from right to left in the left area are 0.6±0.2μm, 0.4±0.1μm, 0.2±0.05μm, and 0.1±0.02μm respectively. The roughness Ra of the four small areas from left to right in the right area are 0.6±0.2μm, 0.4±0.1μm, 0.2±0.05μm, and 0.1±0.02μm respectively.

3. The method for improving the forming quality of polyester drawn yarn according to claim 1, characterized in that: The spindle shaft length is 1150~1800mm.

4. A method for improving the forming quality of polyester drawn yarn according to claim 3, characterized in that: The number of silk cakes arranged on the spindle shaft is 8 to 16.

5. The method for improving the forming quality of polyester drawn yarn according to claim 1, characterized in that: The diameter of the silk cake roll ranges from 360 to 380 mm.

6. The method for improving the forming quality of polyester drawn yarn according to claim 1, characterized in that: The length of the friction roller is equal to that of the spindle shaft, and the diameter of the friction roller is 84.5-85.5 mm.

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