JPH03193948A - Production of self-elongating polyester filament yarn - Google Patents

Abstract

PURPOSE:To obtain the title yarn having improved self-elongation ratio, coloring properties in dyeing, fastness, soft handle, etc., readily manifesting bulkiness, by treating undrawn highly orientated polyester yarn by dry heat and then drawing and heat-treating under a specific condition. CONSTITUTION:Undrawn highly orientated polyester filament yarn having 20-90X10<-3> n double refraction is heated by dry heating under <=0.05g/g low tension at 125-145 deg.C preferably while subjecting the yarn to air interlacing treatment. Then, the resulting yarn is drawn and heat-treated at >=Tg of the undrawn highly orientated polyester yarn (preferably 100-110 deg.C) at >=1.3 draw ratio to give the objective filament yarn.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing polyester filament yarn that spontaneously stretches by performing a free dry heat treatment after a free shrinkage treatment with wet heat.

[Prior Art] Conventionally, as a method for producing spontaneously elongating polyester filament yarn, for example, as described in Japanese Patent Publication No. 63-46167, polyester filament yarn is
Next, hot stretching is carried out at a temperature above the transition point and below 110°C, and further 2
A method of obtaining a potentially spontaneously extensible polyester filament yarn by drawing at a low temperature below the next transition temperature has been proposed.

[Problems to be Solved by the Invention] However, since the yarn obtained by this method is heat-treated under conditions that do not produce a relatively high degree of crystallinity, it becomes susceptible to changes in room temperature and over time, resulting in uneven elongation. This caused deterioration in quality, such as increased likelihood of oxidation occurring and a decrease in dyeing strength after dyeing.

In addition, high-temperature dyeing causes severe embrittlement and reduces the tear strength of the knitted fabric.

In view of the above-mentioned points, the object of the present invention is to improve the above-mentioned deterioration of quality, improve color development, and soften texture by repeating hot stretching under conditions that produce relatively high crystallinity. It is an object of the present invention to provide a method for producing a polyester filament yarn that stretches spontaneously.

[Means for Solving the Problems] The method for producing spontaneously elongated polyester filament yarn of the present invention, which achieves the above-mentioned objects, has the following configuration.

That is, a polyester highly oriented undrawn yarn having a birefringence Δn in the range of 20 to 90×10′3 was heated at 0°05 g/d.
Dry heat treatment is performed in a temperature range of 125 to 145°C under the following low tension, and then 7g of the highly oriented undrawn polyester yarn
This is a method for producing a spontaneously elongated polyester filament yarn, which is characterized by carrying out a stretching heat treatment of 1.3 times or more at the above temperature.

The polyester filament yarn after the drawing heat treatment obtained by the above method is subjected to free shrinkage with moist heat after the drawing heat treatment, and then subjected to a free dry heat treatment at 150° C. or higher to become a yarn that stretches spontaneously.

Note that when performing the low tension dry heat treatment, it is preferable to perform the air entanglement treatment.

The present invention will be explained in more detail below.

The present invention, for example, has a spinning speed of 1500 to 450 Qm/m.
The birefringence Δn obtained by high-speed spinning in is 20 to 90
A highly oriented undrawn polyester yarn in the range of X10'B is used.

If the birefringence Δn is smaller than 20X10-3, the structure of the undrawn yarn is unstable, so it becomes susceptible to room temperature and changes over time, causing spontaneous elongation unevenness and unstable yarn processability. Prone. Furthermore, when dyed, the dyeing strength becomes low and stable quality cannot be supplied.

On the other hand, if Δn exceeds 90x10'', crystallization has already progressed inside the fiber, so the shrinkage rate after shrinking with boiling water is extremely low, and spontaneous elongation occurs after dry heat treatment at 150°C or higher. ability is almost lost.

Next, in the method of the present invention, the highly oriented undrawn polyester yarn described above is subjected to a dry heat treatment at a temperature of 125 to 145°C. If the temperature of the dry heat treatment is lower than 125° C., as will be described later, the shrinkage rate after free shrinkage with wet heat becomes too large, and the shrinkage during dyeing becomes too large, making it unsuitable for general clothing processing. Furthermore, if the dry heat treatment temperature exceeds 145° C., the dry heat treatment temperature is too high and the yarn becomes brittle, making it extremely difficult to process the yarn under low drawing tension. The stretching tension in this case is 0.05 g/d or less.

Although it is preferable that the stretching tension be as low as possible, sufficient consideration must be given to workability, since this increases the reduction in strength and embrittlement.

As a method for improving the deterioration of processability, it is effective to perform air entanglement treatment using, for example, an interlace nozzle during the dry heat treatment. The air entanglement process gives the filament yarn cohesiveness and roundness, and at that time, the entanglement causes shrinkage in the length direction of the yarn, so the length is absorbed and the yarn can be processed by significantly lowering the drawing tension. I can do it. In other words, the stretching ratio can be lowered. However, if the pressure of the air entanglement treatment is high or if the flow rate is large, it is easy to cause uneven spots, so it is preferable to select the conditions appropriately. Generally, a pressure of 3 kg/a1 or less is suitable for the air entanglement treatment. Further, the nozzle for the air entanglement treatment may be either for interlacing or for turbulent flow, but the nozzle for interlacing is preferable in terms of workability and cost.

Note that the stretching ratio at which the stretching tension is 0.05 g/d or less is equivalent to approximately ζ1°1 to 1.5 times.

In this way, the filament yarn subjected to the low tension dry heat treatment is subjected to a drawing heat treatment of 1.3 times or more at a temperature of 7 g or more, which is the secondary transition point. The stretching temperature is set to 7 g or more, but a temperature range of 100 to 110°C is suitable.

If the stretching temperature is lower than Tg, it is not preferable because the shrinkage rate after wet heat treatment becomes too high and the internal structure of the fiber becomes unstable.

Note that a stretching temperature as high as 130° C. or higher is not preferable because crystallization and orientation progress and the spontaneous elongation is reduced.

In this way, polyester filament yarns that have been repeatedly subjected to drawing heat treatment under special conditions potentially have the ability to spontaneously elongate.

The shrinkage rate of the filament yarn after free shrinkage in boiling water is in the range of 10 to 20%, which is comparable to ordinary polyester filament yarn. Note that the boiling water may be high-temperature water under high pressure of 98° C. or higher.

Subsequently, by subjecting the filament yarn to a free dry heat treatment at 150°C or higher, ordinary polyester filament yarns undergo further shrinkage, shrinking by 3 to 10%, but with the spontaneously elongated polyester filament yarns of the present invention, on the contrary. This shows an elongation of 1% or more. In other words, it grows spontaneously. The elongation rate varies from 5 to 5 depending on the stretching heat treatment.
The cost is as high as 10%.

An example of using this property is to improve the texture of knitted fabrics. For example, by relaxing the fabric during the finishing process, applying sufficient shrinkage during the dyeing process, and then applying dry heat treatment during the finishing process, the previously dense structure is loosened and the fabric becomes more flexible and bulky. It can give softness.

To further explain the manufacturing method of the present invention based on an example shown in the drawings, FIG. 1 is an example diagram showing the manufacturing process of a spontaneously elongated polyester filament yarn according to the present invention.

In FIG. 1, a highly oriented undrawn polyester yarn 1 is unwound from a spool, fed from a guide 2 to a feed roller 3, and subjected to dry heat treatment by a first heater 5 between it and the feed roller 6. In order to carry out the dry heat treatment under low tension, an air entanglement treatment nozzle 4 may be used for the purpose of lowering the stretching ratio. Next, feed roller 6 and delivery roller 8
After being subjected to a stretching heat treatment with a second heater 7 between the two, the cheese is rolled up into cheese by a winding roller 9.

Example 1 Highly oriented undrawn polyester yarn with a birefringence Δn of 46.2×10'3 obtained by high-speed spinning at a spinning speed of 3500 m/min, 75 denier, 36 filament yarn was heated at a temperature of 13
0℃, under tension of 1.2g (0,016g/d) (1,
Dry heat treatment was performed at a stretching ratio of 25 times, and then 110 times
A filament yarn having spontaneous elongation performance was produced by heat treatment at a draw ratio of 1.5 times at °C.

The shrinkage rate of the obtained filament yarn after free shrinkage in boiling water (98° C.) was 15.6%. 18 more
A shrinkage rate of 13.3% was obtained by performing free dry heat treatment at 0°C. That is 2°3% (15,3-13,3)
It had a spontaneous elongation rate of .

Example 2 Similarly, a highly oriented undrawn polyester yarn of 75 denier and 36 filament yarn with a birefringence index Δn of 46.2×10” obtained by high-speed spinning at a spinning speed of 3500 m/min was spun at a temperature of 140° C. and a tension of 0.7 g. Dry heat treatment was performed while performing air entanglement treatment at a compressed air pressure of 2 Kg/d at a stretching ratio of 1.5 times (stretching ratio of 1.15 times), and then heat treatment was performed at a stretching ratio of 1.5 times at 110°C to evaluate spontaneous elongation performance. A polyester filament yarn having the following properties was produced.

Similarly, the shrinkage rate of the filament yarn after free shrinking with boiling water was 18.2%, and by further subjecting it to free dry heat treatment at 180°C, a shrinkage rate of 12.5% was obtained. In other words, it had a spontaneous elongation rate of 5.7% (18°2-12.5).

Example 3 A highly oriented undrawn polyester yarn of 75 denier and 36 filament yarn with a birefringence Δn of 46.2×10'3 obtained by high-speed spinning at a spinning speed of 3500 m/min was heated at a temperature of 80 m/min.
~160°C, tension 0.7~1°8g (stretching ratio is 1.
low tension dry heat stretching at a temperature of 110
A polyester filament yarn having spontaneous elongation performance was obtained by carrying out a heat treatment for stretching 1.5 times at ℃. Figure 2 shows the relationship between dry heat treatment temperature and spontaneous elongation rate.

When the heat treatment temperature exceeds 125℃, spontaneous elongation occurs and 1
It shows a peak around 35°C, and spontaneous elongation stops when the temperature reaches 140°C or higher.

Therefore, the heat treatment temperature at which spontaneous elongation of the spontaneously elongated polyester filament yarn obtained under the above conditions occurs is 125 to 140°C.

In addition, in FIG. 2, the shrinkage rate after shrinking the filament yarn with boiling water is 81. Further, the shrinkage rate after dry heat treatment at 180°C was determined as S2, and the spontaneous elongation rate was determined as 31-32. Here, if 31-82 is positive (+), spontaneous expansion is occurring, and if it is negative (-), spontaneous expansion is not occurring.

Example 4 A highly oriented undrawn polyester yarn of 75 denier and 36 filament yarn with a birefringence Δn of 46.2×10'3 obtained by high-speed spinning at a spinning speed of 3500 m/min was heated at a temperature of 13
A low tension dry heat treatment was performed at 0° C. under a tension of 0.9 g (1°, 25 times the stretching ratio), and a stretching heat treatment was performed at a stretching ratio of 1.5 times. Figure 3 shows the relationship between the stretching heat treatment temperature and the shrinkage rate after shrinkage with boiling water.

If the drawing heat treatment temperature is 80° C. or higher, that is, the Tg temperature of the highly oriented undrawn polyester yarn, the shrinkage rate will be significantly reduced and fall within a preferable range for clothing.

Generally, if the shrinkage rate is not 20% or less, the texture becomes hard, which is not preferable, so the stretching heat treatment temperature is preferably set to Tg temperature or higher. Further, if the temperature is 120° C. or higher, orientation and crystallization will proceed and the shrinkage rate will decrease, as well as the spontaneous elongation ability will decrease, which is not preferable.

[Effects of the Invention] With the above configuration, the present invention provides the following excellent effects.

In other words, if a polyester filament yarn with spontaneous elongation is made into a knitted fabric and sufficiently shrunk by relaxing dyeing, the shrinkage rate will be 20% or less, making it a normal drawn polyester filament yarn, so the texture will be particularly hard. There isn't.

After dyeing, finishing setting is performed to stretch the polyester yarn, which has shrunk at one end, thereby loosening the binding force of the structure, making the texture soft and bulky.

In particular, when combining filament yarns with differential shrinkage,
For example, by using the yarn of the present invention in the core portion and the filament yarn having a lower shrinkage rate than the yarn of the present invention in the sheath portion, a knitted fabric with high density and a soft texture can be obtained.

Further, by using the yarn of the present invention in the core portion of the sheath portion and using filament yarn with a higher shrinkage rate than the yarn of the present invention, a texture with high density and bulk can be obtained.

Since the dry heat treatment temperature is 7 g or more, it is set at a high degree of crystallinity, and is less affected by room temperature and changes over time.

Furthermore, since the temperature is set at 125 to 140°C, the color development and brightness in dyeing are high.

By applying heat treatment while performing air entanglement treatment,
imparting cohesiveness and roundness to the filament yarn;
Since the yarn shrinks in the longitudinal direction due to entanglement, the length is absorbed and the yarn can be processed with considerably lower stretching tension. In other words, the stretching ratio can be lowered. Therefore, the effects of the present invention, such as spontaneous elongation rate, color development in dyeing, and waxiness, are improved, and the texture is soft.

[Brief explanation of drawings]

FIG. 1 is an example diagram showing the manufacturing process of a spontaneously elongated polyester filament yarn according to the present invention. Figure 2 shows
It is a graph showing the relationship between heat treatment temperature and spontaneous elongation rate. FIG. 3 is a graph showing the relationship between the stretching heat treatment temperature and the shrinkage rate after shrinkage with boiling water. 1: Polyester highly oriented undrawn yarn 2 guide 3: Feed roller 4: Air entangling nozzle 5: First heater 6: Feed roller 7: Second heater 8: Delivery roller 9: Take-up roller

Claims (2)

[Claims] (1) Highly oriented undrawn polyester yarn with a birefringence Δn in the range of 20 to 90 x 10^-^3 at 0.05 g/d
Dry heat treatment is performed in a temperature range of 125 to 145°C under the following low tension, and then the Tg of the highly oriented undrawn polyester yarn is
1. A method for producing spontaneously elongated polyester filament yarn, which comprises subjecting a stretching heat treatment to 1.3 times or more at a temperature above. (2) The method for producing spontaneously elongated polyester filament yarn according to claim 1, characterized in that a low tension dry heat treatment is performed while performing an air entanglement treatment.