JPS6136094B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a high-speed false twisting method of 1000 m/min or more,
More specifically, the present invention relates to an improvement in a high-speed false-twisting process in which a spinning process and a false-twisting process are directly connected. In the following description, the term "the high-speed false twisting method" means a high-speed false-twisting and crimp method. In recent years, bulking technology for polyester fibers has shifted from a method in which drawn yarn is false-twisted in a separate process to a so-called DTY method in which high-speed spun yarn POY is simultaneously stretched and false-twisted in a false-twisting process with the intention of streamlining the process. death,
There is a trend toward faster speeds using this DTY method.
However, the speed increase with this DTY method has a limit of about 1000 m/min, and increasing the speed beyond this not only presents a fatal flaw in that bulkiness, which is the most important thing for processed yarn, cannot be obtained, but also has a problem with the process. However, since spinning and processing are separate processes, the current situation is that this does not necessarily lead to significant process rationalization. In contrast to these methods, the so-called method that performs spinning and processing continuously
The SDTY method is being considered, but this method also treats the spun yarn with an oil agent, then stretches it, and then false-twists it, so the yarn entering the false-twisting process is cooled to around room temperature. In order to process such yarns at high speed, a long heater with a high temperature is required from the viewpoint of heat setting. On the other hand, however, as the length of the heater increases, the rate of twisting by the false twisting device is extremely reduced, and a problem arises in that bulk processing cannot be performed sufficiently due to the insufficient number of twists. In this way, under high-speed false-twisting processing, especially high-speed processing of 1000 m/min or more, there is a clear trade-off between the increase in heater length and the twisting rate. ) The current situation is that even the basic requirement of sufficient heat fixation of the thread under the threads has not been realized. Therefore, the object of the present invention is to eliminate the trade-off between heater length and twist number, and in particular to
The object of the present invention is to provide a bulky yarn having sufficient crimpability for practical use even at high speeds of min or higher. Furthermore, another object of the present invention is to provide a high-speed false twisting method of 1000 m/min or more that can impart sufficient crimpability to the yarn even under the conventional heater length of at most 20 m. be. The inventors of the present invention limited the length of the heater in the course of various studies aimed at achieving the above object.
We considered taking advantage of the fact that the conventional method of reheating and giving false twist to the once cooled and solidified yarn cannot be applied under high-speed processing of 1,000 m/min or more, and we decided to take advantage of this in particular. It has been found that by utilizing the high thermal potential of the discharged yarn in an uncooled state, it is possible to sufficiently compensate for the lack of heat treatment on the heater. however,
With this alone, it is difficult to ensure sufficient crimpability in high-speed processing, and we have discovered that the thermal properties of the discharged yarn can only be utilized when the various factors of the false twisting process satisfy certain conditions, and we have arrived at the present invention. That's what I did. Thus, according to the present invention, the polyester filament yarn discharged from the melt spinneret is passed through a twisting device, a heat treatment heater, a cooling device, a false twisting device, and a take-up roller in this order, and then passed through a winding device for 1000 m/s. In the high-speed false twisting method that directly connects the spinning process and the processing process, which involves winding at a speed of min.
The yarn is introduced into a twisting device heated to ~190°C, and then (b) the yarn temperature is raised to ~140°C on a heat treatment heater.
Heat treated for at least 0.01 seconds while maintaining the temperature at 230°C to fix the false twist. but
A high-speed false twisting process is provided, which is characterized by cooling by contacting with a cooling plate of 10 cm to 100 cm. Furthermore, regarding this, the present invention does not rely only on external heating for heat treatment (false twist setting) under high-speed processing, but also utilizes the high potential thermal energy of the discharged yarn, and also utilizes non-cooling The aim is to utilize the "easiness of twisting" of the discharged yarn in this state to effectively heat-fix and cool the twist. Figure 1 shows a comparison of the thermal properties of the discharged yarn (polyester) with that of a conventional filament yarn that has been cooled and solidified.The vertical axis shows the specific volume of each yarn, and the horizontal axis shows the specific volume of each yarn. The yarn temperature is plotted.
Here, curve A shows the relationship between specific volume and yarn temperature when a conventional filament yarn is gradually heated.At temperature _T1 , the specific volume suddenly increases, and after that, as the temperature increases, the specific volume decreases. It becomes larger and larger and reaches a maximum at the melting point of Tm. On the other hand, yarn spun from a molten state is
It is in a supercooled state, and its cooling tendency is shown by curve B, where the specific volume exceeds curve A at the same yarn temperature. Here, T ₂ indicates _the lower limit of yarn temperature (usually 160℃) in normal false twisting processing;
The specific volume of the discharged yarn is T ₁ which is lower than T ₂ , corresponding to
This means that in the case of discharged yarn, even if the temperature is lower than T ₂ , the conventional T ₂
This means that it has an inherent heat treatment effect equivalent to . Similarly, at the same yarn temperature _T2 , the discharged yarn has a specific volume higher than that of the conventional yarn by ΔV, which indicates that a heat treatment effect shifted to the high temperature side of _T3 of the conventional yarn is possible. The present invention utilizes the characteristics of the discharged yarn as described above for false twisting, and embodiments thereof will be described below with reference to FIGS. 2 and 3. In Fig. 2, 1 is a spinneret, and the spun yarn 2 discharged from the spinneret
The yarn is introduced into a twisting device 3 in the form of a hot roller, where the yarn temperature is maintained while passing through a heat treatment heater 4, a cooling device 5, a false twisting device 6, and then taken up by a delivery roller 7 and taken up by a winding device. It is wound up at 8. Here, a false twist is applied to the spun yarn 2 by a false twisting device 6, which is heat-set by a heat treatment heater 4, and then set by a cooling device 5.
Also, Fig. 3 shows the method shown in Fig. 2 with the twist stopper changed, and the tip of the heater 4 is improved to have a structure like 4', which is used as a heated twist stop. Furthermore, by using the guide pin 3' in combination, effective twist prevention can be expected. In this process, the present invention has various improvements made with an overall balance in view of high-speed false twisting processing, and these points will be described in detail below. First, the temperature of the spun yarn 2 entering the twisting device 3 is 70°C.
Must be kept within the range of ~180℃. 70℃
If it is below, it will be lower than the glass transition temperature Tg and it will be difficult to twist, and therefore it will be difficult to shape.
If the temperature exceeds 180°C, the threads in step 2 will be too soft and will stick to the hot roller in step 3, making it impossible to twist them.
The preferred yarn temperature is 100°C to 160°C, which varies depending on the peripheral speed of 3. For example, the speed of 3 is
100℃~130℃ is preferable when the speed is 1000m/min or less, and 140℃ when this speed is 3000~4000m/min.
~160°C is preferred. In order to maintain the yarn temperature at a predetermined temperature, it is preferable to use a hot roller, and the roller 3 serves to prevent the twist from moving in the direction of the spinneret 1. The temperature of the hot roller 3 used can be controlled between 100°C and 190°C. At this time, in order to keep the yarn temperature constant, it is particularly preferable to control the yarn temperature at a temperature 5 DEG C. to 10 DEG C. higher than the yarn temperature of the spun yarn 2 entering the hot roller 3. This hot roller is usually installed within 100 cm, preferably within 70 cm, of the spinneret 1 to keep the temperature of the spun yarn at least as low as possible.
Can be maintained above 70℃. On the other hand, the heat treatment heater No. 4 must have a length that can maintain the yarn at 140° C. to 230° C. and process it for at least 0.01 seconds in order to twist and fix the twisted yarn. The heater 4 may be a plate heater with a certain curvature, or a slit-shaped heater to improve twisting. It is also possible to integrate the twisting device 4' and the heat treatment heater 4 as shown by 4 and 4' in FIG. At this time, it is more effective to use a guide pin as shown by 3'. The cooling device No. 5 is essential for rapidly cooling the heat-set yarn below its glass transition point.
Through this device, the twisting by the false twisting device 6 is uniformly carried out by the upstream heater 4 and the twisting hot roller 3.
It is also important to trace back the surface roughness to 1.
A plate having a diameter of μ to 8 μ is particularly preferably a grooved plate. This plate is made of metal with good thermal conductivity and has a length of 10 mm to ensure rapid cooling.
~1 m is required, and the position must be located within at least 1 m from the outlet of the heater 4. This is because when the yarn coming out of the heater 4 is slowly cooled by air, the cooling becomes slow and the bulkiness deteriorates.
This is because ballooning occurs between the cooling device and the cooling device, causing spots. As for the false twisting device No. 6, although there are no particular limitations, a friction type device is effective from the viewpoint of threading performance and number of twists, and its circumferential speed is related to the yarn speed, and is usually twice the yarn speed. is necessary. Also, this position is 15 cm from the outlet of the cooling device 5.
It is preferable to provide a guide in the range of ~50 cm, and if a large amount of pruning occurs within this range, it is preferable to provide a guide to prevent pruning. The yarn 22 leaving the false twisting device 6 is untwisted and becomes a bulky textured yarn, which is taken up by a delivery roller 7. This speed is related to speed 3, but speed 3 is at least 250 m/min, and if the speed is lower than this, stable yarn protection conditions will not be achieved, resulting in uneven spinning.
Causes crimp spots. Since the yarn spun at 250 m/min needs to be drawn at least 4 times, the minimum speed of the delivery roller 7 is 1000 m/min. If the speed of hot roller 3 becomes greater than 2500 m/min, the speed of roller 7 increases accordingly. When the speed of the hot roller 3 is 3000 m/min, the appropriate speed of the delivery roller 7 is about 4800 m/min. The yarn leaving the delivery roller 7 is wound up by a winding machine 8. In this series of processing methods, if the speed of the take-up roller 7 is 4000 m/min or more, even the third twisting device can be used to process the material without unevenness. The examples shown in Figures 2 and 3 are all false twisting processes using a single heater method. It is also possible to provide a second heater after the roller 7 to perform secondary relaxation heat treatment. On the other hand, the spun yarn is not limited to the example of discharging the same yarn (single filament group), but the spinneret is configured with tandem or more spinnerets to spin two or more groups of filaments, and in this case, between the filaments or The filament groups may have different cross-sections, have different dyeability, or may have different elongations, and then be subjected to processing. Further, such filaments are made of polyester, and polyethylene terephthalate is most preferably used as the polyester. Of course, the polyethylene terephthalate may be modified or modified to the extent that its essential properties are not impaired, but even in that case, at least 85 mol% or more of the repeating units are preferably 90% by mole or more.
Preferably, a mole percent is accounted for by ethylene terephthalate units. As described above, according to the present invention, by subjecting the spun yarn to the false twisting process while it is at a specific temperature without being cooled down, the problems of shaping and heat treatment associated with high-speed processing can be solved at once. Since this problem has been solved and the occurrence of negative factors that affect the crimp performance of the yarn after shaping has been suppressed, it is possible to provide a bulky yarn that is excellent even at high speeds of 1000 m/min or higher. Moreover, the process of the present invention itself is of great significance from the point of view of streamlining the process, since the once-cooled spun yarn is directly subjected to the bulking process (without being wound up). Example 1 Polyethylene terephthalate with a chip intrinsic viscosity [η] = 0.65 was spun at a spinning temperature of 290°C and a discharge amount of 62 g/
The fibers were spun at a rate of 30 minutes and 30 filaments and processed in the manner shown in Figure 2. The conditions at this time are that the hot roller 3 has a diameter of 150 mm, the temperature is 130°C, it makes 5 turns, the wind speed is 1000 m/min, and the temperature of yarn 2 is
It was installed at a temperature of 100℃ (at a location 60cm directly below the cap). Heat treatment heater No. 4 was a grooved plate heater with a length of 1.2 m and a temperature of 180° C., and the distance between the outlet of hot roller 3 and the inlet of heater 4 was 10 cm. Also, place a distance of 15 cm from the outlet of heater 4, and a length of 30 cm.
cm, a grooved cooling plate 5 with a surface roughness of 3 μm is placed, a false twist friction disk rotating at a surface speed of 6660 m/min is placed 20 cm away from this outlet, and a circumferential speed is placed 40 cm away from this outlet. A take-up roller 7 with a speed of 3,700 m/min was installed, and then the film was wound up with a tension of 11 g in a winding machine 8. The crimp rate TC of this processed yarn is
It was 35%, denier 150, and in good condition with no spots. The measurement of TC is expressed as TC=l ₁ -l ₂ /l ₀ ×100%. Here, l ₀ is the length at a load of 200 mg per denier before boiling water treatment l ₁ is 200 mg per denier after 20 minutes of boiling water treatment
The length l ₂ when loaded with mg is the length when loaded with 2 mg per denier after l ₁ measurement. Example 2 Table 1 shows the results of processing the spun yarn by adjusting the yarn temperature of the spun yarn by varying the distance from the spinneret to the twisting device in Example 1. The hot roller temperature is 5℃ higher than the yarn temperature.
I set it high.

[Table] From the above results, it can be seen that when the spinning speed is about 1000 m/min, it is preferable to provide the twisting device where the yarn temperature is between 70°C and 160°C. Example 3 Table 2 shows the results of processing in Example 1 while varying the hot roller temperature.

【table】

[Table] From the above results, the hot roller temperature is
100°C to 115°C, preferably 5°C higher than the temperature of the spun yarn
It turns out that ~10℃ higher is better. If the roller temperature is less than 100°C, TC ₁ dyeing, denier, etc. spots are likely to occur. Also, such spinning speed
For yarn running at 1000m/min, the hot roller temperature should be
If it is sipped at a temperature higher than 160℃, it will fuse and cannot be processed. Example 4 In Example 1, the temperature of the heat treatment heater 4 was
Table 3 shows the results when the heat treatment time was varied at 180°C, only the length was varied.

[Table] From the above results, if the heat treatment time is less than 0.01 seconds, sufficient heat fixation will not occur and the TC will decrease. On the other hand, when this time exceeds 0.05 seconds, TC and staining spots are observed, but this is thought to be due to the increase in heater length (more than 3 m) and worsening of twisting. Example 5 Table 4 shows the results of processing in Example 1 with various changes in the installation conditions of the cooling device and others.

[Table] The distance to the heater is clear from No. 24 to 28.
About 10 to 100 cm is good. Also, the surface roughness is 2~
8μ is good, and in the case of Nos. 29 and 30, the surface roughness is so small that the dynamic frictional resistance is large, and the twisting is insufficient and uneven, causing low TC and staining. Furthermore, even if the diameter is increased to 10μ or more, it will damage the processed yarn and will not result in a good processed yarn. or,
If the cooling length is increased by more than 100 cm, twisting will not be sufficient and TC spots and staining will occur. As mentioned above, it is better to set the distance to the heater so that the yarn coming out of the heater is rapidly cooled rather than slowly air-cooled.
In addition, if the cooling surface has a certain degree of roughness, there will be less frictional resistance and it will be better in terms of twisting, and if it is too rough it will damage the processed yarn. In addition, the cooling length is about 10 to 100 cm, which is good in terms of cooling effect and twisting. Example 6 Polyethylene terephthalate with [η] = 0.65
Spinning was carried out at 290°C, with a discharge rate of 85 g/min and a number of filaments of 30, as shown in Figure 3. The processing conditions at this time are that the yarn temperature of spun yarn 2 is
Install a hot pin 3' at 130°C at 110°C, and then install a twisting device 4' at a distance of 5 cm.
A 1.5 m, 200°C grooved hot plate 4 was provided.
3' and 4' are twisting devices and have a radius of curvature of 20 mm. The positions of the cooling device 5 and the false twisting device 6 were the same as in Example 1. In addition, the surface speed of the false twisting disk in 6 is 9700 m/min, and the speed of the take-up roller in 7 is
5100 m/min, the winding device of No. 8 had a tension of 15 g. Under these conditions, pruning was large between 5 and 6 and between 6 and 7, so guides were provided for each to prevent it. The denier of the finished processed yarn is 150 de.
The TC was 30%, which was no different from the conventional one. Comparative Example 1 Polyethylene terephthalate POY of 240 denier and 30 filaments was spun at a speed of 3300 m/min, and once wound, this POY was subjected to in-draw processing using the DTY method. The processing conditions at this time were a heater length of 2 m, a temperature of 240°C, a stretching ratio of 1.6, a friction false twisting desk peripheral speed of 1440 m/min, a take-up roller speed of 800 m/min, and a winding tension of 10 g. The denier of this processed yarn is 150 de and TC is 23%, so it is low TC.
It is. Comparative Example 2 Completely the same as Example 1 except that hot roller 3 was provided at the point where the spun yarn temperature was 40°C in the processing step shown in Figure 2.
Processed under the same conditions. The TC at this time was 5%, and the bulk was lower than in Example 1. As is clear from the above examples, the high-speed false twisting method according to the present invention can produce textured yarn with higher bulkiness at a lower heat treatment temperature and shorter heat treatment time than the DTY processing method, and also streamlines the process. is clear.

[Brief explanation of the drawing]

FIG. 1 is a graph illustrating the relationship between yarn temperature and specific volume of spun yarn, and FIGS. 2 and 3 are schematic diagrams showing specific steps of the processing method of the present invention. 1 is a spinneret, 2 is a spun yarn, 3, 3', 4' are twisting devices, 4 is a heater, 5 is a cooling device, 6 is a false twisting device, 7 is a take-up device, 8 is a winder, 1
2 and 22 are threads.

Claims (1)

[Claims] 1. The polyester filament yarn discharged from the melt spinneret is passed through a twisting device, a heat treatment heater, a cooling device, a false twisting device, and a take-up roller in this order, and then passed through a winding device for 1000 m. In a high-speed false twisting method that directly connects the spinning process and the processing process, which involves winding at a speed of 1/min or more, (a) the spun yarn is heated at 100°C while the final temperature is between 70°C and 180°C;
The yarn is introduced into a twisting device heated to ~190°C, and then (b) the yarn temperature is raised to ~140°C on a heat treatment heater.
Heat treated for at least 0.01 seconds while maintaining the temperature at 230°C to fix the false twist. Saga
Cool by contacting with a 10cm to 100cm cooling plate. This is a high-speed false twisting method that is characterized by: 2. The polyester has at least 85 mol% of its repeating units consisting of ethylene terephthalate.
The high-speed false twisting method according to claim 1, which is a polyethylene terephthalate-based material. 3. The high-speed false twisting method according to claim 1, wherein the spun yarn is introduced into a twisting device while the yarn temperature is 100°C to 160°C. 4. The high-speed false twisting method according to claim 1, wherein the twisting device is heated to a temperature of 5° C. to 10° C. higher than the temperature of the spun yarn introduced into the device. 5. The high-speed false twisting method according to claim 1, wherein the twisting device is a hot roller.