JPH10130944A - Apparatus for producing polyester fiber and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit the turbulence of the accompanying air flow occurring near the inlet of the heating chimney to suppress the yarn sway thereby improving U%, unevenness in dyeing, running condition and yarn physical properties. SOLUTION: This polyester fiber-manufacturing equipment comprises the cooling unit 4 that blows cooling wind to a multi-filament yarn of extruded polyester to cool the yarn lower than the glass transition point, the heating chimney 5 that heats the extruded, once cooled yarn under non-contact conditions and draws the yarn and the winder 3 for taking up the drawn yarn at a speed of more than 3,000m/min. An air flow-straightening member 4a is set to straighten the flow of the cooling air blown from the cooling unit 4 to the yarn-running direction. Further, the inlet 4b for the cooling air is opened to introduce the air into the heating chimney 5 communicating to the yarn inlet on the upper part of the heating chimney 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for producing multifilament fibers made of polyester. More specifically, the present invention relates to a direct spinning and drawing apparatus and a manufacturing method of polyester fiber, which melt-spuns polyester, cools it once, heats it in a non-bundle state, draws it at high speed, and draws it.

[0002]

2. Description of the Related Art As a method for producing a polyester fiber having a high elongation that can be put to practical use only by a spinning process, 70% is used.
An ultrahigh-speed spinning method of drawing at a high speed of at least 00 m / min is known (for example, see Japanese Patent Publication No. 60-47928).

However, in such a high-speed spinning method, the workability at the time of threading or spinning is poor, and the cost of equipment such as a high-speed winder is increased. This increases the paper core cost and the amount of waste, which is not desirable in terms of running costs after equipment depreciation. In addition, although a fiber having physical properties different from those of conventionally used polyester fibers and having a practically usable elongation can be obtained, it is necessary to perform post-processes and post-treatments different from the conventional ones. In addition, in the case of fabrics for use in the market, the tension and waist are insufficient, and it cannot be said that the fabrics meet the needs of the market. For this reason, compared with the fiber obtained by the spinning method of spinning at a low speed, winding once, and then stretching in a separate process, or the straight-rolling method of continuously drawing after spinning, without winding. It has not reached the point where it draws out the special characteristics.

On the other hand, as a method for obtaining a practically usable polyester fiber at a take-off speed of 3000 to 6000 m / min, a method as shown in FIG. 4 is performed. That is,
A cooling device 4 and a heating device 6 having a heater 5 are provided between the spinneret 1 and the spinning take-off rollers 2 and 3, and the polyester yarn Y melted and discharged from the spinneret 1 is once cooled to a glass transition temperature or lower. This is a method in which the film is cooled, stretched by heating while continuing to run in the heating device 6, then taken up by the take-up rollers 2 and 3, and wound around a winder 7. This method is called a so-called direct spin drawing method. FIG.
In the figure, 8 is an oil applying device, 9 is an interlacing device, and both are devices for imparting convergence to the yarn directly after spinning and drawing.

In the above-described direct spinning and drawing method, since the yarn heated in the heating device 6 is subjected to a drawing action by the spinning tension, a polyester having mechanical properties that can be practically used even at a relatively low take-off speed. Fiber can be obtained.

However, when the tension of the running yarn in the heating device 6 is too low, uniform heating and drawing is not performed, the yarn sway becomes large, and the fineness unevenness (hereinafter referred to as U%) becomes large. Then, when the resulting yarn is woven and knitted, spots occur, and the mechanical properties such as the strength and elongation of the yarn itself are insufficient. And the like. On the other hand, if the tension of the yarn becomes too high, single fiber breakage (single yarn breakage), spun yarn breakage, etc. occur frequently, and more than necessary tension is applied to the single fiber.
This may cause an increase in fineness unevenness and U%.

[0007] In order to solve the above-mentioned problems, a method for uniformly controlling the tension of the yarn in the heating device has been proposed (for example, Japanese Patent Publication No. 59-51603, Japanese Patent Application Laid-Open No. 62-162015). No.). However, even with these methods, the unevenness of fineness and U% cannot be improved to a sufficiently satisfactory degree, and moreover, single fiber breakage and spun yarn breakage still occur frequently. It is presumed that such a method of controlling the tension of the yarn cannot solve the above-mentioned problem because the yarn sway generated by an air current accompanying the yarn traveling at a high speed is the cause.

[0008] On the other hand, in the direct spinning and drawing method, low-temperature air (cooling air or the like) flowing into the heating device accompanying the yarn running at a high speed causes a temperature drop or a temperature fluctuation in the heating device. In order to prevent a decrease in the heating efficiency of the heating device, a device for preventing the accompanying airflow of the traveling yarn from flowing into the heating device has been proposed (Japanese Patent Application Laid-Open No. 54-13 / 1979).
No. 8613, JP-A-62-69815).

[0009] However, these devices are intended to prevent the accompanying airflow of the traveling yarn from flowing into the heating device, thereby fluctuating the temperature and reducing the energy efficiency. It is not intended to solve the problem caused by the yarn sway caused by the accompanying airflow of the running yarn. Therefore, even when these devices are used, in the direct spinning and drawing method, the yarn sway caused by the accompanying airflow of the running yarn is prevented, the U% and the spots are reduced, and the single fiber breakage and the spinning breakage (spinning process) are performed. It is difficult to improve the tone).

Japanese Patent Application Laid-Open No. 4-263608 discloses that a multi-filament having high homogeneity can be obtained by using a heating device in which the internal cross-sectional area is continuously reduced at least at the bottom in the direct spin drawing method. It is stated that it can be obtained.

However, even with the use of this heating device, little consideration is given to yarn sway caused by turbulence in the airflow accompanying the running yarn, and U%, spots, The deterioration of the spinning process cannot be improved. In addition, there is a problem that equipment costs are increased because a heating device having a special shape is used.

[0012]

SUMMARY OF THE INVENTION In the direct spinning and drawing method, the present inventors have found that the U% is large, the spots are deteriorated, the single fiber breakage and the spun yarn are frequently generated, and the spinning process is deteriorated. It has been found that this is mainly due to the yarn sway caused by the turbulence of the air flow accompanying the yarn running at high speed. In addition, it has been found that the amount of the accompanying airflow flowing into the heating device together with the yarn also leads to improvement in physical properties. Therefore, in order to minimize the influence of the turbulence of the air flow and to allow the air flow accompanying the traveling yarn to flow uniformly into the heating device together with the yarn, the traveling of the yarn together with the yarn cooled by the cooling wind is required. The present inventors have determined that it is sufficient to rectify and flow cooling air uniformly into the heating device in the same direction as the direction, and have completed the present invention.

[0013]

That is, the present invention relates to (1) a cooling method in which cooling air is blown onto a multifilament yarn made of spun polyester to cool the yarn to a glass transition temperature or lower. In a polyester fiber manufacturing apparatus including a device, a heating cylinder for drawing the spun yarn once cooled in a non-bundle state while heating it in a non-contact manner, and a take-off device for drawing the yarn at a speed of 3000 m / min or more, A rectifying member for rectifying the flow of the cooling air blown from the cooling device in the running direction of the yarn is provided, and a member for introducing cooling air to the heating cylinder connected to the lower part of the rectifying member and the yarn inlet at the upper part of the heating cylinder. An apparatus for producing a polyester fiber, characterized in that a rectifying member has an opening for receiving cooling air along the yarn running direction, and a semi-cylindrical plate-like body is provided. In multiple layers The polyester fiber manufacturing apparatus according to claim 1, which is a member that is cut off, (Claim 3) The cooling air introduction member according to Claim 1 is gradually reduced in a funnel shape toward the heating cylinder, and The polyester fiber manufacturing apparatus according to claim 1 or 2, wherein the straightening member and the yarn inlet of the heating cylinder are connected to each other. (Claim 4) The heating cylinder includes a plurality of multifilament yarn groups, The heating region for heating each line is an independent heating cylinder for each yarn, and a gap is not formed between adjacent rectifying members of a rectifying member group provided corresponding to each of the heating cylinder groups. The polyester fiber manufacturing apparatus according to any one of claims 1 to 3, which is continuously provided in the apparatus.

Further, the present invention provides (claim 5): a cooling air is blown onto a multifilament yarn made of spun polyester to cool the yarn once to a glass transition temperature or less, and then to continuously heat the filament. In a method for producing polyester fiber which is stretched while contactlessly heating in a non-bundle state and drawn at a speed of 3000 m / min or more, the cooling air is blown until the yarn enters the heating cylinder.
A method for producing a polyester fiber, characterized in that, while being rectified in the running direction of the yarn, the rectified cooling air flows into the heating cylinder along with the running yarn without being separated from the running yarn.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a polyester fiber is mainly made of polyethylene terephthalate, and has a repeating unit of 85 mol% or more, preferably 95 mol% or more.
% Of ethylene terephthalate or other polyesters such as polyhexamethylene terephthalate, nylon-
6, nylon-6,6, polyethylene-2,6-naphthalate, polycarbonate, polymethyl methacrylate and the like may be mixed in small amounts. Further, these polyesters may contain known additives, for example, pigments, dyes, matting agents, dye-proofing agents, optical brighteners, flame retardants, stabilizers, ultraviolet absorbers, lubricants and the like.

The intrinsic viscosity IV (calculated using an o-chlorophenol solution at 35 ° C.) of the polymer of the polyester fiber obtained in the present invention is 0.3 to 1.0, particularly 0.5 to 1.0.
A range of 0.7 is appropriate.

The above polyester can be directly spun and drawn by, for example, the apparatus shown in FIG. In the figure, 1 is a spinneret, 2 and 3 are spinning take-off rollers, and between the spinneret 1 and the spinning take-off rollers 2 and 3.
A non-contact heating / heating device 6 having a spinning cooling device 4 and a heating cylinder 5 is provided. Reference numeral 7 denotes a winder for winding the yarn Y, 8 denotes an oil applying device, and 9 denotes an interlace device. Here, the heating cylinder 5 generally plays a role of non-contact heating of many multifilament yarns Y in a non-bundle state. And, on the upper part of the heating cylinder 5,
A rectifying member 4a for rectifying the flow of the cooling air blown from the cooling device 4 in the running direction of the yarn Y is provided, and below the rectifying member 4a, a lower portion of the rectifying member 4a and a yarn inlet at an upper portion of the heating cylinder 5. Member 4 for introducing cooling air to heating cylinder 5 connected to
b is attached. Reference numeral 10 denotes a shutter provided below the heating cylinder 5 in order to prevent a decrease in the heating efficiency of the heating cylinder 5.

Here, the process from the substantially spinning step to the winding step according to the present invention will be briefly described. First, the polyester is melted at a temperature from the melting point (Tm) to the melting point + 50 ° C. (Tm + 50 ° C.). Spin from 1. The spinneret 1 in which the spinning holes are arranged in a line on the circumference is ideal for uniformly cooling the spun yarn.
They may be arranged at equal intervals in up to three rows or arranged in a lattice.

The yarn Y spun from the spinneret 1 is once cooled by the spinning cooling device 4. At this time, if the cooling of the spun yarn Y is insufficient, it is difficult to uniformly perform the heating and drawing in the next heating cylinder 5, and the uniformity of the obtained polyester fiber becomes poor. It is desirable that the yarn Y is cooled to a glass transition temperature (Tg) or less until immediately before the yarn entrance of the heating cylinder 5.

Then, the thus cooled yarn Y is heated in a non-bundle state in the heating cylinder 5 in a non-contact state, and is 3,000 m long.
The take-up winding is performed by the spinning take-off rollers 2 and 3 at a speed of not less than / min. Here, the heating cylinder 5 has a length of 50 to 1
It is desirable that the inner atmosphere temperature is 50 to 200 ° C. If the ambient temperature is too low, the running action of the running yarn in the heating cylinder 5 caused by friction with air becomes insufficient, resulting in an incompletely drawn state, causing spotting and U%. As the size increases, the microstructure of the fiber does not stabilize and the shrinkage increases. On the other hand, if the ambient temperature is too high, mechanical properties such as high elongation are significantly improved, but spun yarns and fusion between single fibers frequently occur, and yarn sway in the heating cylinder 5 increases. , U% and staining become worse.

The mechanical characteristics and U% are also greatly affected by the accompanying airflow brought by the yarn Y entering the heating cylinder 5. That is, the drawing effect is not exhibited unless a certain amount of tension is applied to the yarn Y flowing into the heating cylinder 5 in a non-bundle state. This is because the traveling yarn Y needs to be heat-set while being stretched in the heating cylinder 5, and the temperature in the heating cylinder 5 is reduced by the accompanying airflow brought in by the yarn Y. This is because this has a great effect on the drawing and heat setting of the yarn.

The inventor of the present invention has observed in detail the change in the fineness of the yarn, that is, the so-called slender deformation behavior when the yarn travels in the heating cylinder 5 with the accompanying airflow. As a result, it is understood that the drawing is gradually performed in the heating cylinder 5, and the temperature, the length, and the accompanying airflow brought in by the yarn, for example, the accompanying airflow in the heating cylinder 5 It was found that the yarn having the optimum physical properties could be obtained even if it was introduced.

That is, as the heating cylinder 5 used in the present invention, a cylindrical one having a circular cross section is usually used, but the heating cylinder 5 is not particularly limited to a cylindrical shape, and may have any shape. For example, a tubular body having a rectangular cross section, a square, an ellipse, or the like is used. However, in terms of the uniformity and homogeneity of the yarn treatment, multi-spindle picking is common, and the method of jointly heating and drawing all the yarn weights is not preferable because the turbulence of the accompanying airflow greatly affects the method. Preferably, a cylindrical heating cylinder in which the yarns of each weight are independently heat-treated. As a heating means of the heating cylinder 5, as shown in FIG. 1, a heater 5 for externally heating by electricity may be provided, or heating air, steam or the like may be blown into the heating cylinder. good. Furthermore, in order to improve productivity, in the case of multi-spindle taking in which two or more yarns are simultaneously processed, it is preferable to adopt a heating medium heating method in which a jacket is provided outside the heating cylinder 5. Because, when a heating medium heating method of circulating a heating medium whose temperature is controlled in the jacket is adopted, the temperature difference between the weights can be reduced, and the physical properties of the obtained polyester fibers, weights such as spots, etc. At the same time as eliminating the difference, it is possible to reduce the unevenness in the yarn weight, that is, in the longitudinal direction, and the difference in the weight, which is more preferable.

The take-up speed when the spun yarn is finally taken out needs to be 3000 m / min or more. If it is less than 3000 m / min, the friction between the running yarn and the air is reduced. Stretching action by the action is insufficient, for this reason, physical properties such as strong elongation, Young's modulus become insufficient,
When weaved, the fabric becomes tight and waistless.
On the other hand, if the take-up speed is too high, the crystallization of the yarn proceeds, and not only does the woven fabric have a paper-like feel, but also the number of spun yarns and broken single fibers increases, and the workability deteriorates.
Preferably, it is 4000 to 5500 m / min.

Here, in the present invention, a cooling device provided above the heating cylinder 5 is important. Because, in the present invention, the conventional method and apparatus are significantly different,
This is because the cooling air is forced to flow into the heating cylinder. Moreover, even if 80% or more of the cooling air flows into the heating cylinder, a yarn having excellent physical properties can be obtained. However, as a condition required for this, it is necessary to rectify the cooling air so as to flow along the running direction of the yarn. This is because, if the cooling air is caused to cross the running direction of the yarn, the yarn will sway and the U% will be deteriorated and spotted as described above.

Therefore, in the cooling device 4 of the present invention, the details thereof are shown in FIGS. 2 and 3, but in cooling the yarn by the cooling air, the following measures are taken. That is, a rectifying member 4a that rectifies the flow of the cooling air blown out from the cooling device 4 in the running direction of the yarn Y.
And a rectifying member 4 is provided below the rectifying member 4a.
a, a cooling air introduction member 4b connected to the lower portion and the yarn inlet at the upper portion of the heating cylinder 5 is additionally provided. Here, the rectifying member 4
“a” has an opening for receiving cooling air along the yarn running direction, and has a structure in which semi-cylindrical plate-like bodies are provided in multiple layers. Further, the cooling air introduction member 4b is gradually narrowed down in a funnel shape in the direction of the heating cylinder, and has a structure in which the straightening member 4a and the yarn inlet of the heating cylinder 5 are connected.

Further, when the number of spindles is increased, mutual interference between adjacent yarns Y becomes remarkable. Therefore, it is preferable that the cooling air is cooled for each spindle and flow into the heating cylinder.
In view of this, a plurality of multifilament yarn groups are divided into heating tubes 5 each having an independent heating region for each yarn (each weight). It is preferable that the rectifying member group 4a provided with the rectifying member group 4a has a structure in which adjacent rectifying members 4b are continuously formed without forming a gap.

For this reason, after the yarn Y is cooled by the cooling air, the cooling air flows along the running direction of the yarn by the plate-like body in which the rectifying member 4a is provided in a multilayer structure in a cylindrical shape. Is rectified. Then, along with the traveling yarn Y, it is forcibly introduced together with the cooling air from the yarn inlet of the heating cylinder 5 into the heating cylinder 5 together with the yarn Y. At this time, since the cooling air introduction member 4a is gradually narrowed down in a funnel shape toward the heating cylinder 5 and the flow straightening member 4a is connected to the yarn inlet of the heating cylinder 5, the traveling yarn The yarn sway hardly occurs with respect to the line Y. Here, the cooling air introduction member 4
The reason why the cooling air is flowed into the heating cylinder 5 with ease is to gradually narrow it in a funnel shape toward the heating cylinder 5 in order to further enhance the rectifying effect of the cooling air. At this time, a structure in which almost all of the cooling air is finally collected and allowed to flow into the heating cylinder may be used.Also, a structure in which the cooling air is released without generating yarn sway may be used to partially remove the cooling air. It is good also as a structure which flows into the heating cylinder 5.

The rectifying member 4a is divided into a plurality of layers in a cylindrical shape in order to improve the rectifying effect of the cooling air, and the turbulence of the cooling air in the yarn running direction is generated. No, it is effective in eliminating U% and spots. Also, unless the cooling air is gradually reduced by the cooling air introduction member 4a, the accompanying airflow does not sufficiently flow into the heating cylinder, so that the mechanical properties and physical properties of the yarn are reduced and the accompanying airflow is discontinuously reduced. Inflow leads to U% and spots.

Furthermore, it is important for quality stabilization to continuously connect to the inlet of each heating cylinder, and if the cooling air is not continuously introduced even if the cooling air is continuously introduced even if the squeezing is gradually reduced, the U% is deteriorated and the yarn sway is caused. It becomes large and adversely affects the spinning process.

In order to cope with a large number of brands, when the number of filaments is small, depending on the spinning speed, a sufficient accompanying airflow may not be generated, so that the take-up rollers 2 and 3 shown in FIG. After the yarn Y is drawn and heat-set by the heating cylinder 5, it is also possible to further perform drawing and heat setting. In particular, in the case of a polymer having a low melting point, for example, a polyester having a large amount of isophthalic acid component, a high-temperature thermal stress is required in order to produce a grain / bulge in the case of a woven fabric. When applying, such a method is effective.

[0032]

The present invention will be described more specifically below with reference to examples and comparative examples. The measurement, judgment and overall judgment of mechanical properties (general physical properties) and process conditions in Examples and Comparative Examples were performed as follows.

(1) Strong elongation, 10% stress It was determined from a load-elongation curve obtained using a Tensilon tensile tester. Strong elongation indicates strength and elongation at break, and
The 0% stress indicates the stress (strength) when the test yarn is elongated by 10%.

(2) U% Measuring Instruments
An inert test was performed and determined by an integrator.

(3) Spotting The knitted knitted sample was dyed and evaluated by visual evaluation at 1 to 5 points. The higher the score, the better the dyeing,
Indicates that there is little staining.

(4) Process Condition The number of times of spinning and breaking per spindle per day was measured and indicated as an average when running for one week, and evaluated according to the following criteria. ◎: less than 0.5 times: 0.5 times or more and less than 1.0 times Δ: 1.0 times or more and less than 2.0 times ×: 2.0 times or more.

(5) Comprehensive judgment ◎: extremely good ○: good △: slightly poor ×: poor

Examples 1-4, Comparative Examples 1-6 Polyethylene terephthalate having an intrinsic viscosity of 0.64 and containing 0.3% by weight of titanium oxide was melted at 295 ° C. And directly spin-drawing under the conditions shown in Table 1,
A 75 denier polyester filament was obtained.

[0039]

[Table 1]

The diameter of the inlet of the heating cylinder 5 is a perfect circle of 35.
mm, length 120 cm, and temperature were set at 180 ° C. The length of the spinning cooling device 4 is 100 cm, and 3
The speed of the cooling air at 0 cm was 0.2 m / sec. The number of weights was six. The yarn physical properties (mechanical properties) of the obtained polyester filament were as shown in Table 2, and the spinning process condition and the overall judgment were as shown in Table 3. In addition, "with or without circumferential division" described in Table 1 indicates a case where the rectifying member 4a and the introduction member 4b shown in FIGS. 2 and 3 are provided and a case where the rectifying member 4a and the introducing member 4b are not provided.

[0041]

[Table 2]

[0042]

[Table 3]

From the results shown in Tables 2 and 3,
By using the apparatus and method for producing polyester according to the present invention, better results are obtained in all of the yarn physical properties, U%, spots, and process condition as compared with the case of using the conventional apparatus and method. was gotten.

[0044]

According to the present invention, in the direct spinning and drawing step, yarn sway due to cooling air is prevented, and the yarn physical properties are improved.
%, And a polyester fiber having good spots, etc., and a stable process can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view partially showing a vertical section, showing an example of an apparatus for carrying out the present invention.

FIG. 2 is a plan view illustrating a rectifying member and an introduction member of the present invention.

FIG. 3 is a front view in which a vertical cross section illustrating a rectifying member and an introduction member of the present invention is given.

FIG. 4 is a front view partially including a vertical cross-section illustrating an apparatus according to a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spinneret 2, 3 Take-up device 4 Cooling device 4a Straightening member 4b Introducing member 5 Heating cylinder 7 Winding device Y Yarn

Claims (5)

[Claims] 1. A cooling device for blowing a cooling air to a multifilament yarn made of spun polyester to cool the yarn to a glass transition temperature or lower, and to cool the spun yarn once cooled in an unbundled state. In a polyester fiber manufacturing apparatus including a heating cylinder for drawing while performing non-contact heating and a take-up device for drawing the yarn at a speed of 3000 m / min or more, the flow of the cooling air blown out from the cooling device is traveled by the yarn. An apparatus for producing polyester fibers, comprising: a rectifying member for rectifying in a direction, and a member for introducing cooling air to the heating cylinder connected to a lower portion of the rectifying member and a yarn inlet at an upper portion of the heating cylinder. 2. The member according to claim 1, wherein the rectifying member has an opening for receiving cooling air along the yarn running direction, and a half-cylindrical plate is provided in multiple layers. Polyester fiber manufacturing equipment. 3. The cooling air introduction member according to claim 1, wherein the cooling air introduction member is gradually reduced in a funnel shape toward the heating cylinder, and the flow regulating member and the yarn inlet of the heating cylinder are connected. Item 3. An apparatus for producing a polyester fiber according to Item 2. 4. A heating tube for heating a plurality of multifilament yarn groups by the heating tube, and a heating region for heating each of the yarns independently for each yarn. The apparatus for producing polyester fibers according to any one of claims 1 to 3, wherein the apparatus is continuously provided without forming a gap between adjacent rectifying members of the rectifying member group provided corresponding to (i). 5. A cooling air is blown onto a multifilament yarn made of spun polyester to cool the yarn once to a glass transition temperature or lower, and then, in a heating cylinder, in a non-focusing state, non-contact heating. In the method for producing a polyester fiber which is drawn while being drawn at a speed of 3000 m / min or more, while the cooling air is rectified in the running direction of the yarn before the yarn enters the heating tube, the rectified cooling is performed. A method for producing a polyester fiber, wherein a wind is caused to flow along with a traveling yarn into a heating cylinder without being separated from the traveling yarn.