JPS59187618A - Polyester fiber and its production - Google Patents

Abstract

PURPOSE:A polyester composed of, e.g., polyethylene terephthalate, is melt-extruded, taken up with the first taking-up roller which is running at a high speed, then drawn between the first roller and the second one which is running faster than the first, and wound up to give the titled fiber with high tenacity, elongation and good touch. CONSTITUTION:A polyester composed of more than 90mol% of polyethylene terephthalate units is extruded through the nozzle 1, solidified by passing through the cooling chimney 3 and the resultant yarn 2 is taken up with the first taking-up roller 5 which is rotating at 5,000m/min or higher peripheral speed. Then, the drawing is effected by taking up the resultant yarn with the second roller 6 which has a peripheral speed ratio of 1.01-1.30 to the first roller, as the yarn is heated over its glass transition point by the heater 10 between the two rollers. Finally the yarn is wound up around the winder 9 to give the objective yarn of 3.5g/d or higher tenacity, 60% or less elongation, 50-100g/d Young's modulus, 4-10% boiling water shrinkage, 5-15% dry heat shrinkage, 0.3-0.8g/d thermal stress at 100 deg.C and lower than 100 deg.C peak of the stress.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyester fiber suitable for woven or knitted fabrics having moderate strength and elongation and excellent hand, and a method for producing the same, and furthermore provides a production method with excellent process stability. That is.

Conventionally, polyester fibers have been industrially produced in large quantities and widely used for various purposes because of their excellent fiber properties. This polyester fiber is about '+500
m Spinning speed of 7 minutes or less - C Spun to make yarn yarn 1 This was drawn and heat-treated in a separate process and used as yarn for woven and knitted fabrics to yield 9'''C. However, 1-1 In recent years, polyester As a streamlined process for producing fibers at a lower cost, by increasing the spinning speed to 5,000 m/min or higher, it has become possible to produce practically usable polyester fibers all at once without having to wind them up as yarn. Furthermore, according to this method, the polyester fiber obtained by the conventional method has the disadvantage that when it is made into yarn for woven or knitted fabrics, its texture becomes harder than other materials due to its high Young's modulus. However, it became clear that this point could be improved to a considerable degree.
,000 m/min or more, the polyester fiber obtained has a boiling water shrinkage rate (hereinafter abbreviated as Wsr) of 3 or less and a dry heat shrinkage rate (hereinafter abbreviated as Dsr) of 4S or less, which is very small and is suitable for one woven or knitted fabric. It has the disadvantage that wrinkles cannot be corrected due to insufficient shrinkage during the processing process, resulting in a paper-like texture, so it is used only in very limited fields.

3- On the other hand, polyester is spun through a nozzle, cooled and solidified, and then stretched using a difference in circumferential speed between at least two pairs of roller groups. A so-called spindle method is known. For example, JP-A-57-]-6913 and JP-A-57-
The method proposed in Japanese Patent No. 16914 has been shown to increase the heat shrinkage rate and improve the above-mentioned drawbacks by subjecting the traveling yarn to tension treatment without heating during the ultra-high-speed spinning process, but In the tension treatment, yarn breakage and fluffing occur, making it difficult to establish a process for producing the desired polyester fiber. Furthermore, for sufficient shrinkage in the processing process, which is important for improved polyester fiber properties for woven and knitted fabrics as seen in this method, the peak temperature of heat shrinkage stress is 1.
A temperature of less than 00°C is insufficient; the stress at 100°C in the stress curve is important, and it is necessary to control the stress within a certain range. Again, 10,000,
Attempts have also been made to carry out such a spin-drawing method while drawing the yarn under heat treatment, and it is a fact that by this method, a yarn with the same size as a drawn yarn can be obtained. However, no matter which spindle type is used, the take-up speed is 5
．． (l If OOm exceeds 10, the yarns on the first take-up roller will be disturbed, for example, it will cause yarn breakage due to the proximity of adjacent yarns. Therefore, considering the operability, it is desirable to install some kind of yarn disorder prevention mechanism. .

As described above, although the spin-drawing method for polyester fibers has long been attracting attention as a technology that dramatically streamlines the spinning process, it is still only used for some industrial material applications due to problems with the yarn's physical properties and manufacturing process. The actual situation is that it is limited to.

The present inventors, taking into account the above-mentioned problems, have conducted intensive studies to find the physical properties of polyester fiber suitable for woven and knitted fabrics having appropriate strength and elongation and excellent texture in order to produce it at a lower cost. This invention has been achieved. That is, 5 the present invention is a fiber composed of polyethylene terephthalate units of 90 or more molar units (polyester fiber having an additive of less than 10 molar unit), whose strength is 3.5 r/d or more, elongation is 60% or less, and Young's modulus is 60% or less. 50~100f/d
, Wsr 45-10%, Dsr 5-15%, and a thermal stress of 0.3-Q at 100°C, and a peak temperature of 100°C or less at 8 r/d, making this polyester fiber more As an efficient manufacturing method, the spun polyester yarn is cooled and assimilated, then taken up by a first take-off roller rotating at a circumferential speed of at least 5,000 m/min, and then It is rolled up after being stretched under heat between second take-up rollers rotating at a speed ratio of 1.01 to 1.30. Furthermore, as an optimal method, when the polyester fiber is stretched by a difference in circumferential speed between two take-up rollers, it is necessary to
A yarn disorder prevention mechanism is later provided.

To further explain the present invention, it is necessary that the polyester used in the two methods does not contain more than 10 moles of a modifier or copolymer and has polyethylene terephthalate units of more than 90 moles.

The polyester fiber having excellent texture as used in the present invention is
Its physical properties include strength of 3.5 r/d or more and elongation of 6.
It is necessary that it is 0% or less, and it is particularly desirable that the 6-stretch IJj is between 20 and 50%.

When the elongation exceeds 60%, the fiber performance is unstable and cannot sufficiently withstand processing for woven or knitted fabrics. Also, Young's modulus is 50-100? /d, and if it is higher than OC1/d, it approaches that of ordinary polyester fibers, but the hardness increases and the excellent texture is lost.
If it is less than r/d, it will not have the stiffness required for a woven or knitted fabric and will not be of practical use. Furthermore, the shrinkage rate is W s r from 4 to] 0
It is important that the DSR is preferably 5 to 15%, preferably 6 to 10, and DSR is 5 to 15%, preferably 6 to 10. That is, W
If the sr is less than 4% and the Dsr is less than 5%, sufficient shrinkage will not occur during the processing of the woven or knitted material, so wrinkles cannot be corrected, and the texture may become paper-like. However, if the shrinkage rate is controlled within the above-mentioned range, these defects will not only be corrected, but the density of the woven fabric will be higher and the hand will be exceptionally good. The stress at 100°C is 0.3 to Q, 8
By controlling y/d so that the peak temperature in the curve is 100 DEG C. or less, the heat setting property of the woven or knitted fabric during thermal processing becomes good.

What is particularly important in the present invention is to provide a method for producing polyester fibers for woven or knitted fabrics having an excellent texture such as that of a foreskin in a smoother and more efficient manner. In other words, various studies were carried out in the high-speed spinning region of 5.000 mA') and above, and it was found that at speeds where the thinning phenomenon during the cooling and solidification process of polyester yarn was not clearly observed, In the stretching process after the take-off roller, necking points no longer occur.

Brittention as a means for fixing the necking point, which was 8 degrees in the conventional spindle type.

It became clear that hot bottles, heated colas, etc. were unnecessary. As a result, in the drawing process after the first take-up roller, it is only important to be able to smoothly stretch the yarn, and by using the same roller as a heating roller, heating is no longer necessary at the second take-off port. The result was that there was no. Furthermore, no unstretched spots, which are often a problem in the one-spindle one-way process, were observed in the above-mentioned system. However'
As a result, the spin 8-draw device has become very simple and compact,
Energy and energy costs have also fallen significantly. In the present invention, (10) the circumferential speed of the first take-up roller is 5,000 V or more, and the circumferential speed of the second take-up roller is set at a ratio of 1.01 to 1.01.
By setting it to 1.30, it can be used immediately for orinaimono! This polyester fiber with a soft texture can quickly obtain VC.○
Here, if the circumferential speed ratio exceeds 1.30, the stretching condition will be poor and single yarn breaks 1, fuzz, etc. will occur frequently, which is not desirable. It is important to ensure that the stretching is carried out smoothly between the first and second take-up rollers.
The glass transition point of polyester fiber (approximately 70'
C) There is further heating. The heating method is the first
Even if it is heated with the take-up roller, it will still stay in the first place. Between the second take-up rollers, a simple heating device such as a Sunano or an air dicote nozzle is used. : Can be used. The temperature at which the yarn is heated may be 70° C. or higher, but it is preferably 150° C. or lower in terms of yarn properties, texture, or energy cost.

Next, the present invention will be explained with reference to accompanying drawings.

-〇- The apparatus shown in FIG. 1 is a schematic diagram of an example of a spin draw apparatus used in the present invention. The polyester yarn 2 spun from the nozzle 1 is cooled and solidified while passing through the cooling tube 3, and after being completely applied with a prescribed amount of oil by the oil supply device 4, it is taken off by the first take-up roller 5. The pulling force is the polyester yarn.

[first take-off roller size or simple heating device], the temperature is raised from OK to a temperature above its glass transition point, and the circumferential speed of the first take-off roller is The yarn is stretched by a second take-up roller 6 rotating at a high speed, passed through a traversing fixed guide 8, and wound onto a bobbin by winders 1 and 7. In order to maintain the same properties, the vine lace device M7 may be installed at any location. Here, a simple heating device [10
, it is not necessary to provide a heating device to the first take-up roller 5, and if the heating device W is attached to the first take-up roller (the first take-up roller itself may be heated). ) A simple heating device becomes unnecessary.Furthermore, in a preferred embodiment of the present invention, a yarn disturbance prevention mechanism shown as 11 is provided near the first take-up roller at the front ``!'', riha (and) rear. As such a mechanism, it is preferable to have a structure in which, for example, each yarn is separated by a groove-shaped presser so that there is no opportunity for physical contact with adjacent yarns. , just a bar (
It can be seen that even with a presser using a rod-shaped object, the operability is better than when the yarn disorder prevention mechanism is not attached. In other words, the take-up speed is 5. It was observed that when the OOOm exceeds 7 minutes, the adjacent threads sometimes pull together, which was almost non-existent due to long-term operation, and as a result, the threads break in that area and become fluffy. For example, a comparison was made of the time until the first yarn breakage was observed after the start of operation for a spin draw of eight yarns at a take-up speed of 5,000 m/min. If a holding device with a concave-convex shape (shaped like a plurality of solo bread balls connected together) is installed as a disturbance prevention mechanism immediately after the first take-up roller, a holding device with a simple bar as a disturbance prevention mechanism will be used. When implementing the present invention, it is desirable to install a yarn disorder prevention mechanism, as in the case of the 47th hour (1) and the 36th hour (if nothing is provided).

In addition to this method, a take-up roller, especially a first take-up roller, which has a mirror-finished part, followed by a rough-finished part (matte finished) in the direction of yarn progress, and especially a take-up row in which the finished part of the former is more than half of the finished part; It is more preferable to use this method because it reduces the floating phenomenon of the yarn on the roller surface. Furthermore, according to the experiments of the present invention, the take-up speed is 5,000~
Up to about 5,500 m/min, the free roller in the take-up roller (Fig. 1 17)5. Although the smaller roller (6) can be implemented with oil bearings, it has been found that at higher take-up speeds it is necessary to switch to air bearings.

FIG. 2 shows the relationship between Wsr, which is one of the physical property values of the polyester fiber of the present invention, and the draw ratio. As is clear from the figure, it is possible to select a preferable Wsr value depending on the stretching ratio expressed by the peripheral speed ratio of the first take-off roller and the second take-off roller. FIG. 3 is a curve of thermal (shrinkage) stress, which is one of the physical properties of the polyester fiber of the present invention, and 1 to 7 in the figure indicate tests Al to 7.

The method for measuring physical property values used in the present invention will be described below.

Strength and elongation and Young's modulus: using an Instron tensile tester, sample length 20crn, tensile speed fit 20cm1
The measurements were taken under the conditions of 34 r/d and an initial load of 34 r/d.

The Young's modulus is the value obtained by reading the load (ii'/d) at 5% elongation from the SS curve obtained by the method described above and multiplying it by 20.

Boiling water shrinkage rate (Wsr): Skein machine K1 with circumference of 1111
After winding 0 times, adding Q and lr/d, and measuring the original length of 40.

Treated in boiling water at 100°C for 10 minutes, and after drying 0.14
The sample length 11 is measured by applying a weight of /d, and the shrinkage rate is expressed by the following formula.

Dry heat shrinkage rate (1) sr): Calculate using the same formula as Wsr after preparing a sample in the same manner as Wsr and treating it in a constant temperature dryer at 200°C for 10 minutes.

Thermal stress curve: After adjusting by applying an initial load of tenier X0.1 of the yarn to be measured using a thermal stress measuring instrument manufactured by Kanebo Engineering, a 20α sample was looped to a length of 10 m, and the heating rate was 80 °C/min. The temperature is increased at The temperature at which the stress peaks from this curve is defined as the peak temperature.

The present invention will be explained below with reference to Examples.

Example 1 The device M shown in FIG. Polyethylene terephthalate was melt-spun at a spinning temperature of 295°C using a spindle (equipped with a concave-convex presser as a prevention mechanism) with a spindle hole diameter of 0.2 wn *36 holes, a discharge rate of 459/fk, and an oil agent was applied after cooling and assimilation. The first take-up roller rotates at a circumferential speed of 5,000 m10 (6/10 has a mirror finish in the yarn traveling direction, 4
/4o is taken over by a matte finish (14-processed fin/ζ roller), and then the circumferential speed ratio is 1. O1
Stretched between second take-up rollers rotating at ~1.35,
The winding speed was set lower than the circumferential speed of the second take-up roller, and the winding machine was used to wind the material onto a bobbin. At this time, the temperature of the first take-up roller was set at 170°C. Table 1 shows the quality results at various stretching ratios and [-/x] by changing the peripheral speed of the second take-up roller under the above-mentioned conditions. Test plates 2 to 6 shown in Table 1 have dyeing and quality that satisfy the present invention, and test plates A] and 7 show the results of comparative examples -Cβ
Ru.

Example 2 A polyester yarn spun by the same method as in Example 1 was taken up by a first take-up roller, and then stretched between second take-up rollers rotating at a peripheral speed ratio of 1.10 during VC. , various changes in the temperature setting of the first take-up roller] 2/ζ. The yarn quality obtained under each temperature setting is shown in Table 1. When the temperature of the take-up roller was kept at room temperature (test flat 8), fluffing occurred frequently during stretching, and the number of threads wound around the roller increased.

15-

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of the present invention, in which 5 is a first take-up roller, 6 is a second take-up roller, and 11 is a lint disturbance prevention mechanism. FIG. 2 shows the correspondence between Wsr and stretching ratio, and FIG. 3 shows the thermal stress curve. Patent Applicant Rira Co., Ltd. Representative Patent Attorney Ken Honda 17-fo ni 10 120 (30 Companding Le No. 3 Zuken O18 ≧ Yaminakazuki O, Da 70
・31A Okasu Inn (I., D.

Claims (1)

[Scope of Claims] 1) A fiber whose molar ratio is 90 or more composed of polyethylene terephthalate units, having a strength of 3.5 p/d or more, an elongation of 60% or less, a Young's modulus of 50 to 1009/d, and boiling water shrinkage. rate (Wsr) 4-10%, dry heat shrinkage rate (Dsr)
5 to 15%, and the thermal stress at 100°C is 0.3 to 0.8 'li'/d, and the peak temperature is 1.
A polyester fiber characterized by having a temperature of 00°C or less. 2) Spun polyester having 90 moles or more of polyethylene terephthalate units through a nozzle, and after cooling and assimilation, the polyester yarn is pulled by a first take-up roller rotating at a circumferential speed of 5,000 m7 or more. Then, the circumferential speed ratio to the first take-up roller is 1.01 to 1.3.
1. After stretching the film while heating it to a temperature above the glass transition point between the film and the second take-up roller rotating at zero temperature, the film is wound up.
- The fiber is composed of 90 moles or more of polyethylene terephthalate units, has a strength of 3.5 f/d or more, an elongation of 60% or less, a Young's modulus of 50 to 1007/d, and a boiling water shrinkage rate (Wsr). 4-10%1 Dry heat yield rate (Ds
r) 5 to 15%, and the thermal stress at 100°C is 0.3 to 0. A method for producing a polyester fiber whose peak temperature is 100° C. or less at By, "a." 3) In the preceding section, the production method is characterized in that a yarn disorder prevention mechanism is provided before or (and) after the first take-up roller. Method.