JP2001248029A - Stringy yarn and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain stringy yarns capable of giving woven or knit fabrics with natural feeling of surface unevenness, and to provide a method for producing such stringy yarns. SOLUTION: This method for producing a stringy yarn comprises the following process: a roving 10 of staple fiber is drafted into a fleece 10a, or a spun yarn or a filament is doubled with the fleece 10a, and the resultant yarn is fed at varying speeds from a pair of front rollers 1a and subjected to false twisting into a false-twisted yarn 22 or false-twisted combined yarn 12, which, in turn, is fed at varying feed rate to a knitting machine 3, where the yarn 22 or the combined yarn 12 is knitted to stringy shape. The stringy yarn 14 thus obtained is uneven in the gap of knit stitch. When the stringy yarns 14 thus obtained are woven or knitted into a fabric, the fabric is afforded with unevennesses of natural feeling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a false twisted yarn obtained by adding a false twist to a short fiber fleece, or a false twisted composite formed by adding a spun yarn or filament to a short fiber fleece as a core and adding a false twist. The present invention relates to a string-like yarn formed by knitting a yarn into a string, and particularly to a string-like yarn having unevenness in the stitch length and thickness of the string-like yarn.

[0002]

2. Description of the Related Art String-like yarns include yarns belonging to twisted yarns, yarns belonging to braided yarns, yarns woven with ribbons and the like, and yarns knitted with lily yarns. Some of these can change the color, such as Lilyan.

[0003]

However, in the above-mentioned string-like thread, the thread is supplied at a constant speed to form the string-like thread, so that the finished string-like thread also has a uniform thickness. The fabric to be woven or knitted could only be flat without irregularities. On the other hand, in recent years, consumer needs have been diversified, and cloths having a natural textured surface have been gaining in popularity.

[0004] The present invention was conceived in view of the above, and an object of the present invention is to provide a string-like yarn capable of giving a natural uneven feeling when made into a fabric by weaving or knitting, and a method of manufacturing the same. And

[0005]

In order to achieve the above-mentioned object, a string-like yarn of the present invention is a string-like yarn formed by knitting a yarn containing a fleece of short fibers, and has a stitch length and / or a thickness. It is characterized by unevenness.

[0006] Further, the yarn is a false twisted yarn formed by adding a false twist to a short fiber fleece.
A configuration in which the yarn is a false twisted composite yarn having a spun yarn or filament as a core and a short fiber fleece as a sheath, or a configuration in which the unevenness is unevenness due to 1 / f fluctuation.

Alternatively, it is formed by knitting a false twisted composite yarn in which a portion consisting only of a core made of a spun yarn or a filament and a portion forming a sheath made of a short fiber fleece are alternately arranged around the core. It is characterized by: In this case, it is possible to adopt a configuration in which the pitches arranged alternately by the 1 / f fluctuation.

In the method for producing a cord-like yarn of the present invention, a roving of short fibers is supplied from a back roller of a draft part, drafted in a plurality of zones, spun out from a front roller as a fleece, and the fleece is false twisted. Producing a false twisted yarn, and a step of continuously supplying the produced false twisted yarn to a knitting machine and knitting in a string shape, wherein at least one of a plurality of rollers constituting the draft part 1
The present invention is characterized in that the speed of the roller is changed to produce a string-like yarn having an irregular stitch length and / or thickness.

Alternatively, a short fiber roving is supplied from a back roller of a draft part, drafted in a plurality of zones, spun out as a fleece from a front roller, and a spun yarn or filament serving as a core is stacked on the fleece, and the fleece is stacked. A method of producing a false twisted composite yarn by false-twisting a core and a fleece, and a process of continuously supplying the produced false-twisted composite yarn to a knitting machine and knitting the yarn into a string shape. In addition, the speed of at least one of the plurality of rollers constituting the draft part is changed to manufacture a string-like yarn having a non-uniform stitch length and / or thickness.

The draft part includes a back roller, an apron roller, and a front roller. The draft between the back roller and the apron roller is kept constant to change the speed of the draft roller and the speed of the front roller. The draft part consists of a back roller, an apron roller and a front roller, the speed of the back roller and the apron roller is kept constant, and the speed of the front roller is changed.The draft part consists of a back roller, an apron roller and a front roller. By changing the speed of the back roller, the speed of the apron roller and the speed of the front roller can be kept constant.

The draft part includes a back roller, an apron roller, and a front roller, wherein the speed of the back roller is constant, and the draft between the apron roller and the front roller is kept constant to change both speeds. The draft part includes a back roller, an apron roller, and a front roller, wherein the draft between the rollers is kept constant to change the speed of all the rollers, or the speed is changed according to 1 / f fluctuation. It can be.

The change in the speed is given by setting the speed of the front roller at the time when the stitch is the densest to 1, and giving the speed of the front roller in the range of 1 to 3 in accordance with 1 / f fluctuation, or the speed of the back roller. To the normal spinning time
, The speed of the front roller is set in two steps, the alternation pitch is varied according to 1 / f fluctuation, the speed of the back roller is set in two steps, and the alternation pitch is set to 1 / F fluctuation.

Further, the rotation of the back roller and the apron roller is intermittently stopped at the same time so that the short fiber fleece is supplied intermittently, or the intermittent stop is changed according to 1 / f fluctuation. It is also possible to make it.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view of an apparatus for producing a string-like yarn comprising a false twisted composite yarn of the present invention. The device shown in the figure includes a draft part 1, a false twist part 2, a small knitting machine 3,
The winding unit 4 includes a drive motor 6, a motor 8 for driving the draft part 1, and a control unit 9.

The draft part 1 includes a back roller 1b,
This is an apron type consisting of a three-line roller of an apron roller 1c and a front roller 1a, which is used for a draft part of an ordinary ring spinning machine. The false twist portion 2 is a portion that applies false twist to the yarn sent from the front roller 1a of the draft part 1. The small knitting machine 3 is a small-diameter cylindrical knitting machine having 1 to 6 needles, and is a part for forming a string-like thread.

Pulleys 2a, 3a are provided below the false twisting section 2 and the small knitting machine 3, and belts are hung thereon. These belts are connected to pulleys 6b, 6c of a drive shaft 6a of a drive motor 6.
Is driven. In the present invention, these false twisted portions 2
The rotation speed of the drive motor 6 for driving the small knitting machine 3 is constant.

At the rear of the draft part 1, there is a roving 10 formed of short fibers, from which the roving 10 is supplied to the back roller 1b of the draft part 1. As the roving 10, various natural fibers such as cotton, synthetic fibers such as polyester, regenerated fibers such as cupra, or a mixture of two or more of these can be used.

The roving yarn 10 reaches the front roller 1a from the back roller 1b via the apron roller 1c, but since the surface speed of each roller is sequentially increased, between the back roller 1b and the apron roller 1c and between the apron roller 1c. The draft is received in a plurality of zones between the front roller 1a and the front roller 1a, and the fleece 10a is sent out from the front roller 1a to the false twist portion 2.

Above the front of the front roller 1a is a core 11 made of spun yarn or filament.
Is placed on the apron roller 1c side (rear side) of the front roller 1a and overlaps with the fleece 10a.

The draft part 1 is driven and rotated by a drive motor 8, and sends out the roving fleece 10a and the core 11 in an overlapping manner at the surface speed of the front roller 1a. on the other hand,
The drive motor 8 increases or decreases the rotation speed of the drive motor 8 according to a signal from the 1 / f fluctuation signal generator 9a in the control unit 9.

Each of the back roller 1b, apron roller 1c and front roller 1a of the draft part 1
When the number of rotations of the drive motor 8 is increased by n times, the number of rotations of each of the back roller, the apron roller, and the front roller is also increased by n times. become. Therefore, if the rotation speed of the drive motor 8 fluctuates with 1 / f fluctuation, the rotation speed of the front roller also fluctuates with 1 / f fluctuation.
The total draft magnification applied to the roving does not change. That is, the thickness of the fleece discharged from the front roller does not change, and the spinning speed changes. Since the core 11 is also sent out from the front roller, the thickness of the overlapped core and fleece is constant.

When the power spectrum of a time-series signal is analyzed, the intensity of the frequency (f) of the 1 / f fluctuation signal is almost inversely proportional to the frequency (proportional to 1 / f).
This is related to the fluctuation of the basic rhythm of the human body, and it fluctuates in the same way as a change in the natural world or unevenness made by hand. From another point of view, human beings get tired of receiving the same stimulus continuously, but stimuli that change too much are rather uncomfortable, and the fluctuation that appropriately combines these two is 1 / It can be said that the fluctuation is f.

The 1 / f fluctuation signal can be obtained from a numerical sequence formed by calculating a predetermined number of coefficients on a random number sequence.
It can be created by a known method using a computer or the like (for example, see JP-A-7-243137). The 1 / f fluctuation signal generator 9a of the apparatus of the present invention forms a fluctuation signal in this manner.

The fluctuation signal generated by the 1 / f fluctuation signal generator 9a is input to the controller 9b, and the controller 9b changes the rotation speed of the motor 8 according to the fluctuation. If the rotation of the motor 8 changes, the surface speed of the front roller 1a of the draft part changes, and the speed (supply speed) of the roving fleece 10a and the core 11 spun from the front roller 1a changes.

The overlap of the fleece 10a and the core 11 of the roving sent from the front roller enters the false twisting section 2, and the false twisting section 2 has the same number of opposite directions on the inlet side and the outlet side. Is added to the overlap of the fleece 10a and the core 11. That is, the twist applied on the inlet side is released on the outlet side, and the total twist becomes zero. However, the short fiber fleece 10a is wrapped around the core 11 so as to be entangled as a sheath, and becomes a false twisted composite yarn 12 in a converged state.

Next, the false twisted composite yarn 12 coming out of the false twisting section 2 is continuously supplied to the small knitting machine 3 as it is.
It is knitted here and knitted. Since the knitting machine is a small-sized cylindrical knitting machine having about 1 to 6 needles, the knitting machine becomes a string-like yarn 14 thicker than the original false twisted composite yarn 12 rather than a knitted material. Taken.

False twisted composite yarn 1 supplied to small knitting machine 3
In contrast to the change in the supply speed of No. 2, the key needle of the knitting machine knits the string-like thread 14 with a constant stroke. Here, when the supply speed is high, the stitch becomes large (the loop length becomes long),
When the supply speed is low, the stitch becomes small (the loop length becomes short).

FIG. 2 shows the knitting structure of the string-like yarn 14 when the number of needles of the small knitting machine 3 is one. FIG. 2 (a) shows a conventional string-like yarn 14 ', and a false twisted composite yarn 12 is supplied at a constant rotation speed of the front roller 1a. as a result,
Since a large number of loops of the same size are continuously formed in a line in the longitudinal direction, the thickness of the string-like thread 14 'becomes constant.

FIG. 2B shows a case where the supply speed of the false twisted composite yarn 12 is changed by the 1 / f fluctuation signal in the string-like yarn 14 of the first embodiment of the present invention. Here, the speeds of the back roller and the front roller change at the same rate of change. FIG. 2C is a diagram illustrating a fluctuation signal corresponding to the string-like yarn 14, in which the horizontal axis represents the length of the string-like yarn, the vertical axis represents the supply speed, and the curve represents the change state of the supply speed. I have.

The string yarn 14 of the present invention is a false twisted composite yarn 1
Since the supply speed of the stitch 2 changes, as shown in FIG. 2B, the stitch length changes like a long portion A, an intermediate portion B, and a short portion C. In the portion A having a long stitch length, the supply speed is high, and the stitch is coarse, thin, soft, and loose. The portion C having a short stitch length has a slow supply speed, and the stitches are dense, thick, and tight. The middle portion B is a stitch having the same length as the conventional example.

Here, the relationship between the speed of the front roller and the stroke speed of the needle of the knitting machine is as follows. If the speed of the front roller cannot keep up with the stroke speed, thread breakage occurs. The speed at which the thread break does not occur is the minimum speed of the front roller, and the stitch length is minimized. On the other hand, when the speed of the front roller is increased, the stitch speed is constant, so that the stitch length is increased. However, an excessive knitting yarn is entangled, causing trouble. The maximum speed at which this trouble does not occur is the maximum speed of the front roller, and the stitch length is maximum. When actually performed, the ratio between the minimum and maximum stitch lengths was about 1: 3. That is, if a change is given within this range, a change in the stitch length based on 1 / f fluctuation can be given in one string-like yarn 14, and the change changes the texture of the string-like yarn 14. be able to.

When the string-like yarn 14 of the present invention is used for a woven or knitted fabric, a cloth having a rich unevenness and a partially different texture can be obtained. Since the unevenness is based on the 1 / f fluctuation, it becomes a natural unevenness and is felt comfortable.

Although the 1 / f fluctuation is embodied in the stitch length in the above description, the stitch length is set to, for example, a minimum length of 1 and a maximum length of 3 in two stages.
It may be changed by f fluctuation.

FIG. 3 is a view showing another embodiment of the apparatus for producing a cord-like yarn of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals, and thus different portions will be mainly described.

In this embodiment, the motor 18 does not drive the entire draft part 1 but the back roller 1b.
And the apron roller 1c to drive the front roller 1a.
Is driven by another motor (not shown). Since the rotation of the motor 18 fluctuates according to the 1 / f fluctuation signal from the control unit 9, the rotation of the back roller 1b and the apron roller 1c fluctuates. However, the back roller 1b and the apron roller 1
The rotation speed c is always maintained at the same rotation ratio, and the draft (brake draft) magnification between these rollers is kept constant.

On the other hand, since the front roller 1a is driven by a motor (not shown) and always rotates at a constant speed, the thickness of the fleece 10a spun from the front roller 1a varies according to the rotation of the back roller according to the 1 / f fluctuation signal. Will change.

Here, it is preferable that the speed of the back roller does not exceed 1/10 of the speed of the front roller and the total draft does not fall below 10 times in order to prevent a draft defect.

As described above, the change in the thickness of the fleece spun from the front roller is given by the change in the supply speed of the roving yarn. It is appropriate to vary the speed in the range from 1 to 5.

The spun fleece 10a passes through the false twisting section 2 and undergoes false twisting, forming a false twisted yarn 22 in which short fibers are entangled. The false twist yarn 22 immediately enters the small knitting machine 3 and is knitted to form a string-like yarn 24.

Since the false twist yarn 22 is fed into the small knitting machine 3 at a constant speed, the stitch length of the string yarn 24 is constant. However, since the thickness of the false twisted yarn 22 has unevenness due to the 1 / f fluctuation signal, unevenness occurs in both the string-like yarn 24 and the thickness.

The control unit 9 is connected to a motor that rotates the front roller 1a, and the rotation of the front roller 1a is changed while the rotation of the back roller 1b and the apron roller 1c is constant, thereby adding unevenness to the fleece. Can also.

FIG. 4 shows a knitting structure when the number of needles of the small knitting machine 3 is one. FIG. 4 (a) shows a conventional string-like thread 14 'for comparison. FIG. 4B shows a string-like thread 24 of the present invention.
Where the speed of the front roller is constant and the speed of the back roller is changed by the 1 / f fluctuation signal. FIG.
(C) is a diagram showing a fluctuation signal corresponding to the string thread 24, wherein the horizontal axis represents the length of the string thread and the vertical axis represents the draft magnification.

When the supply speed of the roving is high, the fleece is thicker than the stitch, so that the loop is tightened and the texture is hard. On the other hand, when the supply speed of the roving is slow, the fleece is thin and the stitches are loose and soft. That is, a thick and hard part and a thin and soft part in the string-like yarn appear as a change in 1 / f fluctuation.

When a woven fabric or a knitted fabric is made by using such a string-like yarn 24, it is possible to obtain a fabric which is rich in unevenness and has a partially different texture. Since the unevenness is based on the 1 / f fluctuation, it becomes a natural unevenness and is felt comfortable.

The original false twisted yarn 22 of the string-like yarn 24
Because the stitch part is also false twisted just by false twisting the short fiber fleece, the strength of the stitch and the part where the stitch is not entangled is low, and considering the strength when fabricating or knitting, the stitch length is Has limitations. The stitch length depends on the average fiber length of the fibers used in the short fiber fleece irrespective of the spun yarn or filament used as the core. The stitch length is 2 to 6 mm if the fiber is cotton, and 2 to 15 m if worsted wool.
m is appropriate. If a change is given within this range, the stitch length of one string-like thread 14 changes based on 1 / f fluctuation, and the change changes the thickness and texture of the string-like thread 14. .

In the embodiment shown in FIG. 1, a false twisted composite yarn 12 into which the core 11 is inserted is used, but a false twist yarn without the core 11 may be used. In that case, the speed of the false twist yarn is 1 /
Since the stitch length is changed based on the fluctuation, the stitch length changes.

In the embodiment shown in FIG. 3, the core 11 can be inserted. In this case, the sheath surrounding the core 11 has thick and thin unevenness, and as a result, a string-like yarn having uneven thickness can be formed.

Also, in FIG. 3, the 1 / f fluctuation is embodied in the thickness of the false twist yarn. However, the thickness is changed, for example, to two stages in which the minimum thickness is set to 1 and the maximum thickness is set to 5. May be changed by 1 / f fluctuation.

In the embodiment shown in FIG. 1, the motor 8 drives the entire draft part 1. In the embodiment shown in FIG. 3, the motor 18 drives the back roller 1b and the apron roller 1c, and the front roller 1a is connected to another roller. The model is driven by a motor. However, these are merely examples, and a configuration in which each roller is driven by an independent motor is also possible, and the rotation speed of only one of the plurality of rollers may be changed, or the other speed may be maintained by keeping the back roller at a constant speed. It is also possible to add unevenness to the fleece by various modes such as changing two rollers at the same time or changing the speed of the back roller while keeping the apron roller and the front roller constant.

FIG. 5 is a view showing a string-shaped yarn according to another embodiment of the present invention. This is achieved by inserting the core 11 in the apparatus of FIG. 3 in the same manner as in FIG. 1, controlling the supply of fleece by the control unit 9 with an ON-OFF signal as shown in FIG. Are intermittently stopped at the same time, the fleece is intermittently supplied to the front roller to produce a false twisted composite yarn, and the false twisted composite yarn is subsequently knitted into a string-like yarn 31. As shown in FIG. 5B, the size of the stitch is constant, but the portion of only the core 11 (the thin portion of the yarn) and the portion where the fleece false-twisted to the core 11 is entangled as a sheath (the yarn) Because the thickness of the yarn changes with the thick part, the thick part 3
The string-like thread 31 in which 1a and the thin portion 31b appear alternately. The pitches Q1, Q2, Q3,... Between the thick portion 31a and the thin portion 31b also change with 1 / f fluctuation. When a woven fabric or a knitted fabric is made using such a string-like yarn, it is possible to obtain a fabric that is rich in natural unevenness and has a partially different texture. In the present invention, although unevenness due to 1 / f fluctuation is preferable, the present invention is not limited to this, and appropriate unevenness such as unevenness due to random change can be used.

[0051]

As described above, the cord-like yarn of the present invention is formed by knitting a false-twisted composite yarn having a spun yarn or filament as a core and a short fiber as a sheath, or a short yarn. It is a cord-like yarn formed by knitting a fleece false twist yarn, and changes in the stitch length and yarn thickness change the appearance and texture, and weave or knit this cord-like yarn. When fabric is made, the fabric has irregularities, it is rich in change, and
A cloth with a partially different texture can be obtained.

When the above-mentioned unevenness is formed by 1 / f fluctuation, unevenness similar to that in the natural world can be obtained, and a cloth having natural unevenness can be obtained.

[Brief description of the drawings]

FIG. 1 is a view showing a configuration of an apparatus for producing a string-like yarn made of false twisted composite yarn in a first embodiment of the present invention.

2A and 2B are diagrams showing a knitting structure of a string-like yarn knitted by a knitting machine with one needle, wherein (a) is a conventional string-like yarn, (b) is a string-like yarn manufactured by the apparatus of FIG. (c) is a diagram showing a change in the speed of the front roller.

FIG. 3 is a view showing another configuration of an apparatus for producing a cord-like yarn of the present invention.

4A and 4B are diagrams showing a knitting structure of a string-like yarn knitted by a knitting machine with one needle, where (a) is a conventional string-like yarn, (b) is a string-like yarn manufactured by the apparatus of FIG. (c) is a diagram showing a change in roving supply speed.

FIG. 5 is an example of a string-like yarn obtained by knitting a false twisted composite yarn consisting of a core-only portion and a core-covered portion,
(A) is a diagram showing ON and OFF states of fleece supply, and (b) is a diagram showing a knitting structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Draft part 1a Front roller 1b Back roller 1c Apron roller 3 Knitting machine 10 Roving yarn of short fiber 10a Fleece 11 Core 12 False twisted composite yarn 22 False twisted yarn 14, 24, 31 String-like yarn 31a Core-only portion 31b Core only The part where the fleece twisted around is entwined as a sheath

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeo Horikoshi 45 characters, Miai-cho, Okazaki-shi, Aichi F-term in Nisshinbo Industries, Ltd. Miai Plant (reference) 4L002 AB00 AB04 AC07 EA08 FA01 4L036 MA04 MA05 MA08 MA33 MA35 MA37 MA39 PA05 PA31 PA33 PA39 PA46 RA24 RA27 UA01 4L056 AA47 BA03 BA07 BC01 BD11 DA28 EB10 EC05 EC53 EC85

Claims (20)

[Claims] 1. A string-like yarn formed by knitting a yarn containing a fleece of short fibers, wherein the length and / or thickness of the stitch have irregularities. 2. The string-like yarn according to claim 1, wherein the yarn is a false twist yarn formed by adding false twist to a short fiber fleece. 3. The string-like yarn according to claim 1, wherein the yarn is a false twisted composite yarn using a spun yarn or filament as a core and a short fiber fleece as a sheath. 4. The string-like yarn according to claim 1, wherein the unevenness is unevenness due to 1 / f fluctuation. 5. A false twisted composite yarn in which a portion of only a core made of a spun yarn or a filament and a portion of a sheath made of a short fiber fleece are alternately arranged around the core are formed by knitting. A string-like thread characterized by the above. 6. The string-like yarn according to claim 5, wherein the pitch at which the core-only portion and the sheath-containing portion of the false-twisted composite yarn are alternately arranged is 1 / f fluctuation. 7. A process of supplying a roving of short fibers from a back roller of a draft part, drafting in a plurality of zones, spinning out the fleece as a fleece from a front roller, and false twisting the fleece to produce a false twisted yarn. A step of continuously supplying the produced false twisted yarn to a knitting machine and knitting in a string shape, comprising changing the speed of at least one of a plurality of rollers constituting the draft part,
A method for producing a string-like yarn, characterized by producing a string-like yarn having uneven stitch length and / or thickness. 8. A roving of short fibers is supplied from a back roller of a draft part, drafted in a plurality of zones, spun out from a front roller as a fleece, and a spun yarn or filament serving as a core is overlapped on the fleece, and the fleece is overlapped. A method of producing a false twisted composite yarn by false-twisting a core and a fleece, and a process of continuously supplying the produced false-twisted composite yarn to a knitting machine and knitting the yarn into a string shape. So,
A method of manufacturing a string-like yarn, comprising changing a speed of at least one of a plurality of rollers constituting the draft part to manufacture a string-like yarn having uneven stitch length and / or thickness. 9. The method according to claim 1, wherein the draft part includes a back roller, an apron roller, and a front roller, and the draft between the back roller and the apron roller is kept constant to change the speed of both to make the speed of the front roller constant. The method for producing a cord-like thread according to claim 7 or 8, wherein 10. The draft part is a back roller,
The method according to claim 7 or 8, comprising an apron roller and a front roller, wherein the speed of the back roller and the apron roller is constant, and the speed of the front roller is changed. 11. The draft part is a back roller,
9. An apron roller and a front roller, wherein the speed of the back roller is changed to keep the speed of the apron roller and the front roller constant.
A method for producing the string-like yarn according to the above. 12. The draft part comprises a back roller, an apron roller and a front roller, wherein the speed of the back roller is kept constant, and the speed between the apron roller and the front roller is changed while keeping the draft constant. The method for producing a cord-like yarn according to claim 7 or 8. 13. The draft part is a back roller,
9. The method according to claim 7, wherein the speed of all the rollers is changed while keeping the draft between the rollers constant, comprising an apron roller and a front roller. 14. The method according to claim 7, wherein the change in the speed is provided in accordance with 1 / f fluctuation. 15. The speed change of the front roller is given in accordance with 1 / f fluctuation in the range of 1 to 3 with the speed change of the front roller being 1 when the stitch is the densest. The method for producing a cord-like yarn according to any one of 10, 12, and 13. 16. The cord-like yarn according to claim 9, wherein the speed of the back roller is changed in a range of 1 to 5 with 1 being a normal spinning time. Production method. 17. The production of a cord-like yarn according to claim 10, wherein the speed of the front roller is set to two steps, and the alternation pitch is changed in accordance with 1 / f fluctuation. Method. 18. The production of a cord-like yarn according to claim 10, wherein the speed of the back roller is set to two steps, and the alternation pitch is changed according to 1 / f fluctuation. Method. 19. The method according to claim 8, wherein the rotation of the back roller and the apron roller is intermittently stopped at the same time, and the short fiber fleece is supplied intermittently. 20. The method according to claim 19, wherein the intermittent stop is changed in accordance with 1 / f fluctuation.