JPS6065131A - Production of polyester false twisted 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 false-twisted yarn, and more specifically, to produce a false-twisted yarn having sufficient dyeability by subjecting polyester fibers wound at high speed to high-speed false twisting. Relating to a method of manufacturing.

Conventionally, as a manufacturing method for false twisted yarn with easy dyeability, 400
(Japanese Patent Application Laid-Open No. 58-1979-1 discloses a method in which heat treatment and false twisting are continuously performed on high-speed spun fibers wound at a speed of 1 m/min or more.
No. 13728.

However, this method requires relatively long heat treatment, and although it is possible to produce the desired easily dyed yarn, high-speed false twisting of, for example, 500 m/min or more is required for high productivity. If this method were to be applied, the heat treatment heater would have to be long, which is not desirable in practice.

An object of the present invention is to provide a method for obtaining false-twisted yarn having sufficient dyeability during high-speed false-twisting.

As a result of intensive research to solve the above-mentioned problems, the present inventors have found that even under high-speed false twisting conditions intended for high productivity, by using raw yarn spun under specific spinning conditions, a practical length can be achieved. We have discovered that false twisted yarn with sufficient dyeability can be stably produced using a heat treatment heater.

The method for producing polyester false-twisted yarn according to the present invention is performed when high-speed false-twisting is performed, and when the winding speed during spinning is V (m/min) and the average birefringence is Δn as the raw yarn to be supplied. , (δΔn/δV)≦0, and further heat treatment and false twisting are performed continuously.

In general, for polyester fibers, especially polyethylene terephthalate fibers, the higher the winding speed (hereinafter referred to as ■) during spinning, the higher the average birefringence (hereinafter referred to as Δn) of the resulting fibers. It was thought that the internal structure of the first fiber would be more highly oriented. When false-twisting polyester fibers wound at high speed, as proposed in JP-A No. 49-61451, the stretching ratio during false-twisting should be determined by considering the relationship between ■ and Δn. The value of Δn was used as the main guideline to determine the value of Δn.

However, in recent years, it has been found that Δn of polyester fibers wound at high speed behaves as follows depending on ■. That is, when winding polyester fibers, if the winding speed V is gradually increased from the low speed side, the value of Δn of the obtained fiber reaches a maximum at a certain winding speed Vp, as illustrated in FIG. value, and the winding speed is vp
If it is made larger, Δn decreases (V) When Vp, a
It was found that Δn/aV (becomes 0). This phenomenon is
For example, Journal of the Japan Textile Society, 37(4), 1981 No. T-135
It is also described on pages T-142 (published by the Japan Institute of Textile Science and Technology).

As mentioned above, the winding speed V is equal to or higher than Vp, that is, (aΔn
The polyester fiber in the region where /&V)≦O is itself a conventional drawn yarn, that is, the spinning speed is 1000 to 2000 m.
Although it has slightly better dyeability than yarn obtained by stretching an undrawn yarn 3 to 5 times after winding it around /min, the present inventors have further researched and found that ( aΔn/aV)≦0
By successively heat-treating and false-twisting the fibers in this area, we are able to create a false-twisted yarn that has sufficient dyeability with a heat treatment heater of a practical length even during high-speed false-twisting. was found to be obtained.

Note that fibers wound in the (aΔn/eV) ) 0 region are not easily dyed by themselves and require relatively long heat treatment, and in high-speed false twisting, the heat treatment heater is The heat treatment process may become unstable due to airflow inside the heater, making it impossible to produce uniformly processed yarn, and thread hooking is difficult to operate and is also difficult for economical reasons. I don't like it either.

In the present invention, the heat treatment temperature is the melting peak point T of a differential scanning calorimeter (hereinafter referred to as DSC) shown in FIG.
It is preferable to set the temperature to 15° C. lower than p (for example, 243 to 245° C. or higher) in terms of easy dyeability. Note that the upper limit may be below the substantial melting point of the fiber.

In addition, during heat treatment, the feed rate of raw yarn is 10A--5cm (A is the water-making shrinkage rate of the supplied raw yarn.
0) is preferable.

If the feed rate exceeds A-, the heating operation cannot be carried out easily, and if the underfeed rate is less than -5-, there will be a decrease in dyeability and a decrease in processed yarn strength.

During the heat treatment, it is not necessary to use a long heater for the heat treatment; for example, a heater of normal length such as a tube heater or a slit heater may be used. These heaters are preferably of a non-contact type in order to perform the heat treatment and subsequent false twisting process well.

The time for passing the yarn through these heaters (heat treatment time) is desirably 0.15 seconds or more in order to obtain a false twisted yarn having sufficient dyeability.

Furthermore, the stretching ratio D(4) during false twisting in the present invention is
It is preferable to set it as the range of the following formula (% formula %). A stretching ratio outside this range may cause yarn breakage due to insufficient heating tension.

Conventionally, as a method for setting the stretching ratio during false twisting of polyester fibers wound at high speed, Japanese Patent Application Laid-Open No. 49-61451 has been used.
The number is -250×Δn+38≦D−4−700Xjn+
120 has been proposed, but as mentioned above, 4n changes depending on V as shown in Figure 1, so this setting method causes a lot of fuzz and breaks the thread, making it unsuitable. was recognized.

The polyester fiber as used in the present invention refers to a fiber consisting essentially of polyethylene terephthalate, and this polyester can be obtained by a known polymerization method. Even if it contains agents, antistatic agents, etc., it can be used at t/h. The degree of polymerization of polyethylene terephthalate is not particularly limited as long as it is within the range for normal fiber formation, and copolymers with small amounts of other components or mixtures thereof may be used as long as the purpose of the present invention is not impaired. It may be.

In the present invention, the average birefringence Δn is the difference between the average refractive index n/101 and nJJOl at the center of the fiber, and the average refractive index n/101 and nJOl are measured by the method described below.

Further, the winding speed V (m/min) refers to the surface speed of the friction roll 60 in FIG. 3, which is a schematic diagram showing a typical embodiment of a polyester fiber spinning winding device. In the figure, 1 is a spin head, 2 is a spinneret, 3 is a spun filament, 4 is a convergence guide, and 5 is a yarn package.

Stretching ratio D (hook) Regarding FIG. The respective surface speeds are based on R1. Therefore, when D) is 0, it means that false twisting is performed in a state in which the yarn is substantially stretched, that is, in an underfeed state. In addition, in the figure, 7 is a supply system, 8 is a heat treatment roll, 9 is a tube heater for heat treatment (non-contact type), 11 is a first heater for false twisting, 12 is a twisted body, 14 is a second heater for false twisting, 15 is false twist No. 30-ru, 1
6 indicates take-up wine goo, and 17 indicates twisted yarn.

Next, a preferred embodiment of the heating-false twisting step of the method of the present invention will be described with reference to FIGS. 4 and 5.

In FIG. 4, a conventional general false twisting processing device includes a 10th false twisting rule 10, a first false twisting heater 11, a twisted body 12,
False twist No. 20-rule 13, False twist second heater 14, False twist No. 3
The heating-false-twisting processing apparatus used in the present invention includes a heat treatment roll 8 and a tube heater (non-contact type heater) before the false-twisting roll 10. This device differs from the conventional device in that 9 is provided. In the figure, (aΔn/aV)≦0
(9) Supply system 7 wound at a winding speed V (m/min) in the region of
The loosened yarn is transferred to the heat treatment roll 8 and the first false twist
The tube heater 9 is heated while running in a non-contact manner through the center of the tube heater 9 provided between the tube heater 9 and the tube heater 9. Next, the first false-twisting heater 11, the twisted body 12, and the second false-twisting heater 11, the twisted body 12, and the second false-twisting heater 11,
After passing through the 0-ru 13 continuously, the false twisting second heater 1
4. The false twisted yarn 17 passes through the false twisting 30-rule 15 and is wound up by the take-up winder 16.

Next, FIG. 5 shows a heating and false-twisting processing apparatus having the same structure as the apparatus of the embodiment shown in FIG. 4, except that a contact type plate heater 18 is used as the heat treatment heater. Although the dyeability is improved compared to the conventional one, the fourth
Compared to the case of using the non-contact type heater shown in the figure, there was a tendency for the ease of dyeing and the strength of processed yarn to be lower.

As described above, according to the present invention, a supply system that is wound at a winding speed V (m/min) in the range of (aΔrv'aV ) 40 is used, and further heat treatment and false twisting are performed continuously. Therefore, even under high-speed false-twisting conditions, (10) a false-twisted yarn having sufficient dyeability can be obtained.

Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, and the methods for measuring fiber physical properties in the present invention are as follows.

(1) Average refractive index (n/, nu) and average birefringence observed from the side of the fiber by the interference fringe method using a transmission quantitative interference microscope (for example, interference microscope Interfaco manufactured by Karl Zeiss Jena, East Germany) The refractive index distribution can be measured. This method can be applied to fibers with a circular cross section.

The refractive index of a fiber is characterized by the refractive index n/ for polarized light with an electric field vector parallel to the fiber axis and the refractive index nJLK for polarized light with an electric field vector perpendicular to the fiber axis. All measurements described here were performed using green light (wavelength λ=54911μ).

The fibers are made using optically flat glass slides and cover glasses, have a refractive index (N) that provides a shift of the interference fringes within the range of 0.2 to 2 wavelengths, and (11) are inert to the fibers. Several single filaments are immersed in a suitable mounting medium so that they do not touch each other. In this case, the fibers are arranged such that their fiber axes are perpendicular to the optical axis of the interference microscope and to the interference fringes. Photograph this pattern of interference fringes,
Analyze at approximately 1500x magnification.

In FIG. 6, the refractive index of the fiber encapsulant is N.

The refractive index between points s' and s' on the outer periphery of the fiber is n/(or nl) The thickness between B' and B' is t1 The wavelength of the light beam used is λ
, the distance between parallel interference fringes in the background (corresponding to 1λ)
Let d be the deviation of the interference fringes due to the D1 fiber. In the figure, 19 is the fiber, 2° is the interference fringe due to the mounting medium, and 21 is the interference fringe due to the fiber.

When the fiber radius is R, the refractive index of the fiber at each position n/(
t or nl). When r is the distance from the center of the fiber to each position, the average refractive index (n/(
0) or 0)) on n is defined by X = r / R = 0, that is, the refractive index at the center of the fiber (12). For example, the refractive index at the point of X=0.8 is n/(oj) (or on n(OJI
)).

Further, from the average refractive index n/T@ and nJjol, the average birefringence (Δn) is expressed as Δn = n/(01-nii).

(2) Water production shrinkage rate 0.1#/d When the sample length under a load is LO, the load is removed and the sample is treated in boiling water for 30 minutes, the length measured again under the same load is L, It is expressed as water production shrinkage rate.

(3) Melting peak temperature Tp Using DEC-1b type manufactured by Perkin-E1mer,
Sample amount approx. 1. ! M in N2 gas atmosphere at about 180'C
The temperature is increased at a rate of 20° C./maro, and the melting curve is measured. The maximum peak point of the melting curve is Tp (see Figure 2).

(4) Dyeability (13) Disperse dye Resolin Blue
3% by weight (bath ratio 1:50) of FBL (trade name of Bayer AG) was used, and Disper 'l'L was used as a dispersant.
(Kaisei Kagaku ■ trade name) was added at 111/l, the p value was adjusted to 6 with acetic acid, and the mixture was dyed at 100°C. The dyeing rate (equilibrium dyeing rate) is calculated by collecting the dye solution after a predetermined time (1 hour), calculating the amount of dye in the remaining solution based on the absorbance, and subtracting this from the amount of dye used for dyeing. The dyeing rate (hook) was calculated as the amount of dyeing.As a sample, the raw yarn was knitted into a single-knit fabric, and using Score Roll FC-250 (Kao Soap ■trade name) 211/l, the dyeing rate was calculated at 60°C. The mixture was kneaded in a tank for 20 minutes, dried, and kept at a controlled temperature (20°C x 65-RH).

The evaluation of whether the dyeability is easy or not was determined by comparing the dyeing amount of 83 cm when a conventional drawn and false twisted yarn was dyed at 130° C. for 60 minutes under the above-mentioned dyeing conditions.

If the dyeing amount exceeds 83-, it is judged that the dyeing property is good.

(5) The ease of operation is qualitatively expressed using a three-step method (14). O for the conventional false twisting process difference
A mark of X indicates that threading is extremely difficult due to cutting or fuzzing occurs frequently, and a mark of Δ indicates an intermediate level between the two.

Example 1 The winding machine shown in Fig. 3 was used for 3,000 to 10,000 m/
A fiber of 75 denier/24 filaments was obtained by winding at a speed of 1 minute. The measurement results for these fibers are shown in Table 1.

Table 1 From the results in Table 1, the relationship between winding speed V and Δn is illustrated as shown in Figure 1. In this case, it was found that Vp at which Δn becomes maximum is 7000 m/min. . Therefore,
The winding speed Vp, La1n/(15) av) ≦0 is the supply yarn symbol E, F, G.

It can be seen that in case H. Table 3 shows the results of false twisting the fibers E, F, G, and H using a false twisting machine as shown in FIG. 4 under the processing conditions shown in Table 2.

Table 2 (16) From Table 3 of Table 43, it is clear that if a supply system in the (aΔ-v)≦00 region is used and heat treatment and false twisting are performed consecutively, sufficient results can be obtained even in high-speed false twisting. It can be seen that a false twisted yarn with easy dyeability (17) can be obtained. Furthermore, the stretching ratio (D°C) during false twisting is determined by the following formula: 81×Δn −7≦D≦38−
It was found that outside the range of 250XΔn, threading properties tended to deteriorate.

The criteria for marking O and X in the overall evaluation is % (1
), yarn hooking is ○, (2) processed yarn strength 3. The overall evaluation was given as O for those satisfying all three criteria: oII/a or higher and (3) dyeing rate of 83 cm or higher, and otherwise as ×. The comprehensive evaluation was conducted based on the strict criteria mentioned above, and an overall evaluation of "x" does not necessarily mean that the product is outside the scope of the claims, but rather satisfies the conditions of dyeing rate and processed yarn strength. All are included within the scope of the present invention.

Example 2 Using the supply system E used in Example 1, processing was carried out under the false twisting conditions shown in Table 4. The results are shown in Table 5.

Margin below (18) Table 4 Table 5 (19) Note that a mark in the list of measurement items for textured yarn indicates that textured yarn could not be obtained due to poor workability.

From Table 5, the heat treatment temperature is Tp -15℃ or more, the heat treatment time is 0.15 seconds or more, and the feed rate during heat treatment is +A
It can be seen that within the range of -5 inches (2 to -5 inches), a false twisted yarn with excellent dyeability, dyeing rate, textured yarn strength, etc. can be obtained. On the other hand, when the heat treatment temperature is low (Comparative Example 8) or when the heat treatment time is insufficient (Comparative Example 11)
), the dyeability becomes insufficient, and when the feed rate during heat treatment is outside the range of 10A to -5- (Comparative Example 9.10),
It can be seen that the processability is poor or the processed yarn strength is extremely low, making it unsuitable for practical use. Note that the criteria for the marks ○ and × in the overall evaluation are based on Example 1.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between winding speed V and Δn of polyester fiber, Figure 2 is a diagram showing a model of a DSC melting curve, and Figure 3 is a diagram showing a typical spinning winding of polyester fiber. FIG. 4 is a schematic diagram showing one embodiment of the apparatus, and FIG. Schematic diagram showing an embodiment of the method of the present invention using a contact plate heater, No. 6
The figure shows the radial refractive index within the cross-section of the fiber (n/or n).
FIG. 3 is a diagram showing an example of an interference fringe pattern used for measuring distribution. DESCRIPTION OF SYMBOLS 1... Spin head, 2... Spinneret, 3... Spun filament, 4... Convergence guide, 5... Yarn package, 6... Friction roll, 7... Supply system , 8... Heat treatment roll, 9... Tube heater for heat treatment (non-contact type), 10... False twisting 10th roll, 11... False twisting first heater, 12... Application Twisted body, 13
...False twisting 20th rule, 14...False twisting second heater, 1
5... False twist 30th thread, 16... Take up wine goo, 17... False twisted yarn. Agent Patent Attorney Takenaga Kawakita (21) Figure 1 Figure 2 Figure 4 Procedural Amendment Statement September 17, 1982 2. Title of Invention: Process for Manufacturing Polyester False Twisted Yarn 3, Person Making Amendment Case Relationship Patent applicant Address: 1-2-6 Dojimahama, Kita-ku, Osaka-shi, Osaka Name (003) Asahi Kasei Industries, Ltd. Representative: Teru Miyazaki 4, Agent: 103 Address: Kayaba-cho, Nihonbashi, Chuo-ku, Tokyo - Chome 11-8 (
Benimoe Building) Telephone: 03 (639) 5592 Name (7658) Patent Attorney Takeshi Kawakita 5, Date of amendment order Voluntary 6, Subject of amendment Detailed explanation of the invention in the specification. 7. Contents of amendment (1) “Resolin Buri” in the first line of page 14 of the specification
(2) Change r 3.8 J in the processed yarn strength column in the middle row of Table 3 on page 17 of the specification to '3. OJ. (3) Change r 3.8 J to '3. OJ' on page 19 of the specification Change “Figure 5” in the top column of Table 4 to “
Figure 4. that's all

Claims (1)

[Claims] (1) In high-speed false twisting processing of polyester fibers,
When the winding speed during spinning is V (il/min) and the average birefringence is Δn, a polyester fiber in the region satisfying aΔn/a V≦0 is used as the supplied raw yarn, and the fiber is heated. A method for producing polyester false-twisted yarn, which is characterized by successively performing false-twisting and false-twisting processes. (2. In claim (1), the heat treatment temperature is 15°C above the melting peak point of the differential scanning calorimetry needle (DSC).
At a low temperature or higher, and at a feed rate of 10 A- to -51
A method for producing a polyester false-twisted yarn (where A is the water production shrinkage rate of the supplied raw yarn). (3) In claim (1) or (2),
A method for producing polyester false-twisted yarn in which heat treatment is a non-contact process. (4) A method for producing a polyester false twisted yarn according to any one of claims (1) to 3), wherein the heat treatment time is at least 0.15 SIK. (5) The polyester false-twisting process according to any one of claims (1) to 4), characterized in that the false-twisting process is performed under conditions in which the stretching ratio D(a) satisfies the following formula %. Processed yarn manufacturing method.