JPS59125933A - Production of non-stretched polyester yarn - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyester semi-undrawn yarn,
More specifically, the present invention relates to a method for producing semi-undrawn polyester yarn suitable for high-speed drawing and simultaneous false twisting.

Conventionally, simultaneous stretching and false twisting of semi-undrawn polyester yarns has been carried out on an industrial scale. However, in Bichika,
The twisting speed of the simultaneous stretching and false twisting machine is 600 m1 minute to 1 minute.
000 m/min, and while high-speed simultaneous stretching and simultaneous false-twisting machines require more production per unit, false-twisting heaters,
The amount of yarn that passes through the rods and heating element per unit time increases. As a result, the frequency of cleaning the heater increases. Further, if production is continued without cleaning the heater, there is a problem in that fuzz will occur frequently and the quality of the false twisted yarn will deteriorate.

In order to solve this problem, various oil agents with good heat resistance have been studied. We have also investigated the types and combinations of oil agents, but have not been able to fundamentally solve the above problem. Therefore, as a result of further intensive study, the present inventors determined that the oil application rate of semi-undrawn polyester yarn was 0.6.
% or less, heater contamination is significantly reduced, leading to the present invention.

Therefore, the object of the present invention is to provide a method for producing semi-undrawn polyester yarn that significantly reduces heater contamination, particularly during high-speed drawing and simultaneous false twisting of 4080 m7 minutes or more, thereby making it possible to lengthen the heater cleaning cycle. Our goal is to provide the following. In addition, in step 1, the yarn breakage rate during stretching and simultaneous false twisting, ease of handling of semi-undrawn yarn, processed yarn fluff, and number of untwisted portions of processed yarn, etc. It is assumed that this is almost the same as in the case of thread.

That is, in the present invention, after spinning a molten polymer, an oil agent is applied to the yarn so that the oil application rate is from 0.25% to 0.55%, and the number of entanglements is 51 Vrn or less. We present a method for producing semi-undrawn polyester yarn, which is characterized by forcibly applying air pressure using an entangling device.

The polyester semi-undrawn yarn as used in the present invention is obtained by extruding molten polyester using a known extruder and winding it at a winding speed of 2500 m/min or more. Physically, the birefringence Δ is 2.0 or more, and the elongation is 200%.
It targets the following: Since we assume that such semi-undrawn yarn can be supplied for simultaneous drawing and false twisting, we require a winding speed of 2500 m/min or more.

This is because, as is well known, when supplying to simultaneous stretching and false twisting,
For yarn obtained at a winding speed of 2000 m/min or less,
This is because even if the temperature of the first heater of the draw false twisting machine is extremely lowered, fuzz, thread breakage, and untwisted parts occur frequently, making production on an industrial scale impossible.

However, it is possible to apply the technical idea of the present invention to a hook that performs normal stretching before the structure of the undrawn yarn is relaxed.

The oil agent used in the present invention is preferably an emulsion type oil containing polyether as a main component, and this oil agent is forcibly applied to the spun yarn after being measured using a roll method or a gyaponzo. As mentioned above, it is naturally desirable to first select the type of oil that has good heat resistance and maximizes other necessary properties such as antistatic properties, and then adopt the method of the present invention. . However, even if an oil agent with poor heat resistance is used, if the method of the present invention is adopted,
It exhibits a remarkable effect compared to the case otherwise.

An oil agent whose main component is polyether with good heat resistance.
Even with a semi-undrawn yarn with 8% adhesion, if it is stretched and false-twisted at a high speed of 400 m for 7 minutes or more, staining of the heater is unavoidable. Specifically, when a 150 denier yarn with an oil application rate of 0.8 inch is false-twisted at 800 m15+ for 15 days, the surface of the first heater of the drawing false-twisting machine turns into tar and becomes dirty with viscous substances, making it difficult to thread the yarn again. Even if you try, the quality of threading will deteriorate (see Figure 2). Therefore, the first heater must be cleaned to remove tar and viscous substances. Also, if you continue false twisting without cleaning the heater, fluff will easily appear.

However, when the oil adhesion rate is 0.3 inches, there are almost no problems caused by heater contamination even after processing for about 30 days.

According to the criteria for "heater stains" in Table 1 of Example 1, which will be described later, heated multifilament is also! − to L is Δ, and 1 or less is ○. Scold 5 3
5, as is clear from Example 1, even after processing for 30 days, 6
In order to achieve the following condition, the oil application rate must be 0.55% or less, and preferably 0.5% or less.

Here, the method for measuring the oil adhesion rate will be described. Approximately 5g of 7F realester semi-undrawn yarn was sampled, and the sample was heated to temperature 2.
Leave it in a room at 5℃ and 60℃ for one day to condition it. Instead of leaving it alone, the temperature is 25℃ and the humidity is 60%.
Conditioning can also be achieved by leaving it in a device (vibration absorber) in which air is circulated at a wind speed of 5 m/s for 30 minutes. The weight of this sample is W. shall be. Next, after completely removing the oil with a detergent, it is washed with water and then left in the moisture absorber for 30 minutes. Thereafter, the weight of the sample is measured, and the weight is designated as W. The oil application rate in the present invention is -W! Calculated by x1oo.

0 The means for applying the lubricant may be either a roll oil supply method or a method of forcibly applying it to the yarn after metering with a gear pump. However, it is important that the oil adhesion rate measured by the above-mentioned oil adhesion rate measurement method is 0.55% or less.

On the other hand, by lowering the oil adhesion rate, sand and heater contamination can be significantly reduced, but on the other hand, new problems arise. That is, the comparative example of Example 1 (Experiment AI, 2,
As shown in 3), as the oil application rate decreases, the convergence between filaments deteriorates, making it extremely difficult to handle the semi-undrawn polyester yarn. Specifically, when tying the tail, the single thread becomes loose and the thread knot becomes internal.

Furthermore, when pulling out end yarns from the surface layer, it is not clear how far the multifilaments are as a group, and even if you dare to pull them out, a few of all the filaments may remain on the surface layer of the semi-undrawn yarn cheese. As you release this one by one, the thread will pass under the few remaining filaments. Eventually, the release will fail and the thread will break. As described above, it becomes difficult to handle the yarn, and at the same time, even in one-high-speed drawing and simultaneous false-twisting, yarn breakage occurs frequently during false-twisting, which appears to be due to poor release, making industrialization impossible. However, as a result of further searching for effective means to solve this new problem, the inventors of the present invention solved this problem at once by using an entanglement imparting device during spinning to impart convergence to the yarn. They found that it is possible to solve this problem.

The intertwining point is the point where all the filaments are 2 or more long in length and all the filaments are bundled without gaps when visually observed by placing the semi-undrawn yarn on oil-free water. It is. At this time, all the filaments are completely separated in the unentangled portion. The number of entanglements is the number of entanglement points in 1 m of semi-undrawn yarn under no load, and the unit is number/m.

Any known device may be selected as the entangling device. Air pressure, air flow rate, etc. will be described later in Example 2.
As shown in , it may be arbitrarily selected according to the characteristics depending on the combination of the diameter and shape of the air outlet and the spinning equipment. The important point is that when the number of confounds is about 10 or more/m,
Even after simultaneous stretching and false twisting, untwisted portions remain and deteriorate the quality of the woven or knitted fabric in subsequent processes. When the processed yarn of the experimental flat 13 of Example 1 was inserted as the weft of a fabric, untwisted portions remained in the fabric, significantly degrading the quality of the fabric. However, when the number of entanglements of the semi-undrawn yarn was set to 5 or less per meter, there was almost no problem with the quality of the fabric.

It is more desirable that the number be 2 pieces/m or less.

What should be noted here is that when the oil application rate is 0.55% or less, even if the apparent number of entanglements in the upper half undrawn yarn is O pieces/1m, air is applied to the yarn using an entanglement imparting device. There was a significant difference in the ease of handling of the I-liester semi-undrawn yarn and the yarn breakage rate during false twisting between those added to (Experiment A7 of Example 1) and those without (Experiment 163 of Example 1). There is a difference. The yarn in which air was added had a yarn breakage rate of 15 times A during false twisting, showing a false twisting yarn breakage rate that was almost the same as that of the conventional semi-undrawn polyester yarn (Al in Example 1).

On the other hand, when only the oil application rate was simply lowered and no air pressure was applied to the yarn, the false twist yarn breakage rate was 67 times/l, which shows that the method of the present invention has a remarkable effect. Another evaluation method is to suction a 9 kg roll of semi-undrawn yarn using an air sucker for 30 seconds at a release speed of 4000 m/min (see Figure 1).

After that, when the air sucker pressure was set to 01.97 cm2 and the thread tension was set to Om1 minute, all the filaments of the semi-undrawn yarn (for example, flat 7 in Example 1) using the entangling device were bundled. , the semi-undrawn yarn (for example, A3 in Example 1) that did not use the entangling device was
As shown in the figure, the filament has become loose.

At the time of this release test, the ambient temperature was 25° C. and the humidity was 60°C.

However, even if the oil application rate is lowered and compressed air is forcibly applied to the yarn using an entangling device, if the oil application rate is less than 0.25%, yarn breakage during false twisting will increase. At the same time, handling of the semi-undrawn yarn becomes difficult.

The position of the oil application device may be close to the cold end blowing surface of the spinning device or close to the winding section.

However, it is more economical to install the entangling device near the cold air blowing surface because the amount of air consumed when giving the same number of entanglements can be reduced. Moreover, the interlacing imparting device may be provided first or the oil agent imparting device may be provided prior to the spun yarn.

The polyester used in the present invention mainly refers to polyethylene terephthalate, but other polyesters may be used as long as the properties of the sheep are not essentially changed. A copolymerized polyester containing an acid unit or a diol unit may also be used. Further, these polyesters may contain matting agents, colorants, heat stabilizers, flame retardants, antistatic agents, and the like.

When the polyester semi-undrawn yarn obtained by the method of the present invention is high-speed drawing and false-twisting at the same time, heater contamination is significantly reduced, and yarn breakage during false-twisting, processed yarn fuzz, and unevenness in untwisted areas are reduced compared to conventional polyester semi-undrawn yarn. It is almost the same as the case of thread. As an additional effect, the amount of white powder generated on the heating element of the circumscribed friction false twister was significantly smaller than that of the conventional semi-undrawn yarn.

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

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.61 was melted, spun using a known extruder, and wound on a winding speed of 3000 m. The spinneret temperature at this time is 280℃
The discharge amount was 93 g, the denier of the semi-undrawn yarn wound up was 279 d, and the number of filaments was 48. The confounding device was installed 1.5m directly below the visitor to Japan, and the
．． A device was installed at a distance of 52 m to forcibly apply oil using a gear I-non. The operation was carried out under the conditions, number of entanglements, and oil application rate listed in the column of manufacturing conditions in Table 1. One without an entangling device, one with an entangling device and 00 entanglements (air pressure: 0, 5 kg/
Crn2) and the number of entangled pieces (air pressure: 0.8 kg),
4 (air pressure: 1.2 kg/cm2), 5 (air pressure: 1.3 kg/1yn2), and 10 (air pressure: 2.4 to 97 cm2) semi-undrawn yarns were coated with oil at each oil application rate. It was produced in As the oil agent, a heat-resistant oil agent mainly composed of polyether was used.

The yarn tension before reaching the godet roll is 30 ~
It was 40g. In addition, the characteristics of the entangling device are as follows: air pressure i kg% shoulder 2, air flow rate 40 Nb2 min, 2k
76 Nt/min at q/6n2, 100 Nty% at 3 klil/m2, and 128 at 4kq/6n2.
Nb was 2 minutes. A friction type machine was used as the false twisting machine, and the conditions for the false twisting process were a yarn speed of 800 ml/min, a draw ratio of 1.877 times, and a first heater salt of 11ffi.
220℃ (heater length 25m), actual number of twists is 235077
It was set to be m. The finished false twisted yarn is j'5
It was 6d/48f. Table 1 shows the results of the high-speed simultaneous stretching and false twisting. As is clear from this table, according to the method of the present invention, heater contamination was extremely reduced.

Furthermore, the only yarns that are almost equivalent to the conventional semi-undrawn polyester yarn (A1) in terms of yarn breakage during false twisting, ease of yarn handling, etc. Ta.

Example 2 5-Sodium sulfozomethyl isophthalate was added to methyl terephthalate by 5 weight to produce an ethylene terephthalate copolymer. This copolymer was melt-spun and wound at a winding speed of 3500 m/min. The discharge amount is 96.49, and the denier of semi-undrawn yarn is 248d.
, the number of filaments was 48. Gear 1.5m directly below Japan? An oil agent forced application device using a pump was installed, and an entangling application device was installed 1.52 m directly below the arrival point. The oil agent was the same as that in Example 1, and the rotational speed of the Gya Pong was set so that the oil application rate was 0.4. The entangling device has an air flow rate of 16 Nt/min when the air pressure is 1 kg/2, and an air flow rate of 30 Nt/min when the air pressure is 3 kg/1yn20.
1 minute, air pressure 5 kli+/air flow rate 45 at 2
A material having characteristics of N11 minutes was used. Examining the relationship between this winding speed, the air pressure in the entanglement applying device, and the number of entanglements, it is found that 0 pieces/m s2 kg at 1 kg/6n2
/cm, 'Oi vA//rn, 3' 9/cm2 O pieces/m, 4 and 12 2i 1m/m, 5 kg/c
Ivy at 3 pieces/m in m2.

Here, when the air pressure was set to 2.5 kg/6n2, the apparent number of entanglements was 0/m. As a comparative example, a semi-undrawn yarn with an oil application rate of 0.4 was produced without using an entangling device. As a matter of course, the number of entanglements of undrawn yarn was O pieces/m. Two each of the above semi-undrawn yarns with a number of entanglements of 0/m
000 kg at a time, they were stretched and simultaneously false-twisted using a nip twister type friction false-twisting machine. For each condition yarn, use 4 spindles and 2
Processing continued for 5 days. The conditions were set such that the false twisting speed was 800 ml/min, the stretching ratio was 1.633 times, the first heater temperature was 210°C, the second heater temperature was 190°C, and the number of actual twists was 2350 times/m.

Despite running for 25 days, the first heater stain was only slightly tarred in the vicinity of the thread run area in both the original and comparative examples.

There was also no change over time in the occurrence of processed yarn fuzz. However, a significant difference was observed in that the yarn breakage during false twisting was 21 times/l in the method of the present invention, whereas it was 58 times/l in the comparative example. In the comparative examples, when the threads broke, nearly half of the cases were delayed in release or failure in release due to loose threads in one single thread or one thread in the series.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram to explain how to evaluate the yarn convergence state, and Figure 2 is a schematic diagram to explain how the first heater (shown in cross section) in the false twisting machine is contaminated. . 1... Polyester semi-undrawn yarn cheese, 2... Air sucker, 3... Loose part of filament, 4...
- Heater wall surface, 5... heated thread, 6... tar stains. Patent Applicant: Asahi Kasei Kogyo Co., Ltd. Patent Attorney: Akira Aoki, Patent Attorney: Kazuyuki Nishidate, Patent Attorney: Yoshi 1) Tsuyoshi, Patent Attorney: Akira Yamaguchi (Figure 1, Figure 2, Procedure Correction Words and Behaviors) % Formula % 1, Display of the case 1982 Patent Application No. 154505 2 Name of the invention Method for manufacturing polyester semi-undrawn yarn 3 Person making the amendment Relationship to the case Patent applicant name (003) Asahi Kasei Corporation 4 Address of the agent 8-10-5 Toranomon-chome, Minato-ku, Tokyo 105,
Date of amendment order: January 31, 1980 (shipment date) 7. The name of the invention in the statement of contents of the amendment is amended to ``Method for producing polyester semi-undrawn yarn J.''

Claims (1)

[Claims] 1. In producing semi-undrawn polyester yarn, after spinning the molten polymer, the oil application rate is 0.25% with respect to the yarn.
A method characterized by applying an oil agent so that the concentration is ~0.55%, and forcibly applying pressurized air using an entanglement applying device so that the number of entanglements becomes 5 or less/m. 2. The method for producing sf IJ ester semi-undrawn yarn according to claim 1, wherein air pressure is applied so that the number of entanglements is 2/m or less. 3. The method according to claim 1 or 2, wherein pressurized air is applied so that the number of entanglements is O pieces/m. 4. j? according to claim 1, wherein the oil is applied so that the oil application rate is 0.30% to 0.50eI6.
Method for producing IJ ester semi-undrawn yarn.