JPH0453968B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyester thick-and-thin yarn that has excellent thickness ratio and shading effect and can be easily wound even in a winding device that does not have a tension adjustment function.

In recent years, fabrics made from polyester yarn have excellent features such as wash-and-wear properties, wrinkle resistance, appropriate tension, and elasticity, so various materials have been developed for clothing, and the market is becoming more fashionable. In response to this, many differentiating materials such as thick and thin threads have been proposed.

Conventionally, polyester thick and thin yarn was published in 1977.
For example, the birefringence (Δn) is 0.5 to 10.
Supplying undrawn yarn of ^{approximately} Although it has the advantage that the difference is large, it has the disadvantage that the thick yarn portion is easily embrittled by heat processing such as false twisting or dyeing because the degree of orientation of the thick yarn portion is too low.

In addition, in order to avoid the above drawback, the birefringence (Δn) is
Thick and fine yarns using highly oriented undrawn yarns of approximately 15 to 80 x 10 ^-3 as supply yarns are also known, but they are manufactured simply by mechanically changing the stretching conditions such as changing the stretching ratio. Although the problem of thermal embrittlement during processing is eliminated with thick and thin threads, the difference in the degree of orientation between the thick and thin threads is small, so there is a drawback that the thick/thin ratio and dyeing difference are small. .

For this reason, the present applicant previously reported in Japanese Patent Application No. 58-49756 that the birefringence index (Δn) of high-speed spinning was 15×10 ^-3
The above-mentioned highly oriented polyester undrawn yarn was obtained as a supplied yarn and had a thick section in the longitudinal direction, and only the single filament constituting the thick section had a three-dimensional crimp and in its cross section. We have proposed a polyester slab yarn that has thick and thin fibers and in which the birefringence index (Δn) of the single filament is greater than the value of the birefringence index (Δn) of the supplied yarn. Although this slub yarn is a highly oriented yarn,
Although this is a new slub yarn with excellent thickening and shading effects, the thin yarn part does not have a crimp, so the elasticity of the yarn as a whole is extremely low, so it is difficult to wind the slub yarn into a package. In this case, the range of the winding rate to obtain an appropriate winding hardness is extremely narrow, for example, the winding rate is extremely narrow, and for example, the winding rate is rotated by the weight of the package cage and the friction between the winding bottom roller, and only the traverse rotation speed is periodically varied. If you use a winding device that does not have a winding tension adjustment function to wind up a square cheese shape, not only will there be variations in the hardness of the winding and so-called "crossover threads due to surface falling" on the end of the cheese, but also the traverse guide will not fit into the slit groove. In the case of the type, when the yarn becomes slack, it comes off from the guide and cannot be wound into the package cage. Therefore, in order to make it easier to wind up the slab yarn, if a crimp is applied to the fine yarn portion, both the thick yarn portion and the fine yarn portion will have crimps, and the appearance of the two will be similar, and the fine yarn portion will be crimped. It has the disadvantage that it becomes bulky and the thick and thin effect is diminished.

The present invention eliminates the drawbacks of the above-mentioned polyester thick and thin threads, and has excellent thick-to-thin ratio and shading effect.
Furthermore, the present invention provides a polyester thick-and-thin yarn that can be sufficiently wound up even in a winding device that does not have a tension adjustment function.

That is, the present invention has a high speed spinning birefringence (Δn).
The yarn has a thick part in the longitudinal direction obtained by using a highly oriented undrawn polyester yarn with a diameter of 15×10 ^-3 or more as a raw yarn, and only the single filament that makes up the thick yarn part has a three-dimensional shape. This is a polyester thick-and-thin yarn characterized by having crimps and having torque due to the yarn twisting process.

The present invention will be explained in more detail below.

First, the thick-and-thin yarn of the present invention is a yarn having a thick part in the longitudinal direction, obtained from high-speed spun highly oriented polyester undrawn yarn with a birefringence index (Δn) of 15 × 10 ^-3 or more as a raw yarn. , only the single filament constituting the thick thread portion has a three-dimensional crimp.

That is, the thick-and-thin yarn of the present invention is obtained by spinning at high speed and using highly oriented undrawn polyester yarn with a birefringence index (Δn) of 15×10 ^-3 or more as a raw yarn, and has deep dyeability as shown in FIG. It has alternating thick yarn portions a and light dyed thin yarn portions b. In this case, the birefringence of the highly oriented undrawn polyester yarn used as the source yarn is 15×10 ^-3 or more,
A birefringence of less than 15×10 ⁻³ is not preferable because the yarn becomes brittle even with a slight heat treatment. In addition, if the birefringence is too large, it will resemble a drawn yarn, so the difference in the internal structure between the thick yarn section a and the thin yarn section b will be reduced, resulting in a clear thick-to-thin ratio and light/darkness. 80
It is desirable to keep it up to about ×10 ^-3 .

As shown in FIG. 1, the thick-and-thin yarn of the present invention has a structure in which only the single filaments constituting the thick yarn portion a have a three-dimensional crimp. In this way, only the single filaments that make up the thick yarn section a have crimps, so the bending rigidity is lower than in the case where there is no crimp. The bending stiffness is not excessive, and even if the thick-to-thin ratio is large, there is no discomfort due to the difference in bending stiffness between the thick thread portion a and the thin thread portion b.

Further, the thick-and-thin yarn of the present invention has torque due to the false twisting process. In other words, the thick-and-thin yarn of the present invention has torque not only in the thick yarn portion but also in the fine yarn portion, but in this case, if the torque in the fine yarn portion is small, it becomes difficult to wind it into a package, and vice versa. Too much torque is not preferable because not only may the cheese end face fall off due to the torque, but also the thin thread portions will become bulky due to crimping, making it unclear to distinguish them from the thick thread portions. . Therefore, the torque T (t/m) of the yarn is 100/√≦T≦ where the fineness (denier) of the yarn is D.
1000/√ Preferably 200/√≦T≦800/√
It is desirable that Here is the thread torque T
(t/m) is calculated by applying a load of 2 mg/d to the midpoint C of a sample with a length of 60 cm at room temperature, folding it in two to make a length of 30 cm, and with the load suspended, the C end is the free end, and the other It is expressed as the number of twists (t/m) when the end is fixed and rotated freely by the winding force of the yarn.

As described above, the thick-and-thin yarn of the present invention has a torque due to the false twisting process, so even if the thin yarn portion does not have a crimp, it has an elastic force due to the twisting force, and as described above. Even if the cheese is rolled up into a square cheese shape using a winding device that does not have a winding tension adjustment function, only the edges of the cheese may become hard.
There is no possibility that the cheese will be rolled up in a bad manner due to high edges, that there will be cross threads, or that it will not be possible to roll the cheese due to the traverse guide coming off.

In addition, in the thick-and-thin yarn of the present invention, the cross section of only the single filament constituting the thick yarn portion a may have a thick and thin cross section, and in such a case, the thick yarn portion a may have a thin yarn. Compared to part b, the color tone after dyeing has a difference in shading, resulting in a deep dark color, which allows the shading effect of thick thread part a and thin thread part b to be clearly defined, and is highly twisted. Even in the case where the single filaments in the thick yarn section a do not have a close-packed structure, the thin yarn section b has a structure in which the longitudinal thickness of the single filaments in the thin yarn section b is small. Because of the uniformity, each single filament has a close-packed structure, which has the advantage that the thick and thin effect of the thick yarn portion a and the thin yarn portion b becomes clearer. Further, in the thick-and-thin yarn of the present invention, the birefringence index (Δn) of the single filament constituting the thick yarn portion can be made greater than the value of the birefringence index (Δn) of the supplied raw yarn. Since the invention uses highly oriented polyester undrawn yarn with a birefringence index (Δn) of 15×10 ^-3 or more as the supplied yarn, it can be used even in thick yarn portions where the birefringence index (Δn) is relatively low. Birefringence (Δn) is 15×10 ^-3
Therefore, the thick-and-thin yarn of the present invention does not deteriorate due to heat processing such as false twisting or dyeing, which is the case with conventional thick and thin yarns.

As a method for producing the thick-and-thin yarn of the present invention, for example, the birefringence (Δn) is 15×10 ^-3
In order to impart only torque without substantially imparting bulk to the fine filament portion of the thick and fine yarn obtained from the above highly oriented undrawn polyester yarn, without heating it above the secondary transition temperature. , a method of false twisting under low processing tension. In order to obtain the thick and fine yarn to be supplied to the false twisting process, the method is to simply draw the yarn at a draw ratio equal to or lower than the natural draw ratio, or while drawing the undrawn yarn, water or an aqueous liquid is intermittently applied to the yarn in the drawing area. It can be obtained by a method such as attaching the yarn, subjecting it to a drawing heat treatment, and then subjecting it to a relaxation heat treatment while feeding the yarn in excess of the take-up speed.

Below, the birefringence index (Δn) after high-speed spinning is 15×
A method for producing the thick-and-thin yarn of the present invention as a thick and thin yarn by intermittently applying water or an aqueous liquid to an undrawn highly oriented polyester yarn of 10 ^-3 or more, carrying out a stretching heat treatment and then a relaxing heat treatment will be described.

First, while drawing a highly oriented undrawn polyester yarn with a birefringence index (Δn) of 15×10 ^-3 or more, water or an aqueous liquid is intermittently attached to the yarn in the drawing area and a drawing heat treatment is performed. Alternatively, the portion to which the aqueous liquid is attached has no or very small heat treatment effect during the stretching heat treatment, and becomes a cold stretched portion with low orientation, high shrinkage, low heat shrinkage stress, and a small amount of stretching.

On the other hand, a portion to which water or an aqueous liquid is not attached becomes a hot-stretched portion having a high orientation, low shrinkage, high heat shrinkage stress, and a large amount of stretching, where the heat treatment effect is sufficiently imparted. Then, when the yarn treated as described above, in which cold-drawn parts and hot-drawn parts coexist in the longitudinal direction, is fed in excess of the take-up speed and subjected to relaxation heat treatment, only the single filament in the cold-drawn part becomes thicker. At the same time, the yarn becomes a yarn having a three-dimensional crimp. In this case, it is effective to make the single filament thicker by shrinking the cold drawing part as freely as possible, but especially during the relaxation heat treatment, the yarn is supplied downward in excess of the take-up speed. When the yarn is relaxed and heat-treated against its own weight, the cold-stretched part contracts in an almost free state without receiving any drag other than the yarn's own weight, making it appear as if it were an undrawn highly oriented polyester spun at high speed. The yarn can be contracted as if it were freely contracted, and as a result, the single filament constituting the yarn can have a three-dimensional crimp and a thick yarn section with a thick and thin cross section. can. On the other hand, by applying hot stretching conditions and relaxation heat treatment conditions such that the hot-stretched portion hardly shrinks during the relaxation heat treatment, the single filament constituting the yarn does not exhibit a crimp form, and its cross section becomes thick and thin. The result is a thin filament portion that does not have any fibers.

In this relaxation heat treatment, the birefringence index (Δn) of the thick yarn portion decreases, so if the draw ratio at the time of stretching prior to the relaxation heat treatment is set to a draw ratio exceeding the natural draw ratio of the supplied yarn, even after processing, the The yarn can have a birefringence index (Δn) higher than that of the raw yarn,
Effective in preventing heat deterioration of processed yarn.

When the above-mentioned thick and thin yarn is subjected to false twisting without being heated above the secondary transition temperature of the yarn and under low processing tension, the polyester fiber has some thermoplasticity even at room temperature. This is combined with the false twisting process being carried out under a low processing tension so that the crimp in the bulky part does not disappear, making it possible to impart only torque without substantially imparting bulkiness to the fine yarn part. .

Note that if the above-mentioned false twisting process is performed subsequent to the relaxation heat treatment, the heat received during the relaxation heat treatment during the false twisting process will remain only in the core of the yarn, and the thermoplasticity of the core of the yarn will be transferred to the outside of the yarn. It is more effective in imparting only torque to the fine yarn portion without imparting substantial bulkiness to the thin filament portion through false twisting.

The twisting means in the above-mentioned false twisting process may be of any type as long as it can be twisted with a low processing tension, such as an air vortex nozzle or a twisting means using ballooning generated in a hollow cylindrical tube rotating at high speed. Can be mentioned.

FIG. 2 is a process schematic diagram showing an example of the manufacturing process of the thick-and-thin yarn of the present invention. 2 and a second roller rotating at a higher speed than the first roller 2.
The yarn is supplied to the stretching area between the rollers 3 and passes through the yarn swinging width guide 5 which is directly connected to the fulcrum 4 to which the swinging motion of the electromagnetic solenoid 15 is transmitted, and reaches the fulcrum guide 6 which is the fulcrum on which the yarn swings. . This thread swing width guide 5
A device for applying water or an aqueous liquid is installed between the fulcrum guide 6 and the fulcrum guide 6, and 7 is a relatively small diameter rotating roller for applying water, 8 is a water tank, and 9 is water or an aqueous liquid. Here, the thread F is moved from the position where it is in contact with the water application rotating roller 7 with the fulcrum guide 6 as a fulcrum by the swinging action of an electromagnetic solenoid using a random pulse oscillator as a signal source.
Swing between the two points to the farthest position. At this time, the portion where the yarn comes into contact with the water application rotary roller 7 becomes the water application portion, and the portion where it does not come into contact becomes the non-water application portion. The length of the wetted part and the non-watered part and the ratio of the two lengths can be changed freely by using a microcomputer, a film type photo sensor, etc. together with a random pulse generation unit, and the length of the wetted part and the non-watered part can be changed freely along the longitudinal direction of the yarn. It is possible to form a yarn having a mixture of wetted portions and non-wetted portions at a desired and appropriate length. The yarn F passes through the fulcrum guide 6 and enters the first heater 10, where it is subjected to heat treatment while being drawn.

Next, the yarn F passes through the second roller 3 and the third roller rotating at a lower speed than the second roller 3.
The yarn is excessively supplied downward by the roller 12 and then pulled upward while entering the second heater 11 and being contracted against the weight of the yarn to form the thick yarn section a shown in FIG. Ru.

Next, the yarn F passes through the third roller 12 and is false twisted under low processing tension without heating by the twisting means 14 provided between the third roller 12 and the fourth roller 13. Only the torque due to the false twisting process is applied to the yarn portion, which exits the fourth roller 13 and is wound into the package cage 16 by the winding roller 15.

The polyester in the present invention is a polymer having an ester bond in its molecular chain, and includes homopolymers typified by polyethylene terephthalate, copolymers or blend polymers thereof, and the like.

As described above, in the thick-and-thin yarn of the present invention, only the single filaments constituting the thick yarn portion have three-dimensional crimps, so the bending rigidity is lower than that without crimps. The bending rigidity does not become excessive even in the thick yarn section, so it has an excellent thick and thin effect.Furthermore, the thin yarn section has no crimp and has elasticity with torque, so it has a winding tension adjustment function. Even if the cheese is rolled up into a square cheese shape using a winding device that does not have a winding device, only the edges of the cheese will become extremely hard, the ears will be too high and the shape of the cheese will be poor, and threads will occur and the traverse guide will come off. It is possible to smoothly roll up the paper without becoming unable to roll it up.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example Highly oriented polyester undrawn yarn 230d/48f (natural drawing ratio 1.533) with a birefringence index (Δn) of 45×10 ^-3 obtained by high-speed spinning of polyethylene terephthalate was passed to the fourth roller in the process shown in FIG. is first supplied to the first roller as a passively rotating roller guide, and the surface speed of the first roller is 46.8 m/min.
Surface speed of second roller 80m/min (stretching ratio
1.710) while using a microcomputer and a random pulse generation unit to determine the watering time.
After applying water intermittently by repeating 0.04 sec and 0.1 sec non-watering time, heat-treated at 250℃ using the first heater (non-contact heater with lid, heater length 0.6 m), passed through the second roller, The second heater (contact heater with lid, heater length 0.9 m) is supplied downward at an excess supply rate of 16.3% by the second roller and the third roller with a surface speed of 68.8 m/min, and then pulled upward. Relaxation heat treatment at a temperature of 220℃, followed by compressed air supply pressure to the air nozzle
2.0Kg/cm ² , air flow rate 25l/min, false twisting without heating, winding overfeed rate 2.93
%, it was rolled at a twill angle of 11.5°. In this case, the false twisting tension is as low as 0.5 to 1.0 g, and the threads can be clearly observed with the naked eye as they pass through the nozzle, and can be rolled up smoothly, resulting in a square cheese with a good rolled shape. Ta. The torque of the obtained yarn was 40 (t/m) as measured by the above-mentioned measuring method.

The thus obtained thick-and-thin yarn of the present invention has a fineness of 270 d in the thick yarn portion and 156 d in the fine yarn portion, and has a thick-to-thin ratio exceeding a draw ratio of 1.71. The single filament constituting the strip had a three-dimensional crimp and had a thick and thin cross section. On the other hand, in the thin filament portion, no crimp was observed in the constituent single filament, and its cross section did not have thick or thin sections. In addition, the birefringence (Δn) of this thick-and-thin yarn was measured to be 50 x 10 ^-3 in the thick yarn section and 160 x 10 ^-3 in the thin yarn section, both of which exceed that of the supplied raw yarn. It was hot. This thick-and-thin yarn was woven into a plain weave at a warp density of 72/inch and a weft density of 66/inch, and then dyed with a disperse dye at 130°C for 60 minutes. The fabric has almost no embrittlement, is dyed in a deep dark color, has an excellent shading effect, and has a spun-like surface effect with no rough stiffness in the thick threads. Ta.

Comparative Example Using the same sample as in the example, processing was carried out under the same processing conditions as in the example except that the supply of compressed air to the air nozzle was stopped. When a comparative processed yarn was produced and wound into a package, both cheese and When winding up the edge, the winding tension became extremely high, causing the roll to roll up into a gourd-like package, resulting in poor rotation and not being able to be rolled up into a package weighing more than 500 g.

In addition, using the same sample as in the example, a comparative processed yarn was produced under the same processing conditions as in the example except that the pressure of compressed air supplied to the air nozzle was 7.2 kg/cm ² , and when it was wound into a package, Although the winding tension was stable and the winding appearance was good, the torque of the obtained yarn was as high as 150, and crimp crimp was also observed in the thin yarn section, and the thin yarn effect was lacking. It was warm.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of the thick-and-thin yarn of the present invention, and FIG. 2 is a schematic process diagram showing an example of the manufacturing process of the thick-and-thin yarn of the present invention. a... Thick thread section, b... Thin thread section, 1... Spool, 2... First roller, 3... Second roller, 4... Fulcrum, 5... Thread swing width guide, 6... ...Fulcrum guide, 7...Rotating roller, 8...Water tank, 9
...Water or aqueous liquid, 10...First heater, 1
1...Second heater, 12...Third roller, 1
3... Fourth roller, 14... Twisting means, 15...
Winding roller, 16...package, F...yarn.

Claims (1)

[Scope of Claims] 1. A yarn having a thick part in the longitudinal direction obtained from a highly oriented undrawn polyester yarn having a birefringence index (Δn) of 15×10 ^-3 or more spun at high speed as a raw yarn,
A polyester thick-and-thin yarn characterized in that only the single filament constituting the thick yarn portion has a three-dimensional crimp, and the yarn has a torque due to false twisting. 2. The polyester thick-and-thin yarn according to claim 1, wherein the torque T (t/m) is 100/√≦T≦1000/√ (D is the fineness (denier) of the yarn). However, the torque T is determined by applying a load of 2 mg/d to the midpoint C of a 60 cm long sample at room temperature, folding it in half to make a length of 30 cm, and suspending the load.
It is expressed as the number of twists (t/m) when one end is a free end and the other end is a fixed end and is freely rotated by the winding force of the yarn.