JPS636646B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a method for drawing polyester multifilament yarn. More specifically, the total number of filaments (hereinafter referred to as single yarns) that make up the multifilament yarn is 40 or more, and the single yarn fineness is 1.5d.
The present invention relates to a method for drawing a multifilament yarn for high-quality textiles with fine fineness called fine denier yarn as described below. [Prior art and its problems] Conventionally, when drawing a fine denier yarn in which the total number of single yarns constituting a multifilament yarn is 40 or more and the single yarn fineness is 1.5d or less, the single yarn is Since the filaments are completely opened and it becomes virtually impossible to make direct contact with the pin surface, the yarn temperature of the outer single yarns that overlap on the drawing pin and are not in direct contact with the drawing pin surface is lower than the specified temperature. This results in the occurrence of stretching spots, fuzz, and sagging. Therefore, for example, a method using a pin for preheating and a stretching pin for fixing the stretching point as shown in Japanese Patent Publication No. 41-12927, and
A method such as that disclosed in Japanese Patent Publication No. 43-19109 was adopted in which an elastic roller was pressed onto a heating supply roller. However, in the former method, the yarn is preheated by the preheating pin, which has the effect of making the temperature of the yarn uniform on the drawing pin and reducing drawing unevenness, but as the drawing speed increases, the preheating effect becomes insufficient,
Stretching point fluctuations occur on the stretching pins, causing stretching unevenness, and also causing fuzz and sagging. In addition, in the latter method, the heating supply roller is preheated by winding it multiple times, and an elastic roller is pressed onto the heating supply roller to fix the drawing point, so the entire yarn can be sufficiently preheated. Since the elastic roller gradually undergoes thermal deterioration and hardens, maintaining and managing the functionality of the elastic roller becomes complicated and extremely expensive as an industrial production process. Furthermore, fine denier yarn is prized as a yarn for high-grade textiles. For example, Fuji silk, deshin,
High-quality fabrics such as Yangryu have minute irregularities and shrinkage wrinkles called grains on the fabric surface, which give the fabric a fullness, warmth, and deep luster, giving it a luxurious image. In order to uniformly develop fine irregularities on the surface of a fabric made of polyester yarn, the heat shrinkage stress of the raw yarn must be
It is required to be 0.48 g/d or more, more preferably 0.50 g/d or more. However, the heat shrinkage stress level of multifilament yarn preheated and drawn using a heating supply roller without using a drawing pin is 0.42±0.04g/
Therefore, a drawn yarn desirable for use in high-grade textiles cannot be obtained. [Object of the Invention] The object of the present invention is to improve the shortcomings of the prior art, and to provide a method for drawing multifilament yarn for high-grade textiles called fine denier yarn, which has virtually no drawing unevenness, fluff, or sag. It is something to do. [Structure of the Invention] In order to achieve the above object, the present invention has the following structure. That is, when drawing an undrawn polyester multifilament yarn having a total number of 40 or more single yarns into a drawn yarn with a single yarn fineness of 1.5d or less, the undrawn yarn is heated within the range of formula (1) below. A polyester multifilament yarn characterized in that it is wound around a rotating supply roller and preheated by running in contact with it for 0.1 seconds or more, and then wound and drawn around a drawing pin with a diameter of 40 mmφ or less that is heated within the range of formula (2) below. This is a stretching method. Tg + 5 < T ₁ < Tg + 30 ... (1) Tg + 30 < T ₂ < Tg + 70 ... (2) [Tg: Glass transition temperature (℃) T ₁ : Temperature of heated rotating supply roller (℃) T ₂ : Surface of stretching pin Temperature (°C)] The present invention will be described in detail below. The polyester multifilament undrawn yarn used in the present invention is, for example, one in which terephthalic acid is the main dibasic acid and ethylene glycol or cyclohexanedimethanol is the main glycol, or ethylene oxybenzoate is used as the main glycol. It is obtained by melt-spinning polyester-based polymers obtained by copolymerizing various ester-forming compounds. The present invention will be explained using the drawings. FIG. 1 is a schematic diagram of a stretching process showing one embodiment of the present invention. In Fig. 1, reference numeral 1 denotes an undrawn yarn drum on which undrawn yarn is wound.The undrawn yarn 3 passes through a yarn guide 2, is unrolled at a constant speed by an elastic roller 4 and a feed roller 5, and then is unrolled at a constant speed by a heating rotating supply roller. 7.
The undrawn yarn fed to the heated rotating supply roller 7 is run in contact with the heated rotating supply roller 7 heated to (Tg + 5) < T ₁ < (Tg + 30) °C for 0.1 seconds or more, and then continues to run at (Tg + 30). <T ₂ < (Tg + 70) C. It is wound around a drawing pin 8 having a diameter of 40 mmφ or less and is supplied to a drawing roller 11, and the heated drawing is caused by the roller circumferential speed difference between the heating rotation supply roller 7 and the drawing roller 11. It is stretched while creating a tension gradient on the pin 8. The drawn yarn that has passed through the drawing roller 11 is wound onto a bobbin or cheese in a winder (not shown), but before winding, heat treatment and entangling treatment are performed as necessary. In the present invention, the purpose of using the heated rotating supply roller 7 is to preheat all the single yarns constituting the multifilament yarn as uniformly as possible to a temperature higher than the glass transition temperature Tg of the undrawn yarn. If the temperature T ₁ of the heated rotating supply roller 7 is below (Tg + 5) °C, it is practically difficult to preheat the undrawn yarn to a temperature above Tg, while if it is above (Tg + 30) °C, the temperature of the undrawn yarn is sufficiently high to reach Tg. As described above, the plasticization phenomenon of the undrawn yarn occurs, and the yarn tension between the heated rotation supply roller 7 and the separate roller 6 decreases, and the undrawn yarn is Since vibration, the so-called twitching phenomenon, occurs and causes stretching unevenness, the surface temperature of the heated rotating supply roller 7 must be within the range of equation (1) above. In addition, the contact running time on the heated rotating supply roller 7 is
If the heating time is 0.1 seconds or less, it becomes practically difficult to uniformly preheat all the individual filaments constituting the multifilament undrawn yarn, causing drawing unevenness, fluff, and sagging, so it is necessary to carry out contact running for 0.1 seconds or more. Furthermore, the undrawn yarn preheated to the glass transition temperature Tg or higher by the heating rotation supply roller 7 has a temperature of (Tg+30)<T ₂ <(Tg+
The film is wound around a stretching pin 8 having a diameter of 40 mm or less and heated to a temperature in the range of 70)°C, and stretched while creating a tension gradient on the pin. The purpose of using the drawing pin 8 is to spread the multifilament undrawn yarn, which has been preheated to a glass transition temperature Tg or higher and is supplied onto the drawing pin, on the drawing pin as much as possible to reduce the tension gradient. The object is to stretch the paper while causing the stretching, and to fix the stretching point in the shortest possible range on the stretching pin. In the present invention, the temperature of the stretching pin is (Tg + 30)
℃ or below, the amount of heat required to fix the drawing point and draw is insufficient, and the undrawn yarn is not in direct contact with the overlapping single yarns that are in direct contact with the drawing pin. Stretching unevenness is likely to occur due to the temperature difference between single yarns, and when the obtained drawn yarn is dyed, filament yarns with residual undrawn yarn portions are likely to be dyed darkly. will also increase. On the other hand, when the temperature of the drawing pin reaches (Tg+70)° C. or higher, the plasticization phenomenon of the undrawn yarn rapidly progresses on the drawing pin, resulting in increased occurrence of single yarn breakage and fluff during drawing. Therefore, the temperature of the stretching pin must be within the range expressed by equation (2) above. In addition, since it is necessary to fix the stretching point, the diameter of the stretching pin should be as small as possible without causing a shortage of heat required for stretching, and should be 40 mmφ or less in diameter, preferably 30 mmφ or less, and more preferably 30 mmφ or less in diameter. is preferably 25 mmφ or less. Since a drawing pin is used in the present invention, it is possible to obtain a drawn yarn having a heat shrinkage stress of 0.48 g/d or more, which is necessary for high-grade textiles. 0.48g/d or more preferably
When the woven fabric has a heat shrinkage stress of 0.50 g/d or more, grains, so-called fine irregularities, can be uniformly produced. The reason why fine grains, which are highly commercially valuable, occur in textiles in the drawing system using drawing pins is that the drawing pins act as friction bodies and cause sliding drawing, so the drawing tension of the yarn is higher than when no drawing pins are used. Depending on the degree of tension, the proportion of crystalline parts in the yarn structure is high or low, and the torque of the raw yarn is restored when creating a texture using a fabric using yarn that is strongly twisted and set to prevent twisting. It is thought to be related to power. In addition, since the cross-sectional shape of the single yarn in the present invention has a gloss and feel similar to natural silk, it is preferable to use yarn with an irregular cross-section such as triangular or pentagonal. Furthermore, in order to improve the thread passing property during processing in higher-order processes, it is preferable to perform an interlacing treatment after stretching to improve the cohesiveness. The boiling water shrinkage rate and dry heat shrinkage rate of the drawn yarn differ depending on the use for which the drawn yarn is used. The boiling water shrinkage rate of the drawn yarn used in high-grade textured fabrics is generally required to be low, but in that case, a heat treatment plate is used between the drawing pin 8 and the drawing roller 11 to reduce the shrinkage. It is preferable to control the rate. [Effects of the Invention] By adopting the above configuration, the present invention has a multifilament yarn in which the total number of single yarns is 40 or more, the single yarn fineness is 1.5d or less, and the heat shrinkage stress is
It is possible to stably obtain fine denier yarn for high-grade textiles, which has a yield of 0.48 g/d or more and is substantially free from drawing unevenness, fuzz, and sag. The heat shrinkage stress in the present invention was measured by the following method. (Heat shrinkage stress measurement method) A yarn with a sample length of 100 mm was set in a strain meter with an initial load of 1/30 (g/d), and the temperature was raised from room temperature to 250 °C at a heating rate of 2.5 °C/sec in a dry heat state. Record the change in contractile force with an X and Y recorder, and read the MAX stress and peak temperature from the chart on the recorder.
Stress (g)/drawn yarn denier=shrinkage stress (g/
Let the value calculated in d) be the heat shrinkage stress. Hereinafter, this will be explained in more detail with reference to Examples. Example 1 A polyester chip with an intrinsic viscosity of 0.65 (measured in orthochlorophenol at 25°C) was melt-spun using a round hole spinneret with 48 discharge holes at a spinning speed of 1380 m/min to obtain an undrawn yarn A of 140 denier. I got it. In addition, the spinning speed is increased by using a round-hole nozzle with 72 discharge holes.
210 denier undrawn yarn B spun at 1480 m/min
I got it. Each of the undrawn yarns A and B was subjected to the drawing process shown in Figure 1 at a drawing speed of 600 m/min, a drawing ratio of 2.85, and a drawing pin diameter.
The yarn was drawn with a diameter of 20 mm and a drawing pin temperature of 125°C under the conditions shown in Table 1 to obtain a drawn yarn with a Tg: glass transition temperature of 70°C. The drawn yarn was wound onto a bobbin, and the single yarn sag on the surface of the bobbin was judged with the naked eye while being projected with a projector. In addition, the drawn yarn is subjected to a warping test using a warping machine for warping warps of textiles, and the fuzz is counted.The drawn yarn is then dyed by driving it into the weft of a plain woven fabric, and the remaining undrawn yarn is darkly dyed. Stretching unevenness was determined based on the number of parts. Furthermore, after measuring the heat shrinkage stress of the drawn yarn, the drawn yarn was additionally twisted at 800 times/m, and the gray fabric density was determined using the additional twist yarn as the warp and weft.
200 pieces/(inch) Weaving into ₂ plain weave, weight loss rate 20%
The grained state of the fabric after the alkali weight reduction process was evaluated. Displays the results of judgment and evaluation.
Also listed in 1.

[Table] ◎: Extremely good ○: Good △: Slightly poor
×: Poor Experiment Nos. 1, 7, 8, and 11 are comparative examples for clarifying the effects of the present invention. As is clear from Table 1, Experiments Nos. 1 to 8 confirmed the effect of the heated rotating supply roller temperature and were No. 1.
Because the temperature is low, single yarn sagging and drawing unevenness occur frequently.On the other hand, because the temperature is high for No. 7 and 8, the plasticization of the yarn progresses on the heated rotating supply roller, and the yarn on the heated rotating supply roller Since the single yarn vibrates (jitter) at the point where the yarn separates, the number of fuzz increases during the warping test. On the other hand, in Nos. 2 to 6, the sagging, fluff, and stretching unevenness were at a level that caused no practical problems, and the texture of the fabrics was also extremely good. Experiments Nos. 9 to 11 confirmed the effect of the contact time of the undrawn yarn to the heated rotating supply roller.No. .10 has slight fluff and stretching spots, but it is at a level that does not cause any problems in practical use.
No. 11 had increased sagging, fuzz, and stretching spots due to insufficient contact time. In addition, Experiment Nos. 12 and 13 show examples of 72 filaments having a large number of single filaments, but the performance was not much different from that of 48 filaments. Example 2 In the same manner as in Example 1, polyester chips were melt-spun to obtain undrawn yarns A and B. These undrawn yarns were subjected to the drawing process shown in Figure 1, with the temperature of the heated rotating supply roller being 90°C, the roller contact time being 0.15 seconds, and the diameter and temperature of the drawing pins being changed as shown in Table 2. Except for this, drawing was carried out under the same conditions as in Example 1 to obtain a drawn yarn having a glass transition temperature of 70°C. The drawn yarn was evaluated under the same conditions as in Example 1, and the results shown in Table 2 were obtained.

[Table] ◎: Extremely good ○: Good △: Slightly poor
×: Poor Experiment Nos. 14, 15, 18, and 22 are comparative examples for clarifying the effects of the present invention. As is clear from Table 2, Experiments No. 14 to 17 confirmed the effect of the drawing pin diameter, and while No. 3 was extremely good, No. 16 was Although some spots may occur, it is not a problem for practical use.No. 14 and 15 have large stretching pin diameters, so the stretching points are not fixed properly, resulting in sagging,
Fuzz and stretch spots increased. Experiments No. 18 to 22 confirmed the effect of drawing pin temperature, and No. 20 was extremely good, whereas No.
In No. 18, sagging, fluff and stretching spots occurred due to the low temperature, and in No. 22, the occurrence of fluff increased due to the high temperature, whereas in No. 19 and No. 21, sagging, fluff and stretching spots occurred. A slight amount of unevenness occurred, but it was at a level that would pose no problem for practical use, and the texture of the fabric was also good. Comparative Example Spinning and drawing were carried out under the same conditions as in Example 1 No. 4, except that no drawing pins were used, and the evaluation revealed that the occurrence of sagging, fluff, and drawing unevenness was at a level that would pose no problem in practical use, but heat shrinkage stress is as low as 0.39g/d,
The texture of the fabric was poor, and it was not possible to obtain the high-grade yarn for textiles, which is the object of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a stretching process showing one embodiment of the present invention. 1: Undrawn yarn drum, 2: Yarn path guide, 3: Undrawn yarn, 4: Elastic roller, 5: Feeding roller, 6:
Separate roller, 7: heating rotation supply roller,
8: Stretching pin, 9: Separate roller, 10: Stretching roller.

Claims (1)

[Scope of Claims] 1. When drawing a polyester multifilament undrawn yarn having a total number of 40 or more filaments to make a drawn yarn with a filament fineness of 1.5d or less, the undrawn yarn is subjected to the following (1). It is characterized in that it is wound around a rotating supply roller heated to the range of formula (2) and run in contact for 0.1 seconds or more to preheat it, and then wound and stretched around a stretching pin with a diameter of 40 mmφ or less heated to the range of formula (2) below. A method for drawing polyester multifilament yarn. Tg+5<T ₁ <Tg+30 ……(1) Tg+30<T ₂ <Tg+70 ……(2) [Tg: Glass transition temperature (℃) T ₁ : Surface temperature of heating rotating roller (℃) T ₂ : Surface of stretching pin Temperature (℃)〕