JPS628526B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improved method for false twisting polyester thick and thin yarn. In recent years, as part of the efforts to make polyester filament spanlike, various methods have been proposed for false-twisting so-called thick-and-thin yarns, which have alternating thick parts (thick parts) and thin parts (thin parts) along the fiber axis direction. has been done. However, when thick-and-thin yarn is false-twisted, the thick portion becomes brittle due to heat treatment during processing, resulting in a large amount of fluff, and there is a problem in that it lacks adaptability to water jet rooms. The present invention has solved such problems, and the gist of the invention is that when polyester thick-and-thin yarn is false-twisted using a two-heater type false-twisting machine, the temperature of the first heater is set to 150 - 175
℃, overfeed rate to the second heater area 20~
45%, the second heater temperature is 140℃ or higher, and the first
The false twisting method is characterized in that the temperature is set at 0.80 to 1.06 times the heater temperature. The present invention will be described in detail below with reference to the drawings.
FIG. 1 is a side view showing an example of the polyester thick-and-thin yarn used in the present invention, and FIG. 2 is a side view showing an example of the apparatus used to carry out the present invention. When the supplied yarn 3 is subjected to the false twisting process, the thick portion 1 has a low degree of orientation, so when this portion is heat set by the first heater 4, thermal embrittlement occurs, and as a result, more fuzz is generated. In particular, the lower the degree of orientation, the more pronounced this phenomenon becomes, making it impossible to withstand use in economically advantageous post-processing machines such as water jet rooms. Therefore, it is effective to keep the temperature of the first heater 4 as low as possible and perform the false twisting process to prevent the occurrence of fuzz.
The product texture is poor in bulk, which significantly reduces the product value. Table 1 relates to the crimped yarn obtained in yarn path A using the apparatus shown in Figure 2, and shows the relationship between the temperature of the first heater 4 and the generation of fuzz, and the adaptability to water jet from the number of fuzz generation. It was determined that In addition, the tubular knitted fabric can be submerged in hot water at 130°C, which is the industrial condition.
The results of evaluating the texture (particularly bulkiness) after air drying after stirring for 30 minutes are also shown. The properties of the supplied yarn 3 used at this time are shown in the remarks column, but the conditions under which it was obtained were SD270 denier, 48
Using an undrawn filament 8, the temperature of the pin 9 with a matte surface and a diameter of 60 m/m in the drawing/twisting machine shown in Fig. 3 was set to 95°C, the stretching ratio was 1.581, and the winding speed was 490 m/m.
It was a minute.

[Table] From the results in Table 1, judging the adaptability to the water jet room from the number of fuzz generation, it is necessary to adopt a temperature of the first heater of 175°C or less (No. 1 to No. 5). However, judging from the standpoint of bulkiness, these areas were insufficient, resulting in poor product quality. Table 2 shows the results when, like Table 1, the false twisting device shown in FIG. 2 was used, and B in FIG. 2 was used as the yarn path.

【table】

【table】

[Table] From the results in Tables 1 and 2, the following was found. In other words, in order to achieve the number of fuzz generation that is suitable for the water jet room, the first heater temperature needs to be 175℃ or less based on the results shown in Table 1, but in this temperature range, the product texture is particularly low. The bulkiness was insufficient. Table 2 shows the results of studies regarding these improvements.
It is shown that by setting the conditions between the delivery rolls 11 to specific conditions, there is a condition that satisfies both the number of fuzz generation and the bulkiness of the product. To explain further, the heater 4 in the first heater area
Even if the temperature is 175℃ (No. 8 to 13), the second heater 10 temperature is set to 140℃ to 185℃ (first heater temperature x 0.80
~1.06) and an overfeed amount of 20 to 45% in the second heater region, it was found that a crimped yarn with satisfactory adaptability to the water jet room and product texture could be obtained. Similarly, even if the first heater temperature is 150℃ (No.
14-18) By setting the second heater temperature to 140°C to 160°C (first heater temperature x 0.93 to 1.07) and setting the overfeed rate in the second heater region to 20 to 45%, the first heater temperature It was found that the crimped yarn produced at 175°C was slightly inferior to, but similar to, properly crimped. It has also been found that when the overfeed rate exceeds 45%, yarn runnability becomes unstable. That is,
At the same time, it was found that the yarn tension in the second heater area became too low, causing the yarn to wrap around the first delivery roll 6 and the second delivery roll 11. It was also found that conditions for achieving the intended purpose could not be found when the first heater temperature was 145°C (Nos. 19 to 22). These results can be interpreted as follows. That is, when the first heater temperature is 175°C or lower, the heat setting effect on the first heater is low. Poor shrinkage fastness. However, by performing reheat treatment simultaneously with overfeed in the second heater region (heat treatment while bulking out), crimp development and crimp fastness are greatly improved. Furthermore, the relationship between the first heater temperature and the second heater temperature is that if the second heater temperature > the first heater temperature x 1.06, the crimp will conversely weaken, and if the second heater temperature is less than 140°C. The heat treatment effect becomes insufficient. The present invention will be explained in more detail below with reference to Examples. Example An undrawn polyester yarn of SD285d/36f obtained by spinning at a spinning speed of 2000 m/min was used with the same drawing/twisting machine as shown in Fig. 3 at a drawing ratio of 1.88, a hot pin temperature of 80°C, and a winding speed.
It was stretched at 460 m/min. The yarn quality of the obtained raw yarn is fineness = 151.0 denier, DS = 3.21 g/d, DE =
68.5%, BWS=52.7%, Worcester u% (medium cycle)
= 4.6%. This raw yarn was used as the supplied yarn, the false twisting machine was LS-6 (manufactured by Mitsubishi Heavy Industries, Ltd.), and the false twisting conditions were a draw ratio of 1.05, a first heater temperature of 160°C, and a number of twists.
Processing was carried out at 2550T/M, second heater temperature 160°C, second heater area overfeed rate = 40%, and second delivery roll peripheral speed 95m/min. The number of fuzz generated in the obtained crimped yarn was 0.32 pieces/Kg, and this was made into a tube knitted fabric and treated in hot water at 130°C for 30 minutes. The knitted fabric after heat treatment became bulky in terms of texture. As a comparative example, the crimped yarn after passing through the first delivery roll was wound up without passing through the second heater region to form a tubular knitted fabric, which was then treated with hot water in the same manner as in the example, but the texture was poor in bulk. Summer. Also, the bulkiness was similarly insufficient when the overfeed amount in the second heater area was set to 15% and the other conditions were the same as in the example. In addition, the bulkiness was similarly insufficient when the overfeed rate in the second heater area was set to 42% and the second heater temperature was set to 130° C., and the other conditions were the same as in the examples.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of the thick and thin yarn used in the present invention, FIG. 2 is a side view showing an example of the device used to carry out the present invention, and FIG. Figures 1 to 3 are side views showing an example of an apparatus for manufacturing thin yarn.
In the figure, 1 is a thick part, 2 is a thin part, 3 is a supply yarn, 4 is a first heater, 5 is a feed roll, 6 is a first delivery roll, 7 is a twisting device, 8 is an undrawn yarn, and 9 is a heating pin. be.

Claims (1)

[Claims] 1 When false-twisting polyester thick-and-thin yarn with a two-heater type false-twisting machine, the first heater temperature is 150 to 175℃, the overfeed rate to the second heater area is 20 to 45%, and the second heater temperature is A false twisting method characterized by setting the temperature at 140°C or higher and 0.80 to 1.06 times the first heater temperature.