JPH02154017A - Production of weld-processed yarn - Google Patents

Abstract

PURPOSE:To obtain the subject yarn exhibiting splashed pattern appearance by remarkable welded part and free from bulky feeling by subjecting a multifilament polyester yarn having a specific birefringence successively to hot-draw false-twisting process and secondary drawing at specific respective draw ratios. CONSTITUTION:A multifilament polyester yarn having a birefringence of 10-100X10<-3> is subjected to draw false-twisting at a heater temperature of 200-250 deg.C and a draw ratio equal to 0.7-0.8 times the natural draw ratio K defined by formula (E is breaking extension % of the multifilament polyester yarn). Thereafter, the drawn yarn is further subjected to the secondary drawing at a draw ratio equal to 0.65-0.8 times the natural draw ratio to obtain the objective yarn. The multifilament polyester yarn is preferably composed of ethylene terephthalate accounting for >=80% of the constituent unit and has a filament number of >=48.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polyester false-twisted fused yarn in which fused portions exist intermittently in the longitudinal direction of the yarn.

(Prior Art) Conventionally, with the trend toward higher quality polyester processed yarns, a wide variety of fusion yarns have been proposed.

For example, as related to false twist fusion yarn,
s-s9y2@, Special Publication 80-3461@, Special Publication 1981
-13011@, etc., and these also disclose simultaneous stretching and false-twisting methods in which stretching is performed at the same time as false-twisting. Also, Japanese Patent Application Publication No. 1982
No. 78227 discloses that a two-stage heater false twisting machine is used to obtain a textured yarn with an excellent potential crimp rate.

(Problem to be Solved by the Invention) However, in order to obtain sufficient shading, it is necessary to increase the ratio of the fused parts, but if this is done with the above-mentioned prior art, the minute fused parts will be reduced. It occurs frequently, and when it is made into a woven fabric, it appears as moth-eaten spots on the surface of the fabric, degrading its quality.

Furthermore, since the stretching ratio during the false twisting step is low, the residual elongation of the processed yarn is high, and if excessive tension is applied in the subsequent step, non-uniform stretching occurs, which also reduces the quality.

The present invention is intended to solve these problems, and aims to provide a false-twisted yarn that produces a Kasuri-like appearance due to the prominent fused portions and does not have a fluffy feel.

(Means for Solving the Problems) That is, the present invention provides polyester multifilament yarn with a birefringence of IO to 10OXlo= to a heater temperature of 200 to 2
A two-stage heater false twisting method in which a second stretching is performed after stretching and false twisting at 60°C, and the first stretching ratio (DRI) and the second stretching ratio (DR2) are set as follows. This is a method for producing a fused processed yarn.

DRI = 0.7 to 0.8 KDR2 = 0.6
5 to 0.8K K = 0.7 5 (E+100)/Ion (where E is the elongation at break (%) of the polyester multifilament yarn) The polyester multifilament yarn used in the present invention is
It is one in which 80% or more of the structural units are ethylene terephthalate, and may also contain a third component such as sulfoisophthalic acid, polyalkylene glycol, and titanium oxide. Further, the fineness is not particularly limited, but if a soft and smooth texture is to be obtained, a single yarn fineness of 1.
It is preferable to use one having a diameter of about 5 denier or less. On the other hand, the number of filaments is preferably a high count number, and it is preferable to use a filament number of 48 or more filaments.

After spinning, such polyester multifilament yarn is a so-called undrawn yarn with a birefringence of about 10 to 100XIO.
The semi-drawn yarn is subjected to drawing and false twisting processing.

The false twisting process uses a so-called two-stage heater false twisting method in which a heater is used in both the heating-untwisting process and the subsequent heat setting process.

Therefore, in the false twisting process using the first heater, in order to fuse the polyester multifilament yarn,
It is necessary to set the heater at a temperature of 0°C, preferably between 2's5 and 245°C. Further, the second heater is used for stretching and setting, and may be set at a temperature of about 160 to 250°C, which is appropriate from the viewpoint of texture.

In the present invention, stretching is performed subsequently after the false twisting step. Setting such a stretching ratio is important, and it is necessary to set it in correspondence with the first stretching performed simultaneously with the false twisting process. In the case of the present invention, the first stretching is 0.75 (E+100)
/loo (E is the elongation at break of polyester multifilament system (%)) 0.7 to 0 of the natural stretching ratio
．． 8 times, and the second stretching is 0.65 to 0 of the natural stretching ratio.
．． It is necessary to increase it by 8 times.

The present false twisting process will be explained in detail below using the drawings.

Figure m1 is an explanatory diagram showing an example of the present false twisting method. In the same figure, (1) is an undrawn yarn bobbin, and the undrawn yarn unwound from the bobbin passes through the first feed roller (2), the first heater (3), and then the cooling plate (
In step 4), the twisted form is fixed by cooling. (5) is a twisting device, and in the same figure, a circumferential friction false twister is used, but other low speed bottle type false twisters may be used. However, in the case of a friction type false twister, fusion tends to occur even if the stretching ratio is low, which is preferable for the present invention.

The yarn passing through the twisting device (5) is passed through the second feed roller (
6) the first feed roller (2) while being untwisted between;
It is stretched between second feed rollers (θ) and subsequently introduced into the stretching zone. (7) is the second heater;
The yarn drawn between the feed roller (6) and the delivery roller (8) is heat set. In this way, the drawn and heat-set yarn is wound around the cheese to become a fused false-twisted yarn.

In the thus obtained fused yarn, fused portions are formed intermittently in the longitudinal direction, and fused portions and non-fused portions are present alternately. The number of fused parts is 5 to 40 per 1 m, and the unit length, for example, is 20 to 45 cm when the total length of fused parts per 1 m is measured, which is different from conventional intermittent fused welding. It consists of a relatively long fused part compared to thread.

The fused portion referred to in the present invention refers to whether 1/6 or more of the single filaments constituting the multifilament are fused to form one block (Fig. 2 (a)), or where fused or The total number of blocks constituted by single yarn is 10 or less (Fig. 2 (b)).

Furthermore, this fused processed yarn is made by elongating the winding net through secondary stretching, so it appears to be uncrimped and no crimp formation is observed, and the actual crimp rate is 5. % or less.

(Function) This fused yarn has a spun-like kasuri-like appearance without any fluffy feeling, but its effect is due to the intermittent and fine fused parts and fusions that are generated intermittently and finely due to the stretching and false twisting treatment of the undrawn yarn. This is because the non-fused portions are individually stretched in the secondary stretching and become thick and thin.

In addition, the residual elongation becomes an appropriate value through secondary stretching, and
The apparent crimp is removed, resulting in a raw silk-like appearance.

(Example) Using a two-stage heater false twister (Kijin Seiki 8D8-8), the first heater temperature was 245°C and the second Heater temperature 200℃, processing yarn speed 40
0 m/min The ratio of the 1'-second stretch ratio to the second stretch ratio was varied. The results are shown in Table 1. Table 2 shows the morphology of the obtained fused yarn.

Figure 1 of Table 1 is a process schematic diagram showing an example of the method for manufacturing the present fused yarn;
FIG. 2 is a schematic diagram showing a cross section of the fused portion of the present fused yarn.

Claims (1)

[Claims] (1) Polyester multifilament yarn with a birefringence index of 10 to 100 x 10^-^3 is heated to a heater temperature of 200 to 250.
A two-stage heater false-twisting method in which a second stretching is performed after stretching and false-twisting at ℃, and the first stretching ratio (DR1) and the second stretching ratio (DR2) are set as follows. A method for producing a fused processed yarn, characterized by: DR1 = 0.7 to 0.8K DR2 = 0.65 to 0.8K K = 0.75 (E x 100) / 100 (E is the elongation at break (%) of polyester multifilament yarn)