JPH059349B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a polyester yarn package. More specifically, the present invention relates to a polyester fiber yarn package that has good stability in winding shape and can be used directly to produce knitted fabrics of good quality. [Prior art and problems to be solved by the invention] In recent years, there has been a strong demand for improved productivity in the production of polyester fiber yarns, and high speeds exceeding 5500 m/min, for example, have been required in the spinning process, especially in the spinning process. Attempts have been made to manufacture the fibers by the so-called high-speed spinning take-off method, which uses take-off speeds of . The polyester yarn obtained by this type of high-speed spinning and take-off method has a fine structure that is manufactured by two processes: a conventional spinning process and a drawing process (for example,
It is significantly different from spun/drawn yarn (as typified by Japanese Patent No. 57-16913), and therefore, spun/drawn yarn is said to have outstanding and useful features in terms of practically required performance. Unexamined Japanese Patent Publication 1987-
It is known from Publication No. 121613 and the like. The most outstanding features are that it has a high degree of dyeability and low heat shrinkage in practical terms. Easy dyeability is excellent to the extent that the practical dyeing temperature obtained by high-temperature, high-pressure dyeing of general-purpose low-speed spun/drawn yarn can be achieved at 110℃ to normal pressure, especially when a take-up speed of 6000 m/min or more is used. It was reported in Japanese Patent Application Laid-Open No. 1983-1983 that the effect of yarn obtained by high-speed spinning is remarkable.
It is disclosed in Publication No. 121613. In addition, low heat shrinkage means that, for example, in textiles, dimensional changes in textiles are extremely minimized during the processing steps that the gray fabric must undergo after weaving, typically during scouring and dyeing processes. As a result, it is possible to omit the presetting step that is performed prior to these wet processing steps. However, contrary to the above-mentioned advantages, polyester yarn obtained by the high-speed take-off method cannot be made into a woven fabric when wound on a conventional high-speed winder (with a driven system and a single track cam as described below). It has a serious drawback in that minute gloss spots called "sink marks" occur on the fabric surface. The reason why such "sink mark" defects occur during high-speed winding of the high-speed spinning take-up method is that when polyester yarn is wound into a cheese-shaped package cage at high speed, the yarn at both ends (edges) of the package cage is This is because the heat generated and the effects of stress such as elongation and compression form filamentous patches and remain internally formed into the package. The polyester yarn obtained by the high-speed spinning draw method is characterized by a birefringence of 0.08 to 0.14, a crystal perfection parameter of 0.50 or less, and a boiling water shrinkage rate of 5% or less. The birefringence value of 0.08 to 0.14 is smaller than the birefringence value of 0.17 or more of the polyester yarn obtained by the conventional two-step spinning-drawing method. This indicates that the orientation of the amorphous portion of the polyester yarn produced by the high-speed spinning draw method is relatively undeveloped, and the physical properties of such polyester yarn tend to change under the influence of heat and stress. As described above, the microstructural characteristics of the polyester yarn obtained by the high-speed spinning draw method lead to the disadvantage that yarn unevenness (sink marks, etc.) is likely to occur. In addition, the polyester yarn obtained by the high-speed spinning draw method has the characteristic that it can be dyed at a low temperature of 110°C or less (easy dyeability), and also exhibits low shrinkage with a boiling water shrinkage rate of 50% or less. Although this in itself is a great advantage, when combined with dyeing at low temperatures, it makes it difficult to eliminate "sink marks" in the post-processing of textiles. It has been found that "sink marks" are directly caused by irregularities in heat shrinkage properties in the yarn length direction, and that areas with high heat shrinkage stress correspond to "sink marks". Such filamentous spots tend to be concentrated at both ends of the cheese-like package. When forming a package cage, as a result of the traversing caused by the traverse, more yarn is stacked on both ends of the package cage in the bobbin axis direction, creating a so-called selvage shape, and this selvage portion is in contact with the roll of the winding machine. This is thought to be due to contact with. For high-speed winding of 5500 m/min or higher, generally a bobbin shaft-driven winding machine is used, which directly drives a bobbin shaft equipped with a contact roll. The winding mechanism of this bobbin shaft-driven winding machine winds a package formed by laminating yarn on a bobbin with good shape stability while pressing it with a contact roll.
At this time, all the power necessary to rotate the contact roll is transmitted through frictional contact between the package and the contact roll. (This type of contact roll drive system is called a "driven system.") In order to perform high-speed winding with a bobbin shaft-driven winder equipped with such a driven system contact roll, the amount of energy to be transmitted is As a result of the study, it became clear that it is difficult to maintain the normal shape during winding unless the package shape is set at ear height because of the large amount of damage. JP-A No. 56-127558 proposes winding by forming a bulge in the center of the package and keeping a contact roll in constant contact with the bulge during winding. When winding at a high speed of more than 1 minute, the ends of the package were not properly laminated, making it impossible to form a package. Japanese Patent Application Laid-Open No. 60-209013 discloses that a conventional bobbin shaft-driven winding machine for producing a cheese-like package
It is mentioned that it is difficult to eliminate thread unevenness due to the provision of contact rolls, and as an alternative, it is proposed that the package cage be wound in a tapered shape without coming into contact with other objects during winding. . Therefore, 5500 without melt spinning and drawing
It is a cheese-like package that is wound at a high speed of more than m/min, and has good shape stability, and the yarn is directly applied to the knitted fabric from the package at normal pressure to 110 m/min.
At present, a cheese-like package of polyester fiber yarn that does not cause "sink" defects even when dyed at ℃ has not yet been found. The present invention is a polyester yarn that is easy to dye and has low heat shrinkage produced by a high-speed spinning draw method, that is, a birefringence of 0.08 to 0.14, a crystal perfection parameter of 0.50 or less, and a boiling water shrinkage rate of 5% or less. Polyester yarn has good shape stability, and even if it is directly applied to knitted fabrics and dyed at normal pressure to 110℃, it does not cause sink marks.
The object of the present invention is to provide a polyester yarn package from which knitted fabrics of good quality without defects can be obtained. [Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have found that thread unevenness that causes "sink marks" has been determined by the winding method of the cheese-like package and the package By focusing on the fact that it is deeply related to the shape of the package, and by making the yarn into a specific package shape, we can reduce sink marks.
The above problem has been solved by discovering the fact that it can be completely resolved. That is, the object of the present invention is to have a birefringence of 0.08 to
0.14, a crystalline perfection parameter of 0.50 or less, a boiling water shrinkage rate of 5% or less, and a cheese-like package made by laminating substantially untwisted polyester yarns, with a center of 2 mm or more from both ends of the package in the bobbin axis direction. There are multiple parts on the end part that have higher hardness than the end parts, and the difference in dry heat shrinkage stress value between the yarns in the parts with higher hardness and the yarns in other parts is 20
This is achieved by a polyester yarn package characterized by a lower than The high-speed winding referred to in the present invention means that the spinning/winding speed is
A method for winding polyester yarn at a speed of 5500 m/min or more, typically using a spinning method that does not use a godet roll as disclosed in JP-A-57-121613, etc., or a method for winding a melt-spun polyester yarn using a godet roll. It is applicable to a method of winding onto a bobbin without substantially stretching. Therefore, the yarn of the package obtained by the method of the present invention is untwisted and is distinguished from yarn that is untwisted by winding or the like. The term "polyester" used in the present invention refers to polyesters represented by polyethylene terephthalate, polybutylene terephthalate, etc., but a small amount of other polyesters may be added as long as the easy dyeability and dimensional stability, which are the characteristics of the yarn of the present invention, are not impaired. It may also contain polymeric components, stabilizers, antistatic agents, and the like. The polyester yarn wound by the method used to melt-spun polyester and form the package of the present invention without drawing at more than 5500 m/min has a birefringence of 0.08 to 0.14, a crystalline perfection parameter of 0.50 or less, It has a structural feature shown by a boiling water shrinkage rate of 5% or less. If the birefringence index is less than 0.08, the mechanical properties such as strength and elongation will not be sufficient to allow the wound package to be directly used as a knitted fabric without going through post-processes such as stretching. If the birefringence exceeds 0.14, the easy dyeing property characteristic of high-speed spun drawn yarn cannot be sufficiently obtained. Furthermore,
To obtain sufficient mechanical properties and dyeability, 0.10~
0.13 is preferable. In addition, the crystal perfection parameter is an index indicating the structure of the crystal part measured by the method described below. becomes good. The polyester yarn obtained by winding according to the present invention has a crystal perfection parameter of 0.50 or less, and as a result, it has excellent low heat shrinkage with a boiling water shrinkage rate of 5% or less. In order to achieve excellent mechanical properties and boiling water shrinkage of 3% or less, the crystal perfection parameter is
It is desirable that it is 0.30 or less. The present invention will now be described in detail with reference to the accompanying drawings, which illustrate embodiments of the invention. The cheese-like package of polyester yarn of the present invention has two ends in the bobbin axis direction from both ends of the package.
The first point is that there are multiple parts (hereinafter referred to as convex parts) that are higher in height than the ends in the central part of mm or more.
The characteristics of The convex portion is a bulge 5 that exists on a line parallel to the bobbin axis direction of the package 1, as illustrated in the cross-sectional view of the package in FIG. 1, and has a winding diameter slightly larger than the other portions. The filaments are layered to look like this. The winding diameter difference Δh is preferably about 0.2 mm to 3 mm from the viewpoint of winding shape stability. More preferably about 0.2mm
~1 mm. The convex portion 5 exists on the center side in the bobbin axial direction from both ends 2 of the package cage 1, and the position from both ends (l ₁ , l ₂ in Fig. 1) is 2 mm or more. It is preferable in terms of the effect of eliminating sink marks. For the purpose of maintaining good shape stability during and after high-speed winding, this position is more preferably 4 mm to 15 mm. Although the positions from both end portions 2 do not necessarily have to be the same on the left and right sides, the same position (l ₁ =l ₂ ) is usually adopted in consideration of ease of traversal. It is necessary that the convex portion 5 is formed at a higher height than both ends 2 (ear portions) of the package. By making the altitude higher than both ends, both ends 2
It is possible to eliminate "sink marks" by weakening the tension in the threads and promoting the relaxation of the threads at both ends after winding. A desirable hardness difference between the end of the package and the convex portion is 5° to 20°. The package of the present invention can be easily distinguished from conventional high-edge packages due to its unique hardness distribution in which the highest hardness exists in areas other than both ends in the axial direction of the bobbin. The convex portions are provided at a plurality of locations on the central portion side of the package in the bobbin axial direction for the purpose of improving shape stability. Usually, there are two to three locations, preferably two locations, considering the complexity of the traverse mechanism. The above-described unique winding shape is such that the packages are laminated almost constantly from the beginning of winding to the end of winding. As a result, it is possible to have extremely good winding shape stability even when winding a large amount of winding, not only several kilograms but also tens of kilograms. In addition to the above-mentioned winding shape, the cheese-like package of the present invention has a difference in dry heat shrinkage stress value of 20% between the yarn in the hard part and the yarn in other parts.
mg/d or less. The dry heat shrinkage stress value is the tensile stress that occurs when fibers shrink when heated in the air. In the present invention, a polyester yarn is suspended under a load of 10 mg/d, and This is the maximum shrinkage stress value when heated at a lifting speed of 150°C/min. The detailed measurement method will be explained in detail in the Examples section. As a result of various in-depth studies on the correspondence between the occurrence of "sink mark" defects and the yarns of the package cage and unevenness of the yarn quality, the present inventors found that the unevenness of the dry heat shrinkage stress value of the yarn of the package cage in the yarn length direction is " It was found that this corresponds well to the occurrence of sink marks. As a result of further investigation, it was found that the yarn in the contact area between the package cage and the contact roll during winding tends to have a higher dry heat shrinkage stress value than the yarn in the non-contact area, and this difference in stress value It has been found that "sink marks" do not occur if the value is below a certain value. In the package of the present invention, the difference in dry heat shrinkage stress value between the yarns in the high hardness portion (convex portion) and the yarns in the other portions is 20mg/
d or less. Preferably, the difference is 15 mg/d or less for the effect of further reducing "sink marks". The high-selvedge package obtained by the conventional winding method is
The feature of the package of the present invention is clear from the fact that the difference in dry heat shrinkage stress between the yarns in the selvage area and other areas cannot be less than 40 mg/d. Such heat shrinkage stress characteristics are satisfied from the beginning to the end of winding the package. The method for manufacturing the cheese-like package of the present invention will be described below. The cheese-like package of the present invention can only be obtained by winding yarn under specific contact pressure conditions using a bobbin shaft-driven winder equipped with a specific traverse mechanism and a self-driven contact roll. Summer. In other words, the method of providing a convex portion from both ends of the package cage to the center side in the bobbin axial direction is described in Japanese Patent Publication No. 46
-A multi-speed traverse device disclosed in Publication No. 16298 or a known cam traverse device is used to reverse the traversing of the yarn by traversing even inside the end in the bobbin axis direction of the package, so that the yarn is harder than the end. This can be effectively achieved by employing a so-called multi-tract traverse that can form a portion with a high surface area. Considering the complexity of the traverse mechanism, the position of the convex portion, the ease of adjusting the amount of stacked yarn, etc., it is preferable to adopt a multi-tract traverse system using a cam. The multi-track traverse is a method in which the traverse is reversed not only at both ends but also at the center, as exemplified in FIGS. 2a and b, and the desired position, It is possible to provide a height protrusion. Figure 2a
are examples of two-track traversal, Fig. 2b and c.
is an example of a three-track traverse, and Figure 2 d
is an example of a traverse that is a conventional high-selvedge package other than the present invention. A method of forming the convex portion closer to the center than the ends in the bobbin axial direction by using this multi-track traverse as illustrated in FIG. 1 will be explained using the three-track example shown in FIG. 2b. The yarn to be traversed is stacked as a yarn in the package cage at the end in the first and second reversal, and then in the following three
In the second reversal, the threads are stacked closer to the center than the ends. At this time, the radius at the time of inversion R , R ,
By selecting the ratio of R, the height of the convex portion formed closer to the center than the end can be adjusted. The package of the present invention can be obtained if the number of tracks is 2 or more, but 2 to 4 is usually employed. The present invention combines the above-mentioned traverse mechanism with a self-driven contact roll for winding.
For the first time, winding of the package is realized. With the combination of the conventional driven contact roll and the above traverse mechanism, the package shape collapses during winding, making normal winding difficult. FIG. 3 shows one embodiment showing the configuration of main parts of a winding machine used for forming the package of the present invention, in which a bobbin shaft 8 is connected to a bobbin shaft drive device 12,
Furthermore, the package 1 is driven by a bobbin shaft drive inverter 13 while controlling the frequency so that the surface peripheral speed of the package 1 wound on the surface of the bobbin 7 inserted into the bobbin shaft 8 is constant. The contact roll 6 is connected to a contact roll drive 10 via a transmission 9, and a contact roll drive inverter 11 controls the frequency and frequency required for the rotation of the contact roll 6 to match the surface circumferential speed of the package 1. Drive power is supplied. The drive inverter for the bobbin shaft and the drive inverter for the contact roll may be mutually adjustable mechanisms as shown in Japanese Patent Application Laid-Open No. 52-21438, but from the point of view of eliminating "sink marks" more completely, It is preferable that both drive inverters are controlled independently of each other so that the speed of the contact rolls can be controlled with high precision. In this case, as a control method to gradually reduce the bobbin shaft rotation speed as the winding diameter of the package increases, a method is used in which the gradual reduction speed is stored in a computer and controlled.
Tension control method that controls the change in the tension applied to the yarn by feeding it back to the bobbin shaft, and controlling the peripheral speed by detecting the change in the circumferential speed of the contact roll or winding body using an optical sensor, etc. and feeding it back to the bobbin shaft. Control methods etc. will be adopted. The contact roll drive device 9 used in the winder used to form the packages of the present invention preferably uses a high speed three-phase induction motor. The connection method of this motor is not limited to the embodiment, and it may be directly connected to the shaft of the contact roll, or it may be built into the contact roll and implemented as an outer rotor type. Furthermore, it is also possible to use an air turbine drive instead of a motor. The driving force supplied to drive the contact roll is determined by the circumferential speed of the contact roll measured without winding and in a non-contact state with the bobbin shaft, and the desired circumferential speed of the package (winding speed) is the same speed
If the ratio is 75% to 125%, the object of the present invention can be sufficiently achieved. Usually 100% is accepted. (Hereinafter, 100% is shown unless specified.) However, regarding the frequency, 0 to 10% is calculated based on the set winding speed.
It should be set within a range exceeding %. FIG. 4a is a schematic diagram showing the contact state of the cheese-like package of the present invention with a contact roll during winding. In comparison, FIG. 4b shows the contact state between the conventional high-edge package and the contact roll. In the winding method of the present invention, the winding contact pressure when winding is performed by the winding machine is 0.3, which is normally employed.
Kg/package 0.2Kg/per 1cm of cage stroke
It is necessary to wind the package with a stroke of 1 cm or less. To further improve quality,
It is preferable to carry out the test at 0.15 kg/package stroke of 1 cm or less. By adopting the self-driven contact roll of the present invention, it is possible to perform winding at an even lower 0.1 kg/package stroke of 1 cm, and this low contact pressure enables extremely good winding shape stability and the elimination of "sink marks". It became. Conditions such as winding tension and winding angle are within the range adopted for normal winding. In order to form the yarn package of the present invention, an easily dyed and low heat shrinkable polyester can be produced at a high speed of 5500 m/min or more without drawing after melt spinning by adopting the above-mentioned winding method. When winding the fiber, it has good shape stability, and there is no "sink" even when it is directly applied to knitted fabrics and dyed at normal pressure to 110℃.
It has become possible to produce a cheese-like package that produces knitted fabrics of good quality without defects. According to the findings of the present inventors, this is due to the fact that when winding the package, the protrusions are not located at both ends but in the center, which causes stress generation due to the impact during traverse reversal and the contact roll. Due to the effect of the self-driven contact roll, the contact between the package cage and the contact roll occurs less frequently at the same position, and the change in the quality of the fibers at the end is small.・Stress generation is suppressed, and since the yarn is wound with low contact pressure, there is no change in yarn quality in the part pressed by the contact roll.Furthermore, the yarn layered on the package cage allows the yarns at both ends to be After winding, it is easily relaxed and more uniformity is achieved, and as a result of the above, it is assumed that a package with a small difference in dry heat shrinkage stress value specified in the present invention was created for the first time, and the occurrence of "sink marks" was eliminated. be done. [Example] Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, in the examples, the evaluation method of each characteristic value used is as follows.・Dry heat shrinkage stress value: Thermal stress measuring device KE− manufactured by Kanebo Engineering Co., Ltd.
Using type 2, the sample length is 10 cm as a loop, and the initial load is 10
mg/d, the temperature was raised at a heating rate of 150° C./min, and a dry heat shrinkage stress curve was drawn. The maximum value of this curve (the value obtained by dividing the read value by the sample denier x 2) was taken as the dry heat shrinkage stress value (Fmg/d). The difference in the dry heat shrinkage stress value in the yarn length direction is determined by measuring the yarn of the package in one traverse (from one end to the other) by making sure to measure the hardest part, that is, the convex part. ) in the direction of several points (for example, 1
When the traverse yarn length is 1.5 m, the thermal stress value is measured at 7 to 8 points). This measurement was performed for 5 traverses. In the obtained measurement results, the average value of the dry heat shrinkage stress value of the convex part is set as ₁ mg/d, and among the measured values other than the convex part, the same number as the convex part is extracted from the smaller value. The average value was determined to be ₂ mg/d. The difference in dry heat shrinkage stress values in the yarn length direction was determined using the following formula. Difference in dry heat shrinkage stress value (ΔF) = ₁ − ₂ (mg/
d) ・Hardness Using Shimadzu HARDNESS TESTER, measure 8 in the circumferential direction across the diameter of the package for each end and convex part in the bobbin axis direction of the package cage.
The hardness of the equally divided positions was measured. n for each
The average value of =8 was determined, and the difference was defined as the hardness difference.・Birefringence Δn Using a transmission quantitative interference microscope (manufactured by Carl Zeiss Jena, East Germany), the interference fringe method was used to measure the refractive index n ₁₁ parallel to the fiber axis and the right angle Measure the refractive index n ₁ and calculate the birefringence Δn
It was determined by =n ₁₁ −n ₁ .・Crystal perfection parameter _CR
A diffraction intensity curve from 2θ of 7° to 35° was drawn under the following conditions. 30kV, 80mA, scanning speed 1°/min, chart speed 10m/min, time constant 1 second, receiving slit 0.3mm. The three main reflections drawn in the range of 2θ = 17° to 26° are designated (100), (010), and (110) from the low angle side. The diffraction intensity curves between 2θ = 7° and 35° are connected with a straight line to form the baseline. A perpendicular line is drawn between each peak and the baseline, and this perpendicular line is taken as the diffraction intensity.
Let the diffraction intensity at the point corresponding to the valley between (010) and (110) be I ₀ , and the diffraction intensity at the peak of (110) be I
Then, the crystal perfection parameter C _R is expressed by the following equation. C _R = I ₀ / I ・Boiling water shrinkage rate Let L ₀ be the sample length under a load of 0.1 g/d, remove the load, treat it in boiling water for 30 minutes, and then measure the length under the same load as L The boiling water shrinkage rate is expressed by the following formula. Boiling water shrinkage rate (%) = L ₀ - L / L ₀ × 100 ・ Dyeing properties Polyester original strips were dyed using disperse dye Resolin Blue FBL (trade name of Bayer), 3% wf, bath ratio 1 The staining rate was calculated by staining at 100° C. for 120 minutes at a ratio of 50% and measuring the absorbance of the dye solution after staining. A dyeing rate of 60% or more indicates good dyeability, and a dyeing rate of 70% or more allows dyeing under normal pressure, which is extremely good. - Display of weft "sink marks" Defect levels were classified into four levels, and W = 0 to 1 were considered to be acceptable. W=0: No sink marks at all, W=1: Extremely small sink marks W=2: Sink marks, W=3: Strong sink marks Example 1 Melt spinning polyethylene terephthalate with intrinsic viscosity [η]=0.60 at 300°C After cooling, all the filaments are collected at a position 20 cm below the thinning completion point, oiled, and made into a 75 ^d / 36 ^f thread without drawing.
Winding with a winder at a speed of 7500 m/min, winding amount 10
Kg of cheese-like packages were obtained. The physical properties of the yarn were as shown in the table below.

[Table] For winding, use a spindle-driven winder equipped with a self-driven contact roll as shown in Figure 3, and a winder equipped with a three-track traverse type cam traverse as shown in Figure 2b. Using. The reversal radius (R) of the yarn due to traverse is:
Yarn, R ₁ , R ₂ = 20mm, yarn R ₃ = 15mm
Packages were obtained by varying the distance between the yarns and the reversal positions of the yarns as shown in Table 1.
For comparison, winding was performed using the conventional one-track traverse shown in FIG. 2d. In this example, the following conditions were used, except that the winding contact pressure was 0.15 kg/package stroke 1 cm. Bobbin outer diameter: 140mmφ Traverse stroke: 160mm Winding tension: 0.25g/d Self-driving contact roll control method: Peripheral speed control method Driving force: 100% Next, the entire amount of yarn is directly taken from these package cages. , Nissan Water Jet Room (LW
-51 type) for weaving, warp density 100 strands/in,
It was made of plain woven fabric with a weft density of 80 threads/in. After scouring this plain woven gray fabric, without presetting it,
It was stained at 100℃ and the quality of the weft "sink mark" was determined. Table 1 shows the shape stability when winding the cheese-like package and the shape characteristics of the 10Kg package.
The difference in heat shrinkage stress value (ΔF) of the surface layer portion and the corresponding fabric quality are shown.

[Table] As is clear from Table 1, the cheese-like package obtained by the winding method of the present invention has good winding shape stability and can be used directly on the weft of a fabric and dyed under normal pressure. It was possible to obtain excellent dyeability and good quality. Comparative Example In the same spinning and winding as in Example 1, a spindle-driven winder equipped with a conventional driven contact roll that does not have self-driving force was used, but the multi-tract traverse used in Example 1 was also installed. I tried winding it using a winder. The interval between the reverse positions of the traverse is set to 3 mm and 5 mm.
I tried winding the seeds, but from the beginning of the winding, the amount of yarn was about approx.
After stacking 0.5 kg, the shape collapsed and it was difficult to continue winding. Next, a 10 kg cheese-like package was obtained using a winding machine that combined this driven contact roll with the conventional traverse mechanism shown in Fig. 2d, with other conditions being the same as in Example 1. . However, the difference in dry heat shrinkage stress value (ΔF) of this package is 60mg/d.
The quality of the fabric was extremely poor, with a weft "sink mark" W=3. Example 2 In Example 1, the traverse reversal position is set to No.
The same conditions were used except that the winding was carried out under the conditions shown in Table 2, and the shape stability and the occurrence of weft "sink marks" due to dyeing at 100° C. were examined.

[Table] According to the present invention, it is possible to wind up even with a low contact pressure of 0.2 kg/package stroke 1 cm or less, furthermore 0.15 kg/package stroke 1 cm or less, and a fabric of extremely good quality was obtained. Example 3 Polyethylene terephthalate with an intrinsic viscosity [η] = 0.61 was melt-spun at 295°C, and after cooling, it was spun at 75 ^d / 36 ^f without stretching, using a pair of unheated godet rolls at the same circumferential speed for all rolls. The yarn was wound at the speed shown in Table 3 to obtain a cheese-like package with a winding weight of 12 kg. For winding, a winding machine equipped with a self-driven contact roll shown in FIG. 3 and a two-track traverse type cam traverse shown in FIG. 2a was used. The reversal radius of the yarn (,) by traverse is R ₁ = 40 mm, R ₃ = 15 mm,
The interval between the reversal positions was set to 4 mm. Other conditions were the same as in Example 1 to obtain a package. The positions of the convex portions of the obtained cheese-like packages from the ends were all 4 mm (l ₁ =l ₂ ), and the shape stability during winding was also good. The physical properties of the obtained yarn, the shape of the 12 kg package, and the difference in dry heat shrinkage stress value of the surface layer (ΔF)
Furthermore, Table 3 shows the weft "sink mark" quality of the fabrics obtained in the same manner as in Example 1 and dyed at 100°C. As is clear from Table 3, the cheese-like package of the present invention not only has good winding shape stability, but also has good dyeability and no weft "sink" when used directly on the weft of a fabric and dyed under normal pressure. It possessed a level of dignity that could never have been achieved.

〔Effect of the invention〕

Since the cheese-like package of thermoplastic synthetic fibers according to the present invention is constructed as described above, the cheese-like package has good shape stability and can be used directly for knitting and weaving under normal pressure to 110%. The knitted fabric obtained by dyeing at ℃ can be of good quality and easy to dye. Particularly, special effects are exhibited when used as the warp and weft of textiles.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of the shape of the cheese-like package according to the present invention, FIG. 2 is a schematic diagram showing the reversal trajectory of the yarn due to traverse, and FIG. 3 is a self-driven contact FIG. 4 is a perspective view showing the mechanism of a winding machine equipped with a roll, and FIG. 4 is a schematic diagram showing the contact state between the contact roll and the package during winding of the package, in which a is the present invention and b is a conventional example. are shown respectively. DESCRIPTION OF SYMBOLS 1...Cheese-like package, 2...Package end, 3...Reversal locus of yarn, 4...Yarn, 5
...Protrusion, 6...Contact roll, 7...Bobbin, 1
0...Contact roll drive device, 12...Bobbin shaft drive device.

Claims (1)

[Claims] 1. Birefringence 0.08 to 0.14, crystal perfection parameter
0.50 or less, a boiling water shrinkage rate of 5% or less, and a cheese-like package formed by laminating substantially untwisted polyester yarns, the ends of the package are 2 mm or more toward the center in the bobbin axis direction from both ends of the package. It is characterized by the fact that there are multiple parts with higher hardness than the other parts, and the difference in dry heat shrinkage stress value between the threads in the parts with higher hardness and the threads in other parts is 20 mg/d or less. The dry heat shrinkage stress value of the polyester yarn package is determined by suspending the polyester yarn under a load of 10 mg/d in the air.
This is the maximum shrinkage stress value when heated at a lifting speed of 150°C/min.