JPH0152491B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a special polyester multifilament yarn having thick and thin filaments in the longitudinal direction. Conventionally, polyester multifilament yarns with microstructural differences in the fiber axis direction are polyester multifilament yarns that have thick and thin sections in the fiber axis direction, with the thicker portions having a lower degree of orientation and the thinner portions having a higher degree of orientation. , the so-called "sick-and-thin yarn" is known. However, such conventional thick-and-thin yarn has a birefringence index of 0.5.
Since it is obtained from an undrawn yarn with a diameter of ×10 ^-3 to 10 × 10 ^-3 , when the portion with a low degree of orientation crystallizes, the yarn becomes brittle and its passability through higher processing steps is significantly reduced. Therefore, it has become a big problem in terms of application development. In order to improve these problems, the present inventors have already developed a polyester yarn having a thick and thin structure obtained from a highly oriented undrawn polyester multifilament yarn in Japanese Patent Application Laid-open No. 18717/1983, and have disclosed a method for producing the same. It was proposed in Japanese Patent Application Laid-Open No. 50-18718, and it was stated that it has good passability through higher-order processing steps and is sufficiently durable for practical use. However, the yarn has a very high heat shrinkage rate, close to 70% in boiling water, and has the disadvantage that if it is made into a woven or knitted fabric as it is, it will have a large width and cannot be used as a product. In addition, although the yarn has a change in heat shrinkage rate in the length direction of the filament, since the difference in heat shrinkage rate between filaments is small, even if post-heat treatment is performed in a high-order processing step, the yarn has little bulk and is highly durable. It has the disadvantage that bulk performance is still insufficient to produce woven or knitted fabrics that have fullness and softness. As a result of intensive studies aimed at resolving these drawbacks, the present inventors have found that by performing interlacing treatment on thick and thin yarns in a relaxed state, and then subjecting them to relaxation heat treatment using a hot plate, the reduction in thickness of thick and thin yarns has been achieved. The present invention was achieved by discovering that it is possible to shrink the filaments, provide a difference in heat shrinkage rate between filaments, and further increase the difference in heat shrinkage rate in the longitudinal direction of the filaments. That is, the object of the present invention is to have a thick and thin filament in the longitudinal direction that has good high-order processability and can impart spun-like marbling shading to woven and knitted fabrics, as well as a high degree of fullness and softness due to surface touch and bulkiness. An object of the present invention is to provide a method for producing a special polyester multifilament yarn having the following properties. The present invention has the following configuration to achieve the above object. That is, the birefringence is between 20×10 ^-3 and 70×
10 ^-3 highly oriented undrawn polyester multifilament yarn at a draw ratio of (1 + constant stress elongation region elongation x 0.6) times to (1 + constant stress elongation region elongation x 1.2) times, This is a method for producing a special polyester multifilament yarn, which is characterized by performing interlacing treatment in a relaxed state, and then subjecting it to relaxation heat treatment using a hot plate. The manufacturing method of the present invention will be explained in more detail using the drawings. FIG. 1 is a manufacturing process diagram showing one embodiment of the present invention. In FIG. 1, 1 is a highly oriented undrawn polyester multifilament yarn used in the present invention, which is drawn with a hot pin at a desired stretching ratio between a feed roller 2 and a draw roller 4 through a hot pin 3. After being made into a yarn, it is interlaced in a relaxed state between a draw roller 4 and a relaxation roller 8 via an interlace nozzle 5, a guide group 6, and a hot plate 7, and
The guide group 6 adjusts the transmission of vibration of the yarn due to the interlacing and the contact angle of the yarn to the hot plate 7.
The film is then subjected to a relaxation heat treatment and wound onto a winder 9. The highly oriented undrawn polyester multifilament yarn 1 used in the present invention has a birefringence of 20×10 ^-3 to 70×
It needs to be 10 ^-3 and more preferably 25 x 10 ^-3 to 60 x 10 ^-3 . If an undrawn yarn with a birefringence index of less than 20 x 10 ^-3 is used, the ratio of thick to thin cross-sectional area will become too large, and if the resulting yarn is dyed as a woven or knitted fabric, the contrast of marbling will become too large. be. On the other hand, 70
When a yarn obtained using an undrawn yarn exceeding ×10 ^-3 is made into a woven or knitted fabric and dyed, there is a drawback that the marbled tone contrast becomes low and a marbled pattern cannot be obtained. In order to give a marbled pattern to the dyed woven or knitted fabric, the U% (described later) of the yarn obtained by the production method of the present invention is preferably 4% to 12%, and preferably 5% to 10%. It is more preferable that Hot pin stretching is carried out using the feed roller 2 and draw roller 4 via the hot pin 3 at a desired stretching ratio. In this case, the temperature of the hot pin 3 is 50 to 100°C.
It is preferable that it is, and it is more preferable that it is 60-90 degreeC. If the temperature of the heating pin 3 is less than 50°C, the generation of thick and thin parts will not be dispersed, and the thick parts will exist for a long time. The pattern tends to be similar to that obtained by cold stretching. Therefore, when dyeing a woven or knitted fabric using the obtained yarn, there are long dark dyed areas and periodicity, which inevitably leads to a so-called moiré pattern, which deteriorates the quality of the woven or knitted fabric. So I don't like it. On the other hand, if the temperature of the hot pin exceeds 100°C, the U% of the yarn obtained will decrease, and when dyed as a woven or knitted fabric, the contrast of marbling will decrease, which is not preferable. In addition, the stretching ratio is (1 + constant stress stretching region elongation ×
0.6) times to (1 + constant stress elongation region elongation x 1.2) times, (1 + constant stress elongation region elongation x 0.8) times to (1 +
It is preferable that the constant stress elongation region elongation x 1.0) times. When the stretching ratio exceeds (1 + constant stress elongation region elongation x 1.2) times, the frequency of occurrence of thick parts decreases.
When a woven or knitted fabric using this yarn is dyed, the resulting woven or knitted fabric is dotted with darkly dyed areas, making it impossible to obtain the marbled pattern that is the object of the present invention. On the other hand, the stretching ratio is (1 + constant stress stretching region elongation ×
If it is less than 0.6 times, there will be too many thick parts, and when a woven or knitted fabric using this yarn is dyed, there will be too many darkly dyed parts, resulting in a woven or knitted fabric with poor aesthetic appearance. In the present invention, interlace processing is performed in the interlace nozzle 5 between the draw roller 4 and the relaxation roller 8 in a relaxed state via the interlace nozzle 5, the guide group 6, and the hot plate 7, and the interlace processing is performed by the guide group 6. The vibration propagation of the yarn and the contact angle of the yarn to the hot plate 7 are adjusted, and then relaxation heat treatment is performed on the hot plate 7. The interlace nozzle 5 may be a known interlace nozzle (for example, JP-A-55-67030, JP-A-55
Air pressure 1~
It is sufficient to pass the test in a relaxed state with a weight of 5 kg/cm ² and a relaxation rate of 1 to 15%. When the interlacing process is performed, each filament undergoes migration (the filament is present near the yarn axis or on the outer periphery), and entanglement is imparted to the filament. When this interlaced yarn is subjected to relaxation heat treatment using a hot plate, the degree of heat treatment differs between the yarn layer in contact with the hot plate and the yarn layer away from the hot plate, so heat is applied in the length direction of the filament and between the filaments. This causes a difference in shrinkage rate. In the present invention, in order to provide a more irregular difference in heat shrinkage rate in the length direction of the filament and between the filaments, the yarn passing through the interlace nozzle 5 does not necessarily have to be spread over the entire yarn surface to prevent migration of slack. It has been found that the effect is not limited to those with good yarns, but even if there are intermittent openings as shown in FIG. 2, the effect can be sufficiently exhibited. When the yarn that has passed through the interlacing nozzle has an interlacing part A and a spread part B as shown in FIG.
This selective heat treatment can further expand the difference in heat shrinkage rate in the length direction of the filaments of the thick and thin filaments, and further reduce the difference in heat shrinkage rate between filaments. can be granted. Only by providing this difference in heat shrinkage rate can it be possible to increase the bulk in the heat treatment after the higher step. The number of entanglements is 10 for a yarn with a good spread part.
It is preferably at least 20 mm/m, and in order to provide finer heat treatment, it is preferably at least 20 mm/m. In FIG. 1, the interlace zone and the heat treatment zone are in the same relaxation zone between the draw roller 4 and the relaxation roller 8, but it is also possible to separate the interlace zone and the heat treatment zone by providing a roller system between them. be. It is also possible to separate the drawing zone and the interlacing and heat treatment zones. The relaxation rate of the relaxation zone is preferably 1 to 15%, more preferably 3 to 12%. The filament does not have thick or thin lines in the length direction.
In the case of so-called normal yarns, the heat shrinkage rate is low, so a relaxation rate of about 1 to 5% is desirable. It is preferable to set the rate slightly higher. When the relaxation rate is less than 1%, the heat treatment effect is high, so the marbling tone contrast that is characteristic of thick and thin yarns decreases, and the yarn is more likely to be uniformly heat treated, making it difficult to increase the difference in heat shrinkage rate. Undesirable. On the other hand, if the relaxation rate exceeds 15%, running stability deteriorates, which is not preferable. The guide group 6 is used to adjust the vibration transmission of the yarn due to the interlacing process and the contact angle of the yarn to the hot plate 7, and may be a fixed guide or a rotating guide, and may be a fixed guide or a rotating guide, depending on the shape and shape of the guide. The number used can be arbitrarily selected. The heat treatment temperature of the hot plate 7 is preferably 100°C or more and 200°C or less, more preferably 120°C or more and 180°C or less. Since the yarn obtained in the drawing process of the present invention has a thick and thin shape, the heat shrinkage rate is very high and the entire yarn tends to shrink uniformly. Therefore, the heat treatment temperature should be set lower than when heat treating ordinary yarn. is desirable.
If the heat treatment temperature is less than 100℃, the effect of increasing the difference in heat shrinkage rate in the filament length direction and between filaments is too small, and when post-heat treatment is performed in a high-order processing step, it is difficult to increase the bulk.
This is not preferable because yarn running stability deteriorates. Furthermore, since it is difficult to achieve a low shrinkage rate, it is undesirable that, for example, high-order processability such as increasing the width of the fabric decreases. On the other hand, if the heat treatment temperature exceeds 200° C., the U% of the obtained yarn decreases, and when dyed as a woven or knitted fabric, the marbled tone contrast decreases, making it impossible to achieve the object of the present invention. Further, the contact time to the hot plate, that is, the heat treatment time, is preferably 0.006 seconds to 0.13 seconds, and more preferably 0.01 seconds to 0.1 seconds. The special polyester multifilament yarn obtained by the present invention is subjected to relaxation heat treatment, so that the spread portion shown in FIG. 2 is heat-shrinked, and the yarn becomes a yarn as shown in FIG. 3 in which the slack has been eliminated and processed. Since it does not differ in appearance from thick and thin yarn that is not coated, it has the characteristic that it passes through higher processing steps very well. In addition, since the yarn has a low shrinkage, it can be used as a strongly twisted yarn, and a woven or knitted fabric having a more natural texture can be obtained. The polyester constituting the highly oriented undrawn polyester multifilament yarn used in the present invention contains 80 mol% or more of ethylene terephthalate units. Examples of copolymerization components include dibasic acids such as adipic acid, sebacic acid, isophthalic acid, diphenyldicarboxylic acid, and naphthalenedicarboxylic acid, oxyacids such as oxybenzoic acid, and diethylene glycol, propylene glycol,
One or more of glycols such as neopentyl glycol, pentaerythritol, and polyethylene glycol monomethyl ether, and 5-sodium sulfoisophthalic acid can be used. As detailed above, when the special polyester multifilament yarn obtained by the production method of the present invention is highly processed into a woven or knitted fabric and dyed, it exhibits the following excellent effects. Because it is thick and thin, it has a slightly uneven surface and a natural span-like surface touch.
The unevenness helps absorb light, increases the depth of the color, and has a natural marbling tone, giving it an excellent aesthetic appearance. Since there is a difference in heat shrinkage rate in the length direction of the filament and between the filaments, it exhibits excellent bulkiness and has a high degree of bulge and softness. Since the heat shrinkage rate of the entire filament is maintained at an appropriate level, the problem of widening in woven or knitted fabrics is eliminated, and high-order processability is improved. Due to the synergistic effect of interlacing treatment and relaxation heat treatment, it has extremely good passability through higher processing steps, and it is possible to weave without twisting and with no glue and water jet loom weaving. Next, the present invention will be explained in more detail with reference to Examples. The definitions of relaxation rate and elongation in the low stress elongation region and various measurement methods are described below. <Definition of relaxation rate> Relaxation rate [%] = Surface speed of draw roller 4 (m/min) - Surface speed of relaxation roller 8 (m/nin)/Draw roller 4
surface speed (m/min) x 100 <Definition of elongation in constant stress elongation region> Read the elongation on the chart shown in Figure 4 obtained with an Instron type tensile tester, and set it as 0.4 if it is 40%, for example. represent (Measurement method of U%) The measurement value was measured using a commercially available Uster Evenness Tester.
(manufactured by Keizoku Kogyo Co., Ltd.) is used. Select the measurement slot to be used depending on the total denier of the yarn, set the yarn speed to 4 m/min, and twist the yarn using a false twister.
Measure by normal test while rotating at 3000 rpm and false twisting. The Worcester spot curve is drawn at a chart speed of 25 cm/min. The U% value is read as the yarn unevenness over 3 minutes using the included integrator. U% is 1 for 3 minutes measurement.
Measurements were made at least 5 times and expressed as the average value. (Method for Measuring Bulk Height) FIG. 5 shows a sketch of the bulk height measuring device, and FIG. 6 shows a sketch for explaining the measuring method using the device. Two notches 15 on the top surface of the sample stage 10
is provided, and the spacing 16 between the outer edges thereof is 6 mm,
A flexible thin cloth tape 11 with a width of 2.5 cm is stretched over this cut 15, and a metal fitting 12 with a pointer and a load 13 are connected to the underside of the flexible thin cloth tape 11. The pointer on the metal fitting 12 is set so as to indicate the 0 position on the scale 14 when no sample is attached. Each skein of the sample is wound 80 times using a skein machine with a circumference of 1 m, and 2 to 10 skeins are prepared depending on the indicated fineness.
The skein is heat-treated by hanging it under no load for a minute, and the surface fineness of the skein after heat treatment is 48,000 denier (for example, if the yarn is 30 denier, it is 30×
80 x 2 = 4800, 48000 ÷ 4800 = 10, 10 skeins, 75 denier yarn, 75 x 80 x 2 = 12000, 48000
÷12000 = 4 (4 skeins)) Align them in parallel. Then,
As shown in Figure 6A, the aligned skeins are
Fold it in half to form a sample 17, and insert it between the thin cloth tape 11 and the sample stage 10 as shown in the front view of FIG. 6 (B) and the cross-sectional view of FIG. 6C. Make sure that the total weight is 50g including the attached metal fittings, and read the value L (cm) indicated by the pointer.
The measurement sample 17 is measured three times in total by moving the position, and the average value (cm) is determined. The bulk height M is calculated from the following formula. M (cc/g) = volume in tape / weight of yarn in tape = ^V _W V = (L/-) ² /π x 2.5 W = D x 100/100 - SH x P x 0.02 x 1/9000 Here Here, D is the fineness (denier) of the sample yarn before heat treatment, and P is the number of parallel yarns in the tape. In addition, SH is the shrinkage rate during dry heat treatment,
This value is determined by measuring the length of the skein used for bulk height measurement under a load equivalent to 0.1 g/d before and after heat treatment, and is expressed as a percentage. Example 1 Polyester containing titanium oxide with [η] = 0.64 was prepared by changing the spinning speed and discharge amount as shown in Table 1.
An undrawn filament polyester multifilament yarn was obtained. The undrawn yarn was stretched at a speed of 450 m/
min, stretching ratio (1 + low stress stretching region elongation x 0.9)
Double, heating pin temperature 80℃, relaxation rate 7%, hot plate temperature 155℃, as an interlaced nozzle in JP-A-55
- 67031 Publication Using a nozzle with a 0.8φ2 hole in the shape shown in Figure 5, stretching-interlacing-relaxation heat treatment is carried out under a compressed air pressure of 2 kg/cm ² , and a special filament having a thick and thin shape in the longitudinal direction is applied. A polyester multifilament yarn was obtained. The yarn was used for the warp and weft to make a pinewood fabric. After the fabric is scoured and passed through an intermediate setting process, it is dyed with the dye Amacron Blue (American Color).
Dyeing was carried out under conditions of 1.0% owf (manufactured by & Chemical Corp.) and 1.0% owf of auxiliary agent Sunsolt (manufactured by NICCA Chemical Corp.). The results are shown in Table 1.

【table】

[Table] In Table 1, Experiment Nos. 1 and 3 are comparative examples for clarifying the effects of the present invention. Experiment No. 1 uses so-called undrawn yarn with a birefringence index of 10 x 10 ^-3 , so the difference in cross-sectional area between the thick and thin parts is large, resulting in an extremely strong contrast between light and shade.
The natural shading contrast of the marbled tone, which is the objective of the present invention, could not be obtained. In addition, the strength of the fabric was lowered, and many parts of the fabric were broken, resulting in extremely low commercial value. In Experiment No. 3, the birefringence index was 78×10 ^-3 , so the cross-sectional area ratio between thick and thin was small, and the difference in internal structure between thick and thin was small, so the contrast between light and shade was very weak, resulting in a marbling-like shade. Nakatsuta. On the other hand, from Experiment No. 2, which met the requirements of the present invention, a fabric was obtained that had a good marbled aesthetic appearance, and had a natural surface touch and fluffiness and softness due to excellent bulk. Example 2 A polyester containing titanium oxide with [η] = 0.64 was melt-spun at a spinning speed of 3000 m/min to obtain a highly oriented 118-denier 36 filament with a birefringence of 37×10 ^-3 and an elongation in the constant stress elongation region of 0.45. An undrawn polyester multifilament yarn was obtained. The yarn was drawn in the process shown in Figure 1 at a drawing speed of 450 m/min, a hot pin temperature of 80°C,
After stretching at a stretching ratio (1 + elongation in the constant stress stretching region x 0.92) times to make a thick and thin yarn, the relaxation rate was 7%, the hot plate temperature was 155°C, and one was described in Figure 5 of JP-A-55-67031. 2Kg/cm ² using a nozzle with 0.8φ2 holes in the shape of
Two types of polyester multifilament yarns were obtained: one was interlaced and the other was not interlaced. Two types of plain woven fabrics were obtained by wefting the two types of yarns respectively. After scouring the fabric, dye Amacron Blue (American
Dyeing was carried out under the conditions of 1.0% owf (manufactured by Color & Chemical Corp.) and 1.0% owf of the auxiliary agent Sunsolt (manufactured by NICCA Chemical Corp.), and higher-level evaluation was conducted. The yarn quality and high-level evaluation results of the two types of polyester multifilament yarns are shown in Table 2.

[Table] ◎ Very good △ Slightly poor × Poor In Table 2, Experiment No. 4 is a comparative example for clarifying the effects of the present invention. In Example 4, thick and fine yarns were subjected to relaxation heat treatment without being subjected to interlacing treatment, and as shown in Table 2, because the bulkiness was low, the resulting fabric had a marbling tone, but had soft bulges. The object of the present invention could not be achieved because there was little texture and it was not possible to weave without twisting or gluing. On the other hand, the yarn of Experiment No. 5, which satisfies the requirements of the present invention, has a bulk level of 30 or more, and can be woven without twisting and weaving, and the obtained fabric has excellent marbling tone and light and shade.
It was an extremely excellent product with an improved soft bulge feeling and a more natural surface touch due to the expanded space between the filaments.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the manufacturing process according to the present invention, Figure 2 is a schematic diagram of the manufacturing process according to the invention;
The figure is a model diagram of the yarn after passing through the interlace nozzle, Figure 3 is a model diagram of the special polyester multifilament yarn obtained by the present invention, and Figure 4 is a strong elongation curve explaining the elongation in the constant stress elongation region. 5 are sketches of the bulk height measuring device, and FIGS. 6A, B, and C are sketches for explaining the bulk height measurement method. 1: Highly oriented undrawn polyester multifilament yarn, 2: Feed roller, 3: Heat pin,
4: Draw roller, 5: Interlace nozzle, 6: Guide group, 7: Hot plate, 8: Relax roller, 9: Winder.

Claims (1)

[Claims] 1 Highly oriented undrawn polyester multifilament yarn with a birefringence of 20×10 ^-3 to 70×10 ^-3 ,
After hot pin stretching at a stretching ratio of (1 + constant stress elongation region x 0.6) times to (1 + constant stress elongation region elongation x 1.2) times, interlacing treatment is performed in a relaxed state, and then relaxation is performed using a hot plate. A method for producing a special polyester multifilament yarn characterized by heat treatment.