JPH0135097B2 - - Google Patents

Description

[Detailed description of the invention]

A. Technical Field of the Invention The present invention relates to a high-speed warping method for highly oriented undrawn polyester yarn. B. Prior art and problems Highly oriented undrawn polyester yarn with a birefringence of 0.06 to 0.135 and a secondary yield point stress of 1 to 2 g/d obtained by high-speed spinning using the conventional melt spinning method does not undergo a drawing process. Excellent productivity and quality uniformity,
By using it as is for the production of knitted fabrics, a significant cost reduction can be expected. However, the secondary yield point stress of the highly oriented undrawn polyester yarn is less than 2/3 of that of normal drawn yarn, so if excessive tension is applied during the warping process, it will be easily stretched, resulting in permanent deformation. . When the knitted fabric is dyed, the stretched portions become dyed in spots, causing a significant decrease in product yield. Excessive tension in the warping process occurs due to an abnormality in the yarn path from the individual thread-like yarn package that makes up the yarn sheet to the take-up beam.
This mainly occurs when the warping machine is stopped or started due to fuzz, yarn breakage, etc. The increase in tension when the warping machine is stopped and started increases as the warping speed increases, and the tension tends to become excessive. The reason for this is that during the warping process from the creel fitted with the yarn package to the take-up beam, the respective stopping and starting behavior of the front roller and the take-up beam located upstream of the take-up beam are This is because there is no synchronization over a range of amounts. In the case of ordinary drawn yarn, the yarn physical properties are stable, so the above-mentioned non-synchronization does not pose a particular problem even in high-speed warping at a warping speed of 500 m/min or more. For the reasons mentioned above, it is difficult to warp highly oriented undrawn polyester yarn at high speed, and in reality warping is usually performed at a low speed of less than 500 m/min. A conventional countermeasure is to prevent sudden changes in tension by increasing the time required to start and stop the warping machine during high-speed warping. However, with this method, the stopping distance must be long when stopping as well as when starting, otherwise fluff and broken yarn ends will be caught in the beam, requiring several times the warping space and equipment. There are problems in terms of investment and work efficiency. As a second measure, there is a method disclosed in JP-A-57-5936, in which the yarn sheet is stretched on a warper to the extent that the physical properties of the highly oriented undrawn polyester yarn are stabilized, and then wound around a beam. According to this method, the physical properties of the constituent threads of the yarn sheet are stabilized, so that the problem of partial stretching due to excessive tension is resolved. However, it is necessary to newly install an expensive dedicated machine, and since the drawing process is involved, high-speed warping is difficult due to a decrease in yarn breakage due to yarn breakage and variations in the quality of the yarn sheet due to stoppage of the warper. It was hot. C. Object of the Invention The present invention provides a low-cost, high-speed warping method for highly oriented polyester undrawn yarn, which improves the drawbacks of conventional high-speed warping methods. D Configuration of the present invention The present invention has the following configuration. That is, in the warping method of highly oriented polyester undrawn yarn with birefringence of 0.06 to 0.135 and secondary yield point stress of 1 to 2 g/d, the maximum warping tension is T≦0.8P, and the warping is performed at a speed of 500 m/min or less. This is a high-speed warping method for highly oriented undrawn polyester yarn, which is characterized by warping. T here
is the maximum warping tension (g/d) and P is the secondary yield point stress (g/d) of the highly oriented polyester undrawn yarn. Hereinafter, the configuration of the present invention will be explained in detail. The highly oriented undrawn polyester yarn in the present invention is a multifilament yarn or monofilament yarn whose main component is ethylene terephthalate units, and has a birefringence of 0.06 to 0.135 and a secondary yield point stress of 1. It has yarn properties of ~2 g/d. Such a yarn can be easily obtained by melt spinning at a high speed of, for example, 4000 m/min or more. If the birefringence is less than 0.06, it will be easily deformed by even a slight external force, and as it is, it will be of no practical use. Also,
When the birefringence exceeds 0.135, it becomes an oriented region of the drawn yarn, which is difficult to achieve only by ordinary high-speed spinning take-off. The secondary yield point stress indicates the stress at the point on the SS curve where plastic deformation starts, and is a characteristic that usually changes depending on the degree of orientation. For example, it can be measured by the method disclosed in Japanese Patent Application Laid-Open No. 58-169549. Next, the present invention will be explained with reference to the drawings. FIG. 1 is a warping process diagram showing an example of an embodiment of the present invention. In FIG. 1, highly oriented polyester undrawn yarn pulled out from a yarn package 2 fitted in a creel 1 passes through a tension adjustment device 3 and a yarn breakage detector 4, and is collected on a porous yarn collection plate 5, and is then collected into a sheet. are arranged to form a yarn sheet H. Then, the tension is adjusted through a pair of front reeds 6, 6', a front reed 7, a fuzz detector 8, and a rear reed 9, and the reeds are wound onto a beam 10 in a parallel arrangement at a speed of 500 m/min or more. In the present invention, the warping speed is replaced with the winding speed of the beam 10.
Further, the warping tension refers to the tension of the yarn sheet between the rear reed 9 and the beam 10 when the yarn runs. During warping, if yarn defects such as fuzz, broken yarn ends, knots, and slack pass through, the yarn breakage detector 4
Alternatively, the fuzz detector 8 outputs a stop signal, which applies braking to the front rollers 6, 6' and the beam 10, thereby stopping the warping machine. Since the inertia of the beam 10 changes depending on the amount of beam winding, it is difficult to completely synchronize the stopping behavior with the front rollers 6, 6' over the entire range of winding amounts.
In addition, if the beam 10 stops earlier than the front rollers 6, 6', the yarn sheet H becomes slack, which significantly reduces the beam quality, and also causes the yarn sheet H to become sagging through the needles forming the front reed 7 and the rear reed 9. Work efficiency deteriorates because the threads of the threads twist each other, causing phenomena such as sticking to the reed needle or not being able to pass through the needle, so-called sticking. Therefore, in a normal warping machine, the beam 10 is adjusted to stop slightly later than the front rollers 6, 6' to prevent troubles caused by slack in the yarn sheet H. Normally, commercially available warping machines have 1200
The time to stop from a warping speed of m/min is 0.3~
Requires about 0.6 seconds, and the beam further increases by 0.05~0.1
It usually stops after about a second. As mentioned above, in warping machines, it is difficult to synchronize the stopping behavior of the front roller and beam roller over the entire range of the beam winding amount, so by stopping the beam a little later than the front roller, The yarn sheet is kept under tension at all times to prevent troubles caused by slack in the yarn sheet. As already mentioned, in the case of ordinary drawn yarn, the above-mentioned increase in tension of the yarn sheet due to the stoppage of the warping machine is absorbed, and troubles due to partial drawing such as dyeing spots do not occur. However, in the case of highly oriented polyester undrawn yarns, the secondary yield point stress is lower than that of drawn yarns, so the above-mentioned increase in tension caused by stopping the warping machine cannot be absorbed, and partial stretching occurs. FIG. 2 shows the relationship between the secondary yield point stress P (g/d) and the warping tension T (g/d) of the highly oriented undrawn polyester yarn, which defines the maximum warping tension in the method of the present invention. Figure 2 shows warping at a speed of 1200 m/min according to the process shown in Figure 1 using various highly oriented undrawn polyester yarns with secondary yield point stress in the range of 1 to 2 g/d. We investigated the relationship between warping tension and staining under high-speed warping by stopping the warping machine, varying the maximum warping tension at the time of stopping, winding it into a beam, then forming it into a tricot and dyeing it. This is what I did. In Figure 2, the area that does not become a stain is the area shown by the shaded line, and the maximum warping tension T that does not cause a stain
(g/d) changes in proportion to the secondary yield point stress P (g/d) of the highly oriented polyester undrawn yarn. Second
In the figure, for areas that do not become stained, the direction coefficient is β
Then, it is expressed by a linear equation such that T≦βP. From the numerical relationship between P and T in FIG. 2, the direction coefficient β of the boundary line is calculated to be β=0.8, and the above equation is expressed as T≦0.8P. That is, in the high-speed warping method for highly oriented undrawn polyester yarn of the present invention, the maximum warping tension is set to T.
Warping is performed at a speed of 500 m/min or more with ≦0.8P. Here, T represents the maximum warping tension (g/d) and P represents the secondary yield point stress (g/d) of the highly oriented undrawn polyester yarn. In the present invention, the maximum warping tension T (g/d) is the secondary yield point stress P of highly oriented polyester undrawn yarn.
Regarding points lower than (g/d), the following can be considered. In other words, the S-S curve is usually 1m/
Measurements are taken at low deformation rates of less than 1 minute. On the other hand, high-speed warping involves high-speed deformation in a short period of 0.6 seconds or less from a speed of about 1200 m/min to stopping. In other words, it is presumed that the tension acts impulsively on the yarn, resulting in different deformation behavior. For example, even if the maximum warping tension is below the secondary yield point stress, it is thought that plastic deformation occurs without elastic recovery due to the impact tension, but this is not clear. The method of the present invention for warping with the above maximum warping tension includes:
This can be carried out in the following manner. The first step is to improve the precision of synchronization of the stopping behavior of the front roller and the beam. In other words, either increase the time it takes for the front roller to stop, or
Alternatively, by shortening the time it takes for the beam to come to a stop, the time it takes for the beam to come to a stop at the beginning of winding, where the beam inertia is small, to be equal to or slightly shorter than the stop time for the front roller, the beam inertia can be reduced. This is a method of reducing the difference in stopping time between the beam and the front roller at the end of winding when the winding becomes large. Specifically, this can be easily achieved by adjusting the electromagnetic brake of the front roller or the beam. This method can be applied to highly oriented undrawn polyester yarns that have a relatively high secondary yield point stress. Further, when the secondary yield point stress is low, the following method is available as a second method. That is, this is a method in which the braking characteristics of either the front roller or the beam are approximated to the braking characteristics of the other by detecting changes in inertia of the beam or changes in tension of the front roller due to the winding amount. That is, there is a method of keeping the difference in stopping time between the two constant within a certain range in response to changes in the inertia of the beam, such as methods such as Japanese Patent Publication No. 52-24144 and Japanese Patent Publication No. 58-7746. As a third method, by incorporating a device such as a dancer roller into the warping process system of the present invention shown in FIG. This method absorbs changes in tension. For example, there are methods such as JP-A-52-70141 and JP-A-56-73135. As the fourth method, there is a method in which the above-mentioned second and third methods are appropriately combined. In any case, any method may be used as long as it can be carried out within the range of the maximum warping tension according to the method of the present invention. In the warping method of the present invention, the warping tension in a steady state is not particularly limited, and is usually 0.2
By setting the g/d to a level around or lower than that, it is possible to suitably warp. Further, the highly oriented undrawn polyester yarn used in the present invention may be a copolymer containing ethylene terephthalate units as a main component, or may be a composite yarn with other polymers having different properties.
Coloring agents such as pigments, matting agents, antistatic agents,
It may contain additives such as moisture absorption. Further, the cross section of the yarn may be of an irregular shape, such as a triangle, in addition to being circular. Further, in order to impart cohesiveness to the yarn, appropriate air entanglement may be applied thereto. E Effects of the present invention According to the present invention, highly oriented polyester undrawn yarn, which has been difficult to warp in the past, can be easily warped at high speed. Therefore, productivity can be improved and costs can be significantly reduced. In addition, since the fabric is not stretched during warping, the resulting knitted fabric does not develop dyed spots. Examples and Comparative Examples Using 588 each of two types of highly oriented polyester undrawn yarns 75D-36F with birefringence of 0.075 and secondary yield point stress of 1.05 g/d and birefringence of 0.11 and secondary yield point stress of 1.62 g/d. The warping tension is 0.2 through the warping process shown in Figure 1.
g/d, warping speed 1000m/min, flange diameter 53cmφ, width
Wind it onto a beam with a diameter of 53cm and a body diameter of 20cmφ, halfway through.
When the winding length is 5000m, the maximum warping tension is
0.64g/d (Example 1) and 0.82g/d (Example 2)
Stop the warping machine at and start warping again.
A winding beam with a winding length of 10,000 m was fabricated. The obtained beam was formed into a half tricot by using a 28G two-reed tricot machine, and dyed with a disperse dye by a conventional method to inspect for spot-like staining. Separately, as a comparative example, only the maximum warping tension was 1.20g/d under the same conditions.
(Comparative Example 1) and 1.86 g/d (Comparative Example 2) were warped, and staining spots were examined in the same manner. Results first
Shown in the table.

[Table] In Examples 1 and 2, no spot-like staining occurred on the knitted fabric, but in Comparative Examples 1 and 2
In some cases, spot-like staining was observed.

[Brief explanation of drawings]

Fig. 1 is a warping process diagram showing an example of an embodiment of the present invention, and Fig. 2 is a diagram showing the relationship between the secondary yield stress and the warping tension, which define the maximum warping tension in the method of the present invention. . 1: Creel, 2: Yarn package, 3: Tension adjustment device, 4: Yarn breakage detector, 5: Porous yarn collector plate, 6, 6': Front roller, 7: Front reed, 8:
Fuzz detector, 9: Rear reed, 10: Beam, H: Yarn sheet, T: Maximum warping tension, P: Secondary yield point stress.

Claims (1)

[Claims] 1. Birefringence is 0.06 to 0.135, and secondary yield point stress is 1.
In the warping method of ~2g/d highly oriented polyester undrawn yarn, the maximum warping tension is T≦0.8P, and 500
A high-speed warping method for highly oriented undrawn polyester yarn, which comprises warping at a speed of m/min or higher. Here, T represents the maximum warping tension (g/d) and P represents the secondary yield point stress (g/d) of the highly oriented undrawn polyester yarn.