JP2007009341A - Method for producing polyester multifilament for yarn division, having excellent dyeing stability and excellent yarn dividableness - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polyester multifilament for yarn division, having excellent dyeing stability (level-dyeing property) and excellent yarn dividableness by a direct spinning drawing method. <P>SOLUTION: This method for producing the polyester multifilament for the yarn division by the direct spinning drawing method is characterized by using a spinning takeoff roller as a heating roller, surrounding the roller with a box having a heating/heat-insulating function, heating the spun multifilament in a state controlling the temperature of the atmosphere in the box to 50 to 100°C, drawing the spun multifilament between the spinning takeoff roller and the drawing roller, heat-setting the drawn multifilament, and then taking off the heat-set multifilament. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a polyester multifilament for splitting excellent in dyeing stability (level dyeing property) and splitting property. More specifically, in the production of a polyester multifilament for splitting by a direct spinning drawing method, the spinning take-off roller (first godet roller) is a heating roller, and the roller is surrounded by a box having a heat retaining function and a heater function. The yarn is heated in a state where the ambient temperature in the box is controlled to a specific temperature, and the uneven heating of the yarn is suppressed, thereby suppressing the fluctuation of the drawing point and reducing the occurrence of dyeing spots. The present invention relates to a method for producing a polyester multifilament for splitting with improved splitting properties.

  With respect to a method for producing a polyester multifilament for splitting by a direct spinning drawing method, for example, it can be seen in Japanese Patent Application Laid-Open No. 59-116405 (Patent Document 1) and Japanese Patent Application Laid-Open No. 59-125904 (Patent Document 2). It has been known for a long time, and has been intensively studied to improve yarn breakage (splitting property) in the process of splitting the multifilament into a monofilament. In addition, regarding dyeing spots, JP 2001-279521 A (Patent Document 3), JP 2003-342829 A (Patent Document 4), and the like improve the uniform adhesion of an oil agent by using an air entangled nozzle, Techniques to improve stained spots are introduced.

  However, until now, there has been no research on uniform heating in the heating roller part in direct spinning drawing, and in the conventional method, uniform heating in the heating roller part is difficult. The deterioration of the fineness could not be avoided. In particular, when the fiber cross-section is triangular or multi-lobed, the yarn swaying at the heating roller becomes large, making uniform heating at the heating roller much more difficult, and the problem of yarn breakage and abnormal stretching (unstretched) Was produced.

JP 59-116405 A JP 59-125904 A JP 2001-279521 A JP 2003-342829 A

  The present inventor has intensively studied to solve the problem of non-uniform heating of the multifilament with the heating roller in the process of producing the polyester multifilament for splitting by the direct spinning drawing method, and to improve dyeing spots and splitting properties. As a result, the inventors have found a method capable of effectively suppressing non-uniform heating at the roller, and have reached the present invention.

  Therefore, the object of the present invention is to suppress uneven heating of unstretched multifilaments when producing polyester multifilaments for splitting by direct spinning and stretching, thereby suppressing fluctuations in stretching points and An object of the present invention is to provide a method for producing a polyester multifilament for splitting with reduced generation and improved splitting property.

  According to the present invention, when the polyester multifilament for splitting is manufactured by the direct spinning drawing method, the above-described object is to form the spinning take-up roller as a heating roller, and surround the roller with a box having a heating / heat-retaining function, By heating the spun yarn in a state where the atmospheric temperature in the box is controlled to 50 ° C. or more and less than 100 ° C., stretching the yarn as it is between the spinning take-up roller and the drawing roller, and winding it after heat setting. Achieved.

  Such a method of the present invention is particularly effective when a polyester multifilament for fiber separation having a single yarn fineness of 10 to 40 dtex and a filament number of 4 to 20 is produced. In the method of the present invention, it is preferable that the single yarn fineness of the multi-filament after stretching heat setting is 10 to 40 dtex, and the number of filaments is 4 to 20.

  In the method of the present invention, it is particularly preferable that the surface temperature of the spun yarn take-up roller is 70 to 120 ° C. in order to achieve better stretchability. In addition, the drawing roller disposed on the downstream side of the spinning yarn take-up roller is also a heating roller, and is heat-set uniformly on the drawing roller so that it is uniformly heat-set and has good splitting properties. Since the polyester multifilament for use can be obtained, it is preferable.

  The term “polyester multifilament” as used in the present invention refers to a yarn in which a plurality of continuous polyester filaments (single yarns of long fibers) are bundled. The polyester constituting the yarn is mainly polyethylene terephthalate, but may be other polyesters such as a copolyester containing 85 mol% or more (preferably 95% or more) of ethylene terephthalate units. The polyester may contain various additives, for example, a matting agent such as titanium oxide, a heat stabilizer, and an ultraviolet absorber. The intrinsic viscosity of the polyester used in the present invention (measured at 35 ° C. with a 0-chlorophenol solution) is preferably in the range of 0.4 to 1.0, and more preferably in the range of 0.5 to 0.8. preferable. By using a polyester having an intrinsic viscosity in this range, a filament excellent in physical properties such as strength can be obtained with good spinnability.

  The cross-sectional shape of the single yarn of the polyester multifilament in the present invention is not particularly limited. For purposes of use, a circular shape, a triangular shape, a flat shape, a 3-8 multi-leaf shape such as trilobal to octaloval, and a hollow shape are used. However, as already mentioned, when the fiber cross section is a non-circular cross section such as a triangle, flat, multi-lobed, hollow, etc., non-uniform heating is not possible with the conventional direct spinning drawing method. Since it is likely to occur, the effect of the present invention is great.

  It is preferable that the monofilament fineness of the monofilament after splitting is 10 to 40 dtex (dtx) in the polyester multifilament for splitting manufactured according to the present invention. If the single yarn fineness is smaller than this range, it becomes difficult to separate the fibers. Conversely, if the single yarn fineness exceeds this range, the package will lose its shape or go out during winding, and the processability tends to be remarkably deteriorated. Moreover, it is preferable that the number of single filaments of a multifilament is 4-20 from a viewpoint of ensuring the splitting property and the process passage property in a splitting process.

  The method of the present invention is not limited to the case where such a multi-filament polyester multifilament is produced by the direct spinning drawing method, and is not limited to the case of drawing a multifilament melted and discharged from a single spinneret and provided with an oil agent. The present invention can also be applied to stretching a multifilament in which yarns melted and discharged from a spinneret and separately provided with an oil agent are bundled.

  In any case, in the method of the present invention, the spinning take-up roller is a heating roller, and the heating roller is surrounded by a box having a heat retaining function and a heater function, and the atmospheric temperature in the box is 50 ° C. or more and less than 100 ° C. It is important that the yarn is heated while being preferably controlled at a temperature of 60 to 90 ° C., stretched as it is with a stretching roller provided on the downstream side, and wound after being heat set.

  The spinning take-up roller (first godet roller) may be composed of a combination of a heating roller and its separate roller (non-heated), or may be composed of a pair of Nelson-type heating rollers.

  In the method of the present invention, when the spinning yarn (polyester multifilament) is drawn at a take-up speed of, for example, 500 m / min to 1500 m / min by such a spin-take roller (first godet roller), the spin-take roller is used. It is a heating roller, its surface temperature is maintained at 70 to 120 ° C., the yarn is wound around the heating roller a plurality of times (turning), and a heating and heat retaining function is provided so as to surround the heating roller. A box is provided, and the ambient temperature in the box is controlled within a temperature range of 50 ° C. or more and less than 100 ° C.

  When the atmospheric temperature in the box is less than 50 ° C., the spinning yarn is wound (turned) around a heating roller and heated when the temperature of the yarn is heated to the glass transition temperature (Tg) or higher. The temperature of the yarn that is not in contact with the roller is lower than the temperature of the yarn that is in contact with the heating roller, and the uniform heating property at the heating roller is reduced, which tends to cause abnormal stretching (unstretched). . In order to prevent this, if the temperature of the heating roller is raised too much, the temperature of the yarn on the side that is in contact with the heating roller will rise too much, and the yarn will be swayed on the heating roller, which will cause the spun yarn to break. Occurs, the multifilament is twisted, and the yarn breakage occurs in the splitting process, so that the process passability is remarkably lowered. On the other hand, when the ambient temperature is 100 ° C. or higher, the yarn temperature is too high and the yarn on the heating roller is severely swayed, resulting in spinning breakage and yarn breakage in the fiber separation process. Is significantly reduced. In the case of polyester multifilament, when the atmosphere in the box is maintained at a temperature of 50 ° C. or more and less than 100 ° C., particularly 60 to 90 ° C., the above-mentioned problem does not occur and good results are obtained. It is preferred to maintain the temperature.

  The form, structure, and size of the box may be any as long as the atmosphere around the target heating roller can be maintained at a predetermined temperature, depending on the shape and dimensions of the direct spinning drawing apparatus, particularly the spinning take-up roller. It is selected appropriately. Therefore, the box is not limited to a square box shape, and the secondary section may have a shape other than a square such as a polygon or an oval. Generally, this box has a mechanism for heating and keeping the internal atmosphere at a predetermined temperature, as well as a hole or slit for introducing and leading the yarn, and allows the operation surface side end surface of the spinning stretcher to be freely opened and closed. It is preferable that the threading operation can be easily performed.

  In the method of the present invention, the spun yarn is heated to a predetermined temperature by the atmosphere in the heating roller and the box, and immediately after that, between the drawing roller (second godet roller) provided downstream thereof. Stretched to a magnification. The draw ratio is appropriately selected according to the spinning conditions and the characteristics of the product multifilament, and is usually selected within a range of 3 to 6 times. The stretched yarn is heat-set, and then wound by a winder (winding machine) to form a package. The heat setting means in the stretching step is not limited, and a plate heater, a slit heater or the like can be used, but it is preferable to perform heat setting on the stretching roller using the stretching roller (second godet roller) as a heating roller. In this case, the surface temperature of a suitable stretching roller is preferably 100 to 180 ° C.

  The polyester multifilament produced by the method of the present invention as described above is sent to a fiber separation process and separated into monofilaments.

  According to the present invention, when producing a polyester multifilament for splitting by direct spinning and drawing, the spun yarn can be uniformly heated and drawn by the spinning take-off roller unit, and the yarn swaying on the roller is also possible. Since it can be effectively suppressed, it is possible to produce a polyester multifilament for splitting that has a good rate of spinning breakage and unevenness and excellent splitting properties. In particular, the effect is remarkable when applied to a polyester multifilament for splitting composed of non-circular cross-section fibers, which were very difficult to uniformly heat in the conventional method.

Hereinafter, specific examples of the method of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.
FIG. 1 is a schematic side view showing an outline of a direct spinning drawing apparatus for carrying out the method of the present invention. In the drawing, the polymer melted and discharged from two spinnerets 1 arranged in parallel passed through a heat retaining region 10. Then, it cools with the cooling air 11 from a horizontal direction, becomes a thread | yarn, and an oil agent is provided with the oiling roller 2. FIG. At this time, each filament is oiled by the yarn dividing guide 3 in a split state.

  Then, the yarns are combined by a converging guide and wound as a single yarn around the first godet roller 4 and the first separate roller 5 which are spinning take-up rollers a plurality of times. The first godet roller 4 includes heating means inside and is heated to a predetermined surface temperature.

  In the method of the present invention, the first godet roller 4 is used as a heating roller, the surface temperature is controlled to 70 to 120 ° C., and a heat insulation box (first godet roller box is enclosed so as to surround both the rollers 4 and 5. ) 12 is provided, and the atmospheric temperature in the box is maintained at a temperature of 50 ° C. or higher and lower than 100 ° C., preferably 60 to 90 ° C., by the heating and heat retaining means provided in the box.

  Thus, the spun yarn heated by the heating roller and the atmosphere is fed toward the second godet roller 6 having a function as a drawing roller, and the second godet roller 6, the second separate roller 7, And is stretched to a predetermined magnification. The second godet roller 6 itself preferably has a surface temperature of 100 to 180 ° C. In this case, the stretched yarn is heat set on the second godet roller 6.

  In the present invention, if necessary, a heat insulation box (second godet roller box) 13 is provided so as to surround the second godet roller 6 and the second separate roller 7, and the atmospheric temperature thereof is substantially the same as the heat setting temperature. The drawn yarn may be heated and heat set more uniformly by adjusting the temperature.

  The multifilament subjected to spinning-drawing-heat setting according to the method of the present invention as described above is wound up by the winder 8 to form a multifilament package 9, and is sent to a subsequent fiber separation process. The obtained multifilament is excellent in splitting properties and leveling properties, and the split monofilament can be effectively used for various applications.

Hereinafter, the present invention will be described more specifically with reference to examples. In addition, each characteristic value in an Example was calculated | required with the following method.
(1) Spinning rate (%)
Excluding yarn breakage caused by artificial or mechanical factors, the number of yarn breaks that occurred during the continuous operation of the spinning machine for 4 days was recorded, and the yarn breakage rate (%) was calculated by the following formula.
Spinning yarn breakage rate (%) = [number of yarn breaks / (number of active winders × number of doughs)] × 100
Here, the number of doughs refers to the number of times the package has been scraped up to 10 kg, and a winder with four winders is taken.

(2) Dyeing After using monofilaments of about 120m after splitting from multifilament, wash with water for 5 minutes and disperse dye "Teratop" Blue (Ciba Specialty) at a ratio of 2% (owf) to the sample weight.・ Chemicals Co., Ltd.), and left at 40 ° C. for 10 minutes with “Polyesca” DS (manufactured by Yoyo Chemical Co., Ltd.) at a rate of 0.2% of the dye bath solution, then 30 minutes The temperature was raised to 100 ° C over a period of 30 minutes and dyed at 100 ° C for 30 minutes. After the dyed product was dried for 10 minutes, the inspector visually determined the stain on the dyed cylinder, and rated it according to the following criteria.
Level 1: There is no streak, speckled spots or unstretched, and the entire surface is uniformly dyed.
Level 2: Some streaky and speckled spots are observed, but there is no unstretched and acceptable as a good product.
Level 3: There is no unstretched but many strong streaky or large speckled dyed spots are observed.
Level 4: Unstretched is observed.

(3) Unbroken yarn rate (%)
The percentage of multifilaments for splitting that can be split at a speed of 600m / min without breaking yarn into a single yarn of a 10kg wound drum package wound with polyester multifilaments for splitting (%) The split amount of monofilament is 1 kg. The pass / fail criterion was 80% or higher.

[Example 1]
Polyethylene terephthalate having an intrinsic viscosity of 0.63 measured at 35 ° C. with o-chlorophenol was obtained from two spinnerets in which 5 holes of discharge holes having a single-filament cross-sectional shape were arranged on the same circumference. Each was melt extruded at a polymer discharge temperature of 280 ° C. so that the discharge amount per single discharge hole was 6.5 g / min, and oiling was performed in a monofilament state. On the downstream side, a total of 10 monofilaments from the two spinnerets are bundled into one multifilament and wound 16 turns on the first roller heated to a surface temperature of 100 ° C. and the first non-heated separate roller. Was taken up at a speed of 700 m / min.

  At this time, a box having a heat retaining function and a heater function (first godet roller box) surrounding the first godet roller and the first separate roller is provided, and the first godet is set to 75 ° C. Winding the winder with the second godet roller rotating at a circumferential speed of 4.3 times the roller and heated to a surface temperature of 130 ° C. The multifilament having 10 single yarns was wound up.

The spinning drawability at this time was good, and the yarn properties and processability of the obtained multifilament were as shown in Example 1 column of Table 1.
As shown in Table 1, the obtained polyester multifilament had few spun cut yarns and split fiber cut yarns, the process tone was good, and the stain was also good.

[Example 2]
The experiment was conducted in the same manner as in Example 1 except that the atmospheric temperature in the box having the heat retaining function and the heater function (first godet roller box) was 80 ° C., and the temperature of the first godet roller was 95 ° C. Went. The thread properties and processability of the multifilament obtained at this time are shown in Example 2 column of Table 1. As in Example 1, this multifilament was good with few spun yarns and split yarns, and the dyed spots were also good.

[Comparative Example 1]
The same as in Example 1 except that the atmospheric temperature in the box having the heat retaining function and the heater function (first godet roller box) was 105 ° C., and the temperature of the heated first godet roller was 85 ° C. The experiment was conducted. The yarn physical properties of the obtained multifilament are shown in Comparative Example 1 column of Table 1.
In this multifilament, the yarn on the heating roller was severely swayed, resulting in high spun yarn and split yarn, resulting in poor dyeing.

[Comparative Example 2]
The experiment was repeated in the same manner as in Example 1 except that the temperature of the heating roller was set to 105 ° C. without the box having the heat retaining function and the heater function (first godet roller box) surrounding the heating roller. The yarn physical properties of the obtained multifilament are shown in Comparative Example 2 column of Table 1. This multifilament has poor dyeing and partially unstretched parts.

  According to the method of the present invention, a polyester multifilament for splitting that is excellent in dyeing stability (leveling property) and splitting properties can be manufactured by a direct spinning drawing method. Useful.

The schematic side view which shows the outline of the direct spinning drawing apparatus which enforces the method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spinneret 2 Oiling roller 3 Thread separation guide 4 1st godet roller 5 1st separate roller 6 2nd godet roller 7 2nd separate roller 8 Winder 9 Multifilament package 10 Insulation area under the spinneret 11 Cooling air 12 First One godet roller box 13 Second godet roller box

Claims (5)

  When producing polyester multifilaments for splitting by the direct spinning drawing method, the spinning take-off roller is a heating roller, and the roller is surrounded by a box having a heating / heat-retaining function, and the ambient temperature in the box is 50 ° C. or higher. Heated spun yarn in a state controlled below 100 ° C, stretched as it is between the spinning take-up roller and the drawing roller, and is wound up after heat setting. A method for producing polyester multifilament for splitting.   The multifilament after stretching heat setting is a multifilament having a single yarn fineness of 10 to 40 dtex and a filament number of 4 to 20 and excellent in dyeing stability and fineness. Manufacturing method of polyester multifilament for splitting.   The method for producing a polyester multifilament for splitting excellent in dyeing stability and splitting property according to claim 1 or 2, wherein the surface temperature of the spinning take-up roller is 70 to 120 ° C.   The method for producing a polyester multifilament for splitting excellent in dyeing stability and splitting property according to any one of claims 1 to 3, wherein the stretching roller is a heating roller and heat-set on the stretching roller. .   The method for producing a polyester multifilament for splitting excellent in dyeing stability and splitting property according to any one of claims 1 to 4, wherein the polyester multifilament comprises fibers having a non-circular cross section.

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