JPH02269821A - Manufacturing method of polyester composite yarn - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to a polyester with low molecular orientation, in which the crimp of the single fibers constituting the crimped yarn is non-uniform in the cross-sectional direction, and which has low crimp fastness. The present invention relates to a method for manufacturing a polyester composite yarn having a silky texture, using a crimped yarn as a sheath portion and other yarns as a core portion.

(Prior Art) As a proposal for improving the hue and texture of composite yarns using highly oriented undrawn polyester yarns, there is a method of false twisting the undrawn polyester yarns while keeping the molecular orientation low.

As a typical example, for example, Japanese Patent Application Laid-Open No. 63-20383
There is No. 9. However, in this proposal, since the number of twists during false twisting is high, it is completely impossible to impart a silky texture. In addition, as is clear from the examples listed in the above-mentioned publication, in this type of conventional technology, the heat temperature during false twisting is generally a condition that firmly imparts crimp, and the above-mentioned high twist In addition to the number, there are extremely inconvenient conditions for expressing a silky texture. For example, 150
Under the surface temperature of the false-twisting heater of .degree. C., the crimp is uniformly and firmly applied, resulting in a rough texture regardless of the number of false twists.

(Problem to be solved by the invention) In any case, it is impossible to obtain a processed yarn with a silky texture using conventional composite yarn manufacturing technology that performs false twisting using highly oriented undrawn polyester yarn. It is possible.

The present invention was developed in light of this situation, and the characteristics of the undrawn polyester yarn serving as the sheath yarn, processing conditions for similar yarns, compound conditions with other yarns, etc. are set to suitable ones, The purpose of this invention is to obtain a polyester composite yarn that has a silky texture and is sufficiently durable for practical use.

(Means and effects for solving the problem) That is, the present invention is a low-molecular-oriented polyester crimped yarn in which the crimp of the single fibers constituting the crimped yarn is uneven in the cross-sectional direction, and the crimp fastness is low. It relates to a manufacturing method for the purpose of obtaining a composite yarn in which a yarn is arranged in a sheath part and another yarn is in a core part, (1)
Birefringence Δn of the highly oriented undrawn polyester yarn serving as the raw yarn of the crimped yarn = 0.025 to 0.080 (2) The stretching ratio of the undrawn yarn during false twisting is less than the natural stretching ratio (3) The heater surface temperature during the same false twisting process is 110 to 140.
℃ (4) The conditions for mixing and intertwining with other yarns are (1+α+)
(1-s 1)/ (1+αg) (t-s z)≧
1.0.

Here, α1. α2; S l + S Z indicates each overfeed rate and each spring shrinkage rate of the crimped yarn and other yarns.

To explain the present invention in more detail along with its operation, firstly, in order to obtain a silky texture, which is the main objective of the present invention, the first structure is that the single fibers constituting the crimped yarn have a low molecular orientation, and the crimps of the single fibers constituting the crimped yarn have a cross-sectional shape. It is essential to obtain a polyester crimped yarn that is non-uniform in the direction and has low crimp fastness. To obtain such a crimped yarn, the false twisting speed and heating method are not particularly limited, and a commonly used false twisting device can be used, and the desired result can be easily obtained. The purpose of can be achieved.

In order to obtain a crimped yarn with low molecular orientation, it is theoretically preferable to use a low-oriented yarn as a supply system and to keep the draw ratio as low as possible during false twisting, but various studies have been carried out. As a result of overlapping, the birefringence of the supply system Δn<0.025
In this case, the physical properties of the supply system change greatly over time and cannot be a practical production technology. Moreover, birefringence Δn >0.
If it is 080, the drawn yarn texture will be emphasized regardless of the conditions during false twisting, and the intended purpose will not be achieved.

In addition, when false-twisting highly oriented undrawn polyester yarn with a birefringence Δn = 0.025 to 0.080, in order to maintain low molecular orientation, false twisting is performed at a draw ratio lower than the natural draw ratio. It is necessary.

By the way, the surface temperature of the false-twisting heater generally employed when false-twisting polyester is <150 as described above.
A temperature range of .degree. C. to 220.degree. C. is employed, and the crimped yarn targeted by the present invention cannot be obtained under such temperature conditions. That is, as mentioned above, the crimp is nonuniform in the cross-sectional direction, and it is impossible to obtain a crimped yarn with low crimp fastness.

On the other hand, at a low false-twisting heater surface temperature of 110 to 140°C, which is adopted in the present invention, the single fibers present in the center of the yarn heated in the heating range during false-twisting and the single fibers present on the surface are separated. There is a difference in the heat treatment effect by the false twisting heater, which causes variations in crimp in the cross-sectional direction of the crimped yarn, which approximates a multilayered yarn. In addition, since the heat treatment is insufficient, the crimp fastness is low and it is difficult to get a rough texture. It is presumed that these synergistic effects create a silky texture.

If the surface temperature of the false twist heater is lower than 110° C., crimp is not applied.

In addition, in order to perform the stretch false twisting process at a false twisting heater surface temperature of 110 to 140°C and below the natural stretching ratio, it is necessary to generate an appropriate false twisting heating tension, but this can be done by changing the heating number. This can be achieved by

In this way, the desired crimped yarn is obtained, and the second main feature of the present invention is to mix and entangle the crimped yarn thus obtained with other yarns. The crimped yarn itself has low crimp fastness and has a high residual elongation because it has been false-twisted at a low draw ratio, so it cannot be put to practical use as it is. Therefore, it is necessary to add reinforcing threads to complement these and make it practical.

The reinforcing threads may be natural fibers or chemical fibers, as long as they match the silky texture, and the reinforcing threads alone can withstand practical use.The conditions for blending and interlacing should be as long as they are suitable for practical use. It is necessary that the crimped yarn constitutes the sheath portion of the composite yarn, and that the reinforcing yarn constitutes the core portion. In order to satisfy this condition, the overfeed rate (%) of the crimped yarn during blending and intertwining must be α1, the overfeed rate of other yarns α2, and the clean water shrinkage rate (%) of the crimped yarn S1. , when the fresh water shrinkage rate of other yarns is 82, (1+α1)(i −s 1)/(i+αg) (I
If Sz)≧1.0, the desired sheath and core structure will be formed.

Incidentally, the fiber mixing and entangling can be achieved by using a generally used Taslan processing nozzle or an interlacing processing nozzle.

Here, the highly oriented undrawn polyester yarn means a polyester fiber whose main component is polyethylene terephthalate, the birefringence Δn is the value measured with a polarizing microscope equipped with a Berenck compensator, and the natural stretching ratio is 20°C, 65% with a test length of 20 cffl and a tensile speed of 100%.
Readings were taken from stress-strain curves in the RH chamber.

The overfeed rate (%) is the difference between the feed roller circumferential speed and the delivery roller circumferential speed divided by the delivery roller circumferential speed, expressed as a percentage, and the fresh water shrinkage rate (%) is the J I
It was measured according to SL-1077, 1073.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples. 1 and 2 are explanatory diagrams showing different embodiments for carrying out the present invention, in which the birefringence is 0.028 and the natural stretch ratio is 1.02, obtained at a spinning winding speed of 2500 m/min. 45 polyester unstretched, semi-dull, round section, 80 denyl, 3
6 filaments were used as supply system 1, a Mitsubishi Heavy Industries LS-6 model was used as the false twisting machine, and the heating tension was 0. Different crimped yarns 4 were obtained by changing the rotational speed of the spindle 2 so as to obtain t5 g/d and variously changing the relationship between the stretching ratio during false twisting and the surface temperature of the false twisting heater 3. Note that the peripheral speed of the delivery roller 5 was 100 m/min. Further, the stretching ratio is the circumferential speed of the delivery roller 5/the circumferential speed of the feed roller 6. The obtained crimped yarn 4 was made into a tubular knitted fabric, treated with spring water, and subjected to a sensory test. As shown in Table 1, the surface temperature of the false twist heater was 110 to 140°C, and the stretching ratio was 1.43 or less. It had a noticeable silky characteristic. When this knitted fabric was observed under a microscope, it was found to be a multilayered crimped yarn with uneven crimp in the cross-sectional direction. The fresh water shrinkage percentage of each crimped yarn obtained at this time is shown in Table 1.

In addition, almost no crimp was observed in the 100° C. conditioned yarn in Table 1, and therefore, it did not become a multilayer structured yarn.

Further, the yarn under the 150° C. condition had uniform crimp and had good crimp fastness, and therefore had less silky characteristics.

The crimped yarn with a silky texture obtained at a false twisting heater surface temperature of 110 to 140°C loses its crimped form or deforms when only a weak stress is applied to it. However, it was not practical.

Therefore, in order to reinforce the crimped yarn and make it durable for practical use, semi-dull, 5° denyl, 36 filament, which is a drawn polyester yarn with a breaking elongation of 30% and a clean water shrinkage rate of 10%, was used.
As shown in FIG. 2, the round cross-section yarn 7 was mixed with the crimped yarn 4 through a feed roller 8, and mixed and entangled through an interlacing air nozzle 9 to obtain a composite yarn. The conditions at this time were that the overfeed rate αl (%) of the crimped yarn was 8%, the overfeed rate αt (%) of the drawn yarn was 5%, and the air nozzle 9 for blending and entangling was Taslan nozzle T3 manufactured by Heperline.
11, the air pressure was 5 kg/-, and the peripheral speed of the delivery roller 5 was 100 m/min.

The obtained composite yarn 10 was made into a tubular knitted fabric, and the knitted fabric which was subjected to relaxation treatment in water introduction was heated at a false twisting heater temperature of 110°C as shown in Table 1.
Although the silky effect was slightly lower at the false twist draw ratio of 1.00, the other sheets had a silky texture with good drapability. In addition, the tension of the composite yarn was sufficient for practical use.

Table 1. Spring water shrinkage rate (%) of crimped yarn (Effects of the invention) As described in detail above, according to the present invention, the sheath portion has a low molecular orientation, and the single fibers constituting the crimped yarn have a A polyester crimped yarn with uneven crimp in the cross-sectional direction and low crimp fastness is used, and other yarns are placed in the core to add practicality, giving it a rich silky texture. It becomes possible to obtain polyester composite yarn in an extremely rational manner without using any special equipment.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a manufacturing mode of a crimped yarn constituting a part of the composite yarn obtained by the present invention, and FIG. 2 is an explanatory diagram showing a typical composite yarn manufacturing mode according to the present invention. Explanation of main parts of the figure 1...Highly oriented undrawn polyester yarn 2--False twist spindle 3-False twist heater 4-Crimped yarn 5--Delivery roller 6--Feed roller 7--=Reinforcing yarn 8.--Feed roller for reinforcing yarn 9---Mixed fiber, interlacing nozzle 10...Compound yarn

Claims (1)

[Claims] After drawing and false twisting the highly oriented undrawn polyester yarn, when mixing and intertwining it with other yarns, (1) the birefringence Δn of the highly oriented undrawn polyester yarn is 0;
．． 025-0.080 (2) Stretching ratio during false-twisting is less than natural stretching ratio (3) Heater surface temperature during false-twisting is 110-140°C
(4) The conditions for mixing and intertwining with other yarns are (1+α_1)(1-S_1)/(1+α_2)(1-
S_2)≧1.0 However, α_1 is the overfeed rate (%) of the false twisted crimped yarn during mixing and entangling α_2 is the overfeed rate (%) of other yarns S_1 is the boiling water shrinkage of the crimped yarn Ratio (%) S_2 is a method for producing a polyester composite yarn, characterized in that it simultaneously satisfies the boiling water shrinkage ratio (%) of other yarns.