JPS60134018A - Drawing of polyester multifilament - Google Patents

Abstract

PURPOSE:To obtain polyester multifilament yarn free from drawing unevenness, fluff, and slack, by winding undrawn yarn of polyester multifilament round a rotary feed roller and a drawing pin heated at specific temperatures, drawing it. CONSTITUTION:The undrawn yarn 3 of polyester multifilament having the total number of filaments of >=40 is fed to the hot rotary feed roller 7, wound round the hot rotary feed roller 7 heated at the temperature shown by the formula I (Tg is glass transition temperature; Ti is temperature of the hot rotary feed roller), is in contact with it for >=0.1sec and made to run, so that it is preheated. Then, the undrawn yarn 3 is wound round the drawing pin 8 having <=40mm.phi diameter heated at the temperature shown by the formula II (T2 is surface temperature of the drawing pin), fed to the drawing roller 10, and drawn, to give stably the desired filament yarn having <=1.5d fineness of filament and >=0.48g/d heat shrinkage stress.

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, and the single yarn fineness is 1.5 d or less. The present invention relates to a stretching method.

[Prior art and its problems]

Conventionally, the total number of single yarns that make up a multifilament yarn is 4.
It is a fact that when drawing fine denier yarns with a fineness of 0 wood J or more and a single yarn fineness of less than 1.5 d Ju, the medium yarns are completely opened in the drawing bin and come into direct contact with the pin surface. As a result, 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 does not reach the specified temperature, causing drawing rows, fuzz, and walnuts. .

Therefore, for example, there is a method using a pin for preheating and a stretching bottle for fixing the stretching point as shown in Japanese Patent Publication No. 41-12927, and
A method such as that shown in Japanese Patent No. 5NO9, in which an elastic roller is pressed onto a heating supply roller, has been adopted.

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 the amount of drawing required, but as the drawing speed increases, the preheating effect decreases. This results in insufficient stretching, resulting in fluctuations in the stretching point on the stretching pin, which causes the stretching process, and also causes fuzz and walnuts.

In addition, in the latter method, the heated supply roller is preheated by winding it multiple times to fix the stretching point.
Second, since the pressure is applied with an elastic roller, it is possible to sufficiently preheat the entire yarn, but the elastic roller gradually deteriorates due to heat and hardens, making maintenance and management of the functionality of the elastic roller complicated, and in the industrial production process. That would be extremely expensive.

Furthermore, fine denier yarn is prized as a yarn for high-grade textiles. For example, high-quality fabrics such as Fuji silk, dechine, and Yangyanagi have fine irregularities and shrinkage called grains on the surface of the fabric, which give the fabric a puffy flavor, warmth, and deep luster. Although it gives off a high-class image, in order to uniformly develop minute irregularities on the surface of a fabric made of polyester yarn like Jin, the heat shrinkage stress of the raw yarn must be zero.
．． 48 g/d or more, more preferably 0.50 g/d or more is required. However, the heat shrinkage stress level of a multifilament yarn preheated and drawn using a heating supply roller without using a drawing pin is about 0.42+0.04 g/d, making it impossible to obtain a drawn yarn desirable for use in high-grade textiles. It is.

[Purpose of the invention]

The purpose of the present invention is to improve the shortcomings of the prior art and provide a method for drawing multi-filament (A) for high-grade textiles called fine denier yarn, which has substantially no fluff or walnuts. It is.

[Structure of the invention]

In order to achieve the above object, the present invention has the following configuration.

That is, a polyester multifilament undrawn yarn consisting of 40 or more single yarns is drawn to have a single yarn fineness of 1.
．． When making a drawn yarn of 5d or less, the undrawn yarn is wound around a rotating supply roller heated to the range of formula (1) below.
This is a method for drawing a polyester multifilament yarn, which is characterized in that the thread is preheated by contact running for 1 second or more, and then wound and drawn around a drawing pin below (diameter 406φ heated to a 2-inch range).

Tg+5<T I<7g+30 ・・・・・・・・・(
11T g +30 < T 2 < Tg +70...
(2) The present invention will be explained in detail below.

The polyester multifilament undrawn yarn used in the present invention includes, for example, terephthalic acid as the main dibasic acid,
Glycols include those that use ethylene glycol or cyclohexane dimetatool as the main glycol, or those that use ethylene oxybenzoate, and are made by melt-spinning polyester polymers obtained by copolymerizing various ester-forming compounds. can be obtained.

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 completely fed to the heating rotation supply roller 7 is (Tg+5)<T'+<(7g+30)
After running in contact with the heated rotating supply roller 7 heated to ℃ for 0.1 seconds or more, (7g+30)<T2
<(Tg+70) It is wound around a stretching pin 8 with a diameter of 408φ or less and heated to <(Tg+70)°C, and is supplied to a stretching roller 11, and is heated by the difference in circumferential speed between the heated rotating supply roller 7 and the stretching roller 11. 8 while creating a tension gradient.

The drawn yarn that has passed through the drawing roller 11 is wound onto a bobbin or cheese in a winder (not shown), or is subjected to heat treatment and entangling treatment as necessary before winding.

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.

When the temperature T1 of the heated rotating supply roller 7 is (1g + 5)°C, it is practically difficult to preheat the undrawn yarn to a temperature higher than Tg. However, the plasticization phenomenon of the undrawn yarn occurs, and the yarn tension between the heating rotation supply roller 7 and the separation roller 6 decreases, and the undrawn yarn becomes higher at the yarn separation point on the heating rotation supply roller. Vibration, the so-called jerking phenomenon, occurs,
In order to cause stretching unevenness, the surface temperature of the heated rotating supply roller 7 must be within the range of formula (1) above.

In addition, if the contact running time with the heated rotating supply roller 7 is 0.1 seconds or less, it is practically difficult to uniformly preheat all the individual filaments constituting the multifilament undrawn yarn, resulting in uneven stretching, fuzz, and walnuts. In order to induce this, it is necessary to run in contact for 0.1 seconds. Further, the undrawn yarn preheated to the glass transition temperature Tg or higher by the heating rotation supply roller 7 is (Tg, +3
0')<T2<(7g+7o) It is wound around a stretching pin 8 having a diameter of 40 mm or less and heated to a temperature in the range of <(7g+7o)°C, and is stretched while creating a tension gradient on the pin. The purpose of using the drawing bin 8 is to spread the multifilament undrawn yarn, which has been preheated to the glass transition temperature TgJ and is supplied onto the drawing pin, on the drawing pin as much as possible to improve the tension gradient. The purpose 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, if the temperature of the drawing bin is below (1 g + 30) °C, the amount of heat necessary to fix the drawing point and draw is insufficient, and the single yarns constituting the undrawn yarn overlap, etc. Drawing unevenness is likely to occur due to the difference in temperature between single yarns that are in contact and those that are not in contact, and there are residual undrawn yarn parts that are darkly dyed when the resulting drawn yarn is dyed. Filament threads are likely to occur, and at the same time, fuzz and walnuts also increase.

On the other hand, when the temperature of the drawing bin reaches (Tg+70)° C. or higher, the plasticization of the undrawn yarn rapidly progresses on the drawing pin, which increases the occurrence of single yarn breakage and fuzz during drawing.

Therefore, the temperature of the stretching bottle 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 bottle should be as small as possible without causing a shortage of heat required for stretching, and should be 40111φ or less in diameter, preferably 30 or less in diameter. , more preferably 25JO1
φ or less is preferable.

Since the present invention uses a drawing bottle, it is possible to obtain drawn yarn with a heat shrinkage stress of 0.48 g/eL or more, which is necessary for high-grade textiles. When the woven fabric has a heat shrinkage stress of 0.48 g/d or more, preferably 50 g/d or more, zeta grain (so-called fine irregularities) can be uniformly produced.

The reason why fine grains, which are highly commercially valuable, occur in textiles in a drawing system using a drawing bottle is that the drawing bottle acts as a friction body and causes sliding stretching, so the drawing tension of the yarn is higher than when no drawing bottle is used. Depending on the degree of tension, whether the proportion of crystalline parts in the yarn structure is high or low, the restoring force of the torque of the raw yarn when creating the grain in a fabric using yarn that is strongly twisted and set to prevent twisting. It is thought that they are related.

In addition, since the cross-sectional shape of the single yarn in the present invention has a texture and gloss similar to natural silk, it is preferable to use triangular or triangular cross-sectional yarns.

Furthermore, in order to improve thread passing properties during processing in higher-order processes, it is preferable to perform cross-path treatment after stretching to improve 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 for high-grade/void fabrics is generally required to be low, but in that case, by heat-treating it using a hot plate for heat treatment between the drawing pin 8 and the drawing roller 11, It is preferable to control the shrinkage rate.

〔Effect of the invention〕

By adopting the above configuration, the present invention has a multifilament yarn with a total number of 40 single yarns, a single yarn fineness of 1.5 d JJ, and a heat shrinkage stress of [1,48
It is possible to stably obtain a fine denier yarn for high-grade textiles which has a good value of g/aJJ or more and is substantially free from drawing unevenness, fluff, and walnuts.

The heat shrinkage stress in the present invention was measured by the following method.

(Heat shrinkage stress measurement method) Attempt 100 - Initial load of the thread of 1/30 (g/a
) and set it on a strain meter in a dry heat state at a heating rate of 2.5℃/
Record the change in shrinkage force when the temperature is raised from room temperature to 250℃ in a trench with a X and Y recorder, read the MAX stress and peak temperature from the chart on the recorder, and calculate MAX stress (g)/drawn yarn denier = The value calculated from shrinkage stress (g/c1.) is defined as heat shrinkage stress.

Hereinafter, this will be explained in more detail with reference to Examples.

Example 1 A polyester chip with an intrinsic viscosity +ff1o of 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, and an undrawn 140-denier polyester chip was spun. Yarn A was obtained. Further, spinning was carried out at a spinning speed of 1480 m/min using a round-hole die with 72 discharge holes to obtain an undrawn yarn B of 210 deniers.

Each of the undrawn yarns A and B was subjected to the drawing process shown in Fig. 1 at a drawing speed of 600 m/min, a drawing ratio of 2.85, and a drawing pin diameter of 20a.
φ and the drawing pin temperature of 125°C under the conditions shown in Table 1 to obtain a drawn yarn with a glass transition temperature of 70°C.

The drawn yarn was wound onto a bobbin, and the single yarn walnuts on the surface of the bobbin were evaluated 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 the warp 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 woven into a plain fabric with a gray fabric density of 200 wood/(inch) using the additional twist yarn as the warp and weft. Alkali reduction with weight loss rate of 20%]
- The grained state of the fabric after processing was evaluated.

The results of the judgment and evaluation are also listed in Table-1.

Experiments A1.7.8 and 11 are comparative examples for clarifying the effects of the present invention.

As is clear from Table 1, experiments A1 to A8 confirmed the effect of the temperature of the heated rotating supply roller.In A1, since the temperature was low, single yarn walnuts and drawing unevenness occurred frequently, while in A7 and 8, the temperature was low. Because of this, plasticization of the yarn progresses on the heated rotating supply roller 2, and vibration (jitter) of the single yarn occurs at the point where the yarn separates on the heated rotating supply roller, resulting in an increase in the number of fuzz during the warping test. . Compared to Stiffness 5, Flatness 2 to 6 had sagging, fluff, and stretching unevenness at levels that were problematic for practical use, and the texture of the fabric was also extremely good.

Experiments JF; 9 to 11 confirmed the effect of the contact time of the undrawn yarn to the heated rotating supply roller. JP611 had a slight amount of fluff and stretching spots, but it was not a problem for practical use, but JP611 had increased sagging, fluff, and stretching spots due to insufficient contact time.

Experiment A 12.13 shows an example of 72 filaments with a large number of single yarns.

The quality was similar to that of 48 filament.

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 FIG.
The roller contact time was 0.15 seconds, and the diameter and temperature of the drawing pin were changed as shown in Table 2. Outside U, the drawing was carried out under the same conditions as in Example 1 to obtain a drawn yarn with 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.

Experimental plates 14, 15, 18 and 22 are comparative examples to clearly demonstrate the effects of the present invention.

As is clear from Table 2, experimental flats 14 to 17 confirmed the effect of the drawing pin diameter, and while A3 was extremely good, AI 6 had only slight sagging, fuzz, and drawing spots. However, in JIG, 14, and 15, the drawing pin diameter was large, so the drawing points were insufficiently fixed, and walnuts, fuzz, and drawing spots increased.

Experiments 18 to 22 confirmed the effect of the drawing pin temperature, and while flat 20 was extremely good, A 1 B
Because the temperature was low, walnuts, fluff, and stretching spots occurred; in A22, the occurrence of fluff increased because the temperature was too high, whereas in A 19 and A 21, sagging, fluff, and stretching spots were slightly observed. However, it was at a level that poses 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 1A4 except that no drawing pin was used, and the evaluation revealed that the occurrence of sagging, fluff, and amount of drawing was at a level that would pose no problem for practical use, but heat shrinkage stress Since the amount of fiber was as low as 0.39 g/d, the texture of the fabric was poor, and it was not possible to obtain the high-quality raw yarn for fabrics, which is the object of the present invention.

[Brief explanation of drawings]

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: Feed roller 6: Separate roller 7: Heated rotating supply roller 8: Stretch pin 9: Separate roller 10: Stretch roller Patent applicant Toshi Co., Ltd. Figure 1

Claims (1)

[Claims] When drawing an undrawn polyester multifilament yarn having a total number of 40 or more filaments to form a drawn yarn with a filament fineness of 1.5 d, the undrawn yarn is ) After winding it around a rotating supply roller heated to the range of the formula and preheating it by running it in contact for more than 01 seconds, the following (
2) A method for drawing polyester multifilament yarn, which comprises winding and drawing the yarn around a drawing pin with a diameter of 40 mm heated to the range of the formula. Tg+5(T+ <Tg+30 ・・・・・・・・・(
1) Tg+50<T2 <Tg+70 ・・・・・・・・・
...(2)